HK1076110B - Piperazinylacylpiperidine derivatives, their preparation and therapeutic use thereof - Google Patents

Description

Substituted 1-piperazinoylpiperidine derivatives, their preparation and therapeutic use

Technical Field

The present invention relates to substituted 1-piperazinoylpiperidine derivatives, processes for their preparation and their use in therapy.

The compounds of the invention are shown to be directed to the neurotrophin receptor p75^NTRHas affinity.

Background

Neurotrophins belong to a family of proteins with similar structure and similar function, including Nerve Growth Factor (NGF), BDNF (brain derived neurotrophic factor), neurotrophin-3 (NT-3), neurotrophin-4/5 (NT-4/5) and neurotrophin-6 (NT-6). These proteins exert biological effects (survival and differentiation) by interacting with membrane receptors with tyrosine kinase activity (trk-A, trk-B and trk-C). (H.Thoenen, Science, 1995, 270: 593-. However, many studies have shown p75^NTRReceptors play a major role in neurotrophin activation.

P75 as a receptor for all neurotrophins^NTRThe receptor, a transmembrane glycoprotein of the Tumor Necrosis Factor (TNF) receptor family (w.j.friedman and l.a.greene, exp.cell.res., 1999, 253: 1)31-42; meldosis et al, Trends pharmacol.sci., 2000, 21: 242-43). Many biological functions are attributed to p75^NTRReceptor: on the one hand, the affinity of neurotrophins for trk receptors may be modulated; on the other hand, in the absence of trk, apoptosis-inducing cell death signaling occurs by homodimerization of the receptor and activation of the ceramide pathway.

Apoptosis or programmed cell death is a physiological mechanism of cell elimination in many tissues. In particular, apoptosis plays a major role in embryonic development, morphogenesis, and cell renewal. Apoptosis is generally a controlled phenomenon that occurs only in the late and irreversible stages of a cellular lesion.

Many studies have shown that apoptosis occurs in several pathological processes in the central nervous system, such as amyotrophic lateral sclerosis, multiple sclerosis, alzheimer's disease, parkinson's disease and huntington's disease, and prion diseases. In addition, apoptotic neuronal cell death also occurs very early after cerebral and cardiac ischemia. Cell death is also a dominant phenomenon in atherosclerosis; it was confirmed that cell death was found in 80% of the primary atherosclerotic disease lesion dead zones in humans (M.L. Bockaton-Pialat et al, am.J. Pathol., 1995, 146: 1-6; H.Perlman, Circulation, 1997, 95: 981-. Apoptosis is also involved in the mechanisms that lead to cell death following cardiac ischemia reperfusion (h. yaoita et al, cardiovasc. res., 2000, 45: 630-.

Several studies have shown that p75 is observed in various cell types, including nerve cells, oligodendrocytes, schwann (nerve sheath) cells and liver cells, cardiac muscle and smooth muscle cells^NTRDependent pro-apoptotic signals (J.M. Frade et al., Nature, 1996, 383: 166- & 168; P.Lasaccia-Bonnefil et al., Nature, 1996, 383: 716- & 719; M.Soilu-Hanning et al., J.Neurosci., 1999, 19: 4828- & 4838; N.Trim et al., Am J.Pathol., 2000, 156: 1235- & 1243; S.Y.Wang et al., AmJ.Pathol., 2000, 157: 1247- & 1258). However, many in vivo experiments have shown p75 after ischemia in brain and heart regions^NTRIncreased expression of (a), extensive apoptosis was noted. Thus, these results suggest p75^NTRMay play a major role in the mechanisms leading to neuronal cell death by apoptosis following ischemia (P.P.Roux et al, J.Neurosci., 1999, 19: 6887-9196; J.A.park et al, J.Neurosci., 2000.20: 9096-9103).

It is reported that p75^NTRThe receptor acts as a cellular target for both prion peptides (V.Della-Bianca et al, J.biol.chem., 2001, to be published) and beta-amyloid peptides (S.Rabizadeh et al, Proc Natl Acad SciUSA, 1994, 91: 10703-06) and may thus be involved in the apoptosis induced by these compounds. These results support the following hypothesis: i.e. p75^NTRPlays an important role in nerve cell death caused by infectious prion protein (transmissible spongiform encephalopathy) or beta-amyloid protein (Alzheimer's disease).

Recent studies suggest p75^NTRReceptors may also play an important role in axonal regeneration through their synergistic receptor function as Nogo receptors (Wong et al, Nature Neurosci, 2002, 5: 1302-08; Kerracher and Winton, Neuron, 2002, 36: 345-48). Indeed, several myelin-associated proteins (myelin-associated glycoprotein, MAG, Nogo-A and OMgp, the myelin glycoprotein of oligodendrocytes) inhibit nerve regeneration at the central level upon spinal or craniocerebral trauma. These proteins are located in the oligodendrocyte membrane, directly adjacent to the axon, and inhibit neurotrophic growth by binding with high affinity to Nogo receptors located on the axon membrane. p75^NTRThe receptor binds to Nogo receptors and is involved in signaling the inhibitory effects of these myelin proteins associated with axonal growth. As a result, p75^NTRReceptors play an important role in regulating neuronal formation and glial interactions and provide selective therapeutic targets for promoting nerve regeneration.

At the peripheral level, recent studies have shown p75 in atherosclerotic lesions^NTRAnd increased expression of neurotrophins, and has broad applicationAnd (4) apoptosis. And the pro-angiogenic and vasodilatory effects of NGF were also recorded. Finally, a novel class of extracellular truncated p75 has been identified^NTRAnd its major role in established angiogenesis (d.von Shack et al, Nature neurosci, 2001, 4: 977-. All these latest data hints, p75^NTRIt may also play an important role in the course of vascular pathology in its whole or in truncated form.

A number of compounds are known which are capable of reacting with trkA/NGF/p75^NTRSystemic interactions or NGF-type activity. For example, patent application WO 00/59893 describes substituted pyrimidine derivatives capable of exhibiting and/or enhancing NGF-like activity on PC12 cells. Patent applications WO 00/69828 and WO00/69829 describe polycyclic compounds which inhibit NGF binding to p75 in cells which do not express trkA receptors^NTRA receptor. Application WO 94/11373 describes pyridazinoquinazolinone derivatives which are capable of interacting with the neurotrophin receptor p75^NTRAnd (4) combining. Application WO 94/22866 describes pyrazoloquinazolinone derivatives which bind NGF specifically and thus avoid their attachment to p75^NTRThe receptor, but enabling it to interact with the trk receptor. Application WO 01/49684 describes substituted tetrahydropyridine derivatives having the activity of modulating TNF- α.

It has now been found that novel 1-piperazinoylpiperidine derivatives exhibit p75 acceptor^NTRHas affinity.

The present invention provides compounds of the general formula (I):

wherein:

-n is 1 or 2;

-p is 1 or 2;

-R₁represents a halogen atom, trifluoroMethyl, C₁-C₄Alkyl radical, C₁-C₄Alkoxy, trifluoromethoxy;

-R₂represents a hydrogen atom or a halogen atom;

-R₃represents a hydrogen atom, -OR₅Group, -CH₂OR₅Group, -NR₆R₇A group; -NR₈COR₉A group; -NR₈CONR₁₀R₁₁A group; -CH₂NR₁₂R₁₃A group; -CH₂NR₈CONR₁₄R₁₅A group; (C)₁-C₄) An alkoxycarbonyl group; -CONR₁₆R₁₇A group;

-or R₃A double bond is formed between the carbon atom to which it is attached and the adjacent piperidine ring carbon atom;

-R₄represents an aromatic group selected from the group represented by the following formulae:

the aromatic group is unsubstituted or independently selected from halogen atom, (C)₁-C₄) Alkyl, (C)₁-C₄) Alkoxy, trifluoromethyl, monosubstituted or disubstituted;

-R₅represents a hydrogen atom, (C)₁-C₄) Alkyl, (C)₁-C₄) An alkylcarbonyl group;

-R₆and R₇Each independently represents a hydrogen atom or (C)₁-C₄) An alkyl group;

-R₈represents a hydrogen atom or (C)₁-C₄) An alkyl group;

-R₉is represented by (C)₁-C₄) Alkyl or- (CH)₂)_m-NR₆R₇A group;

-m is 1, 2 or 3;

-R₁₀and R₁₁Each independently represents a hydrogen atom or (C)₁-C₄) An alkyl group;

-R₁₂and R₁₃Each independently represents a hydrogen atom or (C)₁-C₅) An alkyl group;

-R₁₃may also represent- (CH)₂) q-OH group or- (CH)₂)q-S-CH₃A group;

-or R₁₂And R₁₃And together with the nitrogen atom to which they are bound form a heterocyclic ring selected from aziridine, azetidine, pyrrolidine, piperidine and morpholine;

-q is 2 or 3;

-R₁₄and R₁₅Each independently represents a hydrogen atom or (C)₁-C₄) An alkyl group;

-R₁₆and R₁₇Each independently represents a hydrogen atom or (C)₁-C₄) An alkyl group; r₁₇May also represent- (CH)₂)_q-NR₆R₇A group;

-or R₁₆And R₁₇And together with the nitrogen atom to which they are bound form a moiety selected from azetidine, pyrrolidine, piperidine, morpholine and piperazine (which is unsubstituted or substituted (C) at position 4₁-C₄) Alkyl-substituted) heterocyclic ring.

The compounds of formula (I) may exist in the form of a base or in the form of an acid addition salt. These addition salts form part of the present invention.

These salts may conveniently be prepared from pharmaceutically acceptable acids, but addition salts of other acids used in the purification or isolation of the compounds of formula (I) also form part of the invention.

The compounds of formula (I) may also exist in the form of hydrates or solvates, in particular in association or association with one or more water or solvent molecules. Such hydrates or solvates also form part of the present invention.

The halogen atom is a bromine, chlorine, fluorine or iodine atom.

(C₁-C₄) Alkyl or (C)₁-C₅) The alkyl groups are each a straight-chain or branched alkyl group having 1 to 4 carbon atoms or 1 to 5 carbon atoms, respectively, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl or tert-pentyl.

(C₁-C₄) Alkoxy is a straight-chain or branched alkoxy having 1 to 4 carbon atoms, such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy or tert-butoxy.

Among the compounds of formula (I) provided by the present invention are preferred compounds defined as follows:

-R₁in the 2, 3 or 4 position of the phenyl radical, represents a trifluoromethyl, chlorine atom, methyl, methoxy or trifluoromethoxy radical, and R₂Represents a hydrogen atom; or R₁In the 3-position of the phenyl radical, represents trifluoromethyl, and R₂At the 4-position of the phenyl group, represents a chlorine atom;

-and/or R₃Represents a hydrogen atom, a hydroxyl group, a methoxy group, an (acetoxy) methyl group, a hydroxymethyl group, a dimethylamino group, an acetamido group, an aminomethyl group, a (methylamino) methyl group, a (dimethylamino) methyl group, a (diethylamino) methyl group, an (isopropylamino) methyl group, an (N-methylisopropylamino) methyl group, an (isobutylamino) methyl group, an (N-methylisobutylamino) methyl group, an (isopentylamino) methyl group, an (N-methylisopropylamino) methyl group, an aminocarbonyl group, an azetidin-1-ylcarbonyl group; or R₃A double bond is formed between the carbon atom to which it is bonded and the adjacent carbon atom of the piperidine ring;

-and/or R₄Represents 2-pyridyl, 6-methyl-2-pyridyl, 3- (trifluoromethyl) -2-pyridyl, 5- (trifluoromethyl)Methyl) -2-pyridyl, 3-chloro-5- (trifluoromethyl) -2-pyridyl, 3-pyridyl, 4-pyridyl, 3, 5-dichloro-4-pyridyl, 2-pyrazinyl, 5-chloro-2-pyrazinyl, 6-chloro-2-pyrazinyl, 2-pyrimidinyl, 4- (trifluoromethyl) -2-pyrimidinyl, 6-chloro-2-pyrimidinyl, 4-pyrimidinyl, 6-chloro-4-pyrimidinyl, 5-pyrimidinyl, 3-pyridazinyl, 6-chloro-3-pyridazinyl, 4-pyridazinyl, 3(2H) -pyridazinone-5-yl or 3(2H) -pyridazinone-4-yl.

Particularly preferred among the base forms or acid addition salt forms and the hydrate or solvate forms of the compounds of formula (I) are the following compounds, among which:

-n is 1 or 2;

-p is 1 or 2;

-R₁in the 2, 3 or 4 position of the phenyl radical, represents a trifluoromethyl, chlorine atom, methyl, methoxy or trifluoromethoxy radical, and R₂Represents a hydrogen atom; or R₁In the 3-position of the phenyl radical, represents trifluoromethyl, and R₂At the 4-position of the phenyl group, represents a chlorine atom;

-R₃represents a hydrogen atom, a hydroxyl group, a methoxy group, an (acetoxy) methyl group, a hydroxymethyl group, a dimethylamino group, an acetamido group, an aminomethyl group, a (methylamino) methyl group, a (dimethylamino) methyl group, a (diethylamino) methyl group, an (isopropylamino) methyl group, an (N-methylisopropylamino) methyl group, an (isobutylamino) methyl group, an (N-methylisobutylamino) methyl group, an (isopentylamino) methyl group, an (N-methylisopropylamino) methyl group, an aminocarbonyl group, an azetidin-1-ylcarbonyl group; or R₃A double bond is formed between the carbon atom to which it is bonded and the adjacent carbon atom of the piperidine ring;

-R₄represents 2-pyridyl, 6-methyl-2-pyridyl, 3- (trifluoromethyl) -2-pyridyl, 5- (trifluoromethyl) -2-pyridyl, 3-chloro-5- (trifluoromethyl) -2-pyridyl, 3-pyridyl, 4-pyridyl, 3, 5-dichloro-4-pyridyl, 2-pyrazinyl, 5-chloro-2-pyrazinyl, 6-chloro-2-pyrazinyl, 2-pyrimidinyl, 4- (trifluoromethyl) -2-pyrimidinyl, 6-chloro-2-pyrimidinyl, 4-pyrimidinyl, 6-chloro-4-pyrimidinyl, 5-pyrimidinyl, 3-pyridazinyl, p-pyridazinyl, 6-chloro-3-pyridAn oxazinyl group, a 4-pyridazinyl group, a 3(2H) -pyridazinone-5-yl group or a 3(2H) -pyridazinone-4-yl group.

Among the base forms or acid addition salt forms and the hydrate or solvate forms of the compounds of (I), more preferred are the following compounds, among which:

-n is 1;

-p is 1;

-R₁in the 2, 3 or 4 position of the phenyl radical, represents a trifluoromethyl, chlorine, methoxy or trifluoromethoxy radical, and R is₂Represents a hydrogen atom; or R₁In the 3-position of the phenyl radical, represents trifluoromethyl, and R₂At the 4-position of the phenyl group, represents a chlorine atom;

-R₃represents hydroxy, dimethylamino, aminomethyl, (methylamino) methyl, (dimethylamino) methyl, (diethylamino) methyl, (isopropylamino) methyl, (isobutylamino) methyl, (isopentylamino) methyl, (N-methyl-isopentylamino) methyl or aminocarbonyl; or R₃A double bond is formed between the carbon atom to which it is bonded and the adjacent carbon atom of the piperidine ring;

-R₄represents 2-pyrazinyl, 4-pyrimidinyl, 3(2H) -pyridazinone-5-yl or 5- (trifluoromethyl) -2-pyridinyl.

Among the compounds of formula (I) provided by the present invention, particularly preferred base forms or acid addition salt forms, hydrates or solvates are the following compounds:

-1- [4- (aminomethyl) -4- [3- (trifluoromethyl) phenyl ] -1-piperidinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone;

-5- [4- [2- [ 4-hydroxy-4- [3- (trifluoromethyl) phenyl ] -1-piperidinyl ] -2-oxyethyl ] -1-piperazinyl ] -3(2H) -pyridazinone;

-1- [ 4-hydroxy-4- [2- (trifluoromethyl) phenyl ] -1-piperidinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone;

-2- [4- (4-pyrimidinyl) -1-piperazinyl ] -1- [4- [3- (trifluoromethyl) phenyl ] -3, 6-dihydro-1 (2H) -pyridinyl ] -1-ethanone;

-2- [4- (2-pyrazinyl) -1-piperazinyl ] -1- [4- [2- (trifluoromethyl) phenyl ] -3, 6-dihydro-1 (2H) -pyridinyl ] -1-ethanone;

-1- [2- [4- (2-pyrazinyl) -1-piperazinyl ] acetyl ] -4- [3- (trifluoromethyl) phenyl ] -4-piperidinecarboxamide;

-1- [4- (dimethylamino) -4- [3- (trifluoromethyl) phenyl ] -1-piperidinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone;

-1- [ 4-hydroxy-4- [3- (trifluoromethyl) phenyl ] -1-piperidinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone;

-1- [4- [ (dimethylamino) methyl ] -4- [3- (trifluoromethyl) phenyl ] -1-piperidinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone;

-1- [4- (4-chlorophenyl) -3, 6-dihydro-1 (2H) -pyridinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone;

-1- [ 4-hydroxy-4- (3-methoxyphenyl) -1-piperidinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone;

-1- [4- [ 4-chloro-3- (trifluoromethyl) phenyl ] -3, 6 dihydro-1 (2H) -pyridinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone;

-1- [4- [ 4-chloro-3- (trifluoromethyl) phenyl ] -3, 6-dihydro-1 (2H) pyridinyl ] -2- [4- [5- (trifluoromethyl) -2-pyridinyl ] -1-piperazinyl ] -1-ethanone;

-1- [4- [ (methylamino) methyl ] -4- [3- (trifluoromethyl) phenyl ] -1-piperidinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone;

-1- [4- [ (diethylamino) methyl ] -4- [3- (trifluoromethyl) phenyl ] -1-piperidinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone;

-1- [4- [ (isopropylamino) methyl ] -4- [3- (trifluoromethyl) phenyl ] -1-piperidinyl ] -2- [4-2- (pyrazinyl) -1-piperazinyl ] -1-ethanone;

-1- [4- [ (isobutylamino) methyl ] -4- [3- (trifluoromethyl) phenyl ] -1-piperidinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone;

-1- [4- [ (isopentylamino) methyl ] -4- [3- (trifluoromethyl) phenyl ] -1-piperidinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone;

-1- [4- [ (N-methyl-isopentylamino) methyl ] -4- [3- (trifluoromethyl) phenyl ] -1-piperidinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone;

-1- [ 4-hydroxy-4- [3- (trifluoromethoxy) phenyl ] -1-piperidinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone;

in another aspect, the present invention provides a process for the preparation of a compound of formula (I) wherein n ═ 1, characterized in that:

a1) reacting a compound of formula (IIa)

Wherein R is₁、R₂And R₃Hal represents a halogen atom, preferably a chlorine or bromine atom, as defined for the compounds of formula (I) when R₃Containing a hydroxyl or amine function which can be protected, with a compound of formula (III),

wherein p and R₄As defined for compounds of formula (I);

b1) when appropriate R₃After deprotection of the hydroxyl or amine functional group in (A), the compound of formula (I) can be obtained.

When appropriate, the compound of formula (I) is converted into one of its acid addition salts.

In another aspect, the present invention provides a process for the preparation of a compound of formula (I) wherein n-2 is characterized in that:

a2) reacting a compound of formula (IIb)

Wherein R is₁、R₂And R₃As defined for the compounds of formula (I) when R is₃Containing protected hydroxyl or amine functional groups, with a compound of formula (III),

wherein p and R₄As defined for compounds of formula (I);

b2) when appropriate R₃Deprotection of the hydroxyl or amine functional group in (a) to obtain the compound of formula (I).

When appropriate, the compound of formula (I) is converted into one of its acid addition salts.

In step a1) or step a2), when reacting a compound of formula (IIa) or (IIb) with a compound of formula (III), the reaction is carried out in the presence of a base selected from an organic base such as triethylamine, N-diisopropylethylamine or N-methylmorpholine, or an alkali metal carbonate or bicarbonate such as potassium carbonate, sodium carbonate or sodium bicarbonate, and in the absence or presence of an alkali metal iodide such as potassium iodide or sodium iodide. The reaction is carried out in a solvent such as acetonitrile, N-dimethylformamide, toluene or isopropanol between ambient temperature and the reflux temperature of the solvent.

Where appropriate, in step b1) or step b2), R is removed in accordance with conventional methods well known to the person skilled in the art₃Protection of the upper hydroxyl or amine functional group.

At one endIn the method, R₃represents-CH₂NR₁₂R₁₃Group (wherein R₁₂And R₁₃Each represents a hydrogen atom) of the organic compound,

a3) reacting a compound of the formula (IIc) or (IId)

Wherein R is₁、R₂And R₃Hal represents a halogen atom, preferably a chlorine or bromine atom, as defined for the compounds of formula (I),

with a compound of the formula (III),

in the formula (III), p and R₄As defined for the compound of formula (I), to produce a compound of formula (Ia) below.

b3) Reduction of the cyano group of the compound of formula (Ia) to yield R₃＝CH₂NH₂A compound of formula (I).

When appropriate, the compound of formula (I) is converted into one of its acid addition salts.

In step a3), the reaction between the compound of formula (IIc) or (IId) and the compound of formula (III) is carried out according to step a1) or (a2) above of the process of the invention.

In step b3), the reduction of the cyano group of the compound of formula (Ia) is carried out in a conventional manner. Thus, for example, in the presence of a catalyst such asRhodium on nickel or alumina is subjected to a hydrogenation reduction at a temperature between ambient temperature and 60 ℃ in the presence or absence of ammonia in a solvent such as methanol, N-dimethylformamide or tetrahydrofuran or a mixture of these solvents.

In another mode of the process, when R is₃When a double bond is formed between the carbon atom to which it is attached and the adjacent carbon atom of the piperidine ring; in the formula (I), R₃Compounds of ═ OH (where R is₁、R₂N, p and R₄As defined for the compounds of formula (I)

(I)：R₃＝-OH

Dehydration to produce the following compound of formula (I)

When appropriate, the compound of formula (I) is converted into one of its acid and other salt.

The dehydration is carried out at a temperature between ambient temperature and 140 c, using, for example, an acetic acid/hydrochloric acid mixture or an acetic acid/sulfuric acid mixture. The reaction can also be carried out using p-toluenesulfonic acid, in, for example, a toluene solvent, at a temperature between ambient temperature and reflux temperature.

When R in the compound of formula (I)₃represents-CH₂NR₁₂R₁₃Group, wherein R₁₂＝H、R₁₃＝(C₁-C₅) When alkyl, R can also be prepared by reacting R in the presence of a base such as an alkali metal carbonate (e.g., potassium carbonate) in a solvent such as acetonitrile, N-dimethylformamide or tetrahydrofuran at a temperature between ambient temperature and the reflux temperature of the solvent₃＝-CH₂NH₂Of the formula (I) with (C)₁-C₅) Alkyl halides to prepare the compounds of formula (I).

When R in the compound of formula (I)₃represents-CH₂NR₁₂R₁₃Group, wherein R₁₂H or (C)₁-C₅) Alkyl radical, R₁₃＝(C₁-C₅) Alkyl group, (CH)₂)_qan-OH group or (CH)₂)_q-S-CH₃When radicals are used, R in formula (I) can also be obtained by reacting R in the presence of a reducing agent such as sodium borohydride or sodium triacetoxyborohydride in a solvent such as dichloromethane or tetrahydrofuran and in the presence of an acid such as acetic acid at a temperature between 0 ℃ and ambient temperature₃＝-CH₂NHR₁₂With formaldehyde or with a compound of the formula OHC- (C), respectively₁-C₄) Alkyl, OHC- (CH)₂)_q-1-OH or OHC- (CH)₂)_q-1-S-CH₃The aldehyde shown, or with the corresponding ketone, to prepare the compound of formula (I).

When R in the compound of formula (I)₃represents-CH₂NR₁₂R₁₃Group, wherein R₁₂、R₁₃And together with the nitrogen atom to which they are bound form an aziridine, may also be cyclized by reaction of a compound in which R is present in a solvent such as acetonitrile in the presence of a base such as an alkali metal carbonate (e.g., potassium carbonate) and an alkali metal iodide (e.g., potassium iodide) at a temperature between ambient temperature and the reflux temperature of the solvent₃represents-CH₂NH-CH₂CH₂-the corresponding intermediate of the Cl group to prepare this compound of formula (I); by reacting R with₃＝-CH₂NH₂The compound of formula (I) with chloroacetaldehyde to prepare the corresponding intermediate.

When R in the compound of formula (I)₃represents-CH₂NR₁₂R₁₃Group, wherein R₁₂And R₁₃And together with the nitrogen atom to which they are bound, each independently, an azetidine, pyrrolidine, piperidine or morpholine, may also be in a solvent such as acetonitrile, ethylene glycol or mixtures of these solventsIn the presence of a base such as an alkali metal carbonate (e.g., potassium carbonate) or an alkali metal iodide (e.g., potassium iodide) at a temperature between ambient temperature and the reflux temperature of the solvent₃＝-CH₂NH₂With the formula Hal- (CH)₂)₃-Hal、Hal-(CH₂)₄-Hal、Hal-(CH₂)₅-Hal, or Hal-CH₂CH₂-O-CH₂CH₂-Hal to prepare the compound of formula (I).

When R in the compound of formula (I)₃represents-CH₂NR₈CONR₁₄R₁₅Group, wherein R₈＝R₁₄＝R₁₅When ═ H, R can also be prepared by reaction of R, for example, in dichloromethane solvent at a temperature between ambient temperature and the reflux temperature of the solvent₃＝-CH₂NH₂The compound of formula (I) is prepared by reacting a compound of formula (I) with trimethylsilyl isothiocyanate, followed by hydrolysis in an acidic solution.

When R in the compound of formula (I)₃represents-CONR₁₆R₁₇When R is a group, R may be coupled by a conventional peptide coupling method₃Corresponding intermediates representing a carboxyl group and the formula HNR₁₆R₁₇Reacting the compound to prepare the compound of formula (I); the corresponding intermediate is treated with acid or alkali in a conventional manner₃Is represented by (C)₁-C₄) Alkoxycarbonyl compounds of formula (I) or by reacting a compound of formula (Ia) with a strong base such as an alkali metal hydroxide (e.g. potassium hydroxide) in a solvent such as toluene or ethylene glycol at a temperature between ambient temperature and the reflux temperature of the solvent.

When R in the compound of formula (I)₃represents-NR₈COR₉Group, wherein R₉＝-(CH₂)_m-NR₆R₇When desired, R may also be brought to a temperature between ambient temperature and the reflux temperature of the solvent in a solvent such as methylene chloride or ethanol₃represents-NR₈CO(CH₂)_m-Hal, where Hal represents a halogen atomThe corresponding intermediate, preferably a chlorine atom, with an excess of a compound of formula HNR₆R₇Reacting the compound to prepare the compound of formula (I); the corresponding intermediate is represented by R₃＝-NHR₈In a solvent such as dichloromethane in the presence of a base such as triethylamine or N, N-diisopropylethylamine at a temperature between 0 ℃ and ambient temperature, with a compound of formula (I) of the formula Hal-CO- (CH)₂)_m-Hal (wherein Hal represents a halogen atom, preferably a chlorine or bromine atom).

When R in the compound of formula (I)₃represents-CH₂OR₅Group (wherein R₅Represents a halogen atom), by treating R with an acid or a base₃represents-CH₂OR₅Group (wherein R₅Is represented by (C)₁-C₄) Alkylcarbonyl) compounds of the formula (I).

The compound of formula (I) thus obtained can be isolated from the reaction solution by conventional purification methods such as crystallization or chromatography.

The compound of formula (I) thus obtained is isolated in the form of the free base or salt by conventional techniques.

The compound of formula (IIa) is prepared by reacting a piperidine derivative represented by the following formula (IV)

Wherein R is₁、R₂And R₃As defined for the compounds of formula (I)

With compounds of the formula (V)

Wherein Hal and Hal' each independently represent a halogen atom, preferably a chlorine or bromine atom. The reaction is carried out in a solvent such as dichloromethane, chloroform, tetrahydrofuran, dioxane or mixtures thereof in the presence of a base such as triethylamine, N-diisopropylethylamine or N-methylmorpholine at a temperature between 0 ℃ and ambient temperature.

The compounds of formula (IIb) are prepared by reacting a compound of formula (IV) with a compound of formula (VI) wherein Hal and Hal' are as defined above

Under the above-mentioned operation conditions.

Similarly, compounds of formula (IIc) or (IId) can be prepared by reacting, respectively, a compound of formula (IVa) (wherein R is₁And R₂As defined for the compounds of formula (I)

And (VI) under the same operating conditions as described above.

The compounds of the formula (V) or (VI) are known from the market or can be prepared by known methods.

The compounds of formula (III) are commercially available or may be prepared using techniques such as J Org chem, 1953, 18: 1484-1488; med, chem, 1978, 21 (6): 536 and 542; chem pharm. bull, 1991, 39 (9): 2288-; tetrahedron Letters, 1998, 39: 617-620 or known methods as described in WO 97/28129.

For example, the compounds of the formula (III) can be prepared by reacting a compound of the formula (VII) with a compound of the formula Hal-R₄(VIII) the compound.

Wherein p is as defined for the compound of formula I, W represents a hydrogen atom or an N-protecting group,

wherein R is₄As defined for the compounds of formula I, Hal represents a halogen atom (preferably chlorine, bromine or iodine).

The reaction is carried out in an inert solvent such as ethanol, isopropanol, n-butanol, acetonitrile or toluene, in the presence or absence of a base, at a temperature between 0 ℃ and the reflux temperature of the solvent. When a base is employed, it is selected from an organic base such as diisopropylethylamine, or from an alkali metal carbonate such as sodium or potassium carbonate. The reaction is carried out with an excess of the compound of formula (VII) in the absence of a base. The reaction can also be carried out without solvent by heating a mixture of compounds (VII) and (VIII) at a temperature of from 140 ℃ to 180 ℃.

When W represents an N-protecting group, where appropriate, W may be eliminated by conventional methods to give the desired compound of formula (III).

The compounds of the formula (VII) or (VIII) are known or can be prepared by known methods.

It is known that compounds of formula (IV) are commercially available or can be prepared by known methods as described in EP-0474561, EP-0673928 or WO 96/23787.

The compounds of formula (IV) are generally prepared in a protected form at the piperidine nitrogen atom; the compound of formula (IV) itself is obtained after deprotection.

In particular R₃represents-OR₅Group, R₅A compound of formula (IV) represented by the formula (IX) below by reacting an organomagnesium derivative

Wherein R is₁And R₂As defined for the compounds of formula (I), Hal represents a halogen atom, preferably a bromine atom, in a solvent such as diethyl ether or tetrahydrofuran, at a temperature between ambient temperature and the reflux temperature of the solvent, with 1-benzyl-4-piperidone.

The organomagnesium derivatives of formula (IX) can be prepared from the corresponding halogenated derivatives by methods well known to those skilled in the art.

From R by alkylation or acylation, respectively, using methods known to those skilled in the art₃Preparation of compound of formula (IV) with ═ OH₃＝-OR₅(wherein R is₅Each represents C₁-C₄Alkyl or C₁-C₄Alkoxycarbonyl) compounds of the formula (IV).

According to the method described in EP-0474561, R is reacted in an acidic solution in acetonitrile₃Compounds of formula (IV) ═ OH and with a protecting group on the piperidine nitrogen atom undergo a Ritter reaction to prepare R₃＝-NHCOCH₃A compound of formula (IV). Then preparing R by hydrolysis of strong acid liquid₃＝-NR₆R₇(wherein R is₆＝R₇H) of formula (IV). Preparation of R by the method described in EP-0673928 or WO 96/23787₃＝-NR₆R₇(wherein R is₆And/or R₇Is represented by (C)₁-C₄Alkyl) of formula (IV).

Preparation of R by the method described in W096/23787₃＝-NR₈COR₉(wherein R is₉Is C₁-C₄Alkyl) or R₃＝-NR₈CONR₁₀R₁₁Or R₃＝-CH₂NR₁₂R₁₃(R₁₂And R₁₃Each represents halogen or C₁-C₄Alkyl, or R₃＝-CH₂NR₈CONR₁₄R₁₅Or R₃＝(C₁-C₄) Alkoxycarbonyl or R₃＝-CONR₁₆R₁₇A compound of formula (IV).

Preparation of R from Compounds of formula (IVa) Using the procedures described above for Compounds of formula (I)₃＝-CH₂NR₁₂R₁₃(wherein R is₁₂＝R₁₃H) of formula (IV).

Preparation of R Using the procedure described above for the Compounds of formula (I)₃＝-NR₈COR₉(wherein R is₉＝-(CH₂)_mNR₆R₇) A compound of formula (IV).

Preparation of R Using the procedure described above for the Compounds of formula (I)₃＝-CH₂NR₁₂R₁₃(wherein R is₁₂H or C₁-C₅Alkyl radical, R₁₃＝C₁-C₅Alkyl, - (CH)₂)_q-OH group or- (CH)₂)_q-S-CH₃Group) of the formula (IV).

R₃＝-CH₂NR₁₂R₁₃(wherein R is₁₂H and R₁₃＝-CH₃The compound of formula (IV) in (1) can also be reduced with a reducing agent such as lithium aluminum hydride in a solvent such as diethyl ether or tetrahydrofuran at a temperature between ambient temperature and the reflux temperature of the solvent₃＝-CH₂NHCHO. The corresponding intermediate is prepared by reacting R₃＝-CH₂NH₂With ethyl formate at a temperature between ambient temperature and 60 ℃.

Preparation of R Using the procedure described above for the Compounds of formula (I)₃＝-CH₂NR₁₂R₁₃(wherein R is₁₂And R₁₃Together with the nitrogen atom to which they are bound, form an aziridine, azetidine, piperidine or morpholine).

R₃＝-CONR₁₆R₁₇(wherein R is₁₆＝R₁₇H), or a compound of formula (IVa) protected by the piperidine nitrogen atom, by dissolvingIn a mixture of an agent such as toluene and water, with hydrogen peroxide in the presence of a strong base such as an alkali metal hydroxide, e.g. sodium hydroxide, and a phase transfer catalyst, e.g. a substituted quaternary ammonium salt, triethylammonium chloride, at a temperature between ambient temperature and the reflux temperature of the solvent.

Compounds of formula (IVa) are prepared according to bioorg.med.chem.lett, 1999, 9: 3273-3276 and J MedChem, 1999, 42 (23): 4778 and 4793 by the known methods.

From R by alkylation or acylation, respectively, using methods known to those skilled in the art₃＝-CH₂Preparation of a Compound of formula (IV) of OH₃＝-CH₂OR₅(wherein R is₅Each represents C₁-C₄Alkyl or C₁-C₄Alkoxycarbonyl) compounds of the formula (IV).

R₃＝-CH₂OR₅(wherein R is₅Represents a hydrogen atom), wherein R can be reduced by methods known to those skilled in the art₃A compound of formula (IV) representing methoxycarbonyl.

By means of corresponding intermediates (wherein R is R) by methods known to the person skilled in the art₃Representing a carboxyl group) to produce R₃Is represented by (C)₁-C₄) Alkoxycarbonyl compounds of the formula (IV); the intermediate is prepared by reacting a compound of formula (VIa) with a strong base such as an alkali metal hydroxide such as potassium hydroxide in a solvent such as toluene or ethylene glycol at a temperature between ambient temperature and the reflux temperature of the solvent.

In the preparation of compounds of formula (I) or intermediates of formula (Ia), (IIa), (IIb), (IIc), (IId), (III) or (IV), it may be necessary and/or desirable to protect sensitive or reactive functional groups, such as amine, hydroxyl or carboxyl groups, present in any of the molecules concerned. Such protection can be carried out using conventional protecting groups, which are described in "protecting groups in organic chemistry", J F W McOmie, PleniumPress, 1973; "protecting groups in organic Synthesis", edited by T W Greene and P G M Wuts, JoneWiley & Son, 1991; or a "protecting group" Kocienski P j, 1994, Georg Thieme Verlag. These protecting groups can be eliminated in the corresponding subsequent step by methods known to the person skilled in the art without destroying the rest of the molecule.

Suitable N-protecting groups used are the customary N-protecting groups known to the person skilled in the art, for example tert-butoxycarbonyl, fluorenylmethoxycarbonyl, benzyl, diphenylmethylene or benzyloxycarbonyl.

In another aspect of the invention, there is provided a compound of formula (Ia). These compounds are useful as synthetic intermediates for compounds of formula (I).

Thus. In a further aspect the present invention provides a compound of formula (Ia), in base form or in acid addition salt form, in hydrate or solvate synthetic form,

wherein:

-n is 1 or 2;

-p is 1 or 2;

-R₁represents a halogen atom, a trifluoromethyl group, or a group (C)₁-C₄) Alkyl, (C)₁-C₄) Alkoxy, trifluoromethoxy;

-R₂represents a hydrogen atom or a halogen atom;

-R₄represents an aryl group selected from:

the above aryl group is unsubstituted or substituted by a halogen atom, (C)₁-C₄) Alkyl, (C)₁-C₄) Alkoxy, and trifluoro-methoxy substituent.

The following examples describe the preparation of certain compounds of the present invention. These examples are not intended to be limiting and merely illustrate the invention. Exemplary compounds are shown in Table I below, which describes the chemical structure and physical properties of certain compounds of the present invention.

The following abbreviations have been used in the preparations and examples:

diethyl ether: diethyl ether

Iso-ether: diisopropyl ether

DMSO, DMSO: dimethyl sulfoxide

DMF: n, N-dimethylformamide

THF: tetrahydrofuran (THF)

DCM: methylene dichloride

AcOEt: ethyl acetate

DIPEA: diisopropylethylamine

TFA: trifluoroacetic acid

BOP: benzoltriazol-1-yloxytris (dimethylamino) phosphonium hexafluorophosphate

PyBOP: phenprobriazol-1-yloxytripyrrolidinophosphonium hexafluorophosphate

2N hydrochloric acid ether: 2N Ether hydrochloride solution

m.p. melting Point

AT: ambient temperature

b.p.: boiling point temperature

HPLC: high performance liquid chromatography

Silica H: merck sold as silica gel 60H solid (Darmstadt)

Buffer pH 2: 16.66g KHSO₄And 32.32g K₂SO₄Solution in 1 liter of water.

Proton nuclear magnetic resonance (¹H NMR) Spectroscopy with DMSO-d₆Peaks as reference in DMSO-d₆Medium grade 200MH₇And (5) recording. Chemical shifts (coefficients) δ are typically expressed in parts per million (ppm). The observed signals are expressed as follows: s; single (spectral) line; bs: a wide single spectral line; d: a double line; sd: a double peak doublet; t: a triplet; st: a double peak triplet; q: a quadruple of lines; comp: unresolved complexes; mt: multiple lines.

The structure of these compounds was confirmed by NMR spectroscopy.

The compounds of the invention were analyzed by LC/UV/MS (liquid chromatography/UV detection/mass spectrometry) coupling.

The compounds were checked and their mass spectra obtained in positron emission electrospray (ESI +) were consistent with the calculated molecular weights.

Mass spectrometry of the compounds of the invention is generally carried out as the molecular ion MH⁺As the base peak.

Preparation method

1. Preparation of Compounds of formulae (IV) and (IVa)

Preparation 1.1

4- [3- (trifluoromethyl) phenyl ] -4-piperidinol hydrochloride

(IV)，HCl：R₁＝3-CF₃；R₂＝H；R₃＝-OH。

A) 1-benzyl-4- [3- (trifluoromethyl) phenyl ] -4-piperidinol hydrochloride

A mixture of 180 g of magnesium in 2670ml of THF is heated to 30 ℃ and mixed with 33ml of a solution of 1670g of 1-bromo-3- (trifluoromethyl) benzene in 1330ml of THF, and the remaining solution is then added slowly, the THF is maintained at reflux and stirred at reflux for 2 hours. Then a solution of 1000g of 1-benzyl-4-piperidone in 3200ml of THF was slowly added and the mixture was heated under reflux for 2 hours. After cooling to ambient temperature, the reaction mixture was added over 30 minutes to a solution of 1870g ammonium chloride in 6700ml water and the mixture was stirred at 20-25 ℃ for 2 hours. After draining, the organic phase is washed with 5530ml of water and the solvent is removed by evaporation in vacuo. The residue is dissolved in 5330ml of diethyl ether, a solution of 210g of HCl gas in 800ml of isopropanol is slowly added, the temperature is kept below 25 ℃, the mixture is stirred for 40 minutes, and the crystals formed are isolated by suction. The crystals were dissolved in 2000ml of diethyl ether and isolated by suction. Recrystallization from an isopropanol/ethanol (70/30; V/V) mixture gives 1080g of the expected product.

B)4- [3- (trifluoromethyl) phenyl ] -4-piperidinol hydrochloride

1000g of the compound obtained in the preceding step were hydrogenated with 83g of 10% palladium on carbon (water content 50%) in 2910ml of ethanol and 2910ml of methanol at 50 ℃ under a pressure of 2 bar. The catalyst was filtered off, washed twice with 660ml of methanol and the filtrate and washings concentrated in vacuo. The residue was dissolved in 3320ml of diethyl ether and stirred at ambient temperature for 1 hour 30 minutes. The precipitate formed is separated off with suction, washed with 280ml of diethyl ether and dried in vacuo at 40 ℃. 726g of the expected product are obtained.

Preparation 1.2

4-methoxy-4- [3- (trifluoromethyl) phenyl ] piperidine

(IV)：R₁＝3-CF₃；R₂＝H；R₃＝-OCH₃。

A) 4-hydroxy-4- [3- (trifluoromethyl) phenyl ] -1-piperidinecarboxylic acid tert-butyl ester

20g of the compound obtained from preparation 1.1 are mixed with 17.92g of triethylamine in 80ml of DCM at ambient temperature, a solution of 16.3g of di-tert-butyl dicarbonate in 20ml of DCM is then added dropwise and the mixture is stirred at ambient temperature for 18 hours. Water was added to the reaction mixture, which was then extracted with DCM, and the organic phase was washed with water and 5% KHSO₄Washing with Na₂SO₄After drying, the solvent was removed in vacuo. Recrystallization from a mixture of isodiether/hexane gives 13g of the expected product.

B) 4-methoxy-4- [3- (trifluoromethyl) phenyl ] -1-piperidinecarboxylic acid tert-butyl ester

2g of the compound obtained in the preceding step are mixed in 15ml of DMF and 20ml of THF, mixed in portions at ambient temperature with 0.277g of a 60% oil solution of sodium hydride and the mixture is stirred for 40 minutes. Then 1.3g of methyl iodide was added and the mixture was stirred for 2 hours. The reaction mixture was concentrated in vacuo, the residue was dissolved with water and extracted with AcOEt, the organic phase was washed with water, Na₂SO₄Drying and removing the solvent in vacuum. 2g of the expected product are obtained as a yellow oil.

C) 4-methoxy-4- [3- (trifluoromethyl) phenyl ] piperidine

A mixture of 2g of the compound obtained in the previous step and 5ml of TFA was placed in 15ml of DCM and stirred for 1 hour at ambient temperature. The reaction mixture was concentrated in vacuo, the residue was extracted with DCM and the organic phase was taken up with 5% Na₂CO₃Washing with Na₂SO₄Drying and removal of the solvent in vacuo gave 1.7g of the expected product as an orange-yellow oil.

Preparation 1.3

N, N-dimethyl-4- [3- (trifluoromethyl) phenyl ] -4-piperidineamide

(IV)：R₁＝3-CF₃；R₂＝H；R₃＝-N(CH₃)₂。

A) 1-benzyl-4 [3- (trifluoromethyl) phenyl ] -4-piperidinol

A solution of 20g of the compound (free base) obtained in preparation 1.1 and 11.3ml of triethylamine in 200ml of DCM was cooled in an ice bath, 11ml of benzyl bromide was added dropwise and the mixture was stirred at ambient temperature overnight. Vacuum concentrating with saturated K₂CO₃The residue is dissolved in the solution, extracted with AcOEt and the organic phase is saturated with K₂CO₃The solution and saturated NaCl solution were washed with Na₂SO₄Drying and removing the solvent in vacuum. Dissolving the oily residue with pentane, and separating by suctionA precipitate formed. 17g of the expected product are obtained.

B) N- [ 1-benzyl-4 [3- (trifluoromethyl) phenyl ] -4-piperidine ] acetamide

60ml of concentrated Na are cooled in an ice bath₂SO₄Solution, a solution of 16g of the compound obtained in the previous step in 120ml of acetonitrile is added dropwise, the temperature of the reaction mixture is kept below 30 ℃, the mixture is stirred overnight and the temperature is then returned to ambient temperature. The reaction mixture was poured onto ice, made alkaline by addition of concentrated NaOH solution and the precipitate formed was isolated by suction. The precipitate was dissolved in DCM, the organic phase was washed with water and Na₂SO₄Drying and removing the solvent in vacuum. After recrystallization from acetonitrile 9.7g of the expected product are obtained.

C) 1-benzyl-4 [3- (trifluoromethyl) phenyl ] -4-piperidinamine

A mixture of 9.6g of the compound obtained in the preceding step, 250ml of concentrated HCl solution and 250ml of water is heated at 150 ℃ overnight. The reaction mixture was concentrated in vacuo to half, and the resulting acidic aqueous phase was made alkaline by addition of concentrated NaOH solution, extracted with DCM, and Na₂SO₄The organic phase was dried and the solvent was removed in vacuo. 8.1g of the expected product are obtained and are used directly in the following step.

D) 1-benzyl-N, N-dimethyl-4- [3- (trifluoromethyl) phenyl ] -4-piperidinamine

A mixture of 8.1g of the compound obtained in the preceding step, 3.5ml of 37% aqueous formaldehyde solution and 10ml of acetic acid in 250ml of THF is mixed batchwise with 50g of sodium triacetoxyborohydride at ambient temperature and the mixture is stirred overnight at ambient temperature. Methanol 200ml was added and the reaction mixture was heated at 70 ℃ for 1 hour and concentrated in vacuo. The residue was dissolved in 1N NaOH, extracted with DCM, the organic phase was washed with water and Na₂SO₄Drying and removing the solvent in vacuum. 8.7g of the expected product are obtained as a solidified oil.

E) N, N-dimethyl-4- [3- (trifluoromethyl) phenyl ] -4-piperidinamine

8.2g of the compound obtained in the previous stepA mixture of 5g of ammonium formate and 2g of 10% palladium on carbon in 100ml of methanol is stirred at ambient temperature for 1 hour. The catalyst was removed by filtration and the filtrate was concentrated in vacuo. With saturated K₂CO₃The solution dissolves the residue, extracts with AcOEt, Na₂SO₄The organic phase is dried and the solvent is removed in vacuo to yield 4.8g of the expected product.

Preparation 1.4.

4- [3- (trifluoromethyl) phenyl ] -4-piperidinecarbonitrile hydrochloride

(IVa)，HCl：R₁＝3-CF₃；R₂＝H.

A)2- (2, 2-diethoxyethyl) -4, 4-diethoxy-2- [3- (trifluoromethyl) phenyl ] butanenitrile

30g of 3-trifluoromethylphenylacetonitrile and 14.4g of sodium amide are stirred in 400ml of toluene at ambient temperature for 5 minutes, 66ml of bromoacetaldehyde diethyl acetal are added and the mixture is heated at 60 ℃ for 3 hours. Concentrate in vacuo, dissolve the residue with water and extract with diethyl ether. Na (Na)₂SO₄The organic phase was dried and the solvent was removed in vacuo. The residue was chromatographed on silica H, eluting with a mixture of DCM/AcOEt (100/5; v/v). 26g of the expected product are obtained.

B) 4-oxo-2- (2-oxyethyl) -2- [3- (trifluoromethyl) phenyl ] butanenitrile

23.9g of the compound obtained in the above step was stirred in 90ml of formic acid at 50 ℃ overnight. Water was added to the reaction mixture, which was then extracted with AcOEt, water and 10% NaHCO₃The organic phase is washed with a solution, Na₂SO₄Drying and removing the solvent in vacuum. 16g of the expected product are obtained and used immediately in the next step.

C) 1-benzyl-4- [3- (trifluoromethyl) phenyl ] -4-piperidinecarbonitrile hydrochloride.

A mixture of 16g of the compound obtained in the previous step, 6.25ml of benzylamine, 48.6g of sodium triethoxyborohydride and 5 drops of acetic acid is stirred in 150ml of DCM at ambient temperature overnight. 40ml of methanol are subsequently added dropwise and the mixture is heated at 60 ℃ for 1 hour. The reaction mixture was concentrated in vacuo, the residue was extracted with AcOEt and 10% NaHCO₃The solution and water washed the organic phase, Na₂SO₄Drying and removing the solvent in vacuum. The residue is dissolved with a saturated solution of HCl gas in diethyl ether and the precipitate formed is isolated by suction. 18g of the expected product are obtained.

D)4- [3- (trifluoromethyl) phenyl ] -4-piperidinecarbonitrile hydrochloride

A mixture of 2g of the compound obtained in the previous step, 0.2g of 10% palladium on carbon in 30ml of methanol was hydrogenated at ambient temperature and atmospheric pressure for 3 hours. In thatThe catalyst was filtered off and the filtrate was concentrated in vacuo. 1.5g of the expected product are obtained. The compound can also be prepared by the following three steps:

a') bis (2-chloroethyl) carbamic acid tert-butyl ester

83ml of triethylamine are added dropwise to a mixture of 106g of N, N-bis (2-chloroethyl) amine hydrochloride and 130g of di-tert-butyl dicarbonate in 1500ml of DCM at ambient temperature over 1 hour 30 minutes, and then stirred at ambient temperature overnight. The reaction mixture was washed with water and Na₂SO₄The organic phase was dried and the solvent was removed in vacuo. 150g of the expected product are obtained and are used directly in the following reaction.

B') 4-cyano-4- [3- (trifluoromethyl) phenyl ] -1-piperidinecarboxylic acid tert-butyl ester.

An oil suspension of 56g of sodium hydride in 750ml of DMSO and 250ml of THF, at a concentration of 60%, is mixed dropwise under inert gas and at ambient temperature to 120g of 3- (trifluoromethyl) phenyl]Acetonitrile in 250ml DMSO and then slowly mixed with the previous step of 150g compound in 250ml DMSO solution, 60 degrees C heating overnight. The reaction mixture was poured into an ice/water mixture, extracted with diethyl ether, the organic phase was washed with water and saturated NaCl solution, Na₂SO₄Drying and removing the solvent in vacuum. The residue was chromatographed on silica gel using DCM and then DCM/AcOEt (80/20; v/v) mixtureAnd (4) eluting. 191g of the expected product are obtained as crystals; m.p. ═ 72-73 ℃.

C') 4- [3- (trifluoromethyl) phenyl ] -4-piperidinecarbonitrile hydrochloride

A mixture of 115g of the compound obtained in the preceding step, 500ml of 2N HCl in ether and 150ml of methanol is stirred at ambient temperature for 4 hours. The crystalline product formed is isolated by suction and dried. 75g of the expected product are obtained, m.p. ═ 259 ℃.

Preparation 1.5

[4- [3- (trifluoromethyl) phenyl ] -4-piperidinyl ] methylcarbamic acid tert-butyl ester

(IV)：R₁＝3-CF₃；R₂＝H；R₃＝-CH₂NH-COOC(CH₃)₃

A) [ 1-benzyl-4 [3- (trifluoromethyl) phenyl ] -4-piperidinyl ] methylamine

Preparation 1.4 1.5g of the Compound obtained in step C, 0.15gA mixture of nickel and 5ml of aqueous ammonia in 20ml of methanol was hydrogenated at ambient temperature and atmospheric pressure overnight. The catalyst is removed by filtration and the filtrate is concentrated in vacuo to give 1.45g of the expected product.

B) [ 1-benzyl-4- [3- (trifluoromethyl) phenyl ] -4-piperidinyl ] methylcarbamic acid tert-butyl ester

1.45g of the compound obtained in the above step and 20ml of methanol were heated to 40 ℃ and 0.9g of di-tert-butyl dicarbonate was added, and the mixture was heated under reflux for 30 minutes. Cooling to ambient temperature, mixing with water, extracting with AcOEt, and mixing the organic phase with Na₂SO₄Drying and removal of the solvent in vacuo gave 1.86g of the expected product.

C) [4- [3- (trifluoromethyl) phenyl ] -4-piperidinyl ] methylcarbamic acid tert-butyl ester

A mixture of 1.8g of the compound obtained in the preceding step and 0.18g of 10% palladium on carbon in 20ml of methanol was hydrogenated overnight at ambient temperature and atmospheric pressure. The catalyst was removed by filtration and the filtrate was concentrated in vacuo. 1.3g of the expected product are obtained in the form of an oil.

Preparation 1.6

4- [3- (trifluoromethyl) phenyl ] -4-piperidineamide

(IV)：R₁＝3-CF₃；R₂＝H；R₃＝-CONH₂

A) 1-benzyl-4- [3- (trifluoromethyl) phenyl ] -4-piperidineamide

Preparation 1.4 of the compound obtained in step C5 g, 30ml of toluene, 30ml of 30% H₂O₂A mixture of the solution, 30ml of 30% NaOH solution and 0.5g of an aliquot 336 (trioctylmethylammonium chloride) was heated at 100 ℃ for 48 hours. Vacuum concentrating, dissolving the residue in water, extracting with DCM, Na₂SO₄The organic phase was dried and the solvent was removed in vacuo. The residue was chromatographed on silica H, eluting with DCM/MeOH (100/3; v/v). 2.5g of the expected product are obtained.

B)4- [3- (trifluoromethyl) phenyl ] -4-piperidineamide

A mixture of 2.5g of the compound obtained in the previous step, 0.25g of 10% palladium on carbon in 30ml of methanol was hydrogenated at ambient temperature and atmospheric pressure for 48 hours. The catalyst was removed by filtration and the filtrate was concentrated in vacuo. 1.7g of the expected product are obtained.

Preparation 1.7

4- [2- (trifluoromethyl) phenyl ] -4-piperidinol

(IV)：R₁＝2-CF₃；R₂＝H；R₃＝-OH

A) 1-benzyl-4 [2- (trifluoromethyl) phenyl ] -4-piperidinol

A mixture of 1.52g of magnesium in 25ml of THF was added dropwise over a period of 20 minutes to a solution of 14.25g of 1-bromo-2 (trifluoromethyl) benzene in 15ml of THF, and the mixture was heated under reflux for 30 minutes.After cooling on an ice bath, it is slowly mixed with a solution of 10g of 1-benzyl-4-piperidone in 30ml of THF and stirred at ambient temperature for 3 hours. The reaction mixture was poured into saturated aqueous ammonia chloride solution, extracted with AcOEt, the combined organic phases washed with water, Na₂SO₄Drying and removing the solvent in vacuum. The residue was chromatographed on silica, eluting with DCM/MeOH (70/30; v/v). 4.5g of the expected product are obtained.

B)4- [2- (trifluoromethyl) phenyl ] -4-piperidinol

A mixture of 4.5g of the compound obtained in the previous step and 0.5g of 10% palladium on carbon in 100ml of methanol was hydrogenated overnight at 35 ℃ under atmospheric pressure. The catalyst was removed by filtration and the filtrate was concentrated in vacuo. Recrystallization from isoether gives 2.7g of the expected product.

Preparation 1.8

4- [2- (trifluoromethyl) benzene ] -4-piperidinecarbonitrile hydrochloride

(IVa)，HCl：R₁＝2-CF₃；R₂＝H

A) 4-cyano-4- [2- (trifluoromethyl) phenyl ] -1-piperidinecarboxylic acid tert-butyl ester

An oil suspension of 9g of sodium hydride in 125ml of DMSO and 125ml of THF, at a concentration of 60%, was mixed dropwise with a solution of 20g of 2- (trifluoromethyl) phenylacetonitrile in 50ml of DMSO, then slowly with a solution of 25g of the compound obtained in preparation 1.4 step A in 70ml of DMSO, and the mixture was heated at 60 ℃ for 24 hours. The reaction mixture is poured into 2 l of water, extracted with diethyl ether, the organic phase is washed with water and Na₂SO₄Drying and removal of the solvent in vacuo, chromatography of the residue on silica gel, eluting with DCM and then a mixture of DCM/AcOEt (70/30; v/v) gives 16g of the expected product.

B)4- [2- (trifluoromethyl) phenyl ] -4-piperidinecarbonitrile hydrochloride

6g of the compound obtained in the preceding step, 150ml of 2N chlorinated hydrocarbon and 20ml of methanol are stirred at ambient temperature for 2 hours. Concentration in vacuo, dissolution of the residue with diethyl ether and separation of the precipitate formed by suction. 2.3g of the expected product are obtained.

Preparation 1.9

4- [3- (trifluoromethyl) phenyl ] -4-piperidinecarboxylic acid methyl ester hydrochloride

(IV)，HCl：R₁＝3-CF₃；R₂＝H；R₃＝-COOCH₃

A) 1-benzyl-4- [3- (trifluoromethyl) phenyl ] -4-piperidinecarboxylic acid

A mixture of 5g of the compound obtained in preparation 1.4 step C and 4.25g of KOH granules in 80ml of ethylene glycol was heated under reflux for 3 hours. Cooled to ambient temperature, mixed with 100ml of water, adjusted to pH 6.5 by addition of 10% HCl solution, the precipitate formed is isolated by suction and dried in vacuo. The expected product is obtained in 3.9, m.p. ═ 243 ℃.

B) 1-benzyl-4- [3- (trifluoromethyl) phenyl ] -4-piperidinecarboxylic acid methyl ester hydrochloride

A mixture of 3g of the compound obtained in the previous step and 50ml of thionyl chloride in 100ml of DCM was heated at 60 ℃ for 3 hours. Concentrate in vacuo, dissolve the residue with 100ml of methanol and heat at 60 ℃ overnight. Concentration in vacuo afforded 4g of the expected product, m.p. ═ 230 ℃.

C)4- [3- (trifluoromethyl) phenyl ] -4-piperidinecarboxylic acid methyl ester hydrochloride

A mixture of 4g of the compound obtained in the previous step, 0.4g of 10% palladium on carbon in 200ml of methanol was hydrogenated overnight at ambient temperature and atmospheric pressure. The catalyst was removed by filtration and the filtrate was concentrated in vacuo. 2.5g of the expected product are obtained.

Preparation 1.10

[4- [3- (trifluoromethyl) phenyl ] -4-piperidinyl ] acetic acid methyl ester

(IV)：R₁＝3-CF₃；R₂＝H；R₃＝-CH₂-O-CO-CH₃

A)4- [3- (trifluoromethyl) phenyl ] -1, 4-piperidinedicarboxylic acid-1- (tert-butyl) -4-methyl ester

A mixture of 7g of the compound obtained in preparation 1.9, 5.33g of di-tert-butyl dicarbonate and 3.5ml of triethylamine in 100ml of DCM is stirred at ambient temperature for 2 hours. Vacuum concentrating, dissolving the residue in water, extracting with diethyl ether, washing the organic phase with water, Na₂SO₄Drying and removal of the solvent in vacuo gave 9.3g of the expected product.

B)4- (hydroxymethyl) -4[3- (trifluoromethyl) phenyl ] -1-piperidinecarboxylic acid tert-butyl ester

A mixture of 9.27g of the compound obtained in the above step and 150ml of diethyl ether was cooled to 0 ℃ and 1g of lithium aluminum hydride was added, and the mixture was stirred at 0 ℃ for 4 hours. Reaction mixture with saturated NH₄Mixing Cl solution, filtering to remove inorganic salt, extracting filtrate with AcOEt, and extracting with Na₂SO₄The organic phase is dried, the solvent is removed in vacuo and 15.5g of the expected product are obtained after recrystallization from diethyl ether.

C)4[ (acetoxy) methyl ] -4- [3- (trifluoromethyl) phenyl ] -4-piperidinecarboxylic acid tert-butyl ester

A mixture of 5.5g of the compound obtained in the previous step and 2ml of triethylamine in 50ml of DCM was cooled to-70 ℃ and 1.1ml of acetyl chloride was added and the mixture was stirred overnight, during which time the temperature returned to ambient temperature. Ice was added to the reaction mixture, which was then extracted with DCM and Na₂SO₄The organic phase was dried and the solvent was removed in vacuo. 6g of the expected product are obtained.

D) [4- [3- (trifluoromethyl) phenyl ] -4-piperidinyl ] acetic acid methyl ester

A mixture of 6g of the compound obtained in the previous step and 30ml of TFA in 50ml of DCM was stirred at ambient temperature for 1 hour. Concentrated in vacuo, the residue was iced and then 10% NaHCO was added₃The solution was extracted with DCM and Na₂SO₄The organic phase is dried and the solvent is removed in vacuo to yield 4.5g of the expected product.

Preparation 1.11

4- [4- (trifluoromethyl) phenyl ] -4-piperidinol

(IV)：R₁＝4-CF₃；R₂＝H；R₃＝-OH

A) 1-benzyl-4- [4- (trifluoromethyl) phenyl ] -4-piperidinol

This compound was prepared as described in preparation 1.7, step A, from a suspension of 1.55g magnesium in 25ml THF, a solution of 14.25g 1-bromo-4- (trifluoromethyl) benzene in 15ml THF and a solution of 10g 1-benzyl-4-piperidone in 30ml THF. 7.3g of the expected product are obtained.

B)4- [4- (trifluoromethyl) phenyl ] -4-piperidinol

A mixture of 4.8g of the compound obtained in the previous step and 2g of 10% palladium on carbon in 50ml of methanol was hydrogenated at 30 ℃ under atmospheric pressure for 2 hours. The catalyst was removed by filtration and the filtrate was concentrated in vacuo. Recrystallization from isoether gives 2.4g of the expected product.

Preparation 1.12

4- (4-chlorophenyl) -4-piperidinecarbonitrile hydrochloride

(IVa)，HCl：R₁＝4-Cl；R₂＝H

A)4- (4-chlorophenyl) -4-cyano-1-piperidinecarboxylic acid tert-butyl ester

4.4g of sodium hydride in 300ml of THF in an oil suspension with a concentration of 60% are mixed rapidly with 7.51g of 4-chlorobenzonitrile at ambient temperature and then with 12g of tert-butyl bis (2-chloroethyl) carbamate, heated at 40 ℃ for 28 hours and then stirred at ambient temperature overnight. Saturated ammonium chloride solution was added to the reaction mixture, followed by vacuum concentration to remove THF, after which the remaining aqueous phase was extracted with ether and the organic phase was washed with pH 2 buffer and saturated NaCl solution. Na (Na)₂SO₄Drying and removal of the solvent in vacuo gave 12g of the expected product, which was used directly in the following step.

B)4- (4-chlorophenyl) -4-piperidinecarbonitrile hydrochloride

A mixture of 18g of the compound obtained in the preceding step with 100ml of methanol and 20ml of concentrated HCl solution is heated at 40-50 ℃ for 3 hours. The reaction mixture was concentrated in vacuo and the residue was extracted twice with methanol, the solvent being removed in vacuo each time. After recrystallization from acetone, 5.85g of the expected product are obtained.

Preparation 1.13

4- (3-methylphenyl) -4-piperidinol

(IV)：R₁＝3-CH₃；R₂＝H；R₃＝-OH

A) 1-benzyl-4- (3-methylphenyl) -4-piperidinol

This compound was prepared as described in preparation 1.7, step A, from a suspension of 1.55g magnesium in 25ml THF, a solution of 11g 3-bromotoluene in 15ml THF and a solution of 10g 1-benzyl-4-piperidinone moat in 30ml THF. Chromatography on silica gel eluting with DCM/methanol (97/3; v/v) gave 14.5g of the expected product.

B)4- (3-methylphenyl) -4-piperidinol

A mixture of 14.5g of the compound obtained in the previous step and 2g of 10% palladium on carbon in 500ml of methanol was hydrogenated at 25 ℃ under atmospheric pressure for 48 hours. The catalyst was removed by filtration and the filtrate was concentrated in vacuo. 8.9g of the expected product are obtained.

Preparation 1.14

4- (3-methoxyphenyl) -4-piperidinol

(IV)：R₁＝3-OCH₃；R₂＝H；R₃＝-OH

A) 1-benzyl-4- (3-methoxybenzene) -4-piperidinol

This compound was prepared as described in preparation 1.7, step A, from a suspension of 1.55g magnesium in 25ml THF, a solution of 12g 3-bromoanisole in 15ml THF and a solution of 10g 1-benzyl-4-piperidone in 30ml THF. The product was chromatographed on silica gel eluting with a mixture of DCM/MeOH (97/3-95/5; v/v) to give 13.7g of the expected product.

B)4- (3-methoxyphenyl) -4-piperidinol

A mixture of 13.7g of the compound obtained in the previous step and 2g of 10% palladium on carbon in 500ml of ethanol was hydrogenated at 25 ℃ under atmospheric pressure for 48 hours. The catalyst was removed by filtration and the filtrate was concentrated in vacuo. 10.8g of the expected product are obtained.

Preparation 1.15

N- [4- [ 4-chloro-3- (trifluoromethyl) phenyl ] -4-piperidinyl ] acetamide hydrochloride

(IV)，HCl：R₁＝3-CF₃；R₂＝4-Cl；R₃＝-NHCOCH₃

A) 1-benzyl-4- [ 4-chloro-3- (trifluoromethyl) phenyl ] -4-piperidinol

At ambient temperature, 15g of 4- [ 4-chloro-3- (trifluoromethyl) phenyl]-4-piperidinol, 8.3g K₂CO₃And a mixture of 7.18ml of benzyl bromide in 80ml of DMF was stirred for 2 days. The reaction mixture was poured into water, extracted with AcOEt, filtered to remove the insoluble product, the organic phase was washed with water and with saturated NaCl solution, Na₂SO₄Drying and removing the solvent in vacuum. The residue is chromatographed on silica, eluting with a mixture of DCM/methanol (95/5; v/v) to give 14.6g of the expected product.

B) N- [ 1-benzyl-4- [ 4-chloro-3- (trifluoromethyl) phenyl ] -4-piperidinyl ] acetamide

30ml of concentrated H are cooled in an ice bath₂SO₄7.98g of the compound obtained in the previous step in 60ml of acetonitrile is added dropwise at a temperature below 15 ℃ and the mixture is stirred for 2 days at 15 ℃. The reaction mixture was poured onto ice, NaOH pellets were added to make alkaline and extracted with AcOEt, and the organic phase was Na₂SO₄Drying and removal of the solvent in vacuo gave an impure solid (7.86 g). The residue was chromatographed on silica, eluting with DCM/MeOH (97/3-95/5; v/v) mixture. After recrystallization from DCM/isoether 4.26g of the expected product are obtained, m.p. 198-.

C) N- [4- [ 4-chloro-3- (trifluoromethyl) phenyl ] -4-piperidinyl ] acetamide hydrochloride

The compound obtained in the previous step, 3.1g and 1.05g K, was mixed at ambient temperature₂CO₃The mixture in 25ml DCM was stirred for 15 minutes, then cooled with an ice bath, mixed dropwise with 1.2ml chloroformiate 1-chloroethyl chloride in 5ml DCM and stirred at 4 ℃ for 2 hours. The insoluble material was removed by filtration, the filtrate was concentrated in vacuo, the residue was extracted with methanol, and the solvent was removed in vacuo. The residue was extracted with 80ml of methanol, heated under reflux for 15 minutes and the solvent removed in vacuo. 2.7g of the expected product are obtained.

D)4- (acetylamino) -4- [ 4-chloro-3- (trifluoromethyl) phenyl ] -1-piperidinecarboxylic acid tert-butyl ester

A mixture of 2.7g of the compound obtained in the previous step, 1.9ml of DIPEA and 1.64g of di-tert-butyl dicarbonate in 20ml of DCM is stirred at ambient temperature for 2 hours. The mixture was concentrated in vacuo and the residue was chromatographed on silica, eluting with DCM/MeOH (98/2; v/v). 1.4g of the expected product are obtained.

E) N- [4- [ 4-chloro-3- (trifluoromethyl) phenyl ] -4-piperidinyl ] acetamide hydrochloride

A suspension of 1.4g of the compound obtained in the previous step in 20ml of dioxane was mixed with 4ml of a 2N chlorinated hydrocarbon solution and stirred at ambient temperature for 2 hours. The reaction mixture was concentrated in vacuo to give the desired product, which was used directly in the following step.

Preparation 1.16

4- [3- (trifluoromethoxy) phenyl ] -4-piperidinol hydrochloride

(IV)，HCl：R₁＝3-OCF₃；R₂＝4-Cl；R₃＝-OH

A) 1-benzyl-4- [3- (trifluoromethoxy) phenyl ] -4-piperidinol hydrochloride

This compound was prepared as described in preparation 1.7, step A, from a suspension of 2g magnesium in 25ml THF, a solution of 20g 1-bromo-3- (trifluoromethoxy) benzene in 15ml THF and a solution of 13g 1-benzyl-4-piperidone in 30ml THF. The hydrochloride of the product obtained is formed in a 2N solution of a chlorinated hydrocarbon to give 24.4g of the expected product.

B)4- [3- (trifluoromethoxy) phenyl ] -4-piperidinol hydrochloride

A mixture of 24g of the compound obtained in the preceding step, 16g of ammonium formate and 2g of 10% palladium on carbon in 500ml of methanol is stirred at ambient temperature for 4 hours. The catalyst was removed by filtration and the filtrate was concentrated in vacuo. With saturated K₂CO₃The residue was collected in solution, extracted with ether, the organic phase was washed with saturated NaCl solution, Na₂SO₄Drying and removing the solvent in vacuum. The residue was extracted with a 2N chlorinated hydrocarbon solution and the precipitate formed was isolated by suction. 6.2g of the expected product are obtained, m.p. -. 145-sec 146 ℃.

Preparation 1.17

[ [4- [3- (trifluoromethyl) phenyl ] -piperidin-4-yl ] methyl ] carbamic acid tert-butyl methyl ester

(IV)：R₁＝3-CF₃；R₂＝H；R₃＝-CH₂N(CH₃)-COOC(CH₃)₃

A) N, N-bis (2-chloroethyl) benzylamine

A mixture of 150g N, N-bis (2-chloroethyl) amine hydrochloride and 100ml benzyl bromide in 1000ml DMF was cooled in an ice bath, then 120ml triethylamine was added dropwise and the mixture was stirred at ambient temperature overnight. The reaction mixture was concentrated in vacuo, the residue was collected with water and extracted 3 times with diethyl ether, Na₂SO₄The organic phase was dried and the solvent was removed in vacuo. 113g of the expected product are obtained.

B) 1-benzyl-4- [3- (trifluoromethyl) phenyl ] -4-piperidinecarbonitrile hydrochloride

A suspension of 23.24g of sodium hydride in 100ml of DMSO and 100ml of THF in oil (60% strength) is mixed dropwise with a solution of 50g of 3- (trifluoromethyl) phenylacetonitrile in 150ml of DMSO at ambient temperature under inert gas, and the mixture is stirred for 15 minutes. Followed by addition over 1 hourA solution of 62.43g of compound obtained in the previous step in 150ml of DMSO was stirred overnight at ambient temperature. Adding ice/water mixture, extracting the system with diethyl ether, Na₂SO₄The organic phase was dried and the solvent was removed in vacuo. The residue was collected with 1000ml of hot ethanol, the system was stirred at ambient temperature for 48 hours and the crystalline product formed was isolated by suction. 50g of the expected product are obtained.

C) [ 1-benzyl-4- [3- (trifluoromethyl) phenyl ] -4-piperidinyl ] methylamine

Dissolving 30g of the compound obtained in the previous step in 10% NaOH solution, extracting with diethyl ether, and extracting with Na₂SO₄The organic phase was dried and the solvent was removed in vacuo. The free base form was placed in 500ml methanol and 30ml 20% ammonia solution, 3g was addedNickel, the system was hydrogenated overnight at ambient temperature and atmospheric pressure. The catalyst was removed by filtration and the filtrate was concentrated in vacuo. The residue was collected in water and extracted with AcOEt. With Na₂SO₄The organic phase was dried and the solvent was removed in vacuo. 27g of the expected product are obtained.

D) [ [ 1-benzyl-4- [3- (trifluoromethyl) phenyl ] -4-piperidinyl ] methyl ] carboxamide

A mixture of 27g of the compound obtained in the previous step and 300ml of ethyl formate was stirred at ambient temperature overnight, then heated at 60 ℃ for 6 hours and stirred at ambient temperature for 48 hours. Vacuum concentrating, collecting the residue in 10% HCl solution, washing the acidic aqueous phase with diethyl ether, adding ice, adding 10% NaOH solution to make the mixture alkaline, extracting with diethyl ether, and extracting with Na₂SO₄The organic phase was dried and the solvent was removed in vacuo. The residue was chromatographed on silica H, eluting with DCM and then a DCM/methanol mixture (100/4; v/v). 20g of the expected product are obtained.

E) [ [ 1-benzyl-4- [3- (trifluoromethyl) phenyl ] -4-piperidinyl ] methyl ] methylamine

400ml of the mixture is mixed with the water at the ambient temperatureA suspension prepared from diethyl ether 4g of lithium aluminum hydride was mixed with 20g of the compound obtained in the previous step, followed by stirring at ambient temperature for 16 hours, followed by successively adding 3ml of water, 3ml of 30% NaOH and 1ml of water, and stirring the mixture. The inorganic salts are removed by filtration over Celite, the filtrate is decanted and taken over Na₂SO₄The organic phase was dried and the solvent was removed in vacuo. 18g of the expected product are obtained.

F) [ [ 1-benzyl-4- [3- (trifluoromethyl) phenyl ] -4-piperidinyl ] methyl ] methylcarbamic acid tert-butyl ester

A mixture of 18g of the compound obtained in the preceding step and 9.6g of di-tert-butyl dicarbonate in 300ml of DCM is stirred at ambient temperature for 1 hour. Water was added to the reaction mixture, which was then extracted with DCM and Na₂SO₄The organic phase was dried and the solvent was removed in vacuo. The residue was chromatographed on silica H, eluting with DCM/MeOH (100/2; v/v). 21g of the expected product are obtained.

G) [4- [3- (trifluoromethyl) phenyl ] piperidin-4-yl ] methyl ] carbamic acid tert-butyl methyl ester

A mixture of 21g of the compound obtained in the preceding step and 2g of 10% palladium on carbon in 300ml of methanol is hydrogenated at ambient temperature and atmospheric pressure for 12 hours. The catalyst was removed by filtration and the filtrate was concentrated in vacuo. 16g of the expected product are obtained.

Preparation 1.18

4- (3-chlorophenyl) -4-piperidinecarbonitrile hydrochloride

(IVa)，HCl：R₁＝3-Cl；R₂＝H

A)4- (3-chlorophenyl) -4-cyanopiperidine-1-carboxylic acid tert-butyl ester

An oil suspension of 15.8g of sodium hydride in 400ml of DMSO (60% strength) is mixed dropwise with a solution of 30g of 3-trichlorophenylacetonitrile in 200ml of THF and then with a solution of 45.5g of tert-butyl bis (2-chloroethyl) carbamate in 200ml of DMSO at ambient temperature under an inert gas atmosphere and heated overnight at 60 ℃. The reaction mixture was poured into an ice/water mixture, extracted with diethyl ether,the organic phase is washed with water, Na₂SO₄Drying and removing the solvent in vacuum. The residue was chromatographed on silica gel eluting with DCM. 33g of the expected product are obtained.

B)4- (3-chlorophenyl) -4-piperidinecarbonitrile hydrochloride

A mixture of 6.7g of the compound obtained in the previous step, 100ml of 2N ethereal hydrochloride solution and 20ml of methanol was stirred at ambient temperature for 3 hours. Concentrated in vacuo, the residue was taken up in ether and the precipitate formed was isolated by suction. 4.65g of the expected product are obtained, m.p. ═ 198 ℃.

Preparation 1.19

4- (3-methoxyphenyl) -4-piperidinecarbonitrile hydrochloride

(IVa)，HCl：R₁＝3-OCH₃；R₂＝H

A)4- (3-methoxyphenyl) -4-cyanopiperidine-1-carboxylic acid tert-butyl ester

This compound was prepared as described in preparation 1.8, step A, from a solution of 16.3g of sodium hydride in 400ml of DMSO oil suspension (concentration 60%), 30g of 3-methoxyphenylacetonitrile in 150ml of THF and 47g of tert-butyl bis (2-chloroethyl) carbamate in 100ml of DMSO. 54g of the expected product are obtained.

B)4- (3-methoxyphenyl) -4-piperidinecarbonitrile hydrochloride

A mixture of 48g of the compound obtained in the previous step, 300ml of 2N ethereal hydrochloride solution and 50ml of methanol was stirred at ambient temperature for 2 hours. The precipitate formed is separated off with suction to give 30.5g of the expected product, m.p. ═ 172 ℃.

Preparation 1.20

4- (azetidin-1-yl-carbonyl) -4- [3- (trifluoromethyl) phenyl ] -piperidine

(IV)：R₁＝3-CF₃；R₂＝H；

A)4- (Chloromethyl) -4- [3- (trifluoromethyl) phenyl ] -piperidine hydrochloride

A mixture of 1g of the compound obtained in preparation 1.9, step A and 10ml of thionyl chloride in 10ml of DCM was heated at 60 ℃ for 2 hours. Concentration in vacuo afforded 1.05g of the expected product, which was used directly in the next step.

B)4- (azetidin-1-yl-carbonyl) -1-benzyl-4- [3- (trifluoromethyl) phenyl ] -piperidine

A mixture of 1.05g of the compound obtained in the previous step, 0.283g of azetidine and 1.15ml of triethylamine in 10ml of DCM was stirred at ambient temperature overnight. Adding saturated K to the reaction mixture₂CO₃The solution was then extracted with DCM and Na₂SO₄The extract was dried and the solvent removed in vacuo. The residue was chromatographed on silica, eluting with DCM/MeOH (97/3; v/v). 0.43g of the expected product is obtained.

C)4- (azetidin-1-ylcarbonyl) -4- [3- (trifluoromethyl) phenyl ] -piperidine

A mixture of 0.43g of the compound obtained in the above step, 1g of 10% palladium on carbon and 20ml of methanol was hydrogenated at 25 ℃ under atmospheric pressure overnight. The catalyst was removed by filtration and the filtrate was concentrated in vacuo. 0.33g of the expected product is obtained and used directly in the following reaction.

2. Preparation of the Compound of formula (II)

Preparation 2.1

2-chloro-1- [4- [3- (trifluoromethyl) phenyl ] -1-piperidinyl ] -1-ethanone

(IIa)：R₁＝3-CF₃；R₂＝H；R₃＝H；Hal＝Cl

2.5g of 4- [3- (trifluoromethyl) phenyl]A mixture of piperidine and 4ml triethylamine in 30ml DCM, then mixed dropwise with 0.85ml 2-chloroacetyl chloride, stirred for 3 hours, with the temperature returning to ambient temperature during stirring. Vacuum concentrating, extracting with 1N HCl aqueous solutionThe residue was extracted with AcOEt and the organic phase was washed with saturated NaCl solution, Na₂SO₄Drying and removing the solvent in vacuum. 3.1g of the expected product are obtained and are used directly in the following reaction.

Preparation 2.2

2-chloro-1- [ 4-hydroxy-4- [3- (trifluoromethyl) phenyl ] -1-piperidinyl ] -1-ethanone

(IIa)：R₁＝3-CF₃；R₂＝H；R₃＝-OH；Hal＝Cl

A mixture of 5g of the compound obtained in preparation 1.1 and 10ml of DIPEA in 40ml of DCM was admixed dropwise at ambient temperature with 1.63ml of 2-chloroacetyl chloride and stirred for 30 minutes. The reaction mixture was washed with water and the organic phase was Na₂SO₄Drying and removing the solvent in vacuum. The residue was chromatographed on silica, eluting with DCM/MeOH (97/3; v/v). 5.5g of the expected product are obtained and used directly in the following reaction.

Preparation 2.3

1- [ 4-hydroxy-4- [3- (trifluoromethyl) phenyl ] -1-piperidinyl ] -2-propen-1-one

(IIb)：R₁＝3-CF₃；R₂＝H；R₃＝-OH

A mixture of 5g of the compound obtained in preparation 1.1 and 8ml of triethylamine in 50ml of DCM was cooled in an ice bath and then mixed dropwise with 2.07ml of 3-bromopropionyl chloride, stirred for 2 hours, during which the temperature returned to ambient temperature. With saturated K₂CO₃The solution and water were washed, and the organic phase was Na₂SO₄Drying and removing the solvent in vacuum. The residue was chromatographed on silica, eluting with DCM/MeOH (98.5/1.5-97/3; v/v) mixture. 4.6g of the expected product are obtained and are used directly in the following reaction.

Preparation 2.4

2-chloro-1- [ 4-methoxy-4- [3- (trifluoromethyl) phenyl ] -1-piperidinyl ] -1-ethanone

(IIa)：R₁＝3-CF₃；R₂＝H；R₃＝-OCH₃；Hal＝Cl

A mixture of 1g of the compound obtained in preparation 1.2 and 1.4ml of triethylamine in 20ml of DCM was mixed dropwise at ambient temperature with 0.3ml of 2-chloroacetyl chloride and stirred at ambient temperature for 3 hours. Vacuum concentrating, extracting the residue with 1N aqueous HCl, extracting with AcOEt, washing the organic phase with NaCl solution, Na₂SO₄Drying and removing the solvent in vacuum. 1.2g of the expected product are obtained and are used directly in the following reaction.

Preparation 2.5

2-chloro-1- [4- (dimethylamino) -4- [3- (trifluoromethyl) phenyl ] -1-piperidinyl ] -1-ethanone

(IIa)：R₁＝3-CF₃；R₂＝H；R₃＝-N(CH₃)₂；Hal＝Cl

A mixture of 1g of the compound obtained in preparation 1.3 and 1ml of triethylamine in 20ml of DCM was cooled in an ice bath and then mixed dropwise with 0.35ml of 2-chloroacetyl chloride and stirred, during which the temperature returned to ambient temperature. Concentrate in vacuo, extract the residue with AcOEt, saturate with K₂CO₃The organic phase is washed with a solution, Na₂SO₄Drying and removing the solvent in vacuum. 1.4g of the expected product are obtained and used directly in the following reaction.

Preparation 2.6

1- (2-chloroacetyl) -4- [3- (trifluoromethyl) phenyl ] -4-piperidinecarbonitrile

(IIc)：R₁＝3-CF₃；R₂＝H；Hal＝Cl

A mixture of 4.8g of the free base of the compound obtained in preparation 1.4 and 2.7ml of triethylamine in 50ml of DCM was mixed dropwise at ambient temperature with 1.5ml of 2-chloroacetyl chloride and stirred at ambient temperature for 1 hour. The reaction mixture was added with 10% HCl solution, after decantation, the organic phase was washed with 10% NaOH solution, Na₂SO₄Drying and removing the solvent in vacuum.Recrystallization from ether gives 3.42g of the expected product, m.p. ═ 120 ℃.

Preparation 2.7

[1- (2-Chloroacyl) -4- [3- (trifluoromethyl) phenyl ] -4-piperidinyl ] methylcarbamic acid tert-butyl ester

(IIa)：R₁＝3-CF₃；R₂＝H；R₃＝-CH₂NHCOOC(CH₃)₃；Hal＝Cl

A mixture of 4.95g of the compound obtained in preparation 1.5 and 6.8ml of triethylamine in 50ml of DCM was cooled in an ice bath and then mixed dropwise with 1.65ml of 2-chloroacetyl chloride and stirred, during which the temperature returned to AT. Vacuum concentrating with saturated K₂CO₃Extracting the residue with AcOEt and saturated K₂Ambient temperature of CO₃The organic phase was washed with a solution, pH 2 buffer and saturated NaCl solution, Na₂SO₄Drying and vacuum evaporating the mixture. The residue was chromatographed on silica, eluting with DCM/MeOH (80/20; v/v). 1.8g of the expected product are obtained and are used directly in the following reaction.

Preparation 2.8

1- (2-chloroacetyl) -4- [3- (trifluoromethyl) phenyl ] -4-piperidinecarbonitrile

(IIa)：R₁＝3-CF₃；R₂＝H；R₃＝-CONH₂；Hal＝Cl

A mixture of 0.7g of the compound obtained in preparation 1.6 and 0.37ml of triethylamine in 10ml of DCM and 10ml of dioxane was mixed dropwise at ambient temperature with 0.21ml of 2-chloroacetyl chloride and stirred at ambient temperature for 2 hours. Concentration in vacuo and the residue collected in water, the precipitate formed separated by suction and dried. 0.82g of the expected product is obtained, m.p. ═ 195 ℃ 198 ℃.

Preparation 2.9

2-chloro-1- [ 4-hydroxy-4- [2- (trifluoromethyl) phenyl ] -1-piperidinyl ] -1-ethanone

(IIa)：R₁＝3-CF₃；R₂＝H；R₃＝-OH；Hal＝Cl

A mixture of 1.8g of the compound obtained in preparation 1.7 and 1ml of triethylamine in 20ml of DCM was cooled in an ice bath and then mixed dropwise with 0.65ml of 2-chloroacetyl chloride, stirred for 1 hour, during which the temperature returned to ambient temperature. Water was added to the reaction mixture, DCM was removed by concentration in vacuo, the mixture was extracted with AcOEt, and the organic phase was washed with water and saturated NaCl solution, Na₂SO₄Drying and removing the solvent in vacuum. 1.8g of the expected product are obtained and are used directly in the following reaction.

Preparation 2.10

1- (2-chloroacetyl) -4- [2- (trifluoromethyl) phenyl ] -4-piperidinecarbonitrile

(IIc)：R₁＝2-CF₃；R₂＝H；Hal＝Cl

A mixture of 2.1g of the compound obtained in preparation 1.8 and 2ml of triethylamine in 20ml of DCM was mixed with 0.6ml of 2-chloroacetyl chloride at room temperature and stirred for 30 minutes. Concentrating under vacuum, collecting the residue in 10% HCl, extracting with AcOEt, and collecting the organic phase with water and saturated K₂CO₃Washing the solution with saturated NaCl solution, Na₂SO₄Drying and removal of the solvent in vacuo gave 2.3g of the expected product.

Preparation 2.11

[1- (2-Chloroacyl) -4- [3- (trifluoromethyl) phenyl ] -piperidinyl ] acetic acid methyl ester

A mixture of 1g of the compound obtained in preparation 1.10 and 0.46ml of triethylamine in 20ml of DCM was cooled to 0 ℃ and 0.27ml of 2-chloroacetyl chloride was added and the mixture was stirred at 0 ℃ for 30 minutes. Water was added to the reaction mixture, which was extracted with DCM and the organic phase with Na₂SO₄Drying and removing the solvent in vacuum. 0.9g of the expected product is obtained.

Preparation 2.12

2-chloro-1- [ 4-hydroxy-4- [4- (trifluoromethyl) phenyl ] -1-piperidinyl ] -1-ethanone

(IIa)：R₁＝4-CF₃；R₂＝H；R₃＝-OH；Hal＝Cl

A mixture of 1.2g of the compound obtained in preparation 1.11 and 1.2ml of triethylamine in 20ml of DCM was cooled in an ice bath and then mixed dropwise with 0.38ml of 2-chloroacetyl chloride, stirred for 1 hour, during which the temperature returned to ambient temperature. Water was added to the reaction mixture, which was extracted with DCM, and the organic phase was Na₂SO₄Drying and removing the solvent in vacuum. 1.36g of the expected product are obtained and used directly in the following reaction.

Preparation 2.13

2-chloro-1- [4- (4-chlorophenyl) -4-hydroxy-1-piperidinyl ] -1-ethanone

(IIa)：R₁＝4-Cl；R₂＝H；R₃＝-OH；Hal＝Cl

This compound was prepared from 4- (4-chlorophenyl) -4-piperidinol (commercially available) and 2-chloroacetyl chloride as described in preparation 2.12.

Preparation 2.14

1- (2-Chloroacyl) -4- (4-chlorophenyl) -4-piperidinecarbonitrile

(IIc)：R₁＝4-Cl；R₂＝H；Hal＝Cl

This compound was prepared from the compound obtained in preparation 1.12 and 2-chloroacetyl chloride by the method described in preparation 2.1.

Preparation 2.15

2-chloro-1- [ 4-hydroxy-4- (3-methylphenyl) -1-piperidinyl ] -1-ethanone

(IIa)：R₁＝3-CH₃；R₂＝H；R₃＝-OH；Hal＝Cl

This compound was prepared from the compound obtained in preparation 1.13 and 2-chloroacetyl chloride by the method described in preparation 2. l.

Preparation 2.16

2-chloro-1- [ 4-hydroxy-4- (3-methoxyphenyl) -1-piperidinyl ] -1-ethanone

(IIa)：R₁＝3-OCH₃；R₂＝H；R₃＝-OH；Hal＝Cl

This compound was prepared from the compound obtained in preparation 1.14 and 2-chloroacetyl chloride by the method described in preparation 2.1.

Preparation 2.17

2-chloro-1- [4- [ 4-chloro-3- (trifluoromethyl) phenyl ] -4-hydroxy-1-piperidinyl ] -1-ethanone

(IIa)：R₁＝3-CF₃；R₂＝4-Cl；R₃＝-OH；Hal＝Cl

This compound was prepared from 4- [ 4-chloro-3- (trifluoromethyl) phenyl ] -4-piperidinol and 2-chloroacetyl chloride as described in preparation 2.1.

Preparation 2.18

N- [1- (2-chloroacetyl) -4- [ 4-chloro-3- (trifluoromethyl) phenyl ] -4-piperidinyl ] -1-acetamide

(IIa)：R₁＝3-CF₃；R₂＝4-Cl；R₃＝-NHCOCH₃；Hal＝Cl

This compound was prepared from the compound obtained in preparation 1.15 and 2-chloroacetyl chloride by the method described in preparation 2.2.

Preparation 2.19

2-chloro-1- [ 4-hydroxy-4- [3- (trifluoromethoxy) phenyl ] -1-piperidinyl ] -1-ethanone

(IIa)：R₁＝3-OCF₃；R₂＝H；R₃＝-OH；Hal＝Cl

This compound was prepared from the compound obtained in preparation 1.16 and 2-chloroacetyl chloride by the method described in preparation 2.1.

Preparation 2.20

[ [1- (2-Chloroacetyl) -4- [3- (trifluoromethyl) phenyl ] -4-piperidinyl ] methyl ] methylcarbamic acid tert-butyl ester

(IIa)：R₁＝3-CF₃；R₂＝H；R₃＝-CH₂N(CH₃)COOC(CH₃)₃；Hal＝Cl

A solution of 14g of the compound obtained in preparation 1.17 and 5.5ml of triethylamine in 300ml of DCM was cooled to-40 ℃ and 3.1ml of 2-chloroacetyl chloride was added slowly and the mixture was stirred and the temperature returned to ambient temperature. Vacuum concentrating, extracting the residue in water, extracting with AcOEt, washing the organic phase with pH 2 buffer and water, Na₂SO₄Drying and removing the solvent in vacuum. 15.33g of the expected product are obtained.

Preparation 2.21

1- (2-Chloroacyl) -4- (3-chlorophenyl) -4-piperidinecarbonitrile

(IIc)：R₁＝3-Cl；R₂＝H；Hal＝Cl

This compound was prepared from the compound obtained in preparation 1.18 and 2-chloroacetyl chloride by the method described in preparation 2.1.

Preparation 2.22

1- (2-chloroacetyl) -4- (3-methoxyphenyl) -4-piperidinecarbonitrile

(IIc)：R₁＝3-0CH₃；R₂＝H；Hal＝Cl

This compound was prepared from the compound obtained in preparation 1.19 and 2-chloroacetyl chloride by the method described in preparation 2.1.

Preparation 2.23

4- (azetidin-1-ylcarbonyl) -1- (2-chloroacetyl) -4- [3- (trifluoromethyl) phenyl ] piperidine

(IIa)：R₁＝3-CF₃；R₂＝H；Hal＝Cl

This compound was prepared from the compound obtained in preparation 1.20 and 2-chloroacetyl chloride by the method described in preparation 2.1.

3. Preparation of the Compound of formula (III)

Preparation 3.1

1- (2-pyrazinyl) piperazine

(III)：p＝1；

3g of piperazine, 1.04ml of 2-chloropyrazine and 1.85g K₂CO₃The mixture in 100ml of ethanol was heated under reflux for 48 hours. The reaction mixture was concentrated in vacuo and the residue was taken up in water, the system was brought to alkaline pH 10 by addition of 10% NaOH, extracted with chloroform, the organic phase was washed with water, Na₂SO₄Drying and removing the solvent in vacuum. Recrystallization from hexane gives 1.8g of the expected product.

Preparation 3.2

1- (3-pyridyl) piperazine

(III)：p＝1；

According to Tetrahedron letters 1998, 39: 617-620.

Preparation 3.3

3- (1-piperazinyl) pyridazine trihydrochloride

(III)，3HCl：p＝1；

A)4- (6-chloro-3-pyridazinyl) -1-piperazinecarboxylic acid tert-butyl ester

A mixture of 13.52g of tert-butyl 1-piperazinecarboxylate, 10.81g of 3, 6-dichloropyridazine and 20ml of triethylamine in 100ml of n-butanol was heated under reflux for 5 hours. Concentration in vacuo and chromatography of the residue on silica eluting with a mixture of DCM/AcOEt (90/10; v/v) gave 14g of the expected product, which was used directly in the following reaction.

B)4- (3-pyridazinyl) -1-piperazinecarboxylic acid tert-butyl ester

A mixture of 10.5g of the compound obtained in the previous step and 2.5g of 10% palladium on carbon in 30ml of DMF and 250ml of ethanol was hydrogenated overnight at ambient temperature and atmospheric pressure. The catalyst was removed by filtration and the filtrate was concentrated in vacuo. The residue was chromatographed on silica, eluting with DCM/MeOH (97/3-90/10; v/v) mixture. 9.1g of the expected product are obtained and are used directly in the following reaction.

C)3- (1-piperazinyl) pyridazine trihydrochloride

A mixture of 3.8g of the compound obtained in the previous step, 2N HCl in ether and 20ml of methanol was stirred at ambient temperature overnight. Concentrated in vacuo, the residue was taken up in ether and the precipitate formed was isolated by suction. 3g of the expected product are obtained and are used directly in the following reaction.

Preparation 3.4

3-chloro-6- (1-piperazinyl) pyridazine trihydrochloride

(III)，3HCl：p＝1；

A mixture of 2.96g of compound obtained in preparation 3.3 step a and 30ml of 6N HCl in methanol was stirred at ambient temperature overnight. The reaction mixture was concentrated in vacuo and the residue was extracted several times with DCM and the solvent was removed in vacuo each time. 2.6g of the expected product are obtained and are used directly in the following reaction.

Preparation 3.5

4- (1-piperazinyl) dihydrochloride

(III)，2HCl：p＝1；

A)4- (2-chloro-4-pyrimidinyl) -1-piperazinecarboxylic acid tert-butyl ester

9.55g of tert-butyl 1-piperazinecarboxylate, 7.64g of 2, 4-dichloropyrimidine and 8.6g of NaHCO₃The mixture in 50ml of ethanol was heated under reflux for 1 hour. Concentrated in vacuo, the residue was taken up in water, extracted with DCM and the organic phase with Na₂SO₄Drying and removing the solvent in vacuum. The residue was chromatographed on silica gel, eluting with DCM/AcOEt (90/10-60/40; v/v) mixture. Two compounds were isolated:

-obtaining 1.75g of a less polar compound corresponding to tert-butyl 4- (4-chloro-2-pyrimidinyl) -1-piperazinecarboxylate;

12.9g of the more polar compound, corresponding to the compound of step A, are obtained, which are used directly in the following reaction.

B)4- (4-pyrimidinyl) -1-piperazinecarboxylic acid tert-butyl ester hydrochloride

A mixture of 12.9g of the compound obtained in the preceding step and 3.2g of 10% palladium on carbon in 300ml of methanol and 100ml of DMF is hydrogenated for 2 hours at ambient temperature and atmospheric pressure. The catalyst was removed by filtration and the filtrate was concentrated in vacuo. 13g of the expected product are obtained and used directly in the following reaction.

C)4- (1-piperazinyl) pyrimidine dihydrochloride

A mixture of 4g of the compound obtained in the previous step, 50ml of 2N HCl in ether and 30ml of methanol was stirred at ambient temperature for 2 hours. The precipitate formed is separated off with suction and washed with diethyl ether. 3g of the expected product are obtained and are used directly in the following reaction.

Preparation 3.6

5- (1-piperazinyl) pyrimidine x hydrochloride

(III)，x HCl：p＝1；

A)4- (5-pyrimidinyl) -1-piperazinecarboxylic acid tert-butyl ester

A bubble of argon was bubbled through a mixture of 9.3g of tert-butyl 1-piperazinecarboxylate, 7.95g of 5-bromopyrimidine and 6.5g of sodium tert-butoxide in 250ml of toluene for 15 minutes, then heated to reflux, 0.277g of palladium acetate and 1.7ml of tri-tert-butylphosphine were added, and reflux was continued for 24 hours. 0.277g of palladium acetate was added, and the mixture was heated under reflux for 8 hours. The reaction mixture was cooled to ambient temperature, water was added, the mixture was extracted with AcOEt, the organic phase was filtered and Na was added₂SO₄Drying and removing the solvent in vacuum. The residue was chromatographed on silica, eluting with DCM, then DCM/AcOEt (50/50; v/v) and finally DCM/methanol (95/5; v/v). Recrystallization from a mixture of DCM/hexane/isoether gave 3.95g of the expected product.

B)5- (1-piperazinyl) pyrimidine x hydrochloride

A mixture of 3.5g of the compound obtained in the previous step and 20ml of dioxane was mixed at ambient temperature with 50ml of 2N HCl in ether solution, stirred at ambient temperature for 1 hour and concentrated in vacuo. A yellow solid was obtained and used directly in the following reaction.

Preparation 3.7

4- (1-piperazinyl) pyridazine

(III)：p＝1；

A)5- (4-benzyl-1-piperazinyl) -4-chloro-3 (2H) -pyridazinone

7g of 1-benzylpiperazine, 6.55g of 4, 5-dichloro-3 (2H) -pyridazinone and 11g K₂CO₃Heating the mixture at 110 ℃ in 150ml DMF4 hours, then concentrated in vacuo. The residue was chromatographed on silica, eluting with DCM/MeOH (95/5; v/v). The product obtained is collected in isoether and ground, and the precipitate formed is isolated by suction. Recrystallization from isoether gave 7g of the expected product; m.p. 173-.

B)5- (4-benzyl-1-piperazinyl) -3, 4-dichloropyridazine

1.7g of the compound obtained in the above step and 20ml of phosphorus oxychloride were heated at 85 ℃ for 4 hours. After cooling to ambient temperature, the reaction mixture was poured onto ice, the aqueous phase was made alkaline by addition of concentrated NaOH solution, extracted with DCM, Na₂SO₄Drying and removing the solvent in vacuum. The residue was chromatographed on silica, eluting with DCM/MeOH (97/3-90/10; v/v) mixture. 1.5g of the expected product are obtained and used directly in the following reaction.

C)4- (1-piperazinyl) pyridazine

A mixture of 1.3g of the compound obtained in the preceding step and 0.13g of 10% palladium on carbon in 20ml of methanol was hydrogenated at 30 ℃ and atmospheric pressure for 3 hours. The catalyst was removed by filtration and the filtrate was concentrated in vacuo. 0.85g of the expected product is obtained and used directly in the following reaction.

Preparation 3.8

5- (1-piperazinyl) -3(2H) -pyridazinone hydrochloride

(III)，HCl：p＝1；

A mixture of 0.8g of the compound obtained in preparation 3.8, step A and 0.3g of 10% palladium on carbon in 30ml of methanol is hydrogenated at 30 ℃ and atmospheric pressure for 2 hours. The catalyst was removed by filtration and the filtrate was concentrated in vacuo. 0.38g of the expected product is obtained and used directly in the following reaction.

Preparation 3.9

4- (1-piperazinyl) -3(2H) -pyridazinone hydrochloride

(III)，HCl：p＝1；

A)4- (4-benzyl-1-piperazinyl) -5-chloro-3 (2H) -pyridazinone and 5- (4-benzyl-1-piperazinyl) -4-

Chloro-3 (2H) -pyridazinones

2.77g of 1-benzylpiperazine, 1.3g of NaHCO₃And a mixture of 2.6g of 4, 5-dichloro-3 (2H) -pyridazinone in 300ml of dioxane was heated at 100 ℃ overnight and then concentrated in vacuo. The residue was chromatographed on silica, eluting with DCM/MeOH (98/2; v/v). Two compounds were isolated:

-0.8 g of the less polar compound, 4- (4-benzyl-1-piperazinyl) -5-chloro-3 (2H) pyridazinone is obtained;

1.2g of the more polar compound, 5- (4-benzyl-1-piperazinyl) -4-chloro-3 (2H) -pyridazinone, are obtained.

B)4- (1-piperazinyl) -3(2H) -pyridazinone hydrochloride

A mixture of 0.75g of the less polar compound obtained in the previous step and 0.2g of 10% palladium on carbon in 20ml of methanol was hydrogenated at 30 ℃ under atmospheric pressure for 3 hours. The catalyst was removed by filtration and the filtrate was concentrated in vacuo. 0.46g of the expected product is obtained and used directly in the following reaction.

Preparation 3.10

1- (2-pyrimidinyl) -1, 4-diaza (diazepane)

(III)：p＝2；

A solution of 3g of 2-chloropyrimidine in 20ml of ethanol is cooled in an ice bath and then mixed dropwise with a solution of 13g of 1, 4-diazepine in 50ml of ethanol, stirred cold for 30 minutes and then stirred at ambient temperature for 24 hours. Concentrated in vacuo and the residue taken up in 100ml of AcOEt and 100ml of saturated K₂CO₃The solution was extracted, the system was decanted, the organic phase diluted with 100ml AcOEt and saturated K₂CO₃The organic phase is washed with a solution, Na₂SO₄Drying and removing the solvent in vacuum. The expected product was obtained and used directly in the following reaction.

Preparation 3.11

2-chloro-6- (1-piperazinyl) pyrazine hydrochloride

(III)，HCl：p＝1；

A)4- (6-Chloropyrazin-2-yl) -1-piperazinecarboxylic acid tert-butyl ester

A mixture of 5g of tert-butyl 1-piperazinecarboxylate, 4g of 2, 6-dichloropyrazine and 9.5ml of DIPEA in 40ml of n-butanol was heated under reflux for 3 hours. Concentrate in vacuo, extract the residue with 100ml of ethanol, leave the system overnight, and isolate the crystalline product formed by suction. 4.7g of the expected product are obtained, m.p. ═ 108 ℃.

B) 2-chloro-6- (1-piperazinyl) pyrazine hydrochloride

A mixture of 1.5g of the compound obtained in the preceding step and 100ml of a 2N ethereal hydrochloride solution in 10ml of methanol is stirred at ambient temperature overnight. The precipitate formed is separated off with suction and washed with diethyl ether. 1.2g of the expected product are obtained.

Preparation 3.12

4-chloro-2- (1-piperazinyl) pyrimidine x hydrochloride

(III)，xHCl：p＝1；

A)4- (4-Chloropyrimidin-2-yl) -1-piperazinecarboxylic acid tert-butyl ester and 4- (2-Chloropyrimidin-2-yl) -1-piperazinecarboxylic acid tert-butyl ester

9.55g of tert-butyl 1-piperazinecarboxylate and 7.64g of 2, 4-dichloroPyrimidine and 8.6g NaHCO₃The mixture was heated in 90ml of ethanol at 100 ℃ for 1 hour. Concentrate in vacuo, collect the residue with water, extract with DCM, and extract the organic phase with Na₂SO₄Drying and removing the solvent in vacuum. The residue was chromatographed on silica gel, eluting with DCM/AcOEt (90/10-60/40; v/v) mixture. Two compounds were isolated:

-obtaining 1.75g of the less polar compound, tert-butyl 4- (4-chloropyrimidin-2-yl) -1-piperazinecarboxylate;

12.9g of the more polar compound, tert-butyl 4- (2-chloropyrimidin-4-yl) -1-piperazinecarboxylate, are obtained.

B) 4-chloro-2- (1-piperazinyl) pyrimidine x hydrochloride

A mixture of 1.75g of the less polar compound obtained in the preceding step and 100ml of a 2N ethereal hydrochloride solution in 10ml of methanol is stirred at ambient temperature for 18 hours. Concentration in vacuo and the residue collected with diethyl ether and the crystalline product formed isolated by suction. 1.6g of the expected product are obtained.

Preparation 3.13

6-chloro-4- (1-piperazinyl) pyrimidine hydrochloride

(III)，HCl：p＝1；

A solution of 14.8g of 4, 6-dichloropyrimidine in 100ml of acetonitrile is cooled to 0-5 ℃ and a solution of 20g of anhydrous piperazine in 200ml of acetonitrile is added over 30 minutes, and the mixture is stirred for 2 hours at 0-5 ℃. Concentrated in vacuo and the residue collected with 100ml 2N NaOH and extracted with ether. 15g of the expected hydrochloride product are obtained.

Example 1: compound 1

2- [4- (2-pyrazinyl) -1-piperazinyl]-1- [4- [3- (trifluoromethyl) phenyl]-1-piperidinyl group]-1-ethanone hydrochloride, 2H₂O

(I)，HCl：R₁＝3-CF₃；R₂＝H；R₃＝H；n＝1；p＝1.

0.7g of the compound obtained in preparation 2.1, 0.39g of the compound obtained in preparation 3.1, 0.39g of potassium iodide and K₂CO₃A mixture of 0.635g in 30ml of acetonitrile is stirred at ambient temperature overnight. Water was added to the reaction mixture, extraction was performed with AcOEt, and the organic phase was washed with water and saturated NaCl solution, Na₂SO₄Drying and removing the solvent in vacuum. The residue was chromatographed on silica, eluting with DCM/MeOH (97/3; v/v). The product obtained is dissolved in 2N ethereal hydrochloric acid and, after grinding, the precipitate formed is isolated by suction. 0.42g of the expected product is obtained. Mass spectrum: MH⁺＝434.3。

Example 2: compound 2

1- [ 4-hydroxy-4 [3- (trifluoromethyl) phenyl ] -1-piperidinyl ] -2- [4- [5- (trifluoromethyl) -2-pyridinyl ] -1-piperazinyl ] -1-ethanone dioxalate

(I)，2C₂H₂O₄：R₁＝3-CF₃；R₂＝H；R₃＝-OH；n＝1；p＝1.

0.8g of the compound obtained in preparation 2.2, 0.575g of 1- [5- (trifluoromethyl) -2-pyridinyl]Piperazine, 0.413g potassium iodide and 0.688g K₂CO₃The mixture in 20ml acetonitrile was stirred at ambient temperature for 2 hours. Adding saturated K₂CO₃The solution, the mixture was extracted with AcOEt, the organic phase was washed with water and saturated NaCl solution, Na₂SO₄Drying and removing the solvent in vacuum. The residue was chromatographed on silica, eluting with DCM/MeOH (96/4; v/v). The product obtained is dissolved in diethyl ether, 0.384g of oxalic acid is added, the system is triturated and the precipitate formed is isolated by suction. 1.27g of the expected product are obtained, m.p. ═ 173 ℃.

Example 3: compound 3

1- [ 4-hydroxy-4- [3- (trifluoromethyl) phenyl]-1-piperidinyl group]-3- [4- [ 2-pyrazinyl]-1-piperazinyl]1-propanone 1.5 oxalate, 1.5H₂O

(I)，1.5C₂H₂O₄：R₁＝3-CF₃；R₂＝H；R₃＝-OH；n＝2；p＝1.

A mixture of 0.5g of the compound obtained in preparation 2.3, 0.660g of the compound obtained in preparation 3.1, 0.4ml of triethylamine and 0.23g of potassium iodide in 10ml of acetonitrile was heated at 70 ℃ for 60 hours. Water was added to the reaction mixture, extracted with AcOEt, and saturated K was added₂CO₃The organic phase is washed with a solution, water and saturated NaCl solution, Na₂SO₄Drying and removing the solvent in vacuum. The residue was chromatographed on silica, eluting with DCM/MeOH (96/4; v/v). 0.77g of the product obtained is dissolved in diethyl ether, 0.28g of oxalic acid is added and the precipitate formed is isolated by suction. 0.762g of the expected product is obtained, m.p. ═ 113 ℃.

Example 4: compound 4

1- [4- (aminomethyl) -4- [3- (trifluoromethyl) phenyl ] -1-piperidinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone

(I)：R₁＝3-CF₃；R₂＝H；R₃＝-CH₂NH₂；n＝1；p＝1.

A)1- [2- [4- (2-pyrazinyl) -1-piperazinyl ] acetyl ] -4- [3- (trifluoromethyl) phenyl ] -4-piperidinecarbonitrile

3.42g of the compound obtained in preparation 2.6, 1.7g of the compound obtained in preparation 3.1, 1.7g of potassium iodide and K₂CO₃1.42g of a mixture in 50ml of acetonitrile are stirred at ambient temperature for 18 hours. The mixture was concentrated in vacuo, the residue was taken up in water, extracted with AcOEt and the organic phase with Na₂SO₄Drying and removing the solvent in vacuum. The residue was collected in pure ethanol, the crystals formed were separated off with suction and washed with diethyl ether. 3.5g of the expected product are obtained, m.p. ═ 138 ℃.

B)1- [4- (aminomethyl) -4- [3- (trifluoromethyl) phenyl ] -1-piperidinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone

3g, 0.3g of the compound obtained in the previous step are mixed at ambient temperature and atmospheric pressureA mixture of nickel, 20ml of 20% aqueous ammonia and 200ml of methanol was hydrogenated for 16 hours. The catalyst was removed by filtration and the filtrate was concentrated in vacuo. The residue was collected with water, extracted with AcOEt and the organic phase with Na₂SO₄Drying and removing the solvent in vacuum. Recrystallization from AcOEt gives 2.17g of the expected product, m.p. ═ 155 ℃.

Mass spectrum: MH⁺＝463.4。

¹H NMR：DMSO-d6：δ(ppm)：1.0-1.2：m：2H；1.6-2.2：m：4H；2.4-4.0：m：16H；7.4-7.7：m：4H；7.79：d：1H；8.06：dd：1H；8.29：d：1H。

Compound 4 of example 4 can also be obtained by the following two steps:

a') [1- [2- [4- (2-pyrazinyl) -1-piperazinyl ] acetyl ] -4- [3- (trifluoromethyl) -phenyl ] -4-piperidine ] methylcarbamic acid tert-butyl ester

2.8g of the compound obtained in preparation 2.7, 1.25g of the compound obtained in preparation 3.1, 1.1g of potassium iodide and K₂CO₃1.8g of a mixture in 30ml of acetonitrile are stirred at ambient temperature for 3 hours. Adding saturated K₂CO₃The solution, mixture was extracted with AcOEt and the organic phase was Na₂SO₄Drying and removing in vacuumA solvent. The residue was chromatographed on silica, eluting with DCM/MeOH (97/3; v/v). 1.75g of the expected product are obtained.

B') 1- [4- (aminomethyl) -4- [3- (trifluoromethyl) phenyl ] -1-piperidinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone

1.7g of the compound obtained in the previous step, 50ml of 2N HCl in ether and 30ml of methanol were stirred at ambient temperature for 4 hours. Vacuum concentrating, collecting the residue in water, washing the organic phase with AcOEt, adding K to the aqueous phase₂CO₃Rendered alkaline, the mixture was extracted with AcOEt, the organic phase was washed with saturated NaCl solution and Na₂SO₄Drying and removing the solvent in vacuum. The product was crystallized by evaporation in AcOEt and the crystals formed were isolated by suction. 1.05g of the expected product are obtained, m.p.. 152-.

Mass spectrum: MH⁺＝463.3。

Example 5: compound 5

1- [4- (aminomethyl) -4- [3- (trifluoromethyl) phenyl ] -1-piperidinyl ] -2- [4- (2-pyrimidinyl) -1-piperazinyl ] -1-ethanone trihydrochloride

(I)，3HCl：R₁＝3-CF₃；R₂＝H；R₃＝-CH₂NH₂；n＝1；p＝1.

A)1- [2- [4- (2-pyrimidinyl) -1-piperazinyl ] acetyl ] -4- [3- (trifluoromethyl) -phenyl ] -4-piperidinecarbonitrile

1.28g of the compound obtained in preparation 2.6, 1.1g of 2- (1-piperazinyl) pyrimidine, 0.79g of potassium iodide and K₂CO₃1.23g of a mixture in 30ml of acetonitrile are stirred at ambient temperature for 4 hours. Concentrated in vacuo, the residue was taken up in water, extracted with DCM and the organic phase with Na₂SO₄Drying and removing the solvent in vacuum. The residue was chromatographed on silica, eluting with DCM/MeOH (100/1; v/v). 0.9g of the expected product is obtained。

B)1- [4- (aminomethyl) -4- [3- (trifluoromethyl) phenyl ] -1-piperidinyl ] -2- [4- (2-pyrimidinyl) -1-piperazinyl ] -1-ethanone trihydrochloride

0.9g, 0.1g of the compound obtained in the previous step are mixed at ambient temperature and atmospheric pressureA mixture of nickel, 10ml of 20% aqueous ammonia in 50ml of methanol is hydrogenated for 4 hours. The catalyst was removed by filtration and the filtrate was concentrated in vacuo. The residue was extracted with water, DCM and the organic phase Na₂SO₄Drying and removing the solvent in vacuum. The residue was taken up in 2N HCl in ether and the precipitate formed was isolated by suction. After drying in vacuo, 0.74g of the expected product is obtained, m.p.: 198-.

Example 6: compound 27

2- [4- (4-pyrimidinyl) -1-piperazinyl ] -1- [4- [3- (trifluoromethyl) phenyl ] -3, 6-dihydro-1 (2H) -pyridinyl ] -1-ethanone dioxalate

A mixture of 0.78g of Compound 11, 5ml of 35% HCl solution and 9ml of acetic acid is heated at 110 ℃ for 1 hour. After cooling to ambient temperature, 5% K was added₂CO₃The solution was extracted with AcOEt, the organic phase was washed with saturated NaCl, Na₂SO₄Drying and removing the solvent in vacuum. The residue was chromatographed on silica, eluting with DCM/MeOH (95/5; v/v). The product obtained, 0.7g, is collected in methanol, 0.12g of oxalic acid is added, the system is left to crystallize and the precipitate formed is isolated by suction. 0.502g of the expected product is obtained, m.p. ═ 160 ℃.

Mass spectrum: MH⁺＝432.3。

Example 7: compound 30

1- [4- (aminomethyl) -4- [2- (trifluoromethyl) phenyl]-1-piperidinyl group]-2- [4- (2-pyrazinyl) -1-piperazinyl]1-ethanone 1.5 oxalate, 0.5H₂O

(I)，1.5C₂H₂O₄：R₁＝2-CF₃；R₂＝H；R₃＝-CH₂NH₂；n＝1；p＝1.

A)1- [2- [4- (2-pyrazinyl) -1-piperazinyl ] acetyl ] -4- [2- (trifluoromethyl) -phenyl ] -4-piperidinecarbonitrile 1.5 oxalate

1g of the compound obtained in preparation 2.10, 0.496g of the compound obtained in preparation 3.1, 0.51g of potassium iodide and K₂CO₃A mixture of 0.836g in 20ml of acetonitrile is stirred at ambient temperature overnight. Vacuum concentrating, collecting the residue in water, extracting with AcOEt, washing the organic phase with water and saturated NaCl solution, Na₂SO₄Drying and removing the solvent in vacuum. The residue was chromatographed on silica, eluting with DCM/MeOH (97/3; v/v). The product obtained, 0.29g, was collected with methanol, 0.057g of oxalic acid was added and the precipitate formed was isolated by suction. 0.081g of the expected product are obtained, m.p. -. 125-.

B)1- [4- (aminomethyl) -4- [2- (trifluoromethyl) phenyl]-1-piperidinyl group]-2- [4- (2-pyrazinyl) -1-piperazinyl]1-ethanone 1.5 oxalate, 0.5H₂O

0.8g, 0.08g of the compound obtained in the previous step are mixed at ambient temperature and atmospheric pressureA mixture of nickel, 20ml of 20% aqueous ammonia and 100ml of methanol was hydrogenated for 36 hours. The catalyst was removed by filtration and the filtrate was concentrated in vacuo. The residue was collected with water, extracted with AcOEt, and the organic phase was washed with saturated HaCl solution and Na₂SO₄Drying and removing the solvent in vacuum. The residue was chromatographed on silica gel, washed with a mixture of DCM/MeOH (90/10; v/v)And (4) removing. 0.28g of the product obtained is collected with AcOEt, 0.054g of oxalic acid is added and the precipitate formed is isolated with suction. 0.26g of the expected product are obtained, mass spectrum: MH⁺＝463.4。

Example 8: compound 32

1- [4- (hydroxymethyl) -4- [3- (trifluoromethyl) phenyl ] -1-piperidinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone

(I)：R₁＝3-CF₃；R₂＝H；R₃＝-CH₂OH；n＝1；p＝1.

A mixture of 0.6g of compound 31 and 0.14g of KOH particles and 10ml of methanol and 5ml of water is heated at 70 ℃ for 10 minutes. After cooling to ambient temperature, the crystals formed are isolated by suction, washed with water and dried. 0.3g of the expected product is obtained, m.p. ═ 223 ℃. Mass spectrum: MH⁺＝464.4。

Example 9: compound 33

1- [4- [ (dimethylamino) methyl ] -4- [3- (trifluoromethyl) phenyl ] -1-piperidinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone

(I)：R₁＝3-CF₃；R₂＝H；R₃＝-CH₂N(CH₃)₂；n＝1；p＝1.

A mixture of 40.85g of the compound obtained in example 4, 0.28ml of 37% aqueous formaldehyde, 3.8g of sodium triacetoxyborohydride and 50ml of THF was stirred at ambient temperature overnight. The reaction mixture was concentrated in vacuo and the residue was collected in 100ml of water and the system was heated at 80 ℃ for 30 minutes. After cooling to ambient temperature, the reaction mixture was made basic at pH 9 by addition of 10% NaOH solution and extracted with DCM. Na for organic phase₂SO₄Drying and removing the solvent in vacuum.Recrystallization from diethyl ether gave 0.55g of the expected product, m.p. ═ 118 ℃.

Mass spectrum: MH⁺＝491.4。

¹H NMR：DMSO-d6：δ(ppm)：1.6-2.3：m：10H；2.35-2.7：m：6H；2.8-3.3：m：4H；3.4-4.0：m：7H

Example 10: compound 36

1- [4- (4-chlorophenyl) -3, 6-dihydro-1 (2H) -pyridinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone

A mixture of 0.907g of compound 35 and 0.913g of p-toluenesulfonic acid and 20ml of toluene was heated at 118 ℃ for 24 hours. After cooling to ambient temperature, 5% K was added₂CO₃Solution, extraction of the system with AcOEt, organic phase with Na₂SO₄Drying and removing the solvent in vacuum. The residue was chromatographed on silica, eluting with DCM/MeOH (97/3; v/v). After recrystallization from a DCM/isoether mixture 0.55g of the expected product is obtained, m.p. -. 139-141 ℃.

Example 11: compound 37

1- [4- (aminomethyl) -4- [4- (chlorophenyl) -1-piperidinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone trifluoroacetate

(I)，TFA：R₁＝4-Cl；R₂＝H；R₃＝-CH₂NH₂；n＝1；p＝1.

A)4- (4-chlorophenyl) -1- [2- [4- (2-pyrazinyl) -1-piperazinyl ] acetyl ] -4-piperidinecarbonitrile

1g of the compound obtained in preparation 2.14, preparation 31.56 g of the obtained compound, 0.56g of potassium iodide, and K₂CO₃A mixture of 0.47g in 20ml acetonitrile was stirred at ambient temperature overnight. Vacuum concentrating, collecting the residue in water, extracting with AcOEt, and extracting the organic phase with Na₂SO₄Drying and removing the solvent in vacuum. 1.51g of the expected product are obtained and are used directly in the following reaction.

B)1- [4- (aminomethyl) -4-phenyl-1-piperidinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone trifluoroacetate and 1- [4- (aminomethyl) -4- [4- (4-chlorophenyl) -1-piperidinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone trifluoroacetate

A mixture of 1.51g of the compound obtained in the preceding step and 0.15g of rhodium/aluminium and 100ml of methanol is hydrogenated at ambient temperature and atmospheric pressure for 36 hours. The catalyst was removed by filtration and the filtrate was concentrated in vacuo. The residue was chromatographed on silica H, eluting with a DCM/MeOH (100/5; v/v) mixture. The product was collected as a mixture of the two compounds with ethanol and 2N HCl in ether was added. The precipitate formed was separated by suction. The precipitate was dissolved in water, the aqueous phase was washed with DCM, made basic by the addition of 10% NaOH and extracted with DCM. Na for organic phase₂SO₄Drying and removing the solvent in vacuum. Recrystallization of the residue from AcOEt gave 0.14g of a mixture of the two compounds containing 21.6% of one compound and 75.5% of compound 37. The two compounds were separated using preparative HPLC. Using a Delta Prep4000 preparative HPLC apparatus and a proCHROM column with a kinetic axis pressure, 50mm in diameter, 380gC18 stationary phase, pressurized at 70 bar pressure. The mobile phase was a mixture of eluent A (water + TFA 0.1%) and eluent B (acetonitrile/water (90% + 10%) + TFA 0.1%) at a flow rate of 122 ml/min. UV detection was carried out at a wavelength of 254 nm. After 0.122g of the mixture was isolated, the product was:

-0.037g of the compound identified as 1- [4- (aminomethyl) -4-phenyl-1-piperidinyl]-2- [4- (2-pyrazinyl) -1-piperazinyl]-1-ethanone trifluoroacetate: RT ═ 13 minutes; mass spectrum: MH⁺＝395.4。

-0.15g compound 37: RT 15.9 min; mass spectrum: MH⁺＝429.4。

Example 12: compound 57

1- [4- [ (methylamino) methyl ] -4- [3- (trifluoromethyl) phenyl ] -1-piperidinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone

(I)：R₁＝3-CF₃；R₂＝H；R₃＝-CH₂NHCH₃；n＝1；p＝1.

A) [1- [2- [4- (2-pyrazinyl) -1-piperazinyl ] acetyl ] -4- [3- (trifluoromethyl) -phenyl ] -4-piperidinyl ] methyl ] carbamic acid tert-butyl methyl ester

10g of the compound obtained in preparation 2.20, 3.7g of the compound obtained in preparation 3.1, 3.7g of potassium iodide and K₂CO₃6.2g of a mixture in 200ml of acetonitrile are stirred at ambient temperature for 5 hours. Vacuum concentrating, collecting the residue in water, extracting with AcOEt, and extracting the organic phase with Na₂SO₄Drying and removing the solvent in vacuum. The residue was chromatographed on silica H, eluting with DCM and then with a DCM/methanol mixture (100/2; v/v). 10.7g of the expected product are obtained.

B)1- [4- [ (methylamino) methyl ] -4- [3- (trifluoromethyl) phenyl ] -1-piperidinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone

A solution of 8g of the compound obtained in the preceding step in 100ml of methanol is mixed with 300ml of 2N HCl in ether and stirred at ambient temperature overnight. Vacuum concentrating, collecting the residue with 10% NaOH solution, extracting with AcOEt, and mixing the organic phase with Na₂SO₄Drying and removing the solvent in vacuum. The residue was chromatographed on silica H, eluting with a DCM/MeOH/water (100/5/0.5; v/v/v) mixture. After recrystallization from isoether, 4.5g of the expected product are obtained, m.p. -. 137-139 ℃.

Mass spectrum: MH⁺＝477.4。

¹HNMR：DMSO-d6：δ(ppm)：1.10：s：1H；1.6-2.3：m：7H；2.4-3.8：m：16H；7.4-7.75：m：4H；7.8：d：1H；8.15：dd：1H；8.3：d：1H.

Example 13: compound 58

1- [4- (isopropylamino) methyl ] -4- [3- (trifluoromethyl) phenyl ] -1-piperidinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone

(I)：R₁＝3-CF₃；R₂＝H；R₃＝-CH₂NHCH(CH₃)₂；n＝1；p＝1.

A mixture of 1g of compound 4, 0.16ml of acetone and 5 drops of acetic acid in 10ml of THF is mixed at ambient temperature with 0.5g of sodium triacetoxyborohydride and stirred at ambient temperature overnight. 20ml of methanol were then added and the mixture was heated at 55 ℃ for 1 hour. Concentrated in vacuo, the residue was taken up in 30% NaOH solution, extracted with DCM and the organic phase with Na₂SO₄Drying and removing the solvent in vacuum. The residue was chromatographed on silica, eluting with DCM/MeOH (93/7; v/v). Recrystallization from diethyl ether gave 0.511g of the expected product, m.p. -. 140-. Mass spectrum: MH⁺＝505.3。

Example 14: compound 59

1- [4- (N-Methylisopropylamino) methyl ] -4- [3- (trifluoromethyl) phenyl ] -1-piperidinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone trihydrochloride

(I)，3HCl：R₁＝3-CF₃；R₂＝H；R₃＝-CH₂N(CH₃)CH(CH₃)₂；n＝1；p＝1.

A mixture of 0.36g of compound 58, 0.08ml of 37% aqueous formaldehyde and 5 drops of acetic acid in 10ml of THF is mixed at ambient temperature with 0.605g of sodium triacetoxyborohydride and stirred at ambient temperature for 4 hours. 10ml of methanol were then added and the mixture was heated at 60 ℃ for 1 hour. Concentrated in vacuo, the residue was collected with 30% NaOH solution, extracted with DCM and the extract was Na₂SO₄Drying and removing the solvent in vacuum. The residue was chromatographed on silica, eluting with DCM/MeOH (96/4; v/v). The product obtained is collected in 2N HCl in ether and the precipitate formed is isolated by suction. 0.233g of the expected product is obtained, m.p. 185-. Mass spectrum: MH⁺＝519.3。

Example 15: compound 65

1- [4- [ (aminomethyl) -4- (3-chlorophenyl) -piperidinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone

(I)：R₁＝3-Cl；R₂＝H；R₃＝-CH₂NH₂；n＝1；p＝1.

A)4- (3-chlorophenyl) -1- [2- [4- (2-pyrazinyl) -1-piperazinyl ] acetyl ] -4-piperidinecarbonitrile

2.3g of the compound obtained in preparation 2.21, 1.3g of the compound obtained in preparation 3.1, 1.3g of potassium iodide and 2.2g K₂CO₃The mixture in 40ml acetonitrile was stirred at ambient temperature overnight. Water was added to the reaction mixture, extraction was performed with AcOEt, and the organic phase was saturated with K₂CO₃The solution was washed with water and Na₂SO₄Drying and removing the solvent in vacuum. The residue was chromatographed on silica, eluting with DCM/MeOH (97/3; v/v). 2.3g of the expected product are obtained.

B)1- [4- (aminomethyl) -4- (3-chlorophenyl) -1-piperidinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone

0.62g of the compound obtained in the previous step anda mixture of 0.6g of nickel in 30ml of methanol is hydrogenated for 8 hours. The catalyst was removed by filtration and the filtrate was concentrated in vacuo. The residue was chromatographed on alumina, eluting with DCM/MeOH (97/3; v/v) mixture. After recrystallization from a mixture of DCM/isoether, 0.121g of the expected product is obtained, m.p. ═ 138-: MH⁺＝429.3。

Example 16: compound 69

1- [4- (aminomethyl) -4- (3-methoxyphenyl) -1-piperidinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone dioxalate

(I)，2C₂H₂O₄：R₁＝3-OCH₃；R₂＝H；R₃＝-CH₂NH₂；n＝1；p＝1.

A)4- (3-methoxyphenyl) -1- [2- [4- (2-pyrazinyl) -1-piperazinyl ] acetyl ] -1-piperidinecarbonitrile

1.2g of the compound obtained in preparation 2.22, 0.675g of the compound obtained in preparation 3.1, 0.68g of potassium iodide and K₂CO₃1.2g of a mixture in 30ml of acetonitrile are stirred at ambient temperature for 4 hours. Water was added to the reaction mixture, which was extracted with DCM and the organic phase was saturated with K₂CO₃The solution was washed with water and Na₂SO₄Drying and removing the solvent in vacuum. The residue was chromatographed on silica, eluting with DCM/MeOH (97/3; v/v). 1.5g of the expected product are obtained, of which part of the isoether is recrystallized, m.p. ═ 108 ℃.

B)1- [4- [ (aminomethyl) -4- (3-methoxyphenyl) -1-piperidinyl ] -2- [4- (2-pyrazinyl) -1-piperazinyl ] -1-ethanone dioxalate

1.32g of the compound obtained in the above step was reacted at 31 ℃ under atmospheric pressure,A mixture of 0.2g of nickel and 10ml of concentrated aqueous ammonia in 70ml of methanol is hydrogenated for 30 hours. The catalyst was removed by filtration and the filtrate was concentrated in vacuo. The residue was taken up in 1N HCl, the aqueous phase was washed with AcOEt, 10% NaOH was added to make the aqueous phase basic, the mixture was extracted with DCM, the organic phase was Na₂SO₄Drying and removing the solvent in vacuum. The product obtained, 0.2g, is dissolved in diethyl ether, 0.042g of oxalic acid is added, a precipitate is formed, triturated and separated by suction. 0.19g of the expected product are obtained, m.p. ═ 120 ℃ mass spectrometry: MH⁺＝425.4。

The chemical structures and physical properties of some exemplary compounds of the invention are listed in the following table.

In the context of this table, the values of,

-R₃is a double bond, represents R₃Together with the adjacent piperidine ring carbon atom to form a double bond, as described in example 6;

me, Et, n-Pr, i-Pr, n-Bu, i-Bu, n-Pe and i-Pe represent methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl and isopentyl, respectively.

TABLE 1

(a) The compound obtained by the process described in example 1 was prepared from the compound obtained in preparation 2.2 and the corresponding compound represented by the formula (III).

(b) The compound obtained by the preparation of the compound obtained in preparation 2.2 and the corresponding compound represented by the formula (III) was prepared in the same manner as in example 2.

(c) The compound obtained by the preparation of the compound obtained in preparation 2.3 and the corresponding compound represented by the formula (III) was prepared in the same manner as in example 3.

(d) The compound obtained by the preparation of the compound obtained in preparation 2.4 and the corresponding compound represented by the formula (III) was prepared in the same manner as in example 1.

(e) The compound obtained by the preparation of the compound obtained in preparation 2.5 and the corresponding compound represented by the formula (III) was prepared in the same manner as in example 2.

(f) The compound obtained by the preparation of the compound obtained in preparation 2.8 and the corresponding compound represented by the formula (III) was prepared in the same manner as in example 1.

(g) The compound obtained by the preparation of the compound obtained in preparation 2.9 and the corresponding compound represented by the formula (III) was prepared in the same manner as in example 1.

(h) The compound obtained by the preparation of compound 11 was obtained according to the method described in example 6.

(i) The compound obtained by the preparation of compound 12 was obtained according to the method described in example 6.

(j) The compound obtained by the preparation of compound 26 was obtained according to the method described in example 6.

(k) The compound obtained by the preparation of the compound obtained in preparation 2.11 and the corresponding compound represented by the formula (III) was prepared in the same manner as in example 1.

(l) The compound obtained by the preparation of the compound obtained in preparation 2.12 and the corresponding compound represented by the formula (III) was prepared in the same manner as in example 1.

(m) the compound obtained by the preparation according to the method described in example 1 from the compound obtained in preparation 2.13 and the corresponding compound represented by the formula (III).

(n) the compound obtained by the preparation from the compound obtained in preparation 2.15 and the corresponding compound represented by the formula (III) was prepared as described in example 1.

(o) the compound obtained by the preparation of compound 38 according to the method described in example 6.

(p) the compound obtained by the preparation according to the method described in example 1 from the compound obtained in preparation 2.16 and the corresponding compound represented by the formula (III).

(q) the compound obtained by the preparation from Compound 40 according to the method described in example 6.

(r) the compound obtained by the preparation of the compound obtained in preparation 2.17 and the corresponding compound represented by the formula (III) was prepared as described in example 1.

(s) the compound obtained by the preparation of compound 42 according to the method described in example 6.

(t) the compound obtained by the preparation from Compound 44 according to the method described in example 10.

(u) the compound obtained by the preparation of compound 46 according to the process described in example 10.

(v) The compound obtained by the preparation of compound 48 was obtained according to the method described in example 6.

(w) the compound obtained by the preparation according to the method described in example 2 from the compound obtained in preparation 2.18 and the corresponding compound represented by the formula (III).

(x) The compound obtained by the preparation of the compound obtained in preparation 2.19 and the corresponding compound represented by the formula (III) was prepared in the same manner as in example 1.

(y) the compound obtained by the preparation from Compound 52 according to the method described in example 6.

(z) the compound obtained by the preparation according to the method described in example 4, Steps A 'and B', starting from the compound obtained in preparation 2.7 and the corresponding compound represented by formula (III).

(aa) the compound prepared as described in example 13 from Compound 4 and the corresponding aldehyde.

(bb) the compound obtained by the preparation of the compound obtained in preparation 2.23 and the corresponding compound represented by the formula (III) was prepared as described in example 1.

Biochemical studies were performed on the compounds of the invention.

Cell culture

Strain SH-SY-5Y (human neuroblastoma) was routinely cultured in collagen-coated culture flasks (Becton Dickinson, France) in DMEM medium (Dulbecco's Modified Eagle's medium, Gibco BRL, France) containing 5% FCS (fetal calf serum) (boehringer mannheim, Germany), sodium pyruvate (1mM), anti-PPLO (5ml) (anti-mycoplasma preparation:prepared with physiological saline, 6000 mug/ml), gentamicin 0.1mg/ml) and glutamine (4 mM).

Stock strain SK-N-BE (human neuroblastoma) cultured conventionally and expressing human P75^NTRClone Bep75 of the receptor (SK-N-BE Bep 75), in DMEM medium, FCS (5%), sodium pyruvate (1mM), anti-PPLO (5ml), gentamicin (0.1mg/ml) and glutamine (4 mM).

¹²⁵I-NGF and p75^NTRStudy of receptor binding

The method described by Weskamp (Neuron, 1991, 6: 649-663) was performed on cell suspensions of two lines of SH-SY-5Y and SK-N-BE Bep75 cells¹²⁵Binding of I-NGF (nerve growth factor labelled with radioiodine 125). Non-specific binding was determined by measuring the total binding rate after 1 hour at 37 ℃ of cell pre-incubation in the absence of unlabeled NGF (1. mu.M). Specific binding is calculated from the difference between the total binding and non-specific binding measurements. Using a concentration of 0.3nM¹²⁵I-NGF competitive experiments were performed. The compound of the invention is¹²⁵I-NGF binding to p75^NTR50% Inhibitory Concentration (IC) of receptor₅₀Value) is low at 10^-6-10^-11M。

Determination of apoptosis

Cells were established in DMEM medium with 5% FCS (human neuroblastoma cell lines SH-SY-5Y and SK-N-BE Bep 75) on plates 35mm in diameter (Biocoat collagen I)For 24 hours. The medium was removed, the cells rinsed with PBS (Dulbecco's phosphate buffered saline), and fresh medium containing 5% FCS or medium containing 10ng/ml NGF was added in the presence or absence of the compounds of the invention. The level of apoptosis was determined by quantitative determination of cytoplasmic histones bound to DNA fragments 48 hours after the treatment of the strain SH-SY-5Y and 24 hours after the treatment of the strain SK-N-BE Bep75 (cell death assay ELISA, Boehringer Mannheim, Germany). The level of apoptosis is expressed as the amount of oligonucleosomes per 105 cells ± SD. Each value corresponds to the average of 9 experimental points from three or more independent experiments. Compounds of formula (I) show NGF-induced apoptosis inhibiting activity, IC thereof₅₀Value of 10^-6-10^-11M。

Thus, the compound of the invention is p75^NTRBinding of the receptor results, on the one hand, in a biochemical inhibition of neurotrophin-induced dimerization of the receptor and, on the other hand, in an inhibition of p75 at the cellular level^NTRThe receptor causes a mediated pro-apoptotic effect.

Thus, the compounds of the invention can be used for the preparation of medicaments, in particular for the prophylaxis or treatment of p75^NTRDrugs for any pathological process in which the receptor is involved.

Thus, in another aspect, the present invention provides a medicament comprising a compound of formula (I) or an addition salt thereof, a pharmaceutically acceptable acid, or a solvate or hydrate of a compound of formula (I).

Thus, the compounds of the invention may be used in humans or animals for the treatment or prophylaxis of various p75^NTRDependence disorders, e.g. central or peripheral neurodegenerative disorders such as senile dementia, epilepsy, Alzheimer's disease, Parkinson's disease, Huntington's chorea, Down's syndrome, prion diseases, amnesia, schizophrenia, amyotrophic lateral sclerosis, multiple sclerosis, cardiovascular disorders such as post-ischemic heart injury, cardiomyopathy, myocardial infarction, cardiac insufficiency, cardiac ischemia, cerebral infarction, peripheral neurological disorders (such as diabetic, traumatic or iatrogenic), ocular and retinal injuries, spinal cord injuries, neurodegenerative disordersCord and craniocerebral injury, atherosclerosis, stenosis, scarring, and hair loss.

The compounds of the invention are also useful in the treatment of cancer, such as lung cancer, thyroid cancer, pancreatic cancer, prostate cancer, small bowel cancer, colon cancer, breast cancer, tumor metastasis and leukemia.

The compounds of the invention are also useful in the treatment of chronic neuropathic and inflammatory pain, and in the treatment of autoimmune diseases such as rheumatoid arthritis.

The compounds of the invention are also useful in the treatment of bone fractures, and in the treatment or prevention of bone disorders such as osteoporosis.

In another aspect, the invention relates to pharmaceutical compositions containing a compound of the invention as an active ingredient. These pharmaceutical compositions contain an effective amount of at least one compound of the invention, or a pharmaceutically acceptable salt, solvate or hydrate of said compound, and at least one pharmaceutically acceptable excipient.

The excipients are selected from conventional excipients known to those skilled in the art according to the form of the medicament and the desired mode of administration.

In the pharmaceutical compositions of the present invention for oral, sublingual, subcutaneous, intramuscular, intravenous, topical, intratracheal, intranasal, transdermal or intrarectal administration, the active compounds of formula (I) above, or salts, solvates or hydrates thereof, as a mixture with conventional pharmaceutical excipients, may be administered in unit dosage form to animals and humans for the prevention or treatment of the above-mentioned diseases or conditions.

Suitable unit dosage forms for administration include orally administrable forms such as tablets, soft or hard gelatin capsules, powders, granules and oral solutions or suspensions, sublingually, buccally, intratracheally, intraocularly or intranasally administrable forms, inhalational administration forms, external, transdermal, subcutaneous, intramuscular or intravenous administration forms, intrarectal administration forms and implant forms. For external use, the compounds of the invention may be used as creams, gels, ointments or lotions.

For example, where the dosage form in which the compounds of the present invention are administered is a tablet, the following components may be present:

the compounds of the present invention: 50.0mg

Mannose: 223.75mg

Crosslinked sodium caramel (croscarmellose): 6.0mg

Corn starch: 15.0mg

Hydroxypropyl methylcellulose: 2.25mg

Magnesium stearate: 3.0mg

For oral administration, the dose of active ingredient administered per day may be 0.01-100mg/kg, administered in single or divided doses, preferably 0.02-50 mg/kg.

Higher or lower doses may be appropriate for a particular case, and such doses are also within the scope of the invention. As a matter of routine, the appropriate dosage for each patient will be determined by the physician in view of the mode of administration, the weight and response of the patient in question.

In another aspect, the invention relates to a method for treating the pathologies of the diseases mentioned above, which comprises the administration to a patient of an effective amount of a compound according to the invention, or of a pharmaceutically acceptable salt thereof, or of a hydrate or solvate thereof.

Claims (13)

1. A compound of the general formula (I),

wherein:

-n is 1 or 2;

-p is 1;

-R₁represents a halogen atom, a trifluoromethyl group, or a group (C)₁-C₄) Alkyl, (C)₁-C₄) Alkoxy, trifluoromethoxy；

-R₂Represents a hydrogen atom or a halogen atom;

-R₃represents a hydrogen atom, -OR₅Group, -CH₂OR₅Group, -NR₆R₇A group; -NR₈COR₉A group; -NR₈CONR₁₀R₁₁A group; -CH₂NR₁₂R₁₃A group; -CH₂NR₈CONR₁₄R₁₅A group; (C)₁-C₄) An alkoxycarbonyl group; -CONR₁₆R₁₇A group;

-or R₃A double bond is formed between the carbon atom to which it is attached and the adjacent piperidine ring carbon atom;

-R₄represents an aromatic group selected from the group of formulae:

the aromatic group is unsubstituted or independently selected from halogen atom, (C)₁-C₄) Alkyl, (C)₁-C₄) Alkoxy, trifluoromethyl, monosubstituted or disubstituted;

-R₅represents a hydrogen atom, (C)₁-C₄) Alkyl, (C)₁-C₄) An alkylcarbonyl group;

-R₆and R₇Each independently represents a hydrogen atom or (C)₁-C₄) An alkyl group;

-R₈represents a hydrogen atom or (C)₁-C₄) An alkyl group;

-R₉is represented by (C)₁-C₄) Alkyl or- (CH)₂)_m-NR₆R₇A group;

-m is 1, 2 or 3;

-R₁₀and R₁₁Each independently represents a hydrogen atom or (C)₁-C₄) An alkyl group;

-R₁₂and R₁₃Each independently represents a hydrogen atom or (C)₁-C₅) An alkyl group; or R₁₃Represents- (CH)₂)_q-OH group or- (CH)₂)_q-S-CH₃A group;

-or R₁₂And R₁₃And together with the nitrogen atom to which they are bound form a heterocyclic ring selected from aziridine, azetidine, pyrrolidine, piperidine and morpholine;

-q is 2 or 3;

-R₁₄and R₁₅Each independently represents a hydrogen atom or (C)₁-C₄) An alkyl group;

-R₁₆and R₁₇Each independently represents a hydrogen atom or (C)₁-C₄) An alkyl group;

-or R₁₇Represents- (CH)₂)_q-NR₆R₇A group;

-or R₁₆And R₁₇And together with the nitrogen atom to which they are bound form a heterocycle selected from azetidine, pyrrolidine, piperidine, morpholine and piperazine, said heterocycle being unsubstituted or substituted (C) at position 4₁-C₄) Alkyl substitution;

the compounds exist in the form of a base or an acid addition salt, or in the form of a hydrate or solvate.

2. A compound of formula (I) according to claim 1, characterized in that:

-R₁in the 2, 3 or 4 position of the phenyl radical, represents a trifluoromethyl, chlorine atom, methyl, methoxy or trifluoromethoxy radical, and R₂Represents a hydrogen atom; or R₁In the 3-position of the phenyl radical, represents trifluoromethyl, and R₂At the 4-position of the phenyl group, represents a chlorine atom;

the compounds exist in the form of a base or an acid addition salt, or in the form of a hydrate or solvate.

3. A compound of formula (I) according to claim 1, characterized in that:

-R₃represents a hydrogen atom, a hydroxyl group, a methoxy group, an acetoxymethyl group, a hydroxymethyl group, a dimethylamino group, an ethyl groupAmido, aminomethyl, methylaminomethyl, dimethylaminomethyl, diethylaminomethyl, isopropylaminomethyl, N-methylisopropylaminomethyl, isobutylaminomethyl, N-methylisobutylaminomethyl, isopentylaminomethyl, N-methylisopropylaminomethyl, aminocarbonyl, azetidin-1-ylcarbonyl; or R₃A double bond is formed between the carbon atom to which it is bonded and the adjacent carbon atom of the piperidine ring;

the compounds exist in the form of a base or an acid addition salt, or in the form of a hydrate or solvate.

4. A compound of formula (I) according to claim 1, characterized in that:

-R₄represents 2-pyridyl, 6-methyl-2-pyridyl, 3-trifluoromethyl-2-pyridyl, 5-trifluoromethyl-2-pyridyl, 3-chloro-5-trifluoromethyl-2-pyridyl, 3-pyridyl, 4-pyridyl, 3, 5-dichloro-4-pyridyl, 2-pyrazinyl, 5-chloro-2-pyrazinyl, 6-chloro-2-pyrazinyl, 2-pyrimidinyl, 4-trifluoromethyl-2-pyrimidinyl, 6-chloro-2-pyrimidinyl, 4-pyrimidinyl, 6-chloro-4-pyrimidinyl, 5-pyrimidinyl, 3-pyridazinyl, 6-chloro-3-pyridazinyl, N-trifluoromethyl-2-pyrimidinyl, N-trifluoromethyl-4-pyrimidinyl, N-trifluoromethyl-2-pyrimidinyl, N-pyridyl, N-trifluoromethyl, 4-pyridazinyl, 3(2H) -pyridazinone-5-yl or 3(2H) -pyridazinone-4-yl,

the compounds exist in the form of a base or an acid addition salt, or in the form of a hydrate or solvate.

5. A compound of formula (I) according to claim 1, characterized in that:

wherein the content of the first and second substances,

-n is 1 or 2;

-p is 1;

-R₁in the 2, 3 or 4 position of the phenyl radical, represents a trifluoromethyl, chlorine atom, methyl, methoxy or trifluoromethoxy radical, and R₂Represents a hydrogen atom; or R₁In the 3-position of the phenyl radical, represents trifluoromethyl, and R₂At the 4-position of the phenyl group, represents a chlorine atom;

-R₃represents a hydrogen atom, a hydroxyl group, a methoxy group, an acetoxymethyl group, a hydroxymethyl group, a dimethylamino group, an acetamido group, or ammoniaAminomethyl, methylaminomethyl, dimethylaminomethyl, diethylaminomethyl, isopropylaminomethyl, N-methylisopropylaminomethyl, isobutylaminomethyl, N-methylisobutylaminomethyl, isopentylaminomethyl, N-methylisopropylaminomethyl, aminocarbonyl, azetidin-1-ylcarbonyl; or R₃A double bond is formed between the carbon atom to which it is bonded and the adjacent carbon atom of the piperidine ring;

-R₄represents 2-pyridyl, 6-methyl-2-pyridyl, 3-trifluoromethyl-2-pyridyl, 5-trifluoromethyl-2-pyridyl, 3-chloro-5-trifluoromethyl-2-pyridyl, 3-pyridyl, 4-pyridyl, 3, 5-dichloro-4-pyridyl, 2-pyrazinyl, 5-chloro-2-pyrazinyl, 6-chloro-2-pyrazinyl, 2-pyrimidinyl, 4-trifluoromethyl-2-pyrimidinyl, 6-chloro-2-pyrimidinyl, 4-pyrimidinyl, 6-chloro-4-pyrimidinyl, 5-pyrimidinyl, 3-pyridazinyl, 6-chloro-3-pyridazinyl, N-trifluoromethyl-2-pyrimidinyl, N-trifluoromethyl-4-pyrimidinyl, N-trifluoromethyl-2-pyrimidinyl, N-pyridyl, N-trifluoromethyl, 4-pyridazinyl, 3(2H) -pyridazinone-5-yl or 3(2H) -pyridazinone-4-yl,

the compounds exist in the form of a base or an acid addition salt, or in the form of a hydrate or solvate.

6. A compound of formula (I) according to claim 1, characterized in that:

-n is 1;

-p is 1;

-R₁in the 2, 3 or 4 position of the phenyl radical, represents a trifluoromethyl, chlorine, methoxy or trifluoromethoxy radical, and R is₂Represents a hydrogen atom; or R₁In the 3-position of the phenyl radical, represents trifluoromethyl, and R₂At the 4-position of the phenyl group, represents a chlorine atom;

-R₃represents hydroxy, dimethylamino, aminomethyl, methylaminomethyl, dimethylaminomethyl, diethylaminomethyl, isopropylaminomethyl, isobutylaminomethyl, isopentylaminomethyl, N-methylisopropylaminomethyl or aminocarbonyl; or R₃A double bond is formed between the carbon atom to which it is bonded and the adjacent carbon atom of the piperidine ring;

-R₄represents 2-pyrazinyl, 4-pyrimidinyl, 3(2H) -pyridazinone-5-yl or 5-trifluoromethyl-2-pyridinyl,

the compounds exist in the form of a base or an acid addition salt, or in the form of a hydrate or solvate.

7. A process for the preparation of a compound of formula (I) as claimed in claim 1, wherein:

a1) reacting a compound of the formula (IIa)

Wherein R is₁、R₂And R₃As defined for the compounds of formula (I) in claim 1, Hal represents a halogen atom, with the proviso that when R is₃Containing hydroxyl or amine functional groups which can be protected, with a compound of formula (III),

wherein, p and R₄As defined for compounds of formula (I) according to claim 1;

b1)R₃deprotection of the hydroxyl or amine functional group in (a) to obtain the compound of formula (I).

8. A process for the preparation of a compound of formula (I) as claimed in claim 1, wherein:

a2) reacting a compound of the formula (IIb)

Wherein R is₁、R₂And R₃A compound of formula (I) as defined in claim 1, with the proviso that when R is₃Containing hydroxyl or amine functional groups which can be protected, with a compound of formula (III),

wherein, p and R₄As defined for compounds of formula (I) according to claim 1;

b2)R₃deprotection of the hydroxyl or amine functional group in (a) to obtain the compound of formula (I).

9. R in formula (1) according to claim 1₃Represents the group-CH₂NR₁₂R₁₃And R is₁₂And R₁₃A process for the preparation of compounds each representing a hydrogen atom, characterized in that:

a3) reacting a compound of the formula (IIc) or (IId)

Wherein R is₁And R₂As defined for the compounds of formula (I) according to claim 1, Hal represents a halogen atom, with a compound of formula (III),

wherein, p and R₄As defined for compounds of formula (I) according to claim 1; to obtain a compound of formula (Ia);

b3) reduction of the cyano group of a compound of formula (Ia) to yield R of formula (I) as defined in claim 1₃＝CH₂NH₂The compound of (1).

10. Compounds of the general formula (Ia)

Wherein the content of the first and second substances,

-n is 1 or 2;

-p is 1;

-R₁represents a halogen atom, a trifluoromethyl group, or a group (C)₁-C₄) Alkyl, (C)₁-C₄) Alkoxy, trifluoromethoxy;

-R₂represents a hydrogen atom or a halogen atom;

-R₄represents an aromatic group selected from the group of formulae:

said aromatic group being unsubstituted and independently selected from halogen atoms, (C)₁-C₄) Alkyl, (C)₁-C₄) Alkoxy, trifluoromethyl, mono-or di-substituted;

the compounds exist in the form of a base or an acid addition salt, or in the form of a hydrate or solvate.

11. A medicament comprising a compound of formula (I) according to any one of claims 1 to 6, or an addition salt of said compound with a pharmaceutically acceptable acid, or a hydrate or solvate of the compound of formula (I).

12. A pharmaceutical composition comprising a compound of formula (I), or a pharmaceutically acceptable salt thereof, or a hydrate or solvate thereof, as claimed in any one of claims 1 to 6, and at least one pharmaceutically acceptable excipient.

13. Use of a compound of formula (I) as defined in any one of claims 1 to 6 in the manufacture of a medicament for the prevention or treatment of central or peripheral neurodegenerative disorders, amyotrophic lateral sclerosis, multiple sclerosis, cardiovascular disorders, peripheral nerve disorders, ocular and retinal injuries, spinal and cranial injuries, atherosclerosis, stenosis, scarring, alopecia, cancer, tumours, metastases and leukaemias, chronic neuropathic and inflammatory pain, autoimmune disorders, bone fractures, bone diseases.