HK1089438B - Quinoline and quinazoline derivatives having affinity for 5ht1-type receptors - Google Patents

Description

The present invention relates to a novel compound, processes for its preparation, pharmaceutical compositions containing the same and itsr use as a medicament in the treatment of CNS and other disorders.

The present invention therefore provides, in a first aspect, 1-(3-{2-[4-(2-methyl-5-quinolinyl)-1-piperazinyl]ethyl}phenyl)-2-imidazolidinone of formula (I) or a pharmaceutically acceptable salt thereof:

The compound of formula (I) can form acid addition salts thereof. It will be appreciated that for use in medicine the salts of the compound of formula (I) should be pharmaceutically acceptable. Suitable pharmaceutically acceptable salts will be apparent to those skilled in the art and include those described in J. Pharm. Sci., 1977, 66, 1-19, such as acid addition salts formed with inorganic acids e.g. hydrochloric, hydrobromic, sulfuric, nitric, hydroiodic, metaphosphoric, or phosphoric acid; and organic acids e.g. succinic, maleic, acetic, fumaric, citric, tartaric, benzoic, trifluoroacetic, malic, lactic, formic, propionic, glycolic, gluconic, camphorsulfuric, isothionic, mucic, gentisic, isonicotinic, saccharic, glucuronic, furoic, glutamic, ascorbic, anthranilic, salicylic, phenylacetic, mandelic, embonic (pamoic), ethanesulfonic, pantothenic, stearic, sulfinilic, alginic and galacturonic acid; and arylsulfonic, for example benzenesulfonic, p-toluenesulfonic, methanesulfonic or naphthalenesulfonic acid; base addition salts formed with alkali metals and alkaline earth metals and organic bases such as N,N-dibenzylethylenediamine, chloroprocaine, choline, diethanolamine, ethylenediamine, meglumine (N-methylglucamine), lysine and procaine; and internally formed salts. The compound of formula (I) may form acid addition salts with less than one or one or more equivalents of the acid, for example to form a dihydrochloride salt. The present invention includes within its scope all possible stoichiometric and non-stoichiometric forms. Salts having a non-physiologically acceptable anion or cation are within the scope of the invention as useful intermediates for the preparation of physiologically acceptable salts and/or for use in non-therapeutic, for example, in vitro, situations.

The compound of formula (I) may be prepared in crystalline or non-crystalline form, and, if crystalline, may optionally be hydrated or solvated. This invention includes within its scope stoichiometric hydrates or solvates as well as containing variable amounts of water and/or solvent.

The affinities of the compound of this invention for 5-HT_1A, 5-HT_1B and 5-HT_1D receptors can be determined by the following assay. CHO cells expressing 5-HT_1A receptors (4 × 10⁷ cells/ml) are homogenised in Tris buffer and stored in 1 ml aliquots. CHO cells expressing 5-HT_1B receptors (4 × 10⁷ cells/ml) are homogenised in Tris buffer and stored in 1.5 ml aliquots. CHO cells expressing 5-HT_1D receptors (1 × 10⁸/ml) are homogenised in Tris buffer and stored in 1 ml aliquots. 0.4 ml of a cell suspension is incubated with [³H]-5-HT (4nM) for 5-HT_1B/1D receptors and [³H]WAY100635 (1nM) for 5-HT_1A receptors in Tris Mg HCl buffer (pH 7.7) and test drug, at 37°C for 45 minutes. Each test drug is tested at 10 concentrations (0.01 mM to 0.3 nM final concentration), with non-specific binding defined using 0.01 mM 5-HT. The total assay volume is 0.5 ml. Incubation is stopped by rapid filtration using a Packard Filtermate and radioactivity measured by Topcount scintillation counting. pKi values are calculated from the IC₅₀ generated by an iterative least squares curve fitting programme.

Alternatively, functional potency can be measured by the following GTPγS binding protocol. Cells used in the study are Chinese Hamster Ovary (CHO) Cells, Human Embryo Kidney (HEK293). Cells were transfected with DNA coding for human receptors.

Cell Line HEK293_5-HT1A CHO_5-HT1B CHO_5-HT1D

The compound was initially dissolved in 100% Dimethyl Sulphoxide at a concentration of 10mM. Serial dilution of drugs in 100% Dimethyl Sulphoxide were carried out using a Biomek FX. The final top concentration of compound was 3uM in the assay. The compound at 1.0% total assay volume (TAV) was added to a solid, white, 384 well assay plate (Costar). 50%TAV of precoupled (for 90 mins @ RT) membranes, 5ug/well, and Wheatgerm Agglutinin Polystyrene Scintillation Proximity Assay beads (RPNQ0260 Amersham International), 0.25mg/well, in 20mM HEPES pH 7.4, 100mM NaCl, 3mM MgCl₂ and 10µM GDP was added. The third addition was a 20% TAV addition of either buffer, agonist format, or EC₈₀ final assay concentration (FAC) of agonist, 5HT antagonist format, prepared in assay buffer. The assay was started by the addition of 29%TAV of GTP□S 0.38nM FAC. After all additions assay plates were incubated at RT for 2 -3 hours. Assay plates were counted on a Viewlux, 613/55 filter for 5 mins. Assay plates were read between 2-6 hours after the final addition.

The compound of formula (I) was tested and found to have 5-HT_1A receptor affinity ,having a pKi value in the range 8.0 - 10.0. The compound of this invention also demonstrated comparable affinity for 5-HT_1B and 5-HT_1D receptors.

The intrinsic activity of the compound of this invention can be determined according to the following assay. HEK293 cell membranes stably expressing human 5-HT_1A receptors and CHO cell membranes stably expressing human 5-HT_1B receptors are homogenised in HEPES/EDTA buffer and stored in 1ml aliquots, and [³⁵S]GTPγS binding studies are carried out essentially as described by Lazareno et al., (Life Sci., 1993, 52, 449) with some minor modifications. Membranes from 10⁶ cells are pre-incubated at 30°C for 30 minutes in 20 mM HEPES buffer (pH 7.4) in the presence of MgCl₂ (3 mM), NaCl (100 mM), GDP (10 µM) and ascorbate (0.2 mM), with or without test compounds. The reaction is started by the addition of 50 µl of [³⁵S]GTPγS (100.pM, assay concentration) followed by a further 30 minutes incubation at 30°C. Non-specific binding is determined using nonradiolabelled GTPγS (20 µM) added prior to the membranes. The reaction is terminated by rapid filtration through Whatman GF/B grade filters followed by 5 × 1 ml washes with ice cold HEPES (20 mM) /MgCl₂ (3 mM) buffer. Radioactivity is measured using liquid scintillation spectrometry. This procedure is hereafter referred to as the [³⁵S]GTPγS functional assay.

The efficacy of the compound of this invention to inhibit the re-uptake of serotonin can be measured in a 5-HT uptake assay by measurement of uptake of [³H]-5-HT into LLCPK cells expressing human or rat serotonin transporters. In brief, cells are harvested and plated onto 96-well plates (10,000 cells per well). 24hr later cells are washed 2× with HBSSH (Hanks'balanced salt solution + 20mM HEPES). 50ul of test compound or vehicle is added to each well and incubated for 10min. Subsequently, [³H]5-HT (final concentration 25nM) is added and the test mixture is incubated for a further 7min. The reaction is terminated by aspiration of test mixture and the cells are washed 6× with HBSSH. 50ul of scintillation cocktail (Microscint-20, Packard) is added onto the cells and the top and bottom of the plate is sealed. Plates are read, 30min later, in a Packard TopCount.

Alternatively: the potency of the compound to bind the re-uptake site of serotonin may be assessed using [3H]citalopram binding assays performed in recombinant epithelial pig kidney cells stably transfected with human SERT (hSERT/LLCPK). The cells were grown onto Petri dishes of 500cm². At 80% of confluence the cells were harvested in phosphate buffered saline (PBS) containing 5mM EDTA and centrifuged at 900g for 8 min at 4°C. The pellet was homogenized in 30-50 vols of assay buffer (50mM Tris, 120mM NaCl, 5mM KCI, 10µM Pargyline, 0.1 % Ascorbate (pH=7.7)) and centrifuged at 48000g for 20min at 4°C. The pellet was resuspended in the same volume and after incubation at 37°C for 20min, centrifuged as before and finally alquoted at ∼0.2mg protein/ml in cold assay buffer. [3H]citalopram binding assays consisted of 100µl of test compound, assay buffer (to define total binding) or a final concentration of 10µM paroxetine (to define non-specific binding), 100µl of [3H]Citalopram at final concentration of 0.25nM and 200µl of membranes diluted in assay buffer at concentration of 2µg/well of protein. Membranes were added last to initiate the reaction and incubated at room temperature for 2h. The reaction was then stopped by rapid filtration through GF/B 96-filterplate pre-soaked in 0.5% polyethylenimmine (PEI) using a Packard cell harvester. 96-filterplate was washed 3 times with 1 ml/well cold 0.9% NaCl solution and the radioactivity was counted in Packard TopCount.

The compound of formula (I) and its pharmaceutically acceptable salts are of use in the treatment of certain CNS disorders such as depression (which term includes bipolar depression, unipolar depression, single or recurrent major depressive episodes with or without psychotic features, catatonic features, melancholic features, atypical features or postpartum onset, seasonal affective disorder and dysthymia, depressive disorders resulting from a general medical condition including, but not limited to, myocardial infarction, diabetes, miscarriage or abortion), anxiety disorders (which includes generalised anxiety and social anxiety disorder), schizophrenia, panic disorder, agoraphobia, social phobia, obsessive compulsive disorder, post-traumatic stress disorder, pain (particularly neuropathic pain), memory disorders (including dementia, amnesic disorders and age-associated memory impairment), disorders of eating behaviours (including anorexia nervosa and bulimia nervosa), sexual dysfunction, sleep disorders (including disturbances of circadian rhythm, dyssomnia, insomnia, sleep apnea and narcolepsy), withdrawal from abuse of drugs (such as of cocaine, ethanol, nicotine, benzodiazepines, alcohol, caffeine, phencyclidine and phencyclidine-like compounds, opiates such as cannabis, heroin, morphine, sedative ipnotic, amphetamine or amphetamine-related drugs such as dextroamphetamine, methylamphetamine or a combination thereof), motor disorders such as Parkinson's disease, dementia in Parkinson's disease, neuroleptic-induced Parkinsonism and tardive dyskinesias, as well as other psychiatric disorders, and certain gastrointestinal disorders such as irritable bowel syndrome. The compound may also be useful in treating tumours such as prostate tumours.

It is to be understood that "treatment" as used herein includes prophylaxis as well as alleviation of established symptoms.

Thus the invention also provides the compound of formula (I) or a pharmaceutically acceptable salt thereof, for use as a therapeutic substance, in particular in the treatment of a CNS disorder such as depression (which term includes bipolar depression, unipolar depression, single or recurrent major depressive episodes with or without psychotic features, catatonic features, melancholic features, atypical features or postpartum onset, seasonal affective disorder and dysthymia, depressive disorders resulting from a general medical condition including, but not limited to, myocardial infarction, diabetes, miscarriage or abortion), anxiety disorders (which includes generalised anxiety and social anxiety disorder), schizophrenia, panic disorder, agoraphobia, social phobia, obsessive compulsive disorder, post-traumatic stress disorder, pain (particularly neuropathic pain), memory disorders (including dementia, amnesic disorders and age-associated memory impairment), disorders of eating behaviours (including anorexia nervosa and bulimia nervosa), sexual dysfunction, sleep disorders (including disturbances of circadian rhythm, dyssomnia, insomnia, sleep apnea and narcolepsy), withdrawal from abuse of drugs (such as of cocaine, ethanol, nicotine, benzodiazepines, alcohol, caffeine, phencyclidine and phencyclidine-like compounds, opiates such as cannabis, heroin, morphine, sedative ipnotic, amphetamine or amphetamine-related drugs such as dextroamphetamine, methylamphetamine or a combination thereof), motor disorders such as Parkinson's disease, dementia in Parkinson's disease, neuroleptic-induced Parkinsonism and tardive dyskinesias, as well as other psychiatric disorders, and certain gastrointestinal disorders such as irritable bowel syndrome, and tumours such as prostate tumours.

In particular the invention provides the compound of formula (I) or a pharmaceutically acceptable salt thereof for use as a therapeutic substance in the treatment of depression and/or anxiety.

The compound of the invention may be administered in combination with other active substances such as 5HT3 antagonists, serotonin agonists, NK-1 antagonists, selective serotonin reuptake inhibitors (SSRI), noradrenaline re-uptake inhibitors (SNRI), tricyclic antidepressants and/or dopaminergic antidepressants.

Suitable 5HT3 antagonists which may be used in combination of the compounds of the inventions include for example ondansetron, granisetron, metoclopramide.

Suitable serotonin agonists which may be used in combination with the compounds of the invention include sumatriptan, rauwolscine, yohimbine, metoclopramide.

Suitable SSRIs which may be used in combination with the compounds of the invention include fluoxetine, citalopram, femoxetine, fluvoxamine, paroxetine, indalpine, sertraline, zimeldine.

Suitable SNRIs which may be used in combination with the compounds of the invention include venlafaxine and reboxetine.

Suitable tricyclic antidepressants which may be used in combination with a compound of the invention include imipramine, amitriptiline, chlomipramine and nortriptiline.

Suitable dopaminergic antidepressants which may be used in combination with a compound of the invention include bupropion and amineptine.

It will be appreciated that the compounds of the combination or composition may be administered simultaneously (either in the same or different pharmaceutical formulations), separately or sequentially.

The invention further provides a method of treatment of the above disorders in mammals including humans, which comprises administering to the sufferer a therapeutically safe and effective amount of the compound of formula (I) or a pharmaceutically acceptable salt thereof.

In another aspect, the invention provides for the use of the compound of formula (I) or a pharmaceutically acceptable salt thereof in the manufacture of a medicament for use in the treatment of the above disorders.

In order to use the compound of formula (I) in therapy, it will normally be formulated into a pharmaceutical composition in accordance with standard pharmaceutical practice. The present invention also provides a pharmaceutical composition, which comprises a compound of formula (I) or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier or excipient.

In a further aspect, the present invention provides a process for preparing a pharmaceutical composition, the process comprising mixing the compound of formula (I) or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier or excipient.

A pharmaceutical composition of the invention, which may be prepared by admixture, suitably at ambient temperature and atmospheric pressure, is usually adapted for oral, parenteral or rectal administration and, as such, may be in the form of tablets, capsules, oral liquid preparations, powders, granules, lozenges, reconstitutable powders, injectable or infusible solutions or suspensions or suppositories. Orally administrable compositions are generally preferred.

Tablets and capsules for oral administration may be in unit dose form, and may contain conventional excipients, such as binding agents (e.g. pregelatinised maize starch, polyvinylpyrrolidone or hydroxypropyl methylcellulose);, fillers (e.g. lactose, microcrystalline cellulose or calcium hydrogen phosphate);, tabletting lubricants lubricants (e.g. magnesium stearate, talc or silica);, disintegrants (e.g. potato starch or sodium starch glycollate); and acceptable wetting agents (e.g. sodium lauryl sulphate). The tablets may be coated according to methods well known in normal pharmaceutical practice.

Oral liquid preparations may be in the form of, for example, aqueous or oily suspension, solutions, emulsions, syrups or elixirs, or may be in the form of a dry product for reconstitution with water or other suitable vehicle before use. Such liquid preparations may contain conventional additives such as suspending agents (e.g. sorbitol syrup, cellulose derivatives or hydrogenated edible fats), emulsifying agents (e.g. lecithin or acacia), non-aqueous vehicles (which may include edible oils e.g. almond oil, oily esters, ethyl alcohol or fractionated vegetable oils), preservatives (e.g. methyl or propyl-p-hydroxybenzoates or sorbic acid), and, if desired, conventional flavourings or colorants, buffer salts and sweetening agents as appropriate. Preparations for oral administration may be suitably formulated to give controlled release of the active compound.

For parenteral administration, fluid unit dosage forms are prepared utilising a compound of the invention or pharmaceutically acceptable salt thereof and a sterile vehicle. Formulations for injection may be presented in unit dosage form e.g. in ampoules or in multi-dose, utilising a compound of the invention or pharmaceutically acceptable salt thereof and a sterile vehicle, optionally with an added preservative. The compositions may take such forms as suspensions, solutions or emulsions in oily or aqueous vehicles, and may contain formulatory agents such as suspending, stabilising and/or dispersing agents. Alternatively, the active ingredient may be in powder form for constitution with a suitable vehicle, e.g. sterile pyrogen-free water, before use. The compound, depending on the vehicle and concentration used, can be either suspended or dissolved in the vehicle. In preparing solutions, the compound can be dissolved for injection and filter sterilised before filling into a suitable vial or ampoule and sealing. Advantageously, adjuvants such as a local anaesthetic, preservatives and buffering agents are dissolved in the vehicle. To enhance the stability, the composition can be frozen after filling into the vial and the water removed under vacuum. Parenteral suspensions are prepared in substantially the same manner, except that the compound is suspended in the vehicle instead of being dissolved, and sterilisation cannot be accomplished by filtration. The compound can be sterilised by exposure to ethylene oxide before suspension in a sterile vehicle. Advantageously, a surfactant or wetting agent is included in the composition to facilitate uniform distribution of the compound.

Lotions may be formulated with an aqueous or oily base and will in general also contain one or more emulsifying agents, stabilising agents, dispersing agents, suspending agents, thickening agents, or colouring agents. Drops may be formulated with an aqueous or non-aqueous base also comprising one or more dispersing agents, stabilising agents, solubilising agents or suspending agents. They may also contain a preservative.

The compound of the invention may also be formulated in rectal compositions such as suppositories or retention enemas, e.g. containing conventional suppository bases such as cocoa butter or other glycerides.

The compound of the invention may also be formulated as depot preparations. Such long acting formulations may be administered by implantation (for example subcutaneously or intramuscularly) or by intramuscular injection. Thus, for example, the compounds of the invention may be formulated with suitable polymeric or hydrophobic materials (for example as an emulsion in an acceptable oil) or ion exchange resins, or as sparingly soluble derivatives, for example, as a sparingly soluble salt.

For intranasal administration, the compound of the invention may be formulated as solutions for administration via a suitable metered or unitary dose device or alternatively as a powder mix with a suitable carrier for administration using a suitable delivery device. Thus the compound of formula (I) may be formulated for oral, buccal, parenteral, topical (including ophthalmic and nasal), depot or rectal administration or in a form suitable for administration by inhalation or insufflation (either through the mouth or nose).

The compound of the invention may be formulated for topical administration in the form of ointments, creams, gels, lotions, pessaries, aerosols or drops (e.g. eye, ear or nose drops). Ointments and creams may, for example, be formulated with an aqueous or oily base with the addition of suitable thickening and/or gelling agents. Ointments for administration to the eye may be manufactured in a sterile manner using sterilised components.

The composition may contain from 0.1 % to 99% by weight, preferably from 10 to 60% by weight, of the active material, depending on the method of administration. The dose of the compound used in the treatment of the aforementioned disorders will vary in the usual way with the seriousness of the disorders, the weight of the sufferer, and other similar factors. However, as a general guide suitable unit doses may be 0.05 to 1000 mg, more suitably 1.0 to 200 mg, and such unit doses may be administered more than once a day, for example two or three times a day. Such therapy may extend for a number of weeks or months.

The following Preparations and Examples illustrate the compounds of the present invention and preparation thereof.

Pharmaceutically acceptable salts may be prepared conventionally by reaction with the appropriate acid or acid derivative.

Description 1 2-Methyl-5-quinolinyl trifluoromethanesulfonate (D1)

A solution of 2-methyl-quinolin-5-ol (2.5 g; 1 eq) in dichloromethane (25 mL) and pyridine (6.4 mL; 5 eq) was cooled to 0°C and trifluoromethanesulfonic anhydride (4.2 mL; 1.6 eq) was added dropwise over 10 minutes. The reaction mixture was stirred under an inert atmosphere at r.t. for 1 h, then poured into water (20 mL) and extracted into ethyl acetate (3×15 mL). The organic layers were combined, dried over Na₂SO₄ and concentrated under reduced pressure. The crude was purified by flash chromatography, eluting with ethyl acetate/cyclohexane (4/6) affording the title compound in 92% yield (4.2 g). MS; (ES) m/z: 292.3 [MH⁺]. C₁₁H₈F₃NO₃S requires 291. 1 H-NMR (300 MHz, d _6-DMSO) δ(ppm): 8.05 (d, 1 H), 7.85 (d, 1 H), 7.64 (t, 1 H), 7.48 (d, 1 H), 7.43 (d, 1 H), 2.48 (s, 3 H).

Description 2 1,1-Dimethylethyl 4-(2-methyl-5-quinolinyl)-1-piperazinecarboxylate (D2)

tert-Butyl 1-piperazine carboxylate (1.6 g; 1.2 eq), cesium carbonate (1.7 g; 1.5 eq), palladium acetate (0.33 g; 0.14 eq) and 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl (0.97 mg; 0.15 eq) were added to a solution of 2-methyl-5-quinolinyl trifluoromethanesulfonate (D1) in toluene (20 mL) under an inert atmosphere. The reaction mixture was stirred at reflux under nitrogen for 8 hours. The reaction was quenched at room temperature using a saturated aqueous solution of ammonium chloride (15 mL) and extracted into ethyl acetate (3x20 mL). The organic layers were combined, dried over Na₂SO₄ and concentrated under reduced pressure. The crude was purified by flash chromatography, eluting with ethyl acetate/cyclohexane (317) affording the title compound in 62% yield (1.4 g). MS; (ES) m/z: 328.4 [MH]⁺. C₁₉H₂₅N₃O₂ requires 327. ¹H-NMR (500 MHz, CDCl₃) δ(ppm): 8.40 (d, 1 H), 7.76 (d, 1 H), 7.61 (t, 1 H), 7.29 (d, 1 H), 7.06 (d, 1 H), 3.69 (bs, 4 H), 3.03 (bs, 4 H), 2.74 (s, 3 H), 1.51 (s, 9 H).

Description 3 2-Methyl-5-(1-piperazinyl)quinoline (D3)

1,1-dimethylethyl 4-(2-methyl-5-quinolinyl)-1-piperazinecarboxylate (D2) (1.1 g) in a 25% solution of trifluoroacetic acid in dichloromethane (10 mL) was stirred at r.t. under an inert atmosphere for 3 hours. The reaction mixture was concentrated under reduced pressure and desalted by means of a 20g SCX cartridge affording the title compound in 96% yield (0.74 g). MS; (ES) m/z: 228.4 [MH]⁺. C₁₄H₁₇N₃ requires 227. ¹H-NMR (300.MHz, d₆ -DMSO) δ(ppm): 8.34 (d, 1 H), 7.57 (m, 2 H), 7.35 (m, 1 H), 7.06 (m, 1 H), 2.93 (bm, 8 H), 2.62 (s, 3 H).

Description 4 2-(3-Nitrophenyl)ethyl methanesulfonate (D4)

Methanesulfonyl chloride (0.28 mL) was added dropwise to a stirred solution of 2-(3-nitrophenyl)ethanol (0.5 g; 1 eq) in dichloromethane (3 mL) and triethylamine (0.5 mL; 1.2 eq) at 0°C under an inert atmosphere. The solution was allowed to reach r.t. and stirred for 5 hours. The reaction mixture was diluted with water (3 mL) and extracted into dichloromethane (3×3 mL). The organic layers were combined, dried over Na₂SO₄ and concentrated under reduced pressure. The crude was purified by flash chromatography, eluting with a gradient from dichloromethane to dichloromethane/MeOH (98/2) affording the title compound in 84% yield (0.62 g). ¹H-NMR (300 MHz, CDCl₃) δ(ppm): 8.15 (m, 2 H), 7.53 (m, 2 H), 4.45 (t, 2 H), 3,15 (t, 2H), 2.92 (s, 3 H).

Description 5 2-Methyl-5-{4-[2-(3-nitrophenyl)ethyl]-1-piperazinyl}quinoline (D5)

N,N-Diisopropylethylamine (0.8 mL; 5 eq) was added to a solution of 2-methyl-5-(1-piperazinyl)quinoline (D3) (0.2 g; 1 eq) and 2-(3-nitrophenyl)ethyl methanesulfonate (D4) (0.22; 1 eq) in dimethylformamide (1.5 mL). The reaction mixture was heated to 100°C for 10 hours. The dark solution was concentrated under reduced pressure, diluted with water (3 mL) and brine (1 mL) and extracted into ethyl acetate (3x3 mL). The organic layers were combined, dried over Na₂SO₄ and concentrated under reduced pressure. The crude was purified by flash chromatography, eluting with a gradient from dichloromethane to dichloromethane/MeOH (98/2) affording the title compound in 64% yield (0.21 g). MS; (ES) m/z: 228.4 [MH]⁺. C₂₂H₂₄N₄O₂ requires 376. ¹H-NMR (300 MHz, CDCl₃) δ(ppm): 8.35 (d, 1 H), 8.11 (s, 1 H), 8.05 (d, 1 H), 7.70 (d, 1 H), 7.55 (m, 2 H), 7.45 (t, 1 H), 7.25 (m, 1 H), 7.05 (d, 1 H), 3.10 (mt, 4 H), 2.95 (bm, 2 H), 2.75 (bm, 6 H), 2.70 (s, 3 H).

Description 6 3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}aniline (D6)

A solution of 2-methyl-5-{4-[2-(3-nitrophenyl)ethyl]-1-piperazinyl}quinoline (D5)(0.14 g; 1 eq) in methanol (3 mL) was added dropwise to a suspension of iron powder (0.07 g; 3.2 eq) and ammonium chloride (0.1 g; 5.3 eq) in water (3 mL). The reactants were heated at reflux for 8 hours, adding additional amounts of iron powder (total 0.07g; 3.2 eq) and ammonium chloride (total 0.1 g; 5.03 eq) in 3 portions during the reaction. The reaction mixture was filtered using a Millipore filter. The filtrate was concentrated under reduced pressure, diluted with water (5 mL) and a saturated aqueous solution of sodium hydrogen carbonate (2 mL), extracted into ethyl acetate (3×5 mL), dried over Na₂SO₄ and concentrated under reduced pressure obtaining the title compound in 84% yield (0.11 g). MS; (ES) m/z: 347.4 [MH]⁺. C₂₂H₂₆N₄ requires 346. ¹H-NMR (300 MHz, CDCl₃) δ(ppm): 8.35 (d, 1 H), 7.70 (d, 1 H), 7.55 (t, 1 H), 7.25 (d, 1 H), 7.08 (m, 2 H), 6.65 (md, 1 H), 6.55 (m, 2 H), 3.65 (bs, 2 H), 3.15 (t, 4 H), 2.80 (m, 4 H), 2.75 (s, 3 H), 2.70 (m, 4 H).

Examples General procedure for the synthesis of cyclic ureas and carbamates and their corresponding dihydrochloride salts starting from 3-{2-[4-(2-methyl-5-quinolinyl)-1-piperazinyl]ethyl}aniline:

Diisopropylethylamine (1.5 eq) and a chloroformate or isocyanate (1.2eq) were added sequentially to a stirred solution of 3-{2-[4-(2-methyl-5-quinolinyl)-1-piperazinyl]ethyl}aniline (1 eq) in dichloromethane at 0 °C. The solution was stirred for 1 hr at room temperature, then diluted with dichloromethane and washed with a saturated aqueous solution of NH₄Cl and brine and then dried over Na₂SO₄. The solution was concentrated under reduced pressure. The crude material was dissolved in dimethylformamide, cooled to 0 °C, and NaH (1.1 eq) was added portionwise under an inert atmosphere. The mixture was stirred for 2 hrs at room temperature, then the solvent was removed by means of an SCX cartridge. The crude material was purified on SPE cartridge (Silica) eluting with a gradient from dichloromethane/MeOH 99/1 to dichloromethane/MeOH 98/2 affording the final compound (yields ranged from 22 to 87%). The free base could be converted into its dihydrochloride salt by dissolving the compound in Et₂O and MeOH and adding an 1 M ethereal solution of HCl (2.1 eq) dropwise. A yellow solid precipitated and the suspension was stirred for 15 min. The solvent was removed under reduced pressure affording a crude material which was triturated with Et₂O. The final compound was then recovered by filtration (yield quantitative).

1-(3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}phenyl)-2-imidazolidinone dihydrochloride

The title compound was prepared in 22% yield according to the general procedure for the synthesis of cyclic ureas and carbamates starting from 3-{2-[4-(2-methyl-5-quinolinyl)-1-piperazinyl]ethyl}aniline and 1-chloro-2-isocyanatoethane, via the free base 1-(3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}phenyl)-2-imidazolidinone. MS: (ES) m/z: 416 [MH⁺]. C₂₅H₂₉N₅O requires 415. ¹H-NMR (400 MHz, d₆ -DMSO) δ(ppm): 10.60 (bs, 1H), 8.77 (s, 1H), 7.85 (s, 2H), 7.71 (s, 1 H), 7.59 (s, 1H), 7.38 (dd, 1H), 7.28 (t, 1H), 6.96 (bs, 1 H), 6.92 (d, 1H), 3.83 (m, 2H), 3.71 (d, 2H), 3.7-3.2 (m, 10H), 3.08 (m, 2H), 2.82 (bs, 3H).

Alternative Preparation of 1-(3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}phenyl)-2-imidazolidinone Methyl (3-aminophenyl)acetate hydrochloride

3-Aminophenylacetic acid (1 wt) was suspended in methanol (5 vol) under nitrogen at 20 °C. Chlorotrimethylsilane (1.26 vol) was added over 60 minutes at 20 °C. The reaction mixture was stirred at 20 °C for one hour, then concentrated under reduced pressure to 3 vol. Methyl-t-butyl ether (4 vol) was added and the resulting suspension was stirred at room temperature for 18 hours. The solid was collected by filtration, washing with methyl-t-butyl ether (4 × 1 vol). The material was dried in oven at 40 °C for 5 hours to give the title compound. MS: (ES) m/z: 166 [MH⁺]. C₉H₁₁NO₂ requires 165. ¹H-NMR (300 MHz, d₆ -DMSO) δ(ppm): 7.40 (m, 1H), 7.19 (m, 3H), 3.74 (s, 2H), 3.58 (s, 3H).

Methyl [3-(2-oxo-1-imidazolidinyl)phenyl]acetate

Methyl (3-aminophenyl)acetate hydrochloride was suspended in dichloromethane (7 vol) under nitrogen. Diisopropylethylamine (1.04 vol) was added at 20 °C over 30 minutes, and the reaction mixture was stirred for 30 minutes at 20 °C. 2-Chloroethyl isocyanate (0.44 vol) was added dropwise at 20 °C over 100 minutes. The reaction mixture was stirred at 20 °C for three hours. A saturated solution of ammonium chloride (5 vol) was added dropwise over 10 mins and the resultant mixture was stirred for ten minutes. The organic phase was separated and washed with water (5 vol). Tetrahydrofuran (2 × 3 vol) was added and the mixture was concentrated to 2 vol. Dry tetrahydrofuran (5 vol) was added, and the mixture was concentrated to 2 vol. Dry THF (3 vol) was added, under nitrogen at 20 °C. The reaction mixture was cooled to 0 °C, and potassium tert-butoxide (0.56 wt) was added portion-wise in 5 stages, allowing 20 minutes between two subsequent additions. The reaction mixture was stirred at 20 °C for one hour. Hydrochloric acid (0.5N, 2 vol) was added dropwise over 20 minutes. Ethyl acetate (10 vol) was added and the organic phase was separated. The organic layer was washed with aqueous sodium hydrogencarboante solution (4%, 2 vol) and brine (2 vol), and the organic layer was then evaporated to dryness under vacuum to give the title compound (overall yield: 90%w/w). ¹H-NMR (300 MHz, CDCl₃) δ(ppm): 7.50-7.45 (m, 2H), 7.30 (m, 1H), 7.00 (d, 1H), 4.98 (br. s, 1H), 4.95 (t, 2H), 3.68 (s, 3H), 3.62 (s, 2H), 3.54 (t, 2H).

1-[3-(2-Hydroxyethyl)phenyl]-2-imidazolidinone

Methyl [3-(2-oxo-1-imidazolidinyl)phenyl]acetate was dissolved in dry dichloromethane (10 vol). Lithium borohydride (2M solution in THF, 4.3 vol) was added dropwise over 1 hour at 20 °C. The resulting suspension was stirred at 20 °C for 2.5 hours. Water (2 vol) is added dropwise at 20 °C over 60 minutes. The resulting suspension was concentrated to 2 vol and aqueous ammonium chloride solution (7%, acidity corrected with 10% hydrochloric acid to pH 3, 3 vol) was added. The suspension was stirred at 20 °C for 2 hours then filtered. The filter-cake was washed thoroughly with aqueous ammonium chloride solution (7%, acidity corrected with 10% hydrochloric acid to pH 3, 2 vol) and water (2 vol) until the filtrate had an acidity of pH 7. The filter-cake was dried at 80 °C to give the title compound (75% th.). ¹H-NMR (300 MHz, d₆ -DMSO) δ(ppm): 7.36-7.27 (m, 2H), 7.19 (t, 1H), 7.86 (m, 1H), 7.81 (d, 1 H), 4.58 (br. s, 1H), 3.60 (t, 2H), 3.52 (m, 2H), 3.35 (t, 2H), 2.64 (t, 2H).

2-[3-(2-Oxo-1-imidazolidinyl)phenyl]ethyl methanesulfonate

1-[3-(2-Hydroxyethyl)phenyl]-2-imidazolidinone was suspended in DMF (4 vol) and heated to 35 °C until a clear solution was obtained. Triethylamine (1 vol) was added dropwise at 30 °C over 15 minutes. The mixture was cooled to 20 °C and methanesulfonyl chloride (0.46 vol) was added 30 mins. The resulting suspension was stirred at 20 °C for 15 minutes. Dichloromethane (10 vol) was added, and the organic layer was washed with brine/water (1:1) (5 vol), and then water (3 × 5 vol). The organic phase was concentrated to 1 vol, and methanol was added (4 vol), if complete dissolution was not obtained, the mixture was heated to 35 °C in order to dissolve the solid. Methyl-t-butyl ether (10 vol) was added and the suspension was left to stand for 18 hours at room temperature. The suspension was filtered; the filter-cake was washed with methyl-t-butyl ether (2 vol). The solid was dried at 40 °C for 18 hours to give the title compound (70% th). ¹H-NMR (300 MHz, CDCl₃) δ(ppm): 7.54 (s, 1 H), 7.40-7.25 (m, 2H), 6.92 (d, 1 H), 4.72 (br. s, 1H), 4.41 (t, 2H), 3.92 (t, 2H), 3.60 (t, 2H), 3.09 (t, 2H), 2.87 (s, 3H).

Alternatively, 1-[3-(2-hydroxyethyl)phenyl]-2-imidazolidinone was suspended in acetonitrile (5 vol) at room temperature and under nitrogen. Triethylamine (1 vol) was added dropwise over 15 minutes. The mixture was cooled to 0 °C and methanesulfonyl chloride (0.73 vol) was added over 30 minutes. The reaction mixture was stirred at room temperature for 2 hours, then diluted with ethyl acetate (10 vol). The mixture was washed with a saturated solution of ammonium chloride (2 × 3 vol), followed by water-brine 1:1 (2 × 3 vol). The organic phase was concentrated to 5 vol, ethyl acetate (5 vol) was added and the solution was evaporated to dryness, yielding the title compound as a cream-coloured solid (yield: 90% th).

2-Methyl-5-quinolinyl trifluoromethanesulfonate

5-Hydroxy-2-methylquinoline hydrobromide ( WO2002034754 , Chem. Abstr. 136:355241, 1wt, 1eq) was suspended in ethyl acetate (20 vol) and a saturated solution of sodium hydrogen carbonate (7 vol) was added. The organic layer was washed with a saturated solution of sodium hydrogen carbonate (7 vol) and the two layers were separated. The organic layer was concentrated to 2 vol then ethyl acetate (2 × 3vol) was added and the mixture was concentrated to 2 vol each time. Toluene was added (2 × 10 vol) and the mixture was concentrated to 2 vol each time to give a suspension of 5-hydroxy-2-methylquinoline. Toluene (9 vol) and pyridine (0.68 vol, 1.33eq) were added under nitrogen at room temperature. The mixture was cooled to 0 °C and triflic anhydride (1.27 vol, 1.2eq) was added dropwise maintaining the temperature at 0 °C, then warming to 25 °C for 3 hours. A saturated aqueous solution of ammonium chloride (7 vol) was added and the mixture was stirred for 10 minutes. The two layers were separated and the organic layer was washed with water (7 vol), a 4% solution of sodium hydrogencarbonate (7 vol), water (7 vol), then concentrated to 3 volumes. Toluene (2 × 7 vol) was added and the mixture concentrated to 3 volumes to give a crude brown solution of the title compound (70% th), which was used without further purification.

1,1-Dimethylethyl 4-(2-methyl-5-quinolinyl)-1-piperazinecarboxylate

A solution of 2-methyl-5-quinolinyl trifluoromethanesulfonate (1wt, 1eq) in toluene (7 vol) was degassed under reduced pressure then flushed with nitrogen. To the mixture were added N-Boc-piperazine (1.05 eq), milled cesium carbonate (1.5 eq), (+/-)-bis(diphenylphosphino)-1,1'-binaphthyl (BINAP, 0.15 eq) and palladium acetate (0.05eq). The resulting mixture was stirred at 95°C for 16 hours. The solution was cooled and concentrated to approx. 4 vol and 10 vol of cyclohexane were added giving a suspension. The suspension was stirred for 30 minutes and filtered over a pad of Silica Gel (approx 2.5 vol). The filtrate was washed with 10 vol of water and concentrated under reduced pressure to give the title compound as a brown solid, which was carried through directly to the next stage.

2-Methyl-5-(1-piperazinyl)quinoline

To a solution of 1,1-dimethylethyl 4-(2-methyl-5-quinolinyl)-l-piperazinecarboxylate in 2-propanol (3 vol) was added dropwise hydrochloric acid (37%, 3 vol). The mixture was stirred at 40 °C for 1.5 hours then concentrated. Water (30 vol) was added and the solution was extracted with ethyl acetate (3 × 20 vol). The aqueous layer was basified with an aqueous sodium carbonate solution then extracted with dichloromethane (5 x 40 vol). The combined organic extracts were dried and evaporated to give the title compound as an off-white solid (80% th, 2 steps).

1-(3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}phenyl)-2-imidazolidinone (E85)

2-[3-(2-Oxo-1-imidazolidinyl)phenyl]ethyl methanesulfonate (1.32 wt) and 2-methyl-5-(1-piperazinyl)quinoline (1 wt.) were suspended in acetonitrile (5 vol) at room temperature under nitrogen. Diisopropylethylamine (1.53 vol) was added dropwise over 30 minutes, and the mixture was then stirred at 75 °C for 4 hours. The reaction mixture was cooled to room temperature, concentrated to 2 vol, and diluted with ethyl acetate (7 vol). The organic layer was washed with saturated aqueous ammonium chloride solution (2 × 3 vol), followed by water (1 × 3 vol). The organic layer was evaporated to dryness, yielding the title compound as a brown foam (70%th).

1-(3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}phenyl)-2-imidazolidinone sulfate

1-(3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}phenyl)-2-imidazolidinone (300mg, 1wt) is suspended in methanol (6.0ml, 20 vol) at room temperature under nitrogen. A solution of sulfuric acid (71mg, 1eq) in methanol is dosed. The clear solution is seeded and solid crystallization is observed. The slurry is stirred 16 hrs at room temperature. The solid is filtered and dried at room temperature under vacuum to give the desired salt.

1-(3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}phenyl)-2-imidazolidinone may exist as two different physical forms, form 1 or form 2.

1-(3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}phenyl)-2-imidazolidinone, form 1

The free-base was completely dissolved in DCM (10 volumes) at reflux. The mixture was concentrated under vacuum (rotary evaporator) at 40 °C (external temperature), until crystallisation initiated (mixture reduced to 2-3 volumes). The suspension was cooled to 25 °C, then methyl tert-butyl ether (10 volumes) was added with stirring. The suspension was stirred at 25 °C for 18 hours. The precipitate was filtered off, washed with methyl tert-butyl ether (1 vol) and dried at 40 °C for 18 hours to give the title compound; m.p. 170 °C.

1-(3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}phenyl)-2-imidazolidinone, form 2

The free-base was completely dissolved in DCM (10 volumes) at reflux. The solution was cooled to 25 °C, then methyl tert-butyl ether (10 volumes) was added with stirring. The suspension was stirred at 25 °C overnight. The precipitate thus formed was filtered off, washed with methyl tert-butyl ether-DCM (1:1, 2 × 1 volume) and dried at 40 °C for 18 hours to give the title compound; m.p. 164 °C.

Claims (8)

1-(3-{2-[4-(2-Methyl-5-quinolinyl)-1-piperazinyl]ethyl}phenyl)-2-imidazolidinone of formula (I) or a pharmaceutically acceptable salt thereof.

A compound as claimed in claim 1 for use as a therapeutic substance.

A compound as claimed in claim 1 for use in the treatment of a CNS disorder.

A compound as claimed in claim 3, wherein the disorder is depression or anxiety.

Use of a compound as claimed in claim 1 in the manufacture of a medicament for use in the treatment of a CNS disorder.

Use as claimed in claim 5, wherein the disorder is depression or anxiety.

A pharmaceutical composition comprising a compound as claimed in claim 1, and a pharmaceutically acceptable carrier or excipient.

A process for preparing a pharmaceutical composition as defined in claim 7, the process comprising mixing a compound as claimed in claim 1 and a pharmaceutically acceptable carrier or excipient.