WO1993015072A1 - Antibacterial 1-normon-2-yl thiazolyl ketones - Google Patents

Abstract

Optionally substituted 2-(C1-10)alkoxythiazol-5-yl normonyl ketones of formula (I), in which R1 is 2-(optionally substituted (C¿1-10?)alkoxy)-thiazol-5-yl group are of use in anti-bacterial or anti-mycoplasmal therapy.

Description

Ant1bacter1al l-normon-2-yl thlazolyl ketones

This invention relates to a novel class of compounds having antibacterial and antimycoplasmal activity, to processes for their preparation and to their use in human and veterinary medicine.

Mupirocin, the compound of formula (A):

exhibits good activity against Gram positive bacteria, H.influenzae,

Legionella and mycoplasma. It is marketed as a topical formulation by Beecham Group pic under the Trade Mark BACTROBAN. Mupirocin

(formerly known as pseudomonic acid) is rapidly hydrolysed in vivo to monic acid A, the compound of formula (B):

which is inactive. Various proposals have been made to improve the metabolic stability of mupirocin with respect to enzymatic hydrolysis, by modifying the C-l ester functional group, including, for instance, C-l heterocyclic derivatives (EP-A-0 087 953 and EP-A-0 123 578), C-l amides (EP-A-0 001 914) and C-l ketones including heterocyclic ketones (EP-A-0 029 665). In addition, Klein et al have reported (in a poster presented at the Third Annual Chemical Congress of North America, Toronto, June 1988) the preparation of the C-l fur-2-yl, pyrid-2-yl and N-methylimidazol-2-yl ketones. These are characterised by having the heteroaryl group linked to the ketone carbonyl group by a ring carbon atom which is adjacent to the heteroatom. The limited data provided on these derivatives showed that these compounds were less active than the analogous butyl and phenyl ketones which in turn were less active than methyl pseudomonate. No results of in vivo activity were reported, the inference being that in vitro activity had not been sufficient to warrant in vivo investigation. More recently, WO 92/02518 (published after the priority date claimed for the present application) has disclosed several examples of heteroaryl ketones, including the 2-methylmercapto- and 2-methyl- sulphinyl thiazol-5-yl ketones.

It has now however been surprisingly found that an enhanced antibacterial profile may be obtained with a narrow group of other thiazol- 5-yl ketones.

Accordingly, the present invention provides a compound of formula (I):

in which Rl is a 2-(optionally substituted (Cι.ιo)alkoxy)thiazol-5-yl group, that is a group of the formula:

in which R is optionally substituted (Cι.i_Q)aIkoxy.

Suitable optional substituents for the Qi.iQ)aikoxy group include, for example, halogen, cyano, azido, nitro, carboxy, (Cι_g)alkoxycarbonyl, carbamoyl, mono- and di-(Cι_g)alkylcarbamoyl, sulpho, sulphamoyl, mono- or di-(Cι_g)alkylsulphamoyl, amino, mono-and di-(Cι_ g)alkylamino, acylamino, ureido, (Cι_g)alkoxycarbonylamino, 2,2,2- trichloroethoxycarbonylamino, trialkylthiomethyl, optionally substituted aryl, optionally substituted heterocyclyl, hydroxy, (Cι_g)alkoxy, acyloxy, oxo, acyl, 2-thenoyl, (Cι_g)alkylthio, (Cι_g)alkylsulphinyl, (Cι_ 6)alkylsulphonyl, hydroxyimino, (Cι.g)alkoxyimino, hydrazino, hydrazono, benzohydroximoyl, guanidino, ami din o and iminoalkylamino. Suitably, R is optionally substituted (Cι_g)alkoxy, preferably optionally substituted methoxy, ethoxy or hexoxy, more preferably methoxy, most preferably unsubstituted methoxy. Preferably, Rl is 2- methoxythiazol-5-yl

When used herein, the term 'aryl' includes, unless otherwise defined, phenyl or naphthyl. The aryl ring may be optionally substituted with up to five, preferably up to three substituents. Suitable substituents include, for example, halogen, cyano, (Cχ.g)alkyl, phenyl, (Cι.g)alkoxy, halo(Cχ.g)alkyl, hydroxy, amino, mono- or di-(Cι_g)alkylamino, acylamino, nitro, carboxy, (Cι_g)alkoxycarbonyl, (Cχ.g)- alkoxycarbonyl(Cι_g)alkyl, (Cι_g)alkylcarbonyloxy, (Cι.g)al^lthio, (Cχ_ g)alkylsulphinyl, (Cι_g)alkylsulphonyl, sulphamoyl, mono- or di-(Cι_ g)alkylsulphamoyl, carbamoyl, and mono- or di-(Cι_g)alkylcarbamoyl. When used herein, the term 'heterocyclyl' includes aromatic and non-aromatic single or fused rings comprising up to four hetero-atoms in the ring selected from oxygen, nitrogen and sulphur. Suitably the heterocyclic ring comprises from 4 to 7, preferably 5 to 6, ring atoms. A fused heterocyclic ring system may include carbocyclic rings and need only include one heterocyclic ring. The heterocyclyl ring may be optionally substituted with up to three substituents. Suitable substituents include, for example, halogen, (Cι_g)alkyl, (Cι_g)alkoxy, halo(Cι_g)alkyl, hydroxy, amino, mono- or di-(Cι_g)alkylamino, carboxy, (Cι.g)alkoxycarbonyl, (Cι_ g)alkoxycarbonyl(Cι_g)alkyl, aryl and oxo.

When used herein, the term 'halogen' refers to fluorine, chlorine, bromine or iodine. Compounds of formula (I) may conveniently be named '(l-normon-2- yl ketones'. Normonyl is the trivial name for the 3-[(2S,3R,4R,5S)-5-

[(2S,3S,4S,5S)-2,3-epoxy-5-hydroxy-4-methylhexyl]-3,4- dihydroxytetrahydro-pyran-2-yl]-2-methylprop-l(E)-enyl radical, as shown in formula (II):

It will be appreciated that in compounds of formula (I), substituents within the group R* may contain one or more chiral centres. The present invention encompasses all such resultant isomeric possibilities.

Since the compounds of formula (I) of the present invention are intended for use in pharmaceutical compositions, it will be understood that they are each provided in substantially pure form, for example at least 50% pure, more suitably at least 75% pure and preferably at least 95% pure (% are on a wt/wt basis). Impure preparations of the compounds of formula (I) may be used for preparing the more pure forms used in the pharmaceutical compositions. Although the purity of intermediate compounds of the present invention is less critical, it will be readily understood that the substantially pure form is preferred as for the compounds of formula (I). Preferably, whenever possible, the compounds of the present invention are obtained in crystalline form. When some of the compounds of this invention are allowed to crystallise from, or are recrystallised from, organic solvents, solvent of crystallisation may be present in the crystalline product. This invention includes within its scope such solvates. Similarly, some of the compounds of this invention may be crystallised or recrystallised from solvents containing water. In such cases water of hydration may be formed. This invention includes within its scope stoichiometric hydrates as well as compounds containing variable amounts of water that may be produced by processes such as lyophilisation. A preferred example of a compound within this invention is 2- methoxy-(thiazol-5-yl)- l-(normon-2-yl) ketone.

Compounds of the present invention may be prepared by methods known for the preparation of α,β-unsaturated ketones. Some of these processes will be more appropriate than others. Suitably, compounds of formula (I) may be prepared by a process which comprises treating an arid of formula (IH):

in which Z 2 and 2s- are the same or different and each is hydrogen or a hydroxyl-protecting group, or an activated derivative thereof, with an organometallic reagent; and thereafter, and if necessary, removing any hydroxyl-protecting groups.

Suitable organometallic reagents include:

(i) a Grignard reagent of the formula R^MgX in which Rl is as defined with, respect to formula (I) and X represents chlorine, bromine or iodine, which reaction may optionally be carried out in the presence of copperd) iodide as catalyst;

(ii) an organolithium reagent of formula R^Li in which Ε,³- is as defined with respect to formula (I);

(iii) an organomanganous reagent of the formula R^MnCl in which Rl is as defined with respect to formula (I); and

(iv) an organocerium reagent Rll -CeX3, °- which R^ is as defined with respect to formula (I) and X represents chlorine, bromine or iodine.

The reaction with the organometallic reagent may be conveniently carried out in an ethereal or hydrocarbon solvent, the choice of which is dependent upon the specific requirements of the organometallic reagent. Preferably, the Grignard reagent is generated and used in diethyl ether or tetrahydrofuran.

The reaction is generally carried out in an inert atmosphere such as argon or nitrogen and at ambient temperature or below. The period for which the reaction is allowed to proceed depends upon the particular starting materials employed. The course of the reaction may be followed by conventional methods such as thin layer chromatography and the reaction may be terminated when an optimum quantity of product is present in the reaction mixture.

The compound of formula (III) in which 7 , Z^ and Z^ is each hydrogen is monic acid, the preparation of which is described in GB 1 587 058 (Beecham Group).

Suitable activated derivatives of the acid of formula (III) include thio-esters of formula (IV):

in which Z--, Z^ and Z^ are as hereinbefore defined and the moiety:

represents a 5- or 6-membered heterocyclic ring which may contain, in addition to the nitrogen atom, one or two further heteroatoms selected from oxygen, nitrogen and sulphur and which may be substituted or fused to a benzene ring which may itself be substituted. Preferred thio-esters are of formula (IVa):

in which Z--, Z and Z^ are as hereinbefore defined. A compound of formula (IVa) may be prepared by treating of a compound of formula (III) with 2,2'-dipyridyl disulphide in the presence of triphenylphosphine, by analogy with the metiiod described by E.J. Corey and D.A Clark in Tetrahedron Letters, 1979, 31, 2875. Other suitable activated derivatives of the acid of formula (III) include mixed anhydrides of the formula (V):

in which Z Zp and Z^ are as hereinbefore defined, and R^ is (Cι.g)alkyl; and of the formula (VI):

the same or different and each denotes an optionally substituted aryl group, for instance phenyl, or a (Cι_g)alkoxy group, for instance ethoxy.

A compound of formula (V) may be obtained by treating a compound of formula (III) with, for instance, a suitable derivative of the formula

R²OCOCl using the metiiod described by Crimmin M.J. et al., JCS Perkin 1, 1989, 2047.

A compound of formula (VT) may be obtained by treating a compound of formula (m) with C1POR3R4_} using the metiiod described by Baxter A.J.G. et al., Tetrahedron Letters, 1980, 21, 5071.

Further suitable activated derivatives of the acid of formula (III) include amides of the formula (VII):

(VII) in which Z--, Z² and Z^ are as hereinbefore defined, ^ and R^ are the same or different, and each is (C]_g)alkyl, or the substituents B and R^ form a (C2-7)alkylene chain; and of the formula (VIII):

in which Z--, Z² and Z^ are as hereinbefore defined and B and R^, together with the nitrogen atom to which they are bonded, form an imidazolyl or triazolyl ring.

A preferred compound of formula (VII) is the N-methoxy-N- methylamide (i.e. R^ and R^ is each methyl) as described in WO 91/09855 (Beecham Group). The reaction of an N-methoxy-N-methylamide with an organolithium or a Grignard reagent to form a ketone is described by Nahm and Weinreb in Tetrahedron Letters, 1981, 3815.

A preferred amide of formula (VIII) is the imidazol-1-yl derivative. The reaction of an α,β-unsaturated acid or its imidazolyl derivative with a Grignard reagent is described in Chem. Ber., 1965, 95 1284.

Amides of formulae (VII) and (VIII) may suitably be obtained from monic acid acid by treatment thereof with iso-butyl chloroformate in tetrahydrofuran, in the presence of triethylamine, at a temperature of from -5 to 20°C, for about 30 min, to form an intermediate mixed anhydride (monic acid iso-butyl carbonic anhydride). This intermediate may then be reacted with an amine HN(OR5)R6 in dichloromethane at about 20°C for about 2h or an amine HNR^R8.HC1 in the presence of triethylamine and 4-dimethylaminopyridine, in THF, at about 20°C, to form the compound of formula (VII) in which Z--, Z² and Z^ is each hydrogen (with Rl, R^, R6, R7 and R^ as hereinbefore defined). The hydroxyl groups thereof may then be protected by treatment with a suitable hydroxyl protecting agent such as chlorotrimethylsilane, in a solvent such as THF in the presence of triethylamine and 4-dimethyl- amino pyridine as a catalyst.

A thio-ester of formula (IV) is preferably treated with an organomanganous reagent of formula R^MnCl, as hereinbefore defined whilst an amide of formula (VII) or (VIII) is preferably treated with an organolithium reagent of formula R^-Li as hereinbefore defined.

Preferably, a compound of formula (I) is prepared by a process which comprises treating a compound of formula (VH), as hereinbefore defined, with an organolithium reagent of formula R^Li as hereinbefore defined.

Suitable organometallic reagents may be prepared according to conventional procedures. For instance, suitable organomanganous reagents of the formula RlMnCl may be conveniently prepared by adding an organolithium reagent R^Li to a solution of manganous chloride and lithium chloride in dry THF, or a suspension of anhydrous manganous chloride in dry THF. An excess of R^MnCl is preferably employed.

Alternatively, a Grignard reagent may be used in place of the organolithium reagent, to generate the organomanganous reagent

RlMnCl. Other organomanganous reagents which may be used instead of iMnCl include:

(i) ( ^Mn or ( l^MnM X in which X is as hereinbefore defined, as described in Synthetic Communications, 1979, 9, 639;

(ii) R^Mnl in ether; as described in Synthetic Communications, 1979, 1, 639; and

(iii) R^-MnBr in ether, as described in Tetrahedron Letters, 1976, 3155. As in the case of R^MnCl, the above organomanganous reagents may be prepared in situ when required.

Organocerium reagents may be generated in situ by treating an organolithium compound of the formula R^-Li, in which R^ is as hereinbefore defined, with cerium (III) halide, by analogy with the procedure described by Imamoto et al; J Chem Soc, Chem Commun, 1982,

1042.

Further processes for the preparation of compounds of formula (I) are described in EP-A-0 029 665 (Beecham Group) and include treating an allylic alcohol of formula (IX):

in which B,--, Z--, Z² and Z^ are as hereinbefore defined, with an oxidising agent which converts allylic alcohols into α,β-unsaturated ketones, and thereafter, and if necessary, removing any hydroxyl-protecting groups.

Suitable such oxidising agents include activated manganese dioxide, pyridinium dichromate and pyridinium chlorochromate. Conveniently, the oxidation reaction is carried out in a non-polar organic solvent such as, for example, benzene or toluene.

Compounds of formula (IX) are novel and useful intermediates in the aforementioned process. Accordingly, the invention further provides compounds of formula (IX) as hereinbefore defined. An allylic alcohol of formula (IX) may be prepared by treating the corresponding aldehyde of formula (X):

in which Z^, Z² and Z^ are as hereinbefore defined, with an organometallic reagent as hereinbefore defined, and thereafter, and if necessary, removing any hydroxyl-protecting groups.

An aldehyde of formula (X) may be treated with a Grignard reagent of formula R^MgX or, more preferably, with an organocerium reagent RlLi-CeX3, ^as hereinbefore defined.

An aldehyde of formula (X) may be prepared by treating an amide of formula (Vϋ), as hereinbefore defined, with a suitable reducing agent such as di-iso-butyl-aluminium hydride, and thereafter, and if necessary, removing any hydroxyl-protecting group. Other suitable methods of preparation of an aldehyde of formula (X) are described in EP-A-0 029 665 (Beecham Group). A compound of formula (I) may also be prepared by treating a ketone of formula (XI):

in which Z¹, Z² and Z^ are as hereinbefore defined, with a terminal alkyne of the formula (XII):

H ≡C-Rl cxπ) in which ^ is as hereinbefore defined, to form an intermediate which is treated with £rts-(triphenylsilyloxy)-vanadate and triphenylsilanol, as described by H. Pauling in Helvetica, 1976, 59, 1233 and G.L. Olson, Helvetica, 1976, 59, 567; and thereafter, and if necessary, removing any hydroxyl-protecting groups.

The preparation of a compound of formula (XI) is described in GB 1 587 060 (Beecham Group). When used herein, the term 'hydroxyl-protecting group' refers to any such group known in the art which may be removed without disruption of the remainder of the molecule. Suitable hydroxyl-protecting groups include those described in 'Protective Groups in Organic Synthesis', T.W. Greene, Wiley-Interscience, New York 1981. The hydroxyl groups of the compounds of formulae (IEI) to (XT) may be protected at any stage of the above processes, using conventional methods. The hydroxyl-protecting group may be removed by methods known in the art, including enzymatic methods.

Particularly suitable hydroxyl protecting groups are silyl groups since these are readily removed under mild conditions. Such groups are introduced using conventional silylating agents, including halosilanes and silazanes, of the formulae:

LsSiY L₃SiO-C=NSiL,

L₂SiY₂ LsSiNHCONHSiLs

L3SNL2 LNHCONHSiLs

LaSiNHSiLs tBuMe₂Si-0-S0₂-CFs

LsSiNHCOL

Me₃Si- ^V N

wherein Me denotes methyl and *Bu denotes t-butyl, Y is halogen and each group L is independently selected from hydrogen, (Cχ_g)alkyl, (C^. g)alkoxy, aryl or aryl(Cι_4)alkyl. A preferred silyating agent is trimethylsilyl chloride. Particularly suitable protecting groups are trimethylsilyl, t-butyldimethylsilyl and t-butyldiphenylsilyl groups. Preferred protecting groups are trimethylsilyl groups because of their ease of removal.

The glycol function of the compounds of formulae (HI) to (XI) may be protected by forming a cyclic derivative using a compound of formula σαπ):

R9C(OR¹⁰)(OR )(OR¹²) (Kill) wherein R^ is hydrogen or (Cι.g)alkyl and each of R*0, R^ and R*² is (Cι.g)alkyl, such that in the cyclic derivative Z and Z² together are a moiety R9C(OR* ). Suitably R^ is hydrogen, methyl, ethyl, n- or iso- propyl; most suitably it is hydrogen. The groups R*0, R^ and R*² are suitably methyl, ethyl, n- or zso-propyl, or n-, iso-, sec- or if-butyl; most suitably methyl. Similarly the hydroxyl groups of a compound of formula (I) may be protected prior to conversion to a further compound of formula (I) as described above. In each case the hydroxyl protecting groups described above may be removed by mild acid hydrolysis followed by alkaline hydrolysis, for instance, as described by Clayton et al, JCS Perkin Trans 1, 1979, 308.

This invention also provides a pharmaceutical or veterinary composition which comprises a compound of formula (I) (hereinafter referred to as the 'drug') together with a pharmaceutically or veterinarily acceptable carrier or excipient. The compositions may be formulated for administration by any route, and would depend on the disease being treated. The compositions may be in the form of tablets, capsules, powders, granules, lozenges, liquid or gel preparations, such as oral, topical or sterile parenteral suspensions.

Tablets and capsules for oral administration may be in unit dose presentation form, and may contain conventional excipients such as binding agents, for example syrup, acacia, gelatin, sorbitol, tragacanth, or polyvinylpyrollidone; fillers, for example lactose, sugar, maize-starch, calcium phosphate, sorbitol or glycine; tabletting lubricants, for example magnesium stearate, talc, polyethylene glycol or silica; disintegrants, for example potato starch, or acceptable wetting agents such as 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 suspensions, solutions, emulsions, syrups or elixirs, or may be presented as a dry product for reconstitution with water or other suitable vehicle before use. Such liquid preparations may contain conventional additives such as suspending agents, for example sorbitol, syrup, methyl cellulose, glucose syrup, gelatin, hydrogenated edible fats; emulsifying agents, for example lecithin, sorbitan monooleate, or acacia; non-aqueous vehicles (which may include edible oils), for example almond oil, fractionated coconut oil, oily esters such as glycerine, propylene glycol, or ethyl alcohol; preservatives, for example methyl or propyl p-hydroxy- benzoate or sorbic acid, and if desired conventional flavouring or colouring agents. For topical application to the skin the drug may be made up into a cream, lotion or ointment. Cream or ointment formulations that may be used for the drug are conventional formulations well known in the art, for example, as described in standard text books of pharmaceutics and cosmetics, such as 'Harry's Cosmeticology¹ 7th Ed., ed Wilkinson J.B. and Moore R. J., George Goodwin, London, 1982, and the British

Pharmacopoeia. For topical application to the ear, the drug may be made up into a suspension in a suitable liquid carrier, such as water, glycerol, diluted ethanol, propylene glycol, polyethylene glycol or fixed oils. For topical application to the eye, the drug is formulated as a suspension in a suitable, sterile aqueous or non-aqueous vehicle. Additives, for instance buffers such as sodium metabisulphite or disodium edetate; preservatives including bactericidal and fungicidal agents, such as phenylmercuric acetate or nitrate, benzalkonium chloride or chlorhexidine, and thickening agents such as hypromellose may also be included. The dosage employed for compositions administered topically will, of course, depend on the size of the area being treated. For the ears and eyes each dose will typically be in the range from 10 to 100 mg of the drug.

Suppositories will contain conventional suppository bases, e.g. cocoa-butters or other glyceride. For parenteral administration, fluid unit dosage forms are prepared utilizing the drug and a sterile vehicle. The drug, depending on the vehicle and concentration used, can be suspended in the vehicle. Advantageously, adjuvants such as a local anaesthetic, preservative and buffering agents can be dissolved in the vehicle. To enhance the stability the composition can be frozen after filling into the vial and water removed under vacuum. The dry lypophilized powder is then sealed in the vial. The drug can be sterilised by exposure to ethylene oxide before suspending in the sterile vehicle. Advantageously, a surfactant or wetting agent is included in the composition to facilitate uniform distribution of the drug.

Veterinary compositions for intramammary treatment of mammary disorders in animals, especially bovine mastitis, will generally contain a suspension of the drug in an oily vehicle. The compositions may contain from 0.1% to 99% by weight, preferably from 10-60% by weight, of the drug, depending on the method of administration. Where the compositions are in unit dose form, each dosage unit will preferably contain from 50-500 mg, of the drug. The dosage as employed for treating an adult human (of typical weight about 70 kg) will preferably range from 100 mg to 3 g, per day, for instance 250 mg to 2 g of the drug per day, depending on the route and frequency of administration. Alternatively, the drug may be administered to non- human animals as part of the total dietary intake. In this case the amount of drug employed may be less than 1% by weight of the diet and in preferably no more than 0.5% by weight. The diet for animals may consist of normal foodstuffs to which the drug may be added or the drug may be included in a premix for admixture with the foodstuff. A suitable method of administration of the drug to a non-human animal is to add it to the non-human animal's drinking water. In this case a concentration of the drug in the drinking water of about 5-500 μg/ml, for example 5-200 μg/ml, is suitable.

The compounds of this invention are useful for treating bacterial and mycoplasma-induced infections in non-human and human animals, such as the treatment of respiratory tract infections, otitis, meningitis, skin and soft tissue infections in human animals, mastitis in cattle, and respiratory infections in non-human animals such as pigs and cattle. Accordingly in a further aspect, the present invention provides a method for treating a human or non-human animal which method comprises administering an effective amount of a compound of formula (I) as hereinbefore defined, to a human or non-human animal in need of such therapy. Alternatively, a pharmaceutical composition as hereinbefore described may be employed in the treatment.

In particular aspects of the treatment, there are provided methods for treating bacterial infections of human or non-human animals, especially respiratory infections in human or non-human animals. The compounds of this invention are active against both Gram negative and Gram positive organisms, including Haemophilus, for instance H.influenzae Ql; Branhamella,foτ instance B.Catarrhalis 1502; Streptococci, for instance S.pyogenes CN10 and S.pneumonia PU7; and Staphylococci, for instance S.aureus Oxford; Legionella, for instance L. pneumophila. In addition, compounds of this invention are active against Staphylococci organisms such as S. aureus and S. epidermis which are resistant (including multiply-resistant) to other anti-bacterial agents, for instance, β-Iactam antibiotics such as, for example, methicillin; macrolides; aminoglycosides and lincosamides. The compounds of this invention are also active against mycoplasma-induced infections, in particular infections caused by Mycoplasma fermentans, which has been implicated as a co-factor in the pathogenesis of AIDS. Accordingly in a further aspect, the present invention provides a metiiod of treating humans infected with M. fermentans, in particular humans also infected with HIV, which method comprises treating humans in need of such therapy with an anti- mycoplasmal effective amount of a compound of formula (I).

In a further aspect, the present invention provides a compound of formula (I) for use in the manufacture of a medicament for antibacterial and/or antimycoplasmal therapy in human and nonhuman animals. No adverse toxicological effects are expected from the administration of a compound of formula (I).

The following Examples illustrate the invention, but are not intended to limit the scope in any way.

Example 1 - 2-Methoxy-(tlύazol-5-yl)-l-(normon-2-yl) ketone - A solution of 2-methoxythiazole (G. Lein and B. Prijs, Helv Chim Acta, 1954, 37, 2057) (7.27g) in dry THF (100ml) at -78°C and under an argon atmosphere was treated dropwise with 7i-butyl lithium (1.5M, 42ml) in hexane. After 0.75h at -70°C, N-methoxy-N-methyl-6,7,13-0-i - (trimethylsilyl) monamide (15.4g, l.OOmmolXWO 92/02518, Beecham Group pic) in dry THF (160ml) was added dropwise, whilst maintaining the temperature below -65°C (addition time lh). After 1.25h at -70°C, acetic acid (7.7ml) was added. After extraction with diethyl ether, drying (magnesium sulphate) and evaporation, the residue was dissolved in THF (842ml) and treated, in one portion, with hydrochloric acid (0.4M, 210ml). After 2min of rapid stirring, saturated sodium hydrogen carbonate solution (250ml) was rapidly added. The reaction mixture was partioned between ethyl acetate and water, the organic phase separated, washed with brine, dried, (magnesium sulphate) and evaporated to give the crude title compound (21g).

Material from the above process (for example 36g) was subjected to flash chromatography. The material was dissolved in dichloromethane/toluene and applied to dry silica (1kg) under suction and the column then eluted with ether followed by methanol ether mixtures (2%-6%) to give the title compound as an amorphous solid (24g); δjj (CD3OD) 0.94 (3H, d, H 7.1Hz, I7-H3), 1.20 (3H, d, J 6.5Hz, 14-H₃), 1.32-1.46 (IH, m, 12-H), 1.65-1.73 (2H, m, 9-H₂), 1.91-2.01 (IH, m, 8-H), 2.23 (3H, s, 15-H₃), 2.33 (IH, dd, si 14.3 and 9.5Hz, 4-H), 2.68-2.85 (3H, m, 4, 10 and 11-H), 3.39 (IH, dd, si 9.0 and 3.0Hz, 6-H), 3.60 (IH, d, sϊ 11.3Hz, 16-H), 3.74-3.93 (4H, m, 5, 7, 13 and 16-H), 4.13 (3H, s, OCH3), 6.73 (IH, s, 2-H), 7.95 (IH, s, 4'-H); δc (CD3OD) 12.2 (C-17), 20.2 (C-15), 20.3 (C-14), 33.0 (C-9), 41.8 (C-8), 43.7 (C-12), 44.3 (C-4), 56.9 (C-10), 59.8 (C-11), 61.2 (OC_H₃), 66.4 (C-16), 70.0 (C-6), 70.7 (C-7), 71.6 (C-13), 76.4 (C-5), 121.8 (C-2), 137.1 (C-5'), 143.9 (C-4'), 159.8 (C-3), 181.1 (C-2'), 184.6 (C-l).

Amorphous title compound (48g) was dissolved in ethyl acetate (200ml) and the solution cooled initially to 10°C for 5h and then to -10°C for a further 16h. The resulting solid was collected by filtration and dried to give crystalline title compound (40g); mp 115°C; [α]_D (20°C) = -6° (c,l, MeOH); v_max (KBr) 3452, 3301, 1639, 1592, 1484 cm"¹; λ_max (EtOH) 301nm (ε_m 20,710). Example 2 - 2-(2-Methoxyethoxy)thiazol-5-yl-l-(normon-2-yl) ketone - a) 2-(2-Methoxyethoxy)thiazole - Sodium hydride

(12.75mmol, 0.384g) was added to 2-methoxyethanol (13.5mmol, 1.023g) in tetrahydrofuran (1.0ml). After 0.5 hour 2-bromothiazole (lδmmol, 2.457g) was added and the reaction was heated at 40°C for 1.5 hours. The suspension was cooled, diluted with diethylether, filtered, evaporation to dryness under reduced pressure and purification by column chromatography over silica, using diethyl ether/hexane (20%) as eluent gave 2-(2-methoxyethoxy)thiazole (1.171g, 58%) as a yellow oil; δjj (CDCI3) 3.4 (3H, s, -OMe), 3.75 (2H, m, CH₂-OMe), 4.5 (2H, m, Ar OCH₂), 6.7 (IH, d, J 3.7Hz, 4-H), 17.1 (IH, d, J 3.7Hz, 5-H). b) [2-(2-Methoxyethoxy)thiazol-5-yl]-l-(6,7,13-0-tristrimethylsilyl normon-2-yl) ketone - n-Butyllithium (1.6M in hexane) (2.25mmol, 1.5ml) was added dropwise to 2-(2-methoxyethoxy)thiazole in tetrahydrofuran (5ml) at -78°C. After 20mins. at -78°C N-methoxy-N- methvl-6.7.13-Q-tris(trimethvlsilvl) monamide (l.δmmol, 0.905g) in THF (5ml) was added dropwise whilst maintaining the temperature below - 65°C. After a further 1 hour at -78°C acetic acid (0.23g) was added followed by water (20ml). Extraction with diethyl ether, drying (MgS04.), evaporation to dryness under reduced pressure and purification by column chromatography over silica using ethyl acetate/hexane (0-20%) as eluent gave the title compound as a yellow oil (0.263g, 25%); δπ (CDCI3) 0.01-0.2 (27H, m, 9 x SiCH₃), 0.7-0.8 (3H, d, si 7.0Hz, 17-H₃), 1.0-1.1 (3H, d, si 6.3Hz, U-H3), 2.1 (3H, s, 15-H₃), 3.2-3.3 (3H, s, OMe), 4.4-4.5 (2H, m, s∑ 9.0Hz, ArOCH₂), 6.35 (IH, s, 2-H), 7.55 (IH, s, ArH). c) 2-(2-Methoxyethoxy)thiazol-5-yl-l-(noπnon-2-yl) ketone - The above ketone (0.25mmol, 0.173g) and hydrochloric acid (0.4M, 1.2ml) in THF (5ml) were stirred at room temperature for two minutes. Saturated sodium hydrogen carbonate was added, extraction with diethylether, drying (MgSO.4), evaporation to dryness under reduced pressure and purification by column chromatography over silica, using methanol in dichloromethane (0-8%) as eluent gave the title compound (93.2mg, 78%) as a pale yellow foam; v_maγ (KBr) 2883, 2359, 2330, 1729, 1528cm"¹; λma (EtOH) 302nm (ε_m 16,580); δji (CD3OD) 0.9 (3H, d, 7.1Hz, I7-H3), 1.2 (3H, d, 6.4Hz, 14-H₃), 2.72-2.82 (2H, m, 10 and 11-H), 3.4 (3H, s, OMe), 4.55-4.6 (2H, m, ArOCH₂), 6.72 (IH, s, 2-H), 7.9 (2H, s, ArH); m/z (E.I.) 485 (M⁺, 20%), 59 (100%); (Found: M⁺ 485.2090, C23H35 O8S requires M 485.2083). Example 3 - 2-(2-Isopropoxyethoxy)thiazol-5-yl-l-(normon-2-yl) ketone - a) 2-(2-Isopropoxyethoxy)thiazole - Sodium hydride

(12.75mmol, 0.384g), was added to 2-isopropoxyethanol (13.5mmol, 1.6ml) in tetrahydrofuran (2.0ml) at 40°C. After 0.5 hours 2-bromothiazole (lδmmol, 1.35ml) was added and the reaction was heated at 40°C for 3 hours followed by 1 hour at 80°C. The suspension was cooled, diluted with diethyl ether, filtered, evaporated to dryness under reduced pressure and purification by column chromatography over silica, using diethyl ether/hexane (10%) as eluent gave 2-(2-isopropoxyethoxy)thiazole (0.644g, 27%) as an oil; δπ (CDCI3), 1.2 (6H, d, 2 x CH3), 3.65 (IH, m, CH-OCH₂), 3.8 (2H, m, CH-OCH2), 4.5 (2H, m, ArOCH₂), 6.6 (IH, d, 3.88Hz, 5-H), 7.1 (IH, d, J 3.88Hz, 4-H). b) [2-(2-Isopropoxyethoxy)thiazol-5-yl]-l-(6,7,13-0- trlstrimethylsilyl noπnon-1-yl) ketone - n-Butyllithium (1.6M in hexane) (3mmol, 1.88ml) was added dropwise to 2(2- isopropoxyethoxy)thiazole in tetrahydrofuran (7ml) at -78°C. After 35 minutes at -78°C N-methoxy-N-methyl-6,7,13-0- ϊris(trimethylsilyl)monamide (2mmol, 1.205g) in THF (10ml) was added dropwise whilst maintaining the temperature below -65°C. After a further 1.5 hours at -78°C glacial acetic acid (δmmol, 0.3ml) was added followed by water (lδml). Extraction with diethyl ether, drying (MgS04), evaporation to dryness under reduced pressure and purification by column chromatography over silica using ethyl acetate/hexane (0-20%) as eluent gave the title compound as a yellow oil (0.3122g, 21%); δg[ (CD3OD) 0.1- 5 0.2 (27H, m, 9 x SiCH₃), 0.9 (3H, d, 17-H₃), 1.15 (6H, d, 2 x CH3), 1.2 (3H, d, M-H3), 2.2 (3H, s, I5-H3), 3.8 (2H, m, CH₂OCH), 4.δδ (2H, m, ArOCH₂), 6.7 (IH, s, 2-H), 7.9 (IH, s, ArH). c) 2-(2-Isopropoxyethoxy)thiazol-5-yl-l-(normon-2-yl) ketone - The above ketone (0.425mmol, 0.310g) and hydrochloric acid (0.4M, 2.13ml) in

10 THF (δ.δml) were stirred at room temperature for two minutes. Saturated sodium hydrogen carbonate was added, extraction with diethyl ether, drying (MgS04), evaporation to dryness under reduced pressure and purification by column chromatography over silica, using methanol in dichloromethane (0-7%) as eluent gave the title compound (177mg, 81%) lδ as a foam; υ_max 2926, 2324, 1776, 1379, 806cm"¹; λ_max (EtOH) 301nm (ε_m 19,539); δ_H (CD3OD) 0.95 (3H, d, J 7.12Hz, 17-H₃), 1.15 (6H, d, J 6.44Hz, 2 x CH3), 2.75-2.8δ (2H, m, 10 and 11-H), 4.δδ (2H, m, ArOCH₂), 6.7 (IH, s, 2-H), 17.9δ (IH, s, ArH); m z (E.I.) δl3 (M⁺, 45%), 45 (100%); (found: M⁺ 513.2391, C25H39NO8S requires M 513.239δ). 0 Example 4 - 2-(7,7,7- ι (methylthio)heptoxy)-thiazol-5-yl-l- normon-2-yl ketone - a) 2-(7,7,7-trismethylthioheptoxy)-thiazole - 3,4-Dihydro-2H-pyran (33.1mmol, 3.02ml) was added to 6-bromohexanol (27.6δmmol, 5g) in 80ml diethyl ether. After 1.5 hours at room temperature a further portion of 3,4-dihydro-2H-pyran (33.1mmol, 3.02ml) 5 was added and stirred for 2.5 hours. Saturated sodium hydrogen carbonate solution (100ml) was added, extraction with diethyl ether, drying (M Sθ4), evaporation to dryness under reduced pressure and purification by column chromatography over silica using dichloromethane/hexane (70-100%) as eluent gave 2-6- 0 Bromohexyloxytetrahydropyran as a colourless oil (6.459g, 88%); δjj

(CDCI3) 1.5-1.75 (8H, m, 4 x CH₂), 3.4-3.6 (4H, m, CH₂Br and CH₂0), 4.5 (IH, t, OCHO). n-Butyllithium (1.6M in hexane) (29.24mmol, 19.5ml) was added dropwise to tris(methylthio)methane (24.37mmol, 3.24ml) in tetrahydrofuran (80ml) at -78°C. After 1.5 hours the above compound 5 (24.37mmol, 6.459g) in THF (20ml) was added and stirred for 1 hour at - 6δ°C. Saturated ammonium chloride solution (30ml) was added, extraction with diethyl ether, drying (MgSθ4), evaporation to dryness under reduced pressure and purification by column chromatography over silica using methanol/dichloromethane (0-20%) as eluent gave 7,7,7- trismethylthio-l-tetrahydropyran-2-yloxyheptane as a colourless oil (7.1124g, 86%); δji (CDCI3) 2.1 (9H, s, 3 x SCH3), 3.35-3.5 (2H, m, OCH₂), 3.7-3.9 (2H, m, cyclic OCH2), 4.55 (IH, t, 0-CH-O). Amberlyst-15(0.3g) 5 was added to the above compound (20.98mmol, 7.11g) in methanol (lδOml). After 4 hours filtered, evaporated to dryness under reduced pressure and purification by column chromatography over silica using diethyl ether hexane (4%) as eluent gave 7,7,7-trismethylthio-heptanol as a colourless oil (3.73g, 70%); 1.2-1.9 (10H, m, δ x CH₂), 2.1 (9H, s, 3 x 0 SCH3), 3.6 (2H, t, OCH₂). Sodium hydride (1.89mmol, 0.057g) was added to the above compound (2mm ol, 0.508g) in THF (3ml). After 0.5 hours 2- bromothiazole (2.2mmol, 0.2ml) was added and the reaction heated at 40°C for 4 hours. Cooled, dilution with diethyl ether, filtered, evaporated to dryness under reduced pressure and purification by column 5 chromatography over silica, using diethyl ether/hexane (0-10%) as eluent gave the title compound (0.232g, 34%); δ^~j (CDCI3) 1.3-1.9 (10H, m, 5 x CH₂), 2.1 (9H, s, 3 x SCH3), 4.4 (2H, t, OCH₂), 6.6 (IH, d, 5-H), 7.1 (IH, d, 4-H). b) [2-(7,7,7-fris-(methylthio)heptoxy)-thiazol-5-yl]-l-(6,7,13-0- 0 tristrlmethylsilyl normon-2-yl) ketone - n-Butyllithium (1.6M in hexane) (2m ol, 1.25ml) was added dropwise to 2-(7,7,7- trismethylthioheptoxy)thiazole (2mmol, 0.674g) in THF (6ml) at -78°C. After 40 minutes N-methoxy-N-methyl-6,7,13-0-£ris(trimethylsilyl) monamide (2mmol, 1.206g) in THF (10ml) was added dropwise. After 2 δ hours and warming to -50°C glacial acetic acid (4mm ol, 0.2ml) was added followed by water (10ml). Extraction with diethyl ether, drying (MgS04), evaporation to dryness under reduced pressure and purification by column chromatography over silica using ethyl acetate/hexane (0-20%) as eluent gave the title compound (0.442g, 2δ%); δ^~ι (CDCI3) 0.1-0.2 (27H, m, 9 x 0 SiCH₃). 0.9 (3H, d, 17-H₃), 1.2 (3H, d, 14-H₃), 1.3-1.9 (10H, m, 5 x CH₂), 2.05 (9H, s, 3 x CH3), 2.2 (3H, s, I5-H3), 2.6 (2H, m, 10 and 11-H), 3.3δ (IH, dd, 6-H), 4.4 (2H, t OCH₂), 6.δ (IH, s, 2-H), 7.7 (IH, s, Ar-H). c) 2-(7,7,7-/Hs-(metIιylthio)heptoxy)-thiazol-5-yl-l-normon-2-yl ketone - The above ketone (O.δmmol, 0.439g) and hydrochloric acid (0.4M, δ 2.δml) in THF (10ml) were stirred at room temperature for two minutes. Saturated sodium hydrogen carbonate was added, extraction with ethyl acetate, drying (MgS04), evaporation to dryness under reduced pressure and purification by column chromatography over silica using methanol/dichloromethane (0-7%) as eluent gave the title compound as a colourless oil (0.310g, 93%); )^^ (KBr) 2328, 1734, 1527, 1297, 838, 569cm"¹; λ_max (EtOH) 302nm (ε_m 17,227); δπ (CD₃OD) 0.9 (3H, d, J 7.1Hz, I7-H3), 1.2 (3H, d, J 6.6Hz, 14-H₃), 2.1 (9H, s, 3 x SCH3), 2.25- δ 2.3δ (2H, m, 4-H₂), 2.6δ-2.8 (2H, m, 10 and 11-H), 3.4 (IH, dd, 6-H), 3.δδ (IH, d, 16"-H), 3.7δ-3.9 (4H, m, δ,7,13, 6-H), 4.45 (2H, t, OCH₂), 6.7 (IH, s, 2-H), 7.9 (IH, s, Ar-H).

Example 5 - 2-(6-methoxycarbonylhexoxy)-thiazol-5-yl-l-no_raιon-2- yl ketone - Mercury II oxide (3.38mmol, 0.072g) and Mercury II chloride

10 (l.Olmmol, 0.27g) were added to the ketone in example 5c (0.338mmol, 0.224g) in methanol (6.3ml) at -40°C. After 5δ minutes filtered through celite, washed with saturated ammonium chloride solution (10ml), extracted with dichloromethane (12ml), dried (MgSθ4), evaporated under reduced pressure and purification by column chromatography over silica lδ using methanol/diethyl ether (0-4%) as eluent gave the title compound (0.113g, 60%); v_max (KBr) 1646, 1479, 12δ8, 1187, lOδδcm"¹; l_mSLX (EtOH) 302 (ε_m 20,224,); δji (CD3OD) 0.9δ (3H, d, 17-H₃), 1.2 (3H, d, 14- H3), 2.2 (3H, s, lδ-H₃), 2.2δ-2.4 (3H, m, CH₂C0 and 4-H), 2.7-2.8δ (3H, m, 4,10 and 11-H), 3.4 (IH, dd, 6-H), 3.δδ (IH, d, 16"-H), 3.6 (3H, s,

20 CO2CH3), 3.7δ-3.9 (4H, m, δ,7,13 and 16-H), 4.4δ (2H, t, OCH₂), 6.7 (IH, s, 2-H), 7.9 (IH, s, Ar-H); m/z (E.I.) δ69 £M⁺, δ0%), 83 (100%); (found: M⁺ 569.2667, C28H43NO9S requires M 569.2659). Example 6 - Sodium 2-(6-carboxylatohexoxy)-thiazol-5-yl-l- normon-2-yl ketone - Protease subtilisin Carlsberg (20mg) was added to

25 the ketone in the previous example (0.069mmol, 39mg) in water (5ml) maintained at pH 6.5 over 24 hours by the slow addition of sodium hydroxide solution (0.01M). Reaction mixture was freeze-dried, taken up in ethanol, filtered through celite and evaporated under reduced pressure to give the title compound (42mg, 100%); υ_max (KBr) 2925, 1644, 145δ,

30 1261, lOδScm"¹; λ_maγ (EtOH) 303 (ε_m 13,512); δπ 0.85 (3H, d, 17-H ), 1.1 (3H, d, 14-H3), 1.2-1.6 (9H, m, 4 x CH₂ and 12-H), 1.7 (2H, m, 9-H₂), 1.9 (IH, m, 8-H), 2.05 (2H, t, CH₂C0₂), 2.15 (3H, s, 15-H₃), 2.2 (IH, dd, 4- H), 2.6 (3H, m, 4", 10 and 11-H), 3.2δ (IH, dd, 6-H), 3.4δ (IH, m, 16"-H), 3.6δ-3.8δ (4H, m, δ,7,13 and 16-H), 4.3 (2H, t, OCH₂), 6.6 (IH, s, 2-H),

3δ 17.8 (IH, s, Ar-H); m z (FAB) 578 (MH+13%).

Biological Data

The activity of the exemplified compounds against H. influenzαe Ql, B. catarrhalis 1502, S. pyogenes CN10, S. pneumoniae PU7 and S. aureus Oxford was assayed in vitro using serial dilutions in nutrient agar with δ% chocolated horse blood. The MIC's were determined after incubation for 18h at 37°C and values in the range 0.06 to 4 mg/ml"¹ were observed, δ In addition, the antibacterial activity of the compound of Example 1 against the Legionella organism, L.pneumophila 1624, serogroup 1, was assayed in the following manner:

Culture was thawed from frozen skim milk stocks and streaked onto supplemented buffered charcoal yeast extract agar (BCYEα, Oxoid).

10 Three days later, colonies were suspended in tissue culture mediu

(TCM=Eagle's Minimal Essential Midium + Earles' salts supplemented with 10% foetal calf serum, 2mM L-glutamine and 1% non-essential amino acids) to MacFarland's barium sulphate opacity standard O.δ. The suspension was further diluted 1:100 in TCM to yield a final inoculum of lδ 4.83 x lθ6 cfu ml. Human foetal lung fibroblast (MRC-δ) cells were then inoculated. Thes cells had been previously grown to 80% confluency in 6- well plates, the medium removed and the monolayers washed twice with Dulbecco's PBS. Sixteen hours after inoculation(time 0 h), the medium was removed and the inoculated monolayers washed twice to remove any

20 adherent, non-intracellular, organisms. Test compound, prepared to the required concentrations in TCM, was added to the cells. The compound of Example 1 was tested at O.δ, 2 and 8μg/ml whilst erythromycin at O.δ and 2μg ml was used as a control. At 0, 3, 12, 24, 36, 48 and 72h after the dose, the medium was removed from one well/treatment, and the

2δ monolayers washed twice. Sterile distilled water was added and left for 30 min to lyse the cells. After vigorous trituration, the lysate was serially diluted in Mueller Hinton brother and plated onto BYCEα and δ% horse blood agars. Colonies of L.pneumophila were counted after 72h incubation at 37°C. Positive antibacterial activity against L. 0 pneumophlia was observed.

In addition and by way of confirmation, the stability of the compounds in TCM was examined over a 72h period. Solutions of 2 μg/ml of each of the compounds were prepared in TCM and incubated at 37°C or 4°C and aliquots were removed at intervals. The compund of Example 1 and δ erythromycin were assayed against Bacillus subtilis ATCC 6633 and Sarcina lutea NCTC 8340, respectively, using standards prepared in TCM.

Claims

Claims

1. A compound of formula (I):

δ in which R¹ is 2-(optionally substituted (Cι.ιo)^alkoxy)-thiazol-5-yl group.

2. A compound as claimed in claim 1 in which the (Cι_ιø)alkoxy group in R¹ is methoxy, ethoxy or hexoxy.

10 3. A compound of formula (I) which is:

2-methoxy-(thiazol-5-yl)- l-(normon-2-yl) ketone;

2-(2-methoxyethoxy)thiazol-δ-yl-l-(normon-2-yl) ketone;

2-(2-ϊsσ-propoxyethoxy)thiazol-δ-yl- l-(normon-2-yl) ketone;

2-(7,7,7-trϊs-(methylthio)heptoxy)-thiazol-δ-yl-l-normon-2-yl ketone; lδ 2-(6-methoxycarbonylhexoxy)-thiazol-δ-yl- l-normon-2-yl_ketone;

2-(6-carboxyhexoxy)-thiazol-δ-yl-l-normon-2-yl ketone or the sodium salt thereof.

4. A pharmaceutical or veterinary composition which comprises a 20 compoimd of formula (I) as defined in any one of claims 1 to 3 together with a pharmaceutically or veterinarily acceptable carrier or excipient.

6. A compound of formula (I) as defined in any one of claims 1 to 3 for use in therapy. 2δ

6. The use of a compound of formula (I) as defined in any one of claims 1 to 3for the manufacture of a medicament for use in anti-bacterial therapy.

7. The use of a compound of formula (I) as defined in any one of claims 1 0 to 3 for the manufacture of a medicament for use in anti-mycoplasmal therapy.

8. A process for preparing a compound of formula (I) as defined in any one of claims 1 to 3 which process comprises: i) treating an acid of formula (HI):

in which Z¹, Z² and Z^ are tiie same or different and each is hydrogen or a hydroxyl-protecting group, or an activated derivative thereof, with an organometallic reagent;

(ϋ) treating an allylic alcohol of formula (IX):

in which R¹ is as defined in claim 1 and Z¹, Z² and Z^ are as hereinbefore defined, with an oxidising agent which converts allylic alcohols into α,β- unsaturated ketones; (iii) treating a ketone of formula (XD:

in which Z¹, Z² and Z^ are as hereinbefore defined, with a terminal alkyne of the formula (XH):

HC^C-R¹ (XH) in which R¹ is as hereinbefore defined, to form an intermediate which is treated with £ris-(triphenylsilyloxy)-vanadate and triphenylsilanol; and and thereafter, and if necessary, removing any hydroxyl-protecting groups.