WO2008096128A1

WO2008096128A1 - Oxazole and thiazole derivatives and their uses 2

Info

Publication number: WO2008096128A1
Application number: PCT/GB2008/000406
Authority: WO
Inventors: Harry Finch; Nicholas Charles Ray; Richard James Bull; Jose Antonio Bravo; Barbara Giuseppina Avitabile
Original assignee: Argenta Discovery Ltd
Priority date: 2007-02-07
Filing date: 2008-02-06
Publication date: 2008-08-14
Also published as: GB0702414D0

Abstract

Compounds of formula (I): wherein A, X, R1, R2, R3, R4, R5, R6 and R8 are as defined in the Specification are useful in the treatment of diseases where enhanced M3 receptor activation is implicated, such as respiratory tract diseases.

Description

Oxazole and Thiazole Derivatives and Their Uses 2

Field of the Invention

This invention relates to oxazole and thiazole derivatives, pharmaceutical compositions, methods for their preparation and use in the treatment of diseases where enhanced M3 receptor activation is implicated.

Background to the invention

Anti-cholinergic agents prevent the passage of, or effects resulting from the passage of, impulses through the parasympathetic nerves. This is a consequence of the ability of such compounds to inhibit the action of acetylcholine (ACh) by blocking its binding to the muscarinic cholinergic receptors.

There are five subtypes of muscarinic acetylcholine receptors (mAChRs), termed M1 -M5, and each is the product of a distinct gene and each displays unique pharmacological properties. mAChRs are widely distributed in vertebrate organs, and these receptors can mediate both inhibitory and excitatory actions. For example, in smooth muscle found in the airways, bladder and gastrointestinal tract, M3 mAChRs mediate contractile responses (reviewed by Caulfield, 1993, Pharmac. Then, 58, 319 - 379).

In the lungs, muscarinic receptors M1 , M2 and M3 have been demonstrated to be important and are localized to the trachea, the bronchi, submucosal glands and parasympathetic ganglia (reviewed in Fryer and Jacoby, 1998, Am J Resp Crit Care Med., 158 (5 part 3) S 154 - 160). M3 receptors on airway smooth muscle mediate contraction and therefore bronchoconstriction. Stimulation of M3 receptors localised to submucosal glands results in mucus secretion.

Increased signalling through muscarinic acetylcholine receptors has been noted in a variety of different pathophysiological states including asthma and COPD. In COPD, vagal tone may either be increased (Gross et al. 1989, Chest; 96:984-987) and/or may provoke a higher degree of obstruction for geometric reasons if applied on top of oedematous or mucus-laden airway walls (Gross etal. 1984, Am Rev Respir Dis; 129:856-870). In addition, inflammatory conditions can lead to a loss of inhibitory M2 receptor activity which results in increased levels of acetylcholine release following vagal nerve stimulation (Fryer et al, 1999, Life Sci., 64, (6-7) 449-455). The resultant increased activation of M3 receptors leads to enhanced airway obstruction. Thus the identification of potent muscarinic receptor antagonists would be useful for the therapeutic treatment of those disease states where enhanced M3 receptor activity is implicated. Indeed, contemporary treatment strategies currently support regular use of M3 antagonist bronchodilators as first-line therapy for COPD patients (Pauwels et al. 2001 , Am Rev Respir Crit Care Med; 163:1256-1276)

Incontinence due to bladder hypercontractility has also been demonstrated to be mediated through increased stimulation of M3 mAChRs. Thus M3 mAChR antagonists may be useful as therapeutics in these mAChR-mediated diseases.

Despite the large body of evidence supporting the use of anti-muscarinic receptor therapy for treatment of airway disease states, relatively few anti-muscarinic compounds are in use in the clinic for pulmonary indications. Thus, there remains a need for novel compounds that are capable of causing blockade at M3 muscarinic receptors, especially those compounds with a long duration of action, enabling a once-daily dosing regimen. Since muscarinic receptors are widely distributed throughout the body, the ability to deliver anticholinergic drugs directly to the respiratory tract is advantageous as it allows lower doses of the drug to be administered. The design and use of topically active drugs with a long duration of action and that are retained on the receptor or in the lung would allow reduction of unwanted side effects that could be seen with systemic administration of the same drugs.

Tiotropium (Spiriva ™) is a long-acting muscarinic antagonist currently marketed for the treatment of chronic obstructive pulmonary disease, administered by the inhaled route.

Additionally ipratropium is a muscarinic antagonist marketed for the treatment of COPD.

Ipratropium

Chem. Pharm. Bull. 27(12) 3149-3152 (1979) and J. Pharm. Sci 69 (5) 534-537

(1980) describe furyl derivatives as possessing atropine-like activities.

Med. Chem. Res 10 (9), 615-633 (2001 ) describes isoxazoles and Δ²-isoxazolines as muscarinic antagonists.

WO97/30994 describes oxadiazoles and thiadiazoles as muscarinic receptor antagonists.

EP0323864 describes oxadiazoles linked to a mono- or bicyclic ring as muscarinic receptor modulators.

Summary of the Invention

According to the invention, there is provided a compound of formula (I):

wherein

(i) R¹ is C_rC₆-alkyl or hydrogen; and R² is a group, -Z-Y-W-R⁷; and R³ is a lone pair or C_rC₆-alkyl; or (ii) R¹ and R³ together with the nitrogen to which they are attached form a heterocycloalkyl ring, and R² is a group -Z-Y-W-R⁷; or

(iii) R¹ and R² together with the nitrogen to which they are attached form a heterocycloalkyl ring, said ring being substituted by a group -Y-W-R⁷ or -Z-Y-W-R⁷; and R³ is a lone pair or C_rC₆-alkyl;

R⁴ and R⁵ are independently selected from the group consisting of aryl, aryl-fused- heterocycloalkyl, heteroaryl, C_rC₆-alkyl and cycloalkyl;

R⁶ is OH, CrCe-alkyl, CrC₆-alkoxy, hydroxy-C_rC₆-alkyl, nitrile, a group CONR⁹R¹⁰ or a hydrogen atom;

A is an oxygen or a sulfur atom;

X is a CrC₈-alkylene, C₂-C₈-alkenylene or C₂-C₈-alkynylene group;

W is a direct bond or a CrC₈-alkylene, C₂-C₈-alkenylene or C₂-C₈-alkynylene group;

R⁷ is an CrCe-alkyl, aryl, aryl-fused-cycloalkyl, aryl-fused-heterocycloalkyl, heteroaryl, cycloalkyl or heterocycloalkyl group;

R⁸, R⁹, R¹⁰ and R¹¹ are each independently selected from CrC₆-alkyl or a hydrogen atom;

Z is a CrC₁₆-alkylene, C₂-C₁₆-alkenylene or C₂-C₁₆-alkynylene group; and

Y is -S-, -SO-, -SO₂-, -CO2-, -OC(=O)-, -N(R¹¹)SO₂- or -SO₂N(R¹¹)-;

or a pharmaceutically acceptable salt thereof;

wherein, unless otherwise specified, each occurrence of alkyl, heterocycloalkyl, aryl, aryl-fused-heterocycloalkyl, heteroaryl, cycloalkyl, alkoxy, alkylene, alkenylene, alkynylene or aryl-fused-cycloalkyl may, independently, be optionally substituted; and wherein each alkenylene chain contains, where possible, up to 3 carbon-carbon double bonds and each alkynylene chain contains, where possible, up to 3 carbon-carbon triple bonds.

In one aspect the present invention provides a prodrug of a compound of formula (I) as herein defined, or a pharmaceutically acceptable salt thereof.

In another aspect the present invention provides an N-oxide of a compound of formula (I) as herein defined, or a prodrug or pharmaceutically acceptable salt thereof.

In a further aspect the present invention provides a solvate (such as a hydrate) of a compound of formula (I) as herein defined, or an N-oxide, prodrug or pharmaceutically acceptable salt thereof.

It will be appreciated that the carbon atom to which R⁴, R⁵ and R⁶ are attached can be an asymmetric centre so compounds of the invention may be in the form of single enantiomers or mixtures of enantiomers.

A particular class of compounds of the invention consists of quaternary ammonium salts of formula (I) wherein the aliphatic nitrogen shown in formula (I) is a quaternary nitrogen carrying a positive charge.

Compounds of the invention may be useful in the treatment or prevention of diseases in which activation of muscarinic receptors are implicated, for example the present compounds are useful for treating a variety of indications, including but not limited to respiratory-tract disorders such as chronic obstructive lung disease, chronic bronchitis of all types (including dyspnoea associated therewith), asthma (allergic and non- allergic; 'wheezy-infant syndrome'), adult/acute respiratory distress syndrome (ARDS), chronic respiratory obstruction, bronchial hyperactivity, pulmonary fibrosis, pulmonary emphysema, and allergic rhinitis, exacerbation of airway hyperreactivity consequent to other drug therapy, particularly other inhaled drug therapy, pneumoconiosis (for example aluminosis, anthracosis, asbestosis, chalicosis, ptilosis, siderosis, silicosis, tabacosis and byssinosis); gastrointestinal-tract disorders such as irritable bowel syndrome, spasmodic colitis, gastroduodenal ulcers, gastrointestinal convulsions or hyperanakinesia, diverticulitis, pain accompanying spasms of gastrointestinal smooth musculature; urinary-tract disorders accompanying micturition disorders including neurogenic pollakisuria, neurogenic bladder, nocturnal enuresis, psychosomatic bladder, incontinence associated with bladder spasms or chronic cystitis, urinary urgency or pollakiuria; motion sickness; and cardiovascular disorders such as vagally induced sinus bradycardia.

For treatment of respiratory conditions, administration by inhalation will often be preferred, and in such cases administration of compounds (I) which are quaternary ammonium salts will often be preferred. In many cases, the duration of action of quaternary ammonium salts of the invention administered by inhalation may be more than 12, or more than 24 hours for a typical dose. For treatment of gastrointestinal- tract disorders and cardiovascular disorders, administration by the parenteral route, usually the oral route, may be preferred.

Another aspect of the invention is a pharmaceutical composition comprising a compound of the invention and a pharmaceutically acceptable carrier or excipient.

Another aspect of the invention is the use of a compound of the invention for the manufacture of a medicament for the treatment or prevention of a disease or condition in which muscarinic M3 receptor activity is implicated. Diseases or conditions in which muscarinic M3 receptor activity is implicated include respiratory- tract disorders, gastrointestinal-tract disorders and cardiovascular disorders. Specific examples of such diseases and conditions include those listed above.

Another aspect of the invention provides a compound of the invention for the treatment or prevention of a disease or condition in which muscarinic M3 receptor activity is implicated. Diseases or conditions in which muscarinic M3 receptor activity is implicated include respiratory-tract disorders, gastrointestinal-tract disorders and cardiovascular disorders. Specific examples of such diseases and conditions include those listed above.

Another aspect of the invention provides a method of treatment of a disease or condition in which M3 muscarinic receptor activity is implicated comprising administration to a subject in need thereof a therapeutically effective amount of a compound of the invention. Diseases or conditions in which muscarinic M3 receptor activity is implicated include respiratory-tract disorders, gastrointestinal-tract disorders and cardiovascular disorders. Specific examples of such diseases and conditions include those listed above.

Another aspect of the invention provides a compound of the invention for use in therapy.

Description of Definitions

Unless otherwise qualified in the context in which they are used, the following terms have the following meanings when used herein:

"Alkoxy" means an -O-alkyl group in which alkyl is as described below. Exemplary alkoxy groups include methoxy (-OCH₃) and ethoxy (-OC₂H₅). "Alkyl" as a group or part of a group refers to a straight or branched chain saturated hydrocarbon group having from 1 to 16, such as from 1 to 8, particularly from 1 to 6, carbon atoms, in the chain. Exemplary alkyl groups include methyl, ethyl, 1 -propyl and 2-propyl.

"Alkylene" means a straight or branched chain saturated bivalent radical having from 1 to 16, such as from 1 to 8, particularly from 1 to 6, carbon atoms, in the chain and derived by removal of a H atom from an alkyl group where alkyl is as defined previously. Exemplary alkylene groups include -CH₂-, -(CH₂)₂- and -C(CH₃)HCH₂-.

"Alkenylene" means an alkylene group having from 2 to 16, such as from 2 to 8, particularly from 2 to 6, carbon atoms, in the chain which further comprises up to 3 carbon-carbon double bonds in the chain . Exemplary alkenylene groups include - CH=CH-, -CH=CHCH₂-, and -CH₂CH=CH-.

"Alkynylene" means an alkylene group having from 2 to 16, such as from 2 to 8, particularly from 2 to 6, carbon atoms, in the chain which further comprises up to 3 carbon-carbon triple bonds in the chain. Exemplary alkynylene groups include ethynyl and propargyl.

"Aryl" as a group or part of a group denotes an optionally substituted monocyclic or multicyclic aromatic carbocyclic moiety of from 6 to 14 carbon atoms, preferably from 6 to 10 carbon atoms, such as phenyl or naphthyl. Phenyl is a specifically preferred aryl group. The aryl group, specifically a phenyl group, may be substituted by one or more substituent groups.

"Aryl-fused-cycloalkyl" means a monocyclic aryl ring, such as phenyl, fused to a cycloalkyl group, in which the aryl and cycloalkyl are as described herein. Exemplary aryl- fused-cycloalkyl groups include tetrahydronaphthyl and indanyl. The aryl and cycloalkyl rings may each be substituted by one or more substituent groups. The aryl-fused- cycloalkyl group may be attached to the remainder of the compound by any available carbon atom. "Aryl-fused-heterocycloalkyl" means a monocyclic aryl ring, such as phenyl, fused to a heterocycloalkyl group, in which the aryl and heterocycloalkyl are as described herein. Exemplary aryl-fused-heterocycloalkyl groups include tetrahydroquinolinyl, indolinyl, benzodioxinyl, benxodioxolyl, dihydrobenzofuranyl and isoindolonyl. The aryl and heterocycloalkyl rings may each be substituted by one or more substituent groups. The aryl-fused-heterocycloalkyl group may be attached to the remainder of the compound by any available carbon or nitrogen atom.

"Cycloalkyl" means an optionally substituted saturated monocyclic or bicyclic ring system of from 3 to 12 carbon atoms, such as from 3 to 8 carbon atoms, and particularly from 3 to 6 carbon atoms. Exemplary monocyclic cycloalkyl rings include cyclopropyl, cyclopentyl, cyclohexyl and cycloheptyl. The cycloalkyl group may be substituted by one or more substituent groups.

"Heteroaryl" as a group or part of a group denotes an optionally substituted aromatic monocyclic or multicyclic organic moiety of from 5 to 14 ring atoms, preferably from 5 to 10 ring atoms, in which one or more of the ring atoms is/are element(s) other than carbon, for example nitrogen, oxygen or sulfur. Examples of such groups include benzimidazolyl, benzoxazolyl, benzothiazolyl, benzofuranyl, benzothienyl, furyl, imidazolyl, indolyl, indolizinyl, isoxazolyl, isoquinolinyl, isothiazolyl, oxazolyl, oxadiazolyl, pyrazinyl, pyridazinyl, pyrazolyl, pyridyl, pyrimidinyl, pyrrolyl, quinazolinyl, quinolinyl, tetrazolyl, 1 ,3,4-thiadiazolyl, thiazolyl, thienyl and triazolyl groups. The heteroaryl group may be substituted by one or more substituent groups. The heteroaryl group may be attached to the remainder of the compound of the invention by any available carbon or nitrogen atom.

"Heterocycloalkyl" means an optionally substituted cycloalkyl group of from 4 to

8 ring members which contains one or more heteroatoms selected from O, S or NR and optionally further incorporating one or more carbonyl groups. Examples include tetrahydrofuran, thiolane 1 ,1 -dioxide, tetrahydropyran, 4-oxo-4H-pyran, pyrrolidine, pyrroline, imidazolidine, 1 ,3-dioxolane, succinimidyl, piperidine, piperazine, morpholine, perhydroazepine, pyrrolidone and piperidone. The heterocycloalkyl group may be substituted by one or more substituent groups. The heterocycloalkyl group may be attached to the remainder of the compound by any available carbon or nitrogen atom.

A substituent designation R in any of the above definitions means hydrogen, or alkyl, aryl, or heteroaryl as described herein.

"Pharmaceutically acceptable salt" means a physiologically or toxicologically tolerable salt and includes, when appropriate, pharmaceutically acceptable base addition salts, pharmaceutically acceptable acid addition salts, and pharmaceutically acceptable quaternary ammonium salts. For example (i) where a compound of the invention contains one or more acidic groups, for example carboxy groups, pharmaceutically acceptable base addition salts that may be formed include sodium, potassium, calcium, magnesium and ammonium salts, or salts with organic amines, such as, diethylamine, Λ/-methyl-glucamine, diethanolamine or amino acids (e.g. lysine) and the like; (ii) where a compound of the invention contains a basic group, such as an amino group, pharmaceutically acceptable acid addition salts that may be formed include hydrochlorides, hydrobromides, sulfates, phosphates, acetates, citrates, lactates, tartrates, mesylates, napadisylates (naphthalene-1 ,5-disulfonates or naphthalene-1 -(sulfonic acid)-5-sulfonates), edisylates (ethane-1 ,2-disulfonates or ethane-1 -(sulfonic acid)-2-sulfonates), maleates, fumarates, succinates and the like; (iii) where a compound contains a quaternary ammonium group acceptable counter- ions may be, for example, chlorides, bromides, sulfates, methanesulfonates, benzenesulfonates, toluenesulfonates (tosylates), napadisylates (naphthalene-1 ,5- disulfonates or naphthalene-1 -(sulfonic acid)-5-sulfonates), edisylates (ethane-1 ,2- disulfonates or ethane-1 -(sulfonic acid)-2-sulfonates), isethionates (2- hydroxyethylsulfonates), phosphates, acetates, citrates, lactates, tartrates, mesylates, maleates, malates, fumarates, succinates, xinafoates, p-acetamidobenzoates and the like; wherein the number of quaternary ammonium species balances the pharmaceutically acceptable salt such that the compound of formula (I) has no net charge.

It will be understood that, as used herein, references to the compounds of the invention are meant to also include the pharmaceutically acceptable salts.

"Prodrug" refers to a compound which is convertible in vivo by metabolic means (e.g. by hydrolysis, reduction or oxidation) to a compound of the invention. Suitable groups for forming pro-drugs are described in 'The Practice of Medicinal Chemistry, 2^nd Ed. pp561-585 (2003) and in F. J. Leinweber, Drug Metab. Res. , 18, 379. (1987). It will be understood that, as used in herein, references to the compounds of the invention are meant to also include the prodrug forms.

"Saturated" pertains to compounds and/or groups which do not have any carbon-carbon double bonds or carbon-carbon triple bonds.

The cyclic groups referred to above, namely, aryl, heteroaryl, cycloalkyl, aryl- fused-cycloalkyl, heteroaryl-fused-cycloalkyl, heterocycloalkyl, aryl-fused- heterocycloalkyl, heteroaryl-fused-heterocycloalkyl and cyclic amine may be substituted by one or more substituent groups. Examples of specific optional substituents include chloro, fluoro, methyl, hydroxy, methoxy, cyano, -NHC(O)CH₃, -C(O)NH₂ and -S(O)₂NH₂.

More generally, suitable optional substituent groups in such cyclic groups include acyl (e.g. -COCH₃), alkoxy (e.g., -OCH₃ or -OCH₂CH₃), alkoxycarbonyl (e.g.

-COOCH₃ Or -COOCH₂CH₃), alkylamino (e.g. -NHCH₃ Or -NHCH₂CH₃), alkylsulfinyl (e.g. -SOCH₃ Or -SOCH₂CH₃), alkylsulfonyl (e.g. -SO₂CH₃ Or -SO₂CH₂CH₃), alkylthio (e.g. -SCH₃ Or -SCH₂CH₃), -NH₂, aminoalkyl (e.g. -CH₂NH₂ Or -CH₂CH₂NH₂), cyano, dialkylamino (e.g. -N(CH₃J₂ or -N(CH₂CH₃J₂ Or-N(CH₃)(CH₂CH₃)), halo (e.g. fluoro, chloro, bromo or iodo), haloalkoxy (e.g. -OCF₃ or -OCHF₂), haloalkyl (e.g. -CF₃), alkyl

(e.g. -CH 3 or -CH 2 CH 3J, -OH, -CHO, -NO₂, -C(O)NH₂, alkylaminocarbonyl (e.g.

-C(O)NHCH₃ Or -C(O)NHCH₂CH₃), -SO₂NH₂, alkylaminosulfonyl (e.g. -SO₂NHCH₃ or -SO₂NHCH₂CH₃), acylamino (e.g. -NHCOCH₃) and alkylsulfonylamino (e.g. -NHSO₂CH₃ or -NHSO₂CH₂CH₃).

Alkyl, alkylene, alkenylene and alkynylene groups may be optionally substituted. Suitable optional substituent groups include alkoxy (e.g., -OCH₃ or -OCH₂CH₃), alkylamino (e.g. -NHCH₃ Or -NHCH₂CH₃), alkylsulfinyl (e.g. -SOCH₃ or -SOCH₂CH₃), alkylsulfonyl (e.g. -SO₂CH₃ Or -SO₂CH₂CH₃), alkylthio (e.g. -SCH₃ or -SCH₂CH₃), -NH₂, aminoalkyl (e.g. -CH₂NH₂ or -CH₂CH₂NH₂), cyano, dialkylamino (e.g. -N(CH₃J₂ or -N(CH₂CH₃J₂ Or -N(CH₃)(CH₂CH₃)), halo (e.g. fluoro, chloro, bromo or iodo), haloalkoxy (e.g. -OCF, or -OCHFJ, haloalkyl (e.g. -CFJ, alkyl (e.g. -CK or

-CH 2 CHJ 3 , -OH and arylalkyl (e.g. -CH 2 Ph or -CH 2-CH 2-Ph).

It will be readily appreciated by those skilled in the art that when selecting the above substituents, care should be exercised to ensure that chemically stable combinations are formed.

Compounds of the invention may exist in one or more geometrical, optical, enantiomeric, diastereomeric and tautomeric forms, including but not limited to cis- and frans-forms, E- and Z-forms, R-, S- and mesoforms, keto-, and enol-forms. Unless otherwise stated a reference to a particular compound includes all such isomeric forms, including racemic and other mixtures thereof. Where appropriate such isomers can be separated from their mixtures by the application or adaptation of known methods (e.g. chromatographic techniques and recrystallisation techniques). Where appropriate such isomers may be prepared by the application of adaptation of known methods (e.g. asymmetric synthesis).

In one embodiment, the present invention provides compounds of formula (I) wherein each occurrence of alkyl independently may be optionally substituted with up to three substituent groups independently chosen from d-Cβ-haloalkyl, d-Cβ-haloalkoxy, CN and halo; and each occurrence of heterocycloalkyl, aryl, aryl-fused-heterocycloalkyl, heteroaryl, cycloalkyl, alkoxy, alkylene, alkenylene, alkynylene or aryl-fused-cycloalkyl independently may be optionally substituted with up to three substituent groups independently chosen from d-C₆-alkyl, CrC₆-haloalkyl, CrCVhaloalkoxy, CN, - N(R¹²)C(O)C_rC₆alkyl and halo, wherein R¹² is selected from H and C_rC₆alkyl.

In another embodiment, the present invention provides compounds of formula (I) wherein each occurrence of alkyl, heterocycloalkyl, aryl, aryl-fused-heterocycloalkyl, heteroaryl, cycloalkyl, alkoxy, alkylene, alkenylene, alkynylene or aryl-fused-cycloalkyl is not optionally substituted.

In a further embodiment, the present invention provides compounds of formula (I):

wherein

R¹ is C_rC₆-alkyl or hydrogen; and R² is a group, -Z-Y-W-R⁷; and R³ is a lone pair or d-Cβ-alkyl;

R⁴ and R⁵ are independently selected from the group consisting of aryl, heteroaryl, and cycloalkyl;

R⁶ is OH, C_rC₆-alkoxy, hydroxy-d-Ce-alkyl, nitrile, a group CONR⁹R¹⁰ or a hydrogen atom;

A is an oxygen or a sulfur atom;

X is a CrC₄-alkylene, C₂-C₄-alkenylene or C₂-C₄-alkynylene group; W is a direct bond or a Ci-C₄-alkylene, C₂-C₄-alkenylene or C₂-C₄-alkynylene group;

R⁷ is an aryl, aryl-fused-cycloalkyl, aryl-fused-heterocycloalkyl, or heteroaryl group;

R⁸, R⁹, R¹⁰ and R¹¹ are each independently selected from CVCValkyl or a hydrogen atom;

Z is a CrC₆-alkylene, C₂-C₆-alkenylene or C₂-C₆-alkynylene group; and

Y is -S-, -SO-, -SO₂-, -CO2-, -OC(=O)-, -N(R¹¹JSO₂- or -SO₂N(R¹¹)-;

or a pharmaceutically acceptable salt thereof;

wherein, each occurrence of alkyl, independently, may be optionally substituted with up to three substituent groups independently chosen from Ci-C₆-haloalkyl, C₁-C₆- haloalkoxy, CN and halo; and each occurrence of heterocycloalkyl, aryl, aryl-fused- heterocycloalkyl, heteroaryl, cycloalkyl, alkoxy, alkylene, alkenylene, alkynylene or aryl-fused-cycloalkyl, independently, may be optionally substituted with up to three substituent groups independently chosen from C_rC₆-alkyl, C_rC₆-haloalkyl, C₁-C₆- haloalkoxy, CN, -N(R¹²)C(O)C_rC₆alkyl and halo, wherein R¹² is selected from H and C_rC₆alkyl; and

wherein each alkenylene chain contains, where possible, up to 2 carbon-carbon double bonds and each alkynylene chain contains, where possible, up to 2 carbon- carbon triple bonds.

The present invention also encompasses the following alternative embodiments and combinations thereof:

The groups R\ R² and R³

In some embodiments of the present invention, there are three combinations of groups R¹, R² and R³: In combination (i) R¹ is C_rC₆-alkyl or hydrogen; and R² is a group -Z-Y-W-R⁷; and R³ is a lone pair or d-C₆-alkyl. In those compounds in which R¹ and R³ are each alkyl, then the nitrogen atom to which they are attached is a quaternary nitrogen and carries a positive charge.

In combination (ii) R¹ and R³ together with the nitrogen to which they are attached form a heterocycloalkyl ring, and R² is a group -Z-Y-W-R⁷. In this case, of course, the nitrogen atom to which R² is attached is a quaternary nitrogen and carries a positive charge. In one embodiment, R¹ and R³ together with the nitrogen to which they are attached may form a monocyclic ring of from 3 to 7 ring atoms, in which the hetero- atoms are nitrogen. Examples of such rings include azetidinyl, piperidinyl, piperazinyl, N-substituted piperazinyl such as methylpiperazinyl, and pyrrolidinyl rings.

In combination (iii) R¹ and R² together with the nitrogen to which they are attached form a heterocycloalkyl ring, said ring being substituted by a group -Y-W-R⁷ or -Z-Y- W-R⁷, and R³ is a lone pair (ie the substituent R³ is absent), or CrC₆-alkyl especially methyl. In one embodiment, R¹ and R² together with the nitrogen to which they are attached may form a monocyclic ring of from 3 to 7 ring atoms, in which the hetero- atoms are nitrogen. Examples of such rings include azetidinyl, piperidinyl, piperazinyl, N-substituted piperazinyl such as methylpiperazinyl, and pyrrolidinyl rings Of course, when R³ is alkyl, the nitrogen atom to which it is attached is a quaternary nitrogen and carries a positive charge.

In one embodiment, the present invention provides compounds of formula (I) wherein R¹ is C_rC₆-alkyl or hydrogen; and R² is a group, -Z-Y-W-R⁷; and R³ is a lone pair or CrCβ-alkyl.

In another embodiment, the present invention provides compounds of formula (I) wherein R³ is methyl.

The groups Z. W. Y and R⁷

In one embodiment,

Z and W may independently be, for example -(CH₂)i-₈, said alkylene chain being optionally substituted on up to three carbons in the chain by methyl; or Z is -(CH₂)_V8, optionally substituted on up to three carbons by methyl and W is a direct bond or -(CH₂)i-₃-;

Y is -S-, -SO-, -SO₂-, -CO₂-, -0C(=0)-, -N(R¹¹JSO₂- or -SO₂N(R¹¹) -;

R⁷ may be

C_rC₆-alkyl, such as methyl, ethyl, n- or isopropyl, n-, sec- or tertbutyl;

Optionally substituted aryl such as phenyl or naphthyl, or aryl-fused- heterocycloalkyl such as 3,4-methylenedioxyphenyl, 3,4- ethylenedioxyphenyl, or dihydrobenzofuranyl;

Optionally substituted heteroaryl such as pyridyl, pyrrolyl, pyrimidinyl, oxazolyl, isoxazolyl, benzisoxazolyl, benzoxazolyl, thiazolyl, benzothiazolyl, quinolyl, thienyl, benzothienyl, furyl, benzofuryl, imidazolyl, benzimidazolyl, isothiazolyl, benzisothiazolyl, pyrazolyl, isothiazolyl, triazolyl, benzotriazolyl, thiadiazolyl, oxadiazolyl, pyridazinyl, pyridazinyl, triazinyl, indolyl and indazolyl;

Optionally substituted aryl-fused-cycloalkyl such as indanyl or 1 ,2,3,4- tetrahydronaphthalenyl; or

Optionally substituted cycloalkyl such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl or cyclooctyl.

In one embodiment of the invention, in the group -NR¹R²R³, R¹ is methyl or ethyl; R² is -Z-Y-W-R⁷ as defined and discussed above; Y and W are as defined above; and -Z- is a straight or branched alkylene, alkenylene or alkynylene radical linking the nitrogen to the group -Y-W-R⁷ by a chain of up to 16, for example up to 10, carbon atoms; and R³ is methyl, so that the nitrogen is quaternised and carries a positive charge. In these cases, the group -W-R⁷ is conveniently a lipophilic group such as phenyl, benzyl, dihydrobenzofuryl or phenylethyl.

In another embodiment of the invention, in the group -NR¹R²R³, R² is -Z-Y-W-R⁷ as defined and discussed above; Y and W are as defined above; and -Z- is a straight or branched alkylene radical linking the nitrogen to the group -Y-W-R⁷ by a chain of up to 16, for example up to 10, carbon atoms; and R¹ and R³ together with the nitrogen to which they are attached form a heterocyclic ring of 4-8 ring atoms, conveniently 4-6 ring atoms, optionally containing a further nitrogen, oxygen or sulphur atom, such as azetidinyl, piperidinyl, piperazinyl, N-substituted piperazinyl such as methylpiperazinyl, pyrrolidinyl, morpholinyl, or thiomorpholinyl ring, so that the nitrogen is quatemised and carries a positive charge. In these cases, the group -W-R⁷ is conveniently a lipophilic group such as phenyl, benzyl, dihydrobenzofuryl or phenylethyl group.

In one embodiment, the present invention provides a compound of formula (I) wherein Z is CrC₆-alkylene.

In another embodiment, the present invention provides a compound of formula (I) wherein Z is selected from methylene, ethylene and propylene.

In one embodiment, the present invention provides a compound of formula (I) wherein W is selected from a direct bond and CrCValkylene.

In another embodiment, the present invention provides a compound of formula (I) wherein W is selected from a direct bond, a methylene groups and an ethylene group.

In one embodiment, the present invention provides a compound of formula (I) wherein Y is -S-, -SO-, -SO₂-, -CO₂-, -OC(=O)-, -N(R¹¹)SO₂- or -SO₂N(R¹¹)-.

In another embodiment, the present invention provides a compound of formula (I) wherein Y is -S-, -SO₂-, -CO₂-, or -N(R¹¹)SO₂-

In a further embodiment, the present invention provides a compound of formula (I) wherein Y is -S -, -SO₂ -, -CO₂ -, -OC(=O) - or -NHSO₂ -.

In one embodiment, the present invention provides a compound of formula (I) wherein

R⁷ is an aryl, aryl-fused-cycloalkyl, aryl-fused-heterocycloalkyl, or heteroaryl group, each optionally substituted.

In another embodiment, the present invention provides a compound of formula (I) wherein R⁷ is an aryl, aryl-fused-heterocycloalkyl, or heteroaryl group, optionally substituted with 1 , 2, or 3 substituents independently selected from C_rC₆-alkyl, C₁-C₆- haloalkyl, C_rC₆-haloalkoxy, CN, -N(R¹²)C(O)C₁-C₆alkyl and halo, wherein R¹² is selected from H and C_rC₆alkyl.

In a further embodiment, the present invention provides a compound of formula (I) wherein R⁷ is an aryl group, such as phenyl or naphthyl, or heteroaryl group, such as pyridyl, pyrrolyl or pyrimidinyl, optionally substituted with 1 or 2 substituents independently selected from C₁-C₆-SlKyI, CrCβ-haloalkyl, CrCβ-haloalkoxy, CN, - N(R¹²)C(O)C_rC₆alkyl and halo, wherein R¹² is selected from H and d-Cβalkyl.

The groups R⁴, R⁵ and R⁶

R⁴ and R⁵ may be independently selected from any of those aryl, aryl-fused- heterocycloalkyl, heteroaryl, C_rC₆-alkyl, or cycloalkyl groups specifically mentioned above. R⁶ may be -OH, a hydrogen atom, CrC₆-alkyl such as methyl or ethyl, C₁-C₆- alkoxy such as methoxy or ethoxy, hydroxy-CrCε-alkyl such as hydroxymethyl, nitrile, or a group CONR⁹R¹⁰ wherein each R⁹ and R¹⁰ are independently C_rC₆-alkyl such as methyl or ethyl, or a hydrogen atom. A particular embodiment of the invention is the case where R⁶ is -OH. Another embodiment of the invention provides combinations of R⁴ and R⁵, especially when R⁶ is -OH, including those wherein (i) each of R⁴ and R⁵ is optionally substituted monocyclic heteroaryl of 5 or 6 ring atoms such as pyridyl, oxazolyl, thiazolyl, furyl and especially thienyl such a 2-thienyl; (ii) each of R⁴ and R⁵ is optionally substituted phenyl; (iii) one of R⁴ and R⁵ is optionally substituted phenyl and the other is cycloalkyl such as cyclopropyl, cyclobutyl, or especially cyclopentyl or cyclohexyl; and (iv) one of R⁴ and R⁵ is optionally substituted monocyclic heteroaryl of 5 or 6 ring atoms such as pyridyl, thienyl, oxazolyl, thiazolyl, or furyl; and the other is cycloalkyl such as cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl.

In an alternative embodiment, the present invention provides a compound of formula (I) wherein, R⁴ and R⁵ are both phenyl and R⁶ is -OH.

In another alternative embodiment, the present invention provides a compound of formula (I) wherein one of R⁴ and R⁵ is phenyl, the other one of R⁴ and R⁵ is cycloalkyl and R⁶ is -OH.

In a further alternative embodiment, the present invention provides a compound of formula (I) wherein one of R⁴ and R⁵ is phenyl, the other one of R⁴ and R⁵ is cyclohexyl and R⁶ is -OH.

As previously mentioned, it will be appreciated that certain combinations of R⁴, R⁵ and R⁶ can give rise to enantiomers. In such cases, both enantiomers of the invention generally exhibit affinity at the M₃ receptor, although one enantiomer is generally preferred on criteria of potency at the M₃ receptor and/or selectivity against the M₂ receptor. Compounds of the invention may be in the form of single enantiomers or mixtures of enantiomers. In some embodiments of the invention, the absolute stereochemistry of the preferred enantiomer is known.

Examples of configurations of this carbon atom include:

wherein the bond marked ^* is attached to the ring containing N and A.

In one embodiment R⁴ is a phenyl group; R⁵ is a cyclohexyl or cyclopentyl group; R⁶ is a hydroxyl group; and the carbon atom to which they are attached has the R- absolute configuration as dictated by Cahn-lngold-Prelog rules.

The ring atom A

A may be an oxygen or sulphur atom.

In an alternative embodiment, the present invention provides a compound of formula (I) wherein A is oxygen.

The sυbstituent R⁸

AAlltthhoouugghh RR⁸⁸ mmaay be Ci-C₆-alkyl, such as methyl or ethyl, more conveniently R⁸ is a hydrogen atom.

The Radical X Although X may be an alkylene, alkenylene or alkynylene radical, more conveniently X is alkylene, for example ethylene or methylene.

In one embodiment, the present invention provides a compound of formula (I) wherein X is methylene.

A subclass of compounds with which the invention is concerned consists of those of formula (IA)

wherein A is -O- or -S-; m is 1 or 2; ring D is an optionally substituted phenyl ring, or monocyclic heteroaryl ring of 5 or 6 ring atoms, or phenyl-fused-heterocycloalkyl ring system wherein the heterocycloalkyl ring is a monocyclic ring of 5 or 6 ring atoms; R¹ and R³ are independently methyl or ethyl; R⁴ is phenyl, thienyl, cyclopentyl or cyclohexyl; R⁵ is phenyl, thienyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl or cyclooctyl; s is 1 , 2, 3, 4, 5, 6 or 7 and t is 0, 1 , 2, 3, 4, 5, 6 or 7; Y is -S-, -SO-, - SO₂-, -CO₂-, -OC(=O)-, -N(R¹¹JSO₂- Or -SO₂N(R¹¹)-; and Q^" is a pharmaceutically acceptable anion. In a further subclass, R¹ and R³ are each methyl.

Another subclass of compounds with which the invention is concerned consists of those of formula (IB)

wherein A is -O- or -S-; m is 1 or 2; ring B is a pyrrolidinium or piperidinium ring; ring D is an optionally substituted phenyl ring, or monocyclic heteroaryl ring of 5 or 6 ring atoms, or phenyl-fused-heterocycloalkyl ring system wherein the heterocycloalkyl ring is a monocyclic ring of 5 or 6 ring atoms; R⁴ is phenyl, thienyl, cyclopentyl or cyclohexyl; R⁵ is phenyl, thienyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl or cyclooctyl; s is 1 , 2, 3, 4, 5, 6 or 7 and t is O₁ 1 , 2, 3, 4, 5, 6 or 7; Y is -S-, -SO-,

-SO₂-, -CO₂-, -OC(=O)-, -N(R¹¹JSO₂- or -SO₂N(R¹¹)-; and Q^~ is a pharmaceutically acceptable anion.

In compounds (IA) and (IB), conveniently ring D is (i) optionally substituted phenyl, wherein optional substituents are selected from alkoxy, halo especially fluoro or chloro, C₁-C₃-SIkVi, amino-CrC₃-acyl, amino-CrC₃-alkyl, or (ii) a phenyl-fused- heterocycloalkyl ring system wherein the heterocycloalkyl ring is a monocyclic heterocyclic ring of 5 or 6 ring atoms, such as dihydrobenzofuranyl.

In each of subclasses (IA) and (IB), s+t may be, for example 1 , 2, 3, 4, 5, 6, or 7 and may arise from suitable combinations of t and s such as where t is 0, 1 , 2, 3, 4, 5 or 6 and s is 1 , 2, 3, 4, 5, 6 or 7.

In compounds (IA) and (IB), one combination of t and s is where t is 0 and s is 3. A further combination is where s+t is 2, 3 or 4.

Specific embodiments of the present invention include those compounds described in the Examples provided herein below and pharmaceutically acceptable salts thereof.

In one embodiment, the present invention provides a compound of formula (I) selected from: [2-((R)-cyclohexyl-hydroxy-phenyl-methyl)-oxazol-5-ylmethyl]-dimethyl-(3- phenylsulfanyl-propyl)-ammonium salt;

[2-((R)-cyclohexyl-hydroxy-phenyl-methyl)-oxazol-5-ylmethyl]-dimethyl-(3- benzenesulfonyl-propyl)-ammonium salt;

(2-benzenesulfonylamino-ethyl)-[2-((R)-cyclohexyl-hydroxy-phenyl-methyl)-oxazol-5- ylmethyl]-dimethyl-ammonium salt;

(2-benzenesuIfonylamino-propyl)-[2-((R)-cyclohexyl-hydroxy-phenyl-methyl)-oxazol-5- ylmethylj-dimethyl-ammonium salt;

[3-(4-acetylamino-phenoxycarbonyl)-propyl]-[2-((R)-cyclohexyl-hydroxy-phenyl- methyl)-oxazol-5-ylmethyl]-dimethyl-ammonium salt; (benzyloxycarbonylmethyl)-[2-((R)-cyclohexyl-hydroxy-phenyl-methyl)-oxazol-5- ylmethyl]-dimethyl-ammonium salt;

^-((RJ-cyclohexyl-hydroxy-phenyl-methylJ-oxazol-δ-ylmethylj-dimethyl- phenethyloxycarbonylmethyl-ammonium salt;

{2-[2-(cyclohexyl-hydroxy-phenyl-methyl)-oxazol-5-yl]-ethyl}-dimethyl-(3- phenylsulfanyl-propyl)-ammonium salt;

(2-benzoyloxy-ethyl)-[2-((R)-cyclohexyl-hydroxy-phenyl-methyl)-oxazol-5-ylmethyl]- dimethyl-ammonium salt; and

[2-((R)-cyclohexyl-hydroxy-phenyl-methyl)-oxazol-5-ylmethyl]-dimethyI-(4-methyl- benzyloxycarbonylmethyl-ammonium salt; wherein each ammonium salt comprises a pharmaceutically acceptable anion.

Examples of pharmaceutically acceptable anions that may be present in the ammonium salts according to this embodiment include chlorides, bromides, sulfates, methanesulfonates, benzenesulfonates, toluenesulfonates (tosylates), napadisylates (naphthalene-1 ,5-disulfonates or naphthalene-1 -(sulfonic acid)-5-sulfonates), edisylates (ethane-1 ,2-disulfonates or ethane-1 -(sulfonic acid)-2-sulfonates), isethionates (2-hydroxyethylsulfonates), phosphates, acetates, citrates, lactates, tartrates, mesylates, maleates, malates, fumarates, succinates, xinafoates, p- acetamidobenzoates. More specific examples include chloride, bromide, iodide, mesylate, tosylate, benzenesulfonate and napadisylate.

Each of the compounds identified above, taken alone or with any combination of the other compounds identified herein, represents an independent aspect of the invention.

The present invention is also concerned with pharmaceutical formulations comprising, as an active ingredient, a compound of the invention. Other compounds may be combined with compounds of this invention for the prevention and treatment of inflammatory diseases of the lung. Thus the present invention is also concerned with pharmaceutical compositions for preventing and treating respiratory-tract disorders such as chronic obstructive lung disease, chronic bronchitis, asthma, chronic respiratory obstruction, pulmonary fibrosis, pulmonary emphysema, and allergic rhinitis comprising a therapeutically effective amount of a compound of the invention and one or more other therapeutic agents.

Other compounds may be combined with compounds of this invention for the prevention and treatment of inflammatory diseases of the lung. Accordingly the invention includes a combination of an agent of the invention as hereinbefore described with one or more anti-inflammatory, bronchodilator, antihistamine, decongestant or anti-tussive agents, said agents of the invention hereinbefore described and said combination agents existing in the same or different pharmaceutical compositions, administered separately or simultaneously. Preferred combinations would have two or three different pharmaceutical compositions. Suitable therapeutic agents for a combination therapy with compounds of the invention include:

One or more other bronchodilators such as PDE3 inhibitors; Methyl xanthines such as theophylline; Other muscarinic receptor antagonists; A corticosteroid, for example fluticasone propionate, ciclesonide, mometasone furoate or budesonide, or steroids described in WO02/88167, WO02/12266, WO02/100879, WO02/00679, WO03/35668, WO03/48181 , WO03/62259, WO03/64445, WO03/72592, WO04/39827 and WO04/66920; A non-steroidal glucocorticoid receptor agonist; A β2-adrenoreceptor agonist, for example albuterol (salbutamol), salmeterol, metaproterenol, terbutaline, fenoterol, procaterol, carmoterol, indacaterol, formoterol, arformoterol, picumeterol, GSK-159797, GSK-597901 , GSK-159802, GSK-64244, GSK-678007, TA-2005 and also compounds of EP1440966, JP05025045, WO93/18007, WO99/64035, US2002/0055651 , US2005/0133417, US2005/5159448, WO00/075114, WO01/42193, WO01/83462, WO02/66422, WO02/70490, WO02/76933, WO03/24439, WO03/42160, WO03/42164, WO03/72539, WO03/91204, WO03/99764, WO04/16578, WO04/016601 , WO04/22547, WO04/32921 , WO04/33412, WO04/37768, WO04/37773, WO04/37807, WO0439762, WO04/39766, WO04/45618, WO04/46083, WO04/71388, WO04/80964, EP1460064, WO04/087142, WO04/89892, EP01477167,

US2004/0242622, US2004/0229904, WO04/108675, WO04/108676, WO05/033121 , WO05/040103, WO05/044787, WO04/071388, WO05/058299, WO05/058867, WO05/065650, WO05/066140, WO05/070908, WO05/092840, WO05/092841 , WO05/092860, WO05/092887, WO05/092861 , WO05/090288, WO05/092087, WO05/080324, WO05/080313, US20050182091 , US20050171147, WO05/092870, WO05/077361 , DE10258695, WO05/111002, WO05/111005, WO05/110990, US2005/0272769 WO05/110359, WO05/121065, US2006/0019991 , WO06/016245, WO06/014704, WO06/031556, WO06/032627, US2006/0106075, US2006/0106213, WO06/051373, WO06/056471 ; A leukotriene modulator, for example montelukast, zafirlukast or pranlukast; protease inhibitors, such as inhibitors of matrix metalloprotease for example MMP12 and TACE inhibitors such as marimastat, DPC-333, GW-3333; Human neutrophil elastase inhibitors, such as sivelestat and those described in WO04/043942, WO05/021509, WO05/021512, WO05/026123, WO05/026124, WO04/024700, WO04/024701 , WO04/020410, WO04/020412, WO05/080372, WO05/082863, WO05/082864, WO03/053930;

Phosphodiesterase-4 (PDE4) inhibitors, for example roflumilast, arofylline, cilomilast, ONO-6126 or lC-485; Phosphodiesterase-7 inhibitors; An antitussive agent, such as codeine or dextramorphan; Kinase inhibitors, particularly P38 MAPKinase inhibitors; P2X7 anatgonists; iNOS inhibitors;

A non-steroidal anti-inflammatory agent (NSAID), for example ibuprofen or ketoprofen; A dopamine receptor antagonist;

TNF-α inhibitors, for example anti-TNF monoclonal antibodies, such as Remicade and CDP-870 and TNF receptor immunoglobulin molecules, such as Enbrel;

A2a agonists such as those described in EP1052264 and EP1241176;

A2b antagonists such as those described in WO2002/42298; Modulators of chemokine receptor function, for example antagonists of CCR1 , CCR2,

CCR3, CXCR2, CXCR3, CX3CR1 and CCR8, such as SB-332235, SB-656933, SB-

265610, SB-225002, MCP-1 (9-76), RS-504393, MLN-1202, INCB-3284;

Compounds which modulate the action of prostanoid receptors, for example a PGD₂

(DP1 or CRTH2), or a thromboxane A₂ antagonist eg ramatrobant; Compounds which modulate Th1 or Th2 function, for example, PPAR agonists; lnterleukin 1 receptor antagonists, such as Kineret; lnterleukin 10 agonists, such as llodecakin;

HMG-CoA reductase inhibitors (statins); for example rosuvastatin, mevastatin, lovastatin, simvastatin, pravastatin and fluvastatin; Mucus regulators such as INS-37217, diquafosol, sibenadet, CS-003, talnetant, DNK-

333. MSI-1956, gefitinib;

Antiinfective agents (antibiotic or antiviral), and antiallergic drugs including, but not limited to, anti-histamines.

The weight ratio of the first and second active ingredients may be varied and will depend upon the effective dose of each ingredient. Generally, an effective dose of each will be used.

Any suitable route of administration may be employed for providing a mammal, especially a human, with an effective dosage of a compound of the present invention. In therapeutic use, the active compound may be administered by any convenient, suitable or effective route. Suitable routes of administration are known to those skilled in the art, and include oral, intravenous, rectal, parenteral, topical, ocular, nasal, buccal and pulmonary.

The magnitude of prophylactic or therapeutic dose of a compound of the invention will, of course, vary depending upon a range of factors, including the activity of the specific compound that is used, the age, body weight, diet, general health and sex of the patient, time of administration, the route of administration, the rate of excretion, the use of any other drugs, and the severity of the disease undergoing treatment. In general, the daily dose range for inhalation will lie within the range of from about 0.1 μg to about 10 mg per kg body weight of a human, preferably 0.1 μg to about 0.5 mg per kg, and more preferably 0.1 μg to 50μg per kg, in single or divided doses. On the other hand, it may be necessary to use dosages outside these limits in some cases. Compositions suitable for administration by inhalation are known, and may include carriers and/or diluents that are known for use in such compositions. The composition may contain 0.01 -99% by weight of active compound. Preferably, a unit dose comprises the active compound in an amount of 1 μg to 10 mg. For oral administration suitable doses are 10μg per kg to 100mg per kg, preferably 40μg per kg to 4 mg per kg.

Another aspect of the present invention provides pharmaceutical compositions which comprise a compound of the invention and a pharmaceutically acceptable carrier. The term "composition", as in pharmaceutical composition, is intended to encompass a product comprising the active ingredient(s), and the inert ingredient(s) (pharmaceutically acceptable excipients) that make up the carrier, as well as any product which results, directly or indirectly, from combination, complexation or aggregation of any two or more of the ingredients, or from dissociation of one or more of the ingredients, or from other types of reactions or interactions of one or more of the ingredients. Accordingly, the pharmaceutical compositions of the present invention encompass any composition made by admixing a compound of the invention, additional active ingredient(s), and pharmaceutically acceptable excipients.

The pharmaceutical compositions of the present invention comprise a compound of the invention as an active ingredient or a pharmaceutically acceptable salt thereof, and may also contain a pharmaceutically acceptable carrier and optionally other therapeutic ingredients. The term "pharmaceutically acceptable salts" refers to salts prepared from pharmaceutically acceptable non-toxic bases or acids including inorganic bases or acids and organic bases or acids, and salts of quaternary ammonium compounds with pharmaceutically acceptable counter-ions.

For delivery by inhalation, the active compound is preferably in the form of microparticles. They may be prepared by a variety of techniques, including spray- drying, freeze-drying and micronisation.

By way of example, a composition of the invention may be prepared as a suspension for delivery from a nebuliser or as an aerosol in a liquid propellant, for example for use in a pressurised metered dose inhaler (PMDI). Propellants suitable for use in a PMDI are known to the skilled person, and include CFC-12, HFA-134a, HFA-227, HCFC-22 (CCI₂F₂) and HFA-152 (C₂H₄F₂) and isobutane.

In a preferred embodiment of the invention, a composition of the invention is in dry powder form, for delivery using a dry powder inhaler (DPI). Many types of DPI are known.

Microparticles for delivery by administration may be formulated with excipients that aid delivery and release. For example, in a dry powder formulation, microparticles may be formulated with large carrier particles that aid flow from the DPI into the lung. Suitable carrier particles are known, and include lactose particles; they may have a mass median aerodynamic diameter of greater than 90 μm.

In the case of an aerosol-based formulation, an example is: Compound of the invention 24 mg / canister Lecithin, NF Liq. Cone. 1.2 mg / canister

Trichlorofluoromethane, NF 4.025 g / canister Dichlorodifluoromethane, NF 12.15 g / canister.

The active compounds may be dosed as described depending on the inhaler system used. In addition to the active compounds, the administration forms may additionally contain excipients, such as, for example, propellants (e.g. Frigen in the case of metered aerosols), surface-active substances, emulsifiers, stabilizers, preservatives, flavorings, fillers (e.g. lactose in the case of powder inhalers) or, if appropriate, further active compounds.

For the purposes of inhalation, a large number of systems are available with which aerosols of optimum particle size can be generated and administered, using an inhalation technique which is appropriate for the patient. In addition to the use of adaptors (spacers, expanders) and pear-shaped containers (e.g. Nebulator®, Volumatic®), and automatic devices emitting a puffer spray (Autohaler®), for metered aerosols, in particular in the case of powder inhalers, a number of technical solutions are available (e.g. Diskhaler®, Rotadisk®, Turbohaler® or the inhalers for example as described EP-A-0505321 ). Additionally, compounds of the invention may be delivered in multi-chamber devices thus allowing for delivery of combination agents.

Methods of Synthesis

The compounds of the invention can be prepared according to the procedures of the following schemes and examples, using appropriate materials, and are further exemplified by the following specific examples. Moreover, by utilising the procedures described with the disclosure contained herein, one of ordinary skill in the art can readily prepare additional compounds of the present invention claimed herein. The compounds illustrated in the examples are not, however, to be construed as forming the only genus that is considered as the invention. The examples further illustrate details for the preparation of the compounds of the present invention. Those skilled in the art will readily understand that known variations of the conditions and processes of the following preparative procedures can be used to prepare these compounds.

The compounds of the invention may be isolated in the form of their pharmaceutically acceptable salts, such as those described previously herein above. It may be necessary to protect reactive functional groups (e.g. hydroxy, amino, thio or carboxy) in intermediates used in the preparation of compounds of the invention to avoid their unwanted participation in a reaction leading to the formation of the compounds. Conventional protecting groups, for example those described by T. W. Greene and P. G. M. Wuts in "Protective groups in organic chemistry" John Wiley and Sons, 1999, may be used.

Compounds of the invention may be prepared according to the routes illustrated in Schemes 1 -4. It will be readily apparent to one skilled in the art that in these Schemes it is also possible to vary the order in which the substituents R¹, R² and R³ are introduced.

(l-e)

Scheme 1

(l-n)

Scheme 2

^(VI) (XVlI)

(XX)

Scheme 3

Compounds of formula (l-b) can be prepared from compounds of formula (l-a) by reaction with an alkylating agent of formula (XXI):

R²-L (XXI)

wherein L is a leaving group such as halogen, tosylate or mesylate, and R² is as defined for compounds of formula (I) above. The reaction can be performed in a range of solvents, preferably DMF, chloroform, dichloromethane (DCM), acetonitrile or mixtures thereof, at a temperature from 0 ⁰C to the reflux temperature of the solvent. In a similar manner, compounds of formula (l-e), (l-g), (l-i), (1-k) and (l-n) may be prepared from compounds of formula (l-d), (l-f), <l-h), (l-j) and (l-m) respectively.

It will be apparent that some compounds can contain a chiral centre and thus exist in enantiomeric forms which can be separated by chiral preparative HPLC techniques using conditions known to those skilled in the art and exemplified below.

Compounds of general formula (l-a) may be prepared from compounds of general formula (II):

by reaction with a compound of general formula (XXII):

R⁵M (XXII)

wherein R⁴ and R⁵ are as defined in general formula (I) and M represents a metallic counterion such as Li or MgBr. The reaction may take place in an aprotic organic solvent such as THF or diethyl ether at a range of temperatures, preferably between -78 ⁰C and the reflux temperature of the solvent.

Compounds of general formula (XXII) are well known in the art and are readily available or can be prepared by known methods.

Compounds of general formula (II) can be prepared from compounds of general formula

by reaction with an amine of formula (XXIII):

R¹R³NH (XXIII)

wherein R¹ and R³ are as defined in general formula (I). The reaction is performed in a range of solvents, preferably THF or DCM at a range of temperatures, preferably between 0 and 100 ^°C.

Compounds of general formula (XXIII) are well known in the art and can be prepared by known methods, or are commercially available. Compounds of formula (III) can be prepared from compounds of general formula (IV):

by reaction with a brominating agent such as N-bromosuccinimide in the presence of a radical initiator such as AIBN or benzoyl peroxide. The reaction can be carried out in suitable solvents, such as CCI₄ or chlorobenzene, at a range of temperatures, preferably between ambient temperature and the reflux temperature of the solvent.

Compounds of formula (IV) can be prepared from compounds of general formula (V):

by reaction with an acid such as hydrochloric acid, sulphuric acid, methanesulfonic or trifluoromethansulfonic acid in a range of solvents such as THF, DCM, water, and preferably 1 ,4-dioxan at a range of temperatures, preferably between ambient temperature and the reflux temperature of the solvent.

Alternatively compounds of formula (IV) can be prepared from compounds of general formula (V) by palladium-catalysed cyclisation using a palladium catalyst such as bis(dibenzylideneacetone)palladium in the presence of a ligand such as triphenylphosphine and a base such as sodium tert-butoxide in a solvent such as THF at a temperature from ambient temperature to the reflux temperature of the solvent.

Alternatively compounds of formula (IV) can be prepared from compounds of formula (XVI):

according to the method described in J. Chem. Soc. 1948, 1960. Compounds of general formula (XVI) are known in the art and can be prepared by known methods such as those described in Tetrahedron 2002, 58(14), 2813.

Alternatively compounds of formula (IV) can be prepared from compounds of formula (XVII):

according to the method described in J. Org. Chem., 1938, 2, 319. Compounds of general formula (XVII) are well known in the art and can be prepared by known methods such as those described in GB 2214180.

Compounds of general formula (V) can be prepared from compounds of general formula (Vl):

by reaction with propargylamine in the presence of a suitable coupling agent, such as DCC/HOBt or many other known coupling methodologies. Alternatively compounds of formula (Vl) may be converted to, for example, the acid chloride and amide formation effected optionally in the presence of a suitable non-nucleophilic base and compatible solvent under well known conditions. Compounds of general formula (Vl) are readily available or can be prepared by known methods.

Alternatively compounds of general formula (l-a) can be prepared from compounds of general formula (VII):

according to methods described above for the preparation of compounds of formula (II) from compounds of formula (III). Compounds of general formula (VII) can be prepared from compounds of formula (VIII):

according to methods similar to those used to prepare compounds of formula (III) from compounds of formula (IV) as described above.

Compounds of general formula (VIII) can be prepared from compounds of formula (IV) using methods described above for the preparation of compounds of formula (l-a) from compounds of formula (II).

Alternatively compounds of formula (VIII) may be prepared from compounds of formula (XIX):

using methods described above for the preparation of compounds of formula (IV) from compounds of formula (XVII). Compounds of general formula (XIX) can be prepared by known methods such as those described in GB 2214180.

Alternatively compounds of formula (VIII) may be prepared from compounds of formula (XX):

using methods described above for the preparation of compounds of formula (IV) from compounds of formula (V).

Compounds of general formula (XX) can be prepared from compounds of formula (XVIII) using methods described above for the preparation of compounds of formula (V) from compounds of formula (Vl). Alternatively, compounds of formula (l-b) may be prepared directly from compounds of formula (VII) by quatemisation with a suitably substituted tertiary amine as described above for the preparation of compounds of formula (l-a) from compounds of formula (VII)

Alternatively compounds of formula (l-a) wherein -NR¹R³ is a secondary amine (i.e. R¹ is a hydrogen atom) may be prepared from compounds of formula (l-a) wherein - NR¹R³ is a -NH₂ group by reductive alkylation with a suitably substituted aldehyde. The reaction is carried out in the presence of a reducing agent such as sodium cyanoborohydride or sodium borohydride, preferably sodium triacetoxyborohydride in a range of organic solvents, preferably dichloroethane.

Compounds of formula (l-d) and (l-e) may be prepared from compounds of formula (I- c) by alkylation or reductive alkylation methods as described above and according to standard methods well-known to those skilled in the art.

Compounds of formula (l-c) can be prepared from compounds of general formula (IX):

by reaction with a reducing agent such as lithium aluminium hydride, diisobutyl aluminium hydride, or borane in a range of aprotic solvents such as diethyl ether, or THF or preferably by hydrogenation in the presence of a catalyst such as Raney Nickel in a suitable solvent such as EtOAc or EtOH at a range of temperatures from ambient temperature to the reflux temperature of the solvent.

Compounds of general formula (IX) can be prepared from compounds of general formula (VII) by reaction with a source of cyanide ion such as acetone cyanohydrin or an inorganic cyanide, preferably sodium cyanide, in the presence of a non- nucleophilic base such as tetramethyl guanidine, in a range of solvents, preferably ethanol, at a range of temperatures, preferably between ambient temperature and the reflux temperature of the solvent. Compounds of formula (l-f) can be prepared from compounds of formula (l-a) by reaction with a reducing agent such as triethylsilane in the presence of an acid such as trifluoroacetic acid in a solvent such as DCM from ambient temperature to the reflux temperature of the solvent.

Compounds of formula (l-h) can be prepared from compounds of formula (l-a) by reaction with an alkylating agent of formula (XXIV):

Ci -C6-alkyl-L (XXIV)

wherein L is a leaving group such as halogen, tosylate, mesylate. The reaction is performed in the presence of a base such as sodium hydride in a solvent such as THF from 0 ⁰C to the reflux temperature of the solvent.

Compounds of general formula (l-m) can be prepared from compounds of formula (l-l) using methods described above for the preparation of compounds of formula (l-d) from compounds of formula (l-c).

Compounds of general formula (l-l) can be prepared from compounds of formula (XIV) using methods described above for the preparation of compounds of formula (I- c) from compounds of formula (IX).

Compounds of general formula (XIV) can be prepared from compounds of formula (XIII) using methods described above for the preparation of compounds of formula (IX) from compounds of formula (VII).

Alternatively, compounds of formula (l-k) may be prepared directly from compounds of formula (XIII) by quaternisation with a suitably substituted tertiary amine as described above.

Compounds of general formula (l-j) can be prepared from compounds of formula (XIII) using methods described above for the preparation of compounds of formula (l-a) from compounds of formula (VII).

Compounds of general formula (XIII) can be prepared from compounds of formula (XII) using methods described above for the preparation of compounds of formula (III) from compounds of formula (IV).

Compounds of general formula (XII) may be prepared from compounds of general formula (Xl):

by reaction with a reducing agent such as Raney Nickel in a solvent such as ethanol at a temperature from ambient temperature to the reflux temperature of the solvent according to the method described in J. Org. Chem. 2006, 71(8), 3026.

Compounds of general formula (Xl) may be prepared from compounds of general formula (X):

by reaction with 1 -(methylthio)acetone in the presence of trifluoromethanesulfonic anhydride in a solvent such as DCM at a temperature from 0 °C to the reflux temperature of the solvent according to the method described in J. Org. Chem. 2006, 71(8), 3026.

Compounds of general formula (X) are well known in the art and can be prepared by known methods, or are commercially available.

(XXIX) (XXVIII)

Scheme 4

Compounds of formula (XXIX) may be prepared from compounds of formula (XXVI) by employing a similar sequence of reactions as used to prepare compounds of formula (l-b) from compounds of formula (VIII) in Scheme 1 above.

Compounds of formula (XXVI) wherein R^a and R^b are the same may be prepared from compounds of formula (XXV) where R is a suitable alkyl group (such as ethyl or methyl) by treatment with an appropriate organometallic reagent such as a Grignard reagent, in a suitable solvent such as THF or diethyl ether. Compounds of formula (XXVI) wherein R⁴ and R⁵ are dissimilar may be prepared from compounds of formula (XXV) by converting to an intermediate amide, preferably a Weinreb amide, and performing the introduction of R⁴ and R⁵ through their respective organometallic reagents in a stepwise manner.

Compounds of formula (XXV) are known in the literature - for example, HeIv. Chim. Acta 1946, 29, 1957.

Alternatively, compounds of formula (VII) may be prepared from compounds of formula (XVIII) as illustrated in Scheme 5 below;

Scheme 5

Compounds of formula (VII) may be prepared from compounds of formula (XXXIII);

(XXXIII) wherein R⁴ and R⁵ are as defined above, by reaction with bromine in a compatible solvent such as carbon tetrachloride, at a temperature of 0° C to the reflux temperature of the solvent, typically at a temperature between 0 and 25°C.

Compounds of formula (XXXIII) may be prepared from compounds of formula (XXXII);

(XXXII) wherein R⁴ and R⁵ are as defined above, by treatment with a non-nucleophilic base such as 1 ,5-diazabicyclo[4.3.0]non-5-ene (DBN) or 1 ,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in a compatible solvent, for example toluene, at a temperature from 0-60 ⁰C, typically 0-10 ⁰C.

Alternatively compounds of formula (VII) may be prepared from compounds of formula (VIII);

wherein R⁴ and R⁵ are as defined above, using the methods described above. Compounds of formula (VIII) may be prepared from compounds of formula (XXXII) wherein R⁴ and R⁵ are as defined above, or from compounds of formula (XXXIII) wherein R⁴ and R⁵ are as defined above by treatment with a non-nucleophilic base such as 1 ,5- diazabicyclo[4.3.0]non-5-ene (DBN) or 1 ,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in a compatible solvent, for example toluene, at a temperature from ambient temperature to the reflux temperature of the solvent, typically 80⁰C.

Compounds of formula (XXXII) may be prepared from compounds of formula (XXXI);

wherein R⁴ and R⁵ are as defined above, by cyclisation in the presence of iodine and a base such as potassium t-butoxide or potassium carbonate in a compatible solvent such as toluene. The reaction is typically conducted at a temperature of 10-30 ⁰C.

Compounds of formula (XXXI) may be prepared from compounds of formula (XVIII) using methods analogous to those used in the preparation of compounds of formula (V) from compounds of formula (Vl) as described above.

It will be appreciated that compounds of formula (XVIII) in schemes 3 and 5 are chiral when R⁴ and R⁵ are non-identical. When compounds of formula (XVIII) are scalemic (a single enantiomer) then schemes 3 and 5 constitute methods for the preparation of compounds of formula (l-a) that are themselves homochiral. Scalemic examples of compounds of formula (XVIII) are known in the literature, or may be prepared from the racemic form by separation of enantiomers using chiral chromatographic methods, or by separation of diastereomeric salts formed with scalemic bases, or by asymmetric synthesis; see for example US2004192962, WO2000023414, WO9636584, J. Chromatog. (1988), 450(2), 255-269, J. Chem. Soc C (Organic) (1968), 13, 1693-9.

The following non-limiting Examples illustrate the invention. General Experimental Details:

All reactions were carried out under an atmosphere of nitrogen unless specified otherwise.

NMR spectra were obtained on a Varian Unity Inova 400 spectrometer with a 5mm inverse detection triple resonance probe operating at 400MHz or on a Bruker Avance DRX 400 spectrometer with a 5mm inverse detection triple resonance TXI probe operating at 400MHz or on a Bruker Avance DPX 300 spectrometer with a standard 5mm dual frequency probe operating at 300MHz. Shifts are given in ppm relative to tetramethylsilane.

Where products were purified by column chromatography, 'flash silica' refers to silica gel for chromatography, 0.035 to 0.070 mm (220 to 440 mesh) (e.g. Fluka silica gel 60), and an applied pressure of nitrogen up to 10 p.s.i accelerated column elution. Where thin layer chromatography (TLC) has been used, it refers to silica gel TLC using plates, typically 3 x 6 cm silica gel on aluminium foil plates with a fluorescent indicator (254 nm), (e.g. Fluka 60778). All solvents and commercial reagents were used as received.

All compounds containing a basic centre(s), which were purified by HPLC, were obtained as the TFA salt unless otherwise stated.

Preparative HPLC conditions: C18-reverse-phase column (100 x 22.5 mm i.d Genesis column with 7 μm particle size). UV detection at 230 nm.

LC/MS Systems

The Liquid Chromatography Mass Spectroscopy (LC/MS) systems used:

LC-MS method 1

Waters Platform LCT with a C18-reverse-phase column (100 x 3.0 mm Higgins Clipeus with 5 μm particle size), elution with A: water + 0.1% formic acid; B: acetonitrile + 0.1 % formic acid. Gradient:

Gradient - Time flow ml_/min %A %B 0.00 1.0 95 5

1.00 1.0 95 5

15.00 1.0 5 95

20.00 1.0 5 95

22.00 1.0 95 5

25.00 1.0 95 5

Detection - MS, ELS, UV (100 μl split to MS with in-line UV detector at 254nm)

MS ionisation method - Electrospray (positive ion)

LC-MS method 2

Waters Platform LC with a C18-reverse-phase column (30 x 4.6 mm Phenomenex Luna 3 μm particle size), elution with A: water + 0.1 % formic acid; B: acetonitrile + 0.1 % formic acid. Gradient:

Gradient - Time flow ml_/min %A %B

0.00 2.0 95 5

0.50 2.0 95 5

4.50 2.0 5 95 5.50 2.0 5 95

6.00 2.0 95 5

Detection - MS, ELS, UV (100 μl split to MS with in-line UV detector) MS ionisation method - Electrospray (positive and negative ion)

LC-MS method 3

Waters Micromass ZQ with a C18-reverse-phase column (30 x 4.6 mm Phenomenex Luna 3 μm particle size), elution with A: water + 0.1 % formic acid; B: acetonitrile + 0.1 % formic acid. Gradient:

Gradient - Time flow mL/min %A %B

0.00 2.0 95 5

0.50 2.0 95 5

4.50 2.0 5 95

5.50 2.0 5 95 6.00 2.0 95 5

LC-MS method 4

Waters ZMD with a C18-reverse-phase column (30 x 4.6 mm i.d. Phenomenex Luna with 3 μm particle size), elution with solvent A (water with 0.1 % formic acid) and solvent B (acetonitrile with 0.1 % formic acid). Gradient:

Gradient - Time flow mL/min %A %B

0.00 2.0 95 5

0.50 2.0 95 5

4.50 2.0 5 95

5.50 2.0 5 95

6.00 2.0 95 5

Detection - MS, ELS, UV (200μL/min split to MS with in-line Waters 996 DAD detection). MS ionisation method - Electrospray (positive and negative ion).

LC-MS method 5

Waters Micromass ZQ with a C18-reverse-phase column (100 x 3.0 mm Higgins Clipeus with 5 μm particle size), elution with A: water + 0.1 % formic acid; B: acetonitrile + 0.1 % formic acid. Gradient:

Gradient - Time flow mL/min %A %B

0.00 1.0 95 5

1.00 1.0 95 5

15.00 1.0 5 95

20.00 1.0 5 95

22.00 1.0 95 5

25.00 1.0 95 5

Detection - MS, ELS, UV (100 μl split to MS with in-line UV detector at 254nm)

MS ionisation method - Electrospray (positive ion). LC-MS method 6 (OA110)

Waters Platform LC Quadrupole mass spectrometer with a C18-reverse-phase column (30 x 4.6 mm Phenomenex Luna 3 μm particle size), elution with A: water + 0.1 % formic acid; B: acetonitrile + 0.1 % formic acid. Gradient:

Gradient - Time flow ml_/min %A %B

0.00 2.0 95 5

0.50 2.0 95 5

4.50 2.0 5 95 5.50 2.0 5 95

6.00 2.0 95 5

Detection - MS, ELS, UV (200 μl split to MS with in-line UV detector) MS ionisation method - Electrospray (positive and negative ion).

LC-MS method 7 (OA 310)

Waters ZMD mass spectrometer with a C18-reverse-phase column (30 x 4.6 mm Phenomenex Luna 3 μm particle size), elution with A: water + 0.1 % formic acid; B: acetonitrile + 0.1 % formic acid. Gradient:

Gradient - Time flow mL/min %A %B

0.00 2.0 95 5

0.50 2.0 95 5

4.50 2.0 5 95

5.50 2.0 5 95

6.00 2.0 95 5

Abbreviations used in the experimental section: DCM = dichloromethane

DIPEA = di-isopropylethylamine

DMAP = dimethylaminopyridine

DMF = dimethylformamide

EtOAc = ethyl acetate EtOH = ethanol

IMS = industrial methylated spirit mCPBA = meta-chloroperbenzoic acid

MeOH = methanol

RT = ambient temperature

Rt = retention time

TFA = trifluoroacetic acid

THF = tetrahydrofuran

Sat = saturated

Intermediate 1

Z-Oxo^-phenyl-N-prop-Σ-vnyl-acetamide.

Oxalyl chloride (6.1 g, 48 mmol) was added to a solution of phenylglyoxylic acid (6.0 g, 40 mmol) and 3 drops of DMF in dry DCM (50 mL). The reaction mixture was stirred at ambient temperature for 3 hours then the solvent was removed. The residue was taken up in dry DCM (50 mL) and the solution was cooled to 0 ⁰C. A mixture of propargyl amine (2.2 g, 40 mmol) and triethylamine (4.05 g, 40 mmol) was added cautiously over a period of 10 minutes then the mixture was allowed to warm to ambient temperature. Stirring was continued for 2.5 hours then water (10 mL) was added. The mixture was washed with 1 M HCI (2x20 mL), sat. sodium hydrogencarbonate (aq.) (2x20 mL) then brine. The organic phase was then dried (Na₂SO₄) and the solvent was removed. The residue was crystallized from cyclohexane to afford the product as a light brown solid.

Yield: 5.75 g, 76%

LC-MS (Method 3): Rt 2.47 min, m/z 188 [MH⁺].

Intermediate 2

(5-Methyl-oxazol-2-yl)-phenyl-methanone. Methanesulphonic acid (10 g, 104 mmol) was added drop wise to a solution of 2-oxo- 2-phenyl-N-prop-2-ynyl-acetamide (Intermediate 1) (2.4 g, 12.83 mmol) in 1 ,4-dioxane (20 ml_). The resultant solution was heated at 90 ⁰C for 66 hours. The reaction mixture was cooled and the solvent was removed. The dark residue was partitioned between DCM and water. The DCM fraction was washed with 1 M HCI (2x), sat. sodium hydrogencarbonate (2x) then brine. The solution was dried (Na₂SO₄) and the solvent was removed to give the crude product. Purification was achieved via column chromatography, eluting with 4:1 cyclohexane: ethyl acetate. This gave the product as an off white solid. Yield: 1.0 g (41 %)

LC-MS (Method 3): Rt 2.94 min, m/z 188 [MH⁺]

Intermediate 3

Cvclohexyl-(5-methyl-oxazol-2-yl)-phenyl-methanol.

A solution of (5-methyl-oxazol-2-yl)-phenyl-methanone (Intermediate 2) (3.0 g, 16 mmol) in 32 ml. dry THF at 0 ⁰C under nitrogen was treated dropwise over IOminutes with a 2M solution of cyclohexylmagnesium chloride in diethyl ether (10 ml_, 20 mmol). The resulting deep yellow solution was stirred at 0 °C for about 30mins during which time a precipitate formed, and then at ambient temperature for 1.5 hours. The reaction mixture was cooled to 0 ⁰C again and treated cautiously with sat. ammonium chloride solution (aq) (10 ml_). The mixture was stirred at ambient temperature for 10 mins then diluted with water (10 ml_). The phases were separated and the organic phase was washed with brine. The combined aqueous phase was extracted with DCM (3 x 20 ml_) and the combined organic phase was dried (MgSO₄) and concentrated in vacuo to give the crude product which was triturated with ether (10 ml_), filtered off and dried. Yield: 3.65 g (84%) LCMS (Method 3): Rt 3.78 min, m/z 272 [MH⁺].

Intermediate 4

(S-Bromomethyl-oxazol^-vO-cyclohexyl-phenyl-methanol.

A solution of cyclohexyI-(5-methyl-oxazol-2-yl)-phenyl-methanol (Intermediate 3) (3.0 g, 11.1 mmol) in 1 ,2-dichloroethane (22 ml_) was treated with N-bromo-succinimide (2.16 g, 12.2 mmol) followed by 2,2'-azobis(2-methylpropionitrile) (0.18 g, 2.1 mmol). The mixture was heated to 80 ⁰C for 2.5h and then allowed to cool to ambient temperature. Sat. sodium hydrogen carbonate solution was added and the phases were separated. The organic layer was washed with brine and the combined aqueous layers were extracted with DCM. The combined organic phase was dried (MgSO₄) and concentrated in vacuo to give the crude product as a brown oil. Purification was achieved via column chromatography eluting with 33-100% DCM/cyclohexane followed by 25% EtOAc/DCM. Yield: 1.85 g (48%) LCMS (Method 3): Rt 4.27 min, m/z 350, 352 [MH⁺]

Intermediate 5

(3-Bromo-propylsulfanvP-benzene

A mixture of thiophenol (2.7 g, 24.5 mmol), 1 ,3-dibromopropane (12.4 ml_, 122.5 mmol) and potassium carbonate (5.08 g, 36.7 mmol) in acetonitrile was heated to 70 ^°C for 16h. The solvent was concentrated in vacuo and the residue was partitioned between ethyl acetate and water. The organic layer was separated, dried (MgSO₄) and evaporated to dryness. Purification on a Redisep cartridge provided the title compound. Yield: 3.7 g (65%).

¹H NMR (CDCI₃): J2.10-2.25 (2H, m), 3.05-3.15 (2H, t), 3.50-3.60 (2H, t), 7.15- 7.25 (1 H, m), 7.27-7.43 (4H, m).

Intermediate 6

(3-Bromo-propane-1-sulfonyl)-benzene

To a solution of (3-bromo-propyIsulfanyl)-benzene (Intermediate 5) (200 mg, 0.86 mmol) in 10 mL dry DCM at 0 ⁰C was added mCPBA (77%, 484 mg, 2.16 mmol). The reaction mixture was stirred for 2h at 0⁰C. Aqueous sodium sulfite (10%, 20 mL) was added, and the mixture was stirred for 10 min. at ambient temperature.The organic layer was separated, washed with sat. sodium hydrogen carbonate, washed with brine, dried (MgSO₄) and concentrated in vacuo. Purification on a Redisep cartridge using a gradient 0-80% of AcOEt/petroleum ether provided the title compound as a colourless oil.

Yield: 161 mg (71%).

¹H NMR (CDCI₃): £2.25-2.38 (2H, m), 3.25-3.35 (2H, t), 3.45-3.55 (2H, t), 7.05- 7.12 (2H, m), 7.17-7.25 (1 H, m), 7.92-7.98 (2H, dd).

Intermediate 7

(3-Bromo-ethane-1-sulfonyl)-benzene

A solution of bromoethylamine hydrobromide (4.2 g, 20 mmol) in 10 mL water was treated successively with benzenesulfonyl chloride (2.61 mL, 20 mmol) and a solution of sodium carbonate (6.5 g, 30 mmol) in 20 mL water. The reaction mixture was stirred at ambient temperature for 16h. Diethyl ether and water were added, the two layers were separated and the organic layer was dried (MgSO₄) and concentrated to dryness. Purification on a Redisep cartridge using a gradient 0-100 % of DCM/cyclohexane as eluent provided the title compound. Yield: 3.5 g (66%). LC-MS (Method 4): Rt 2.81 min, m/z no molecular ion observed

Intermediate 8

(3-Bromo-propane-1-sulfonyl)-benzene

Prepared in a similar manner to intermediate 7, using bromopropylamine hydrobromide in place of bromoethylamine hydrobromide. Yield: 51%.

LC-MS (Method 2): Rt 3.1 1 min, m/z no molecular ion observed.

Intermediate 9

4-Bromo-butyric acid 4-acetylamino-phenyl ester

A suspension of p-hydroxyphenyl acetamide (1.95 g, 12.8 mmol) and di- isopropyl-ethylamine (2.45 ml_, 14.08 mmol) in 100 mL dry DCM at 0 ⁰C was treated dropwise with a solution of 4-bromobutyryl chloride (1.49 mL, 12.8 mmol) in 20 mL dry DCM under inert atmosphere, and the reaction mixture was allowed to warm up to ambient temperature. After 16h water and DCM were added. The two layers were separated and the organic layer was dried (MgSO₄), and evaporated to give the title compound as a white solid. Yield: 3.62 g (94%). LC-MS (Method 2): Rt 3.02min, m/z 301 [MH⁺].

Intermediate 10

Bromo-acetic acid phenethyl ester

A solution of bromoacetyl bromide (3 g, 14.8 mmol) in 6 mL dry DCM at 0 °C was treated dropwise with a solution of 2-phenyl-ethanol (1.84 g, 13.44 mmol) in 4 mL dry DCM under inert atmosphere, and the reaction mixture was allowed to warm up to ambient temperature. After 16h water and DCM were added. The two layers were separated and the organic layer was washed with a sat. sodium hydrogen carbonate, and dried (MgSO₄). The solvent was evaporated to give the title compound.

Yield: 2.95 g (90%).

LC-MS (Method 4): Rt 3.35min, m/z no molecular ion observed. Intermediate 11

r2-(Cvclohexyl-hvdroxy-phenyl-methyl)-oxazol-5-vπ-acetonitrile. To a solution of (δ-bromomethyl-oxazol^-yO-cyclohexyl-phenyl-methanol

(Intermediate 4) (1.05 g, 3.0 mmol) in IMS (15 ml_) was added sodium cyanide (169 mg, 3.45 mmol). The mixture was heated at 70 ⁰C for 1 hour then concentrated in vacuo and partitioned between ethyl acetate (30 mL) and water (30 ml_). The aqueous layer was extracted with ethyl acetate (2 x 30 mL) and the combined organics were dried over sodium sulfate, filtered and evaporated to an orange oil. Purification by flash column chromatography over silica gel using a 40 % ethyl acetate : 60 % cyclohexane mixture as eluent then recrystallisation from DCM/hexane gave the title compound as a white crystalline solid. Yield: 700 mg (79 %) LC-MS (Method 3): Rt 3.66 min, m/z 279 [MH⁺-H₂O].

Intermediate 12

rS-te-Amino-ethyD-oxazol^-vIl-cyclohexyl-phenyl-methanol To a solution of ^-(cyclohexyl-hydroxy-phenyl-methylj-oxazol-δ-ylj-acetonitrile (Intermediate 11) (600 mg, 2.0 mmol) in THF (20 mL) heated at 55 ⁰C was added dropwise a solution of borane-dimethylsulfide complex (2 mL of 2M in THF, 4 mmol). The mixture was heated at reflux for 90 minutes then allowed to cool to ambient temperature. The mixture was then cooled in an ice-bath and quenched by the dropwise addition of methanol (5 mL) followed by hydrochloric acid (1 N, 2 mL). This mixture was stirred for 30 minutes then neutralised with sat. aqueous sodium hydrogen carbonate. The mixture was partitioned between water (80 mL) and ethyl acetate (80 mL), the aqueous extracted with ethyl acetate (2 x 50 mL) and the combined organics dried over sodium sulfate, filtered and evaporated to an oil. The residue was purified by SCX cartridge, washing with methanol then eluting with 4N ammonia in methanol to give the title compound as a colourless oil.

Yield: 400 mg (67%) LC-MS (Method 2): Rt 2.18 min, m/z 283 [MH-H-H₂O]⁺

¹H NMR (CDCI₃) .51.10-1.38 (7 H, m), 1.54-1.77 (3 H, m), 2.28 (1 H, m), 2.80 (2H, t), 2.98 (2H, t), 3.67 (1 H, br s), 6.72 (1 H, s), 7.24 (1 H, m), 7.34 (2H, m), 7.62 (2H, m).

Intermediate 13

Cvclohexyl-rS^-dimethylamino-ethyD-oxazol^-yll-phenyl-methanol.

To a solution of [5-(2-amino-ethyl)-oxazol-2-yl]-cyclohexyl-phenyl-methanol (Intermediate 12) (250 mg, 0.83 mmol) in 1 ,2-dichloroethane (5 mL) was added formaldehyde (0.3 mL of 37% solution in water, 4.0 mmol) and sodium triacetoxyborohydride (352 mg, 1.7 mmol). This mixture was stirred at ambient temperature for 6 hours then DCM (10 mL) and sat. aqueous sodium hydrogen carbonate (10 mL) were added and mixed thoroughly. The organics were isolated through a phase separation cartridge and evaporated to an oil. Purification by flash column chromatography over silica gel using a mixture of 10% methanol : 90% DCM as eluent gave the title compound as a white solid. Yield: 200 mg (73%) LC-MS (Method 2): Rt 2.20 min, m/z 329 [MH⁺]

Intermediate 14

Cvclohexyl-rs^-dimethylamino-ethvD-oxazoi-Σ-yll-phenyl-methanol (first elutinq enantiomer)

The title compound was isolated following preparative chiral HPLC of Intermediate 13. (Chiralpax IA, 250 x 20mm i.d.; 5% ethanol / 95% heptane / 0.1% diethylamine; 15 mL/min; Rt 12 mins).

LC-MS (Method 1 ): Rt 6.74 min, m/z 329 [MH⁺]

¹H NMR (CDCI₃) .51.10-1.37 (7H, m), 1.61 -1.76 (3H, m), 2.26 (6H, s), 2.57 (2H, t), 2.81 (2 H, t), 3.66 (1 H, s), 6.69 (1 H, S), 7.24 (1 H₁ m), 7.34 (2H, t), 7.63 (2H, d).

Intermediate 15

Cvclohexyl-rS-rø-dimethylamino-ethvO-oxazol^-yll-phenvi-methanol. (second elutinq enantiomer)

The title compound was isolated following preparative chiral HPLC of Intermediate 13 using the conditions reported for Intermediate 14; (Rt 13.5 mins). LC-MS (Method 1): Rt 6.76 min, m/z 329 [MH⁺]

Scheme 6

The following compounds were prepared using the route shown in Scheme 6.

Intermediate 16

Cvclohexyl-fS-dimethylaminomethyl-oxazol-Σ-vD-phenyl-methanol.

A solution of (δ-bromomethyl-oxazol^-ylj-cyclohexyl-phenyl-methanol (Intermediate 4) (3.2 g, 9.2 mmol) in 40 mL THF was treated with a 2M solution of dimethylamine in THF (40 mL, 80 mmol). A suspension formed after stirring for a few minutes. The reaction mixture was stood at ambient temperature overnight and then the solid was filtered off and discarded. The filtrate was concentrated under reduced pressure and the residue was partitioned between DCM and sat. sodium hydrogen carbonate solution. The organic layer was dried (Na₂SO₄) and evaporated to give the title compound as a solid.

Yield: 2.74 g (95%)

LC-MS (Method 1 ): Rt 6.57min, m/z 315 [MH⁺]

¹H NMR (DMSOd₆): <50.92-1.29 (m, 6H), 1.42-1.74 (m, 4H), 2.10 (s, 6H), 2.22 (m, 1 H), 3.45 (s, 2H), 5.90 (s, 1 H), 6.98 (s, 1 H), 7.18-7.22 (m, 1 H), 7.27-7.34 (m, 2H), 7.40-7.46 (m, 2H).

The two enantiomers of cyclohexyl-(5-dimethylaminomethyl-oxazol-2-yl)-phenyl- methanol (Intermediate 16) (2.74 g) were separated by chiral preparative HPLC using a 250x20 mm chiralpak® IA column packed with amylase tris (3,5- dimethylphenylcarbamate) immobilized on 5μm silica gel. The column was eluted with 5% ethanol in heptane buffered with 0.1 % diethylamine at 15 ml_/min. The first eluting enantiomer (Rt 8.5 min) gave (S)-cvclohexyl-(5-dimethylaminomethyl-oxazol-2-yl)- phenyl-methanol (Intermediate 17) as a white solid.

Intermediate 17

Yield: 0.73g (27%)

LC-MS (Method 1): Rt 6.50 min, m/z 315 [MH⁺]

¹H NMR (CDCI₃): £1.12-1.39 (m, 7H), 1.62-1.76 (m, 3H), 2.25 (s, 6H), 2.29- 2.32 (m, 1 H), 3.54 (dd_AB, 2H), 3.70 (br.s, 1 H), 6.84 (s, 1 H), 7.24 (t, 1 H), 7.33 (t, 2H), 7.64 (d, 2H). The second eluting enantiomer (Rt 10.3 min) gave (R)-cyclohexyl-(5- dimethylaminomethyl-oxazol-2-yl)-phenyl-methanol, (Intermediate 18) as a white solid.

Intermediate 18

Yield: 1.04g (38%)

LC-MS (Method 1 ): Rt 6.48 min, m/z 315 [MH⁺]

¹H NMR (CDCI₃): δλ .10-1.39 (m, 7H), 1.62-1.76 (m, 3H), 2.25 (s, 6H), 2.29- 2.35 (m, 1 H), 3.54 (dd_A8, 2H), 3.70 (br.s, 1 H), 6.84 (s, 1 H), 7.24 (t, 1 H), 7.33 (t, 2H), 7.64 (d, 2H).

Intermediate 19

i-O-Bromo-propylsulfanylmethylM-chloro-benzene

A mixture of 4-chlorobenzyl mercaptan (3.33 g, 25.2 mmol), 1 ,3-dibromopropane (12.9 mL, 126 mmol) and potassium carbonate (5.22 g, 37.8 mmol) in acetonitrile (40 mL) was heated to 70 ^°C for 16h. The solvent was concentrated in vacuo and the residue was partitioned between ethyl acetate (50 mL) and water (50 mL). The organic layer was separated, dried (MgSO₄) and evaporated to dryness. Purification by column chromatography using 0-5% EtOAc/Petroleum ether (40-60⁰C) provided the title compound as colourless oil. Yield: 3.7 g (69%). NMR: ¹H NMR (300 MHz, CDCI₃): δ 7.32-7.22 (m, 4 H), 3.68 (s, 2 H), 3.47 (t, 2 H), 2.55 (t, 2 H), 2.11-2.00 (m, 2 H).

Intermediate 20

1-(3-Bromo-propane-1-sulfonylmethyl)-4-chloro-benzene

To a solution of 1 -(3-Bromo-propylsulfanylmethyl)-4-chloro-benzene (Intermediate 19) (500 mg, 1.79 mmol) in dry DCM (15 mL) at 0 °C was added mCPBA (77%, 1 g, 4.47 mmol). The reaction mixture was stirred for 2h at 0 ⁰C. Aqueous sodium sulfite (10%, 20 mL) was added, and the mixture was stirred for 10 min. at ambient temperature. The organic layer was separated, washed with sat. sodium hydrogen carbonate, washed with brine, dried (MgSO₄) and concentrated in vacuo. Purification by column chromatography using a gradient of 10-100% of EtOAc/Petroleum ether, provided the title compound as a white solid. Yield: 538 mg (96%).

¹H NMR (300 MHz, CDCI₃): δ 7.42-7.33 (m, 4 H), 4.22 (s, 2 H), 3.50 (t, 2 H), 3.07-3.01 (m, 2 H), 2.40-2.30 (m, 2 H).

Intermediate 21

1-(3-Bromo-propylsulfanyl)-4-chloro-benzene

A mixture of 4-chloro thiophenol (4 g, 25.2 mmol), 1 ,3-dibromopropane (14.0 mL, 138.3 mmol) and potassium carbonate (5.73 g, 41.5 mmol) in acetonitrile (40 mL) was heated to 70 ^°C for 16h. The solvent was removed in vacuo and the residue was partitioned between ethyl acetate (50 mL) and water (50 mL). The organic layer was separated, dried (MgSO₄) and evaporated to dryness. Purification by column chromatography using 0-15% DCM/diethyl ether as eluent provided the title compound as colourless oil. Yield: 2.91 g (40%).

¹H NMR (300 MHz, CDCI₃): δ 7.32-7.24 (m, 4 H), 3.52 (t, 2 H), 3.05 (t, 2 H), 2.18-2.07 (m, 2 H).

Intermediate 22

1 -(3-Bromo-propane-1 -sulfonyl)-4-chloro-benzene

To a solution of 1 -(3-Bromo-propylsulfanyl)-4-chloro-benzene (Intermediate 21 ) (500 mg, 1.88 mmol) in dry DCM (15 ml_) at 0 ⁰C was added mCPBA (77%, 1.05 g, 4.77 mmol). The reaction mixture was stirred for 2h at 0 °C. Aqueous sodium sulfite (10%, 20 ml.) was added, and the mixture was stirred for 10 min. at ambient temperature. The organic layer was separated, washed with sat. sodium hydrogen carbonate, washed with brine, dried (MgSO₄) and concentrated in vacuo. Purification by column chromatography using a gradient of 10-100% of EtOAc/Petroleum ether, provided the title compound as a white solid. Yield: 505 mg (90%).

¹H NMR (300 MHz, CDCI₃): δ 7.89-7.83 (m, 2 H), 7.60-7.54 (m, 2 H), 3.48 (t, 2 H), 3.30-3.22 (m, 2 H), 2.35-2.24 (m, 2 H).

Intermediate 23

1-(3-Bromo-propylsulfanyl)-4-methyl-benzene

A mixture of 4-methyl thiophenol (4 g, 32.21 mmol), 1 ,3-dibromopropane (16.35 ml_, 161 mmol) and potassium carbonate (6.7 g, 48.31 mmol) in acetonitrile (40 mL) was heated to 70 ^°C for 16h. The solvent was concentrated in vacuo and the residue was partitioned between ethyl acetate (50 mL) and water (50 mL). The organic layer was separated, dried (MgSO₄) and evaporated to dryness. Purification by column chromatography using 0-15% DCM/diethyl ether as eluent provided the title compound as colourless oil. Yield: 2.7 g (34%). 1H NMR (300 MHz, CDCI₃): δ 7.28 (d, 2 H), 7.1 1 (d, 2 H), 3.52 (t, 2 H), 3.02

(t, 2 H), 2.32 (s, 3 H), 2.12 (p, 2 H).

Intermediate 24

1 -(3-Bromo-propane-1 -sulf onyl)-4-methyl-benzene

To a solution of 1 -(3-Bromo-propylsulfanyl)-4-methyl-benzene (Intermediate 23) (500 mg, 2.0 mmol) in dry DCM (15 mL) at 0⁰C was added mCPBA (77%, 1.14 g, 5.09 mmol). The reaction mixture was stirred for 2h at 0 °C. Aqueous sodium sulfite (10%, 20 mL) was added, and the mixture was stirred for 10 min. at ambient temperature. The organic layer was separated, washed with sat. sodium hydrogen carbonate, washed with brine, dried (MgSO₄) and concentrated in vacuo. Purification by column chromatography using a gradient 10-100% of EtOAc/petroleum ether provided the title compound as a white solid.

Yield: 534 mg (96%).

¹H NMR (300 MHz, CDCI₃): δ 7.80 (d, 2 H), 7.38 (d, 2 H), 3.47 (t, 2 H), 3.28- 3.20 (m, 2 H), 2.47 (s, 3 H), 2.34-2.23 (m, 2 H).

Intermediate 25

(5-Methyl-oxazol-2-yl)-diphenyl-methanol.

The title compound was prepared from (5-methyl-oxazol-2-yl)-phenyl-methanone using phenylmagnesium bromide under similar conditions to those described for the preparation of cyclohexyl-(5-methyl-oxazol-2-yl)-phenyl-methanol (Intermediate 3).

Yield: 2.06 g (73%).

LCMS (Method 6): Rt 3.78 min 266 [MH⁺]

Intermediate 26

(5-Bromomethyl-oxazol-2-yl)-diphenyl-methanol

The title compound was prepared from (5-methyl-oxazol-2-yl)-diphenyl-methanol under similar conditions to those described for (5-bromomethyl-oxazol-2-yl)-cyclohexyl- phenyl-methanol (Intermediate 4).

Yield: 1.63 g (63%).

LCMS (Method 2): Rt 3.53 m/z 326, 328 [MH⁺-H₂O] Intermediate 27

(5-Dimethylaminomethyl-oxazol-2-yl)-diphenyl-methanol

The title compound was prepared from (5-bromomethyl-oxazol-2-yl)-diphenyl- methanol (Intermediate 26) and dimethylamine under similar conditions to those described for the preparation of Cyclohexyl-(5-dimethylaminomethyl-oxazol-2-yl)- phenyl-methanol (Intermediate 16).

Yield: 1.05 g (68%) - LC-MS (Method 7): Rt 2.07 min, m/z 309 [MH]+.

Example 1

r2-((R)-Cvclohexyl-hvdroxy-phenyl-methyl)-oxazol-5-ylmethvn-dimethyl-(3- phenylsulfanyl-propyP-ammonium bromide

A solution of (R)-cyclohexyl-(5-dimethylaminomethyl-oxazol-2-yl)-phenyl-methanol (Intermediate 18) (100 mg, 0.31 mmol) and (3-bromo-propylsulfanyl)-benzene (Intermediate 5) (368 mg, 1.59 mmol) in 10 ml. CH₃CN/CHCI₃ (ratio 2/3) was heated to 50 °C for 4Oh. The solvent was evaporated, .and the mixture was purified by column chromatography using DCM, then AcOEt then 10% MeOH/DCM as the eluent. The combined fractions were concentrated to afford the title compound as a pale yellow foam.

Yield: 146 mg (84%)

LC-MS (Method 1 ): Rt 8.62min, m/z 466 [M⁺]

¹H NMR (CDCI₃): δ 1.05-1.20 (m, 3H), 1.22-1.40 (m, 5H), 1.58-1.80 (m, 4H), 2.00 -2.15 (m, 2H), 2.30-2.40 (m, 1 H), 2.90-2.95 (t, 2H), 3.20-3.25 (s, 6H), 3.50-3.60 (m, 2H), 4.05-4.10 (s, 1 H), 5.10-5.25 (m, 2H), 7.20-7.25 (m, 3H), 7.30-7.35 (m, 4H), 7.50 (s, 1 H), 7.55-7.60 (d, 2H).

Example 2

r2-((R)-Cvclohexyl-hvdroxy-phenyl-methyl)-oxazol-5-ylmethyll-dimethyl-f3- benzenesulfonyl-propyD-ammonium bromide. The title compound was prepared according to the method used to prepare Example 1 , using Intermediate 6 in place of Intermediate 5.

LC-MS (Method 1 ): Rt 7.84min, m/z 497 [M⁺]

¹H NMR (CDCI₃): £0.98-1.15 (m, 3H), 1.16-1.34 (m, 4H), 1.52-1.65 (m, 3H), 2.22- 2.52 (m, 3H), 3.07-3.38 (br.m, 8H), 3.60-3.87 (br.m, 2H), 4.90-5.14 (br.m, 2H), 7.16 (t, 1 H), 7.20 -7.31 (m, 2H), 7.44-7.60 (m, 5H), 7.65 (t, 1 H), 7.88 (d, 2H).

Example 3

(2-Benzenesulfonylamino-ethylH2-((R)-cvclohexyl-hvdroxy-phenyl-metriyl)- oxazol-5-ylmethyll-dimethyl-ammonium bromide

The title compound was prepared according to the method used to prepare Example 1 , using Intermediate 7 in place of Intermediate 5.

LC-MS (Method 1): Rt 7.84min, m/z 498 [M⁺]

¹H NMR (CDCI₃): δλ .02-1.43 (m, 7H), 1.57-1.78 (m, 3H), 2.25-2.37 (m, 1 H), 3.24 (s, 6H), 3.41 (s, 2H), 3.72 (s, 2H), 4.93-5.10 (m, 2H), 7.16-7.31 (m, 3H), 7.45- 7.58 (m, 6H), 7.86-7.92 <m, 2H).

Example 4

(2-Benzenesulfonylamino-propyl)-r2-((R)-cvclohexyl-hvdroxy-phenyl-methyl)- oxazol-5-ylmethyll-dimethyl-ammonium bromide

The title compound was prepared according to the method used to prepare Example 1 , using Intermediate 8 in place of Intermediate 5. LC-MS (Method 1 ): Rt 7.87min, m/z 512 [M⁺]

¹H NMR (CDCI₃): δ: 1.00-2.00 (m, 10H)₁ 2.09-2.23 (m, 2H), 2.25-2.37 (m, 1 H), 2.93-3.05 (m, 2H), 3.17 (s, 6H), 3.62-3.74 (m, 2H), 4.86-5.05 (m, 2H), 7.14-7.32 (m, 3H), 7.45-7.59 (m, 6H), 7.72 (b s, 1 H), 7.89-7.97 (m, 2H).

Example 5

r3-(4-acetylam[no-phenoxycarbonyl)-propyn-r2-((R)-cyclohexyl-hvdroxy-phenyl- methyl)-oxazol-5-ylmethyll-dimethyl-ammonium formate

A solution of (R)-cyclohexyl-(5-dimethylaminomethyl-oxazol-2-yl)-phenyl-methanol (Intermediate 18) (100 mg, 0.31 mmol) and 4-bromo-butyric acid 4-acetylamino- phenyl ester (Intermediate 9) (477 mg, 1.59 mmol) in 5 ml. CH₃CN/CHCI₃ (ratio 2/3) was heated to 50 ⁰C for 16h. The solvent was concentrated, and the mixture was purified on a Jones Si cartridge, using AcOEt then 20% MeOH/DCM as the eluent. The compound was further purified by preparative HPLC, using a gradient 20-80% CH₃CN/H₂O (+0.1 % HCO₂H). The fractions were freeze-dried to afford the title compound as a white solid. Yield: 73 mg (40%) LC-MS (Method 1 ): Rt 7.49min, m/z 534 [M⁺]

¹H NMR (Acetone-de): δλ .01 -1.42 (m, 6H), 1.54-1.77 (m, 4H), 2.29-2.45 (m, 3H), 2.75 (t, 2H), 3.38 (s, 6H), 3.65- 3.77 (m, 2H), 5.00-5.18 (m, 2H), 7.04 (d, 2H), 7.19-7.37 (m, 3H)₁ 7.55-7.63 (m, 3H), 7.76 (d, 2H). Example 6

(Benzyloxycarbonylmethyl)-f2-((R)-cvclohexyl-hvdroxy-phenyl-methyl)-oxazol-5- ylmethyll-dimethyl-ammonium bromide

The title compound was prepared according to the method used to prepare Example 1 using benzyl bromoacetate in place of Intermediate 5.

LC-MS (Method 1 ): Rt 7.86min, m/z 463 [M⁺]

¹H NMR (CDCI₃): δ 1.04-1.39 (m, 8H), 1.47-1.79 (m, 2H), 2.25-2.35 (m, 1 H), 3.45 (s,6H), 4.86 (s, 2H), 5.20 (s, 2H), 5.21-5.42 (m, 2H), 7.19-7.39 (m, 9H), 7.50- 7.56 (m, 2H).

Example 7

f2-((R)-Cvclohexyl-hvdroxy-phenyl-methyl)-oxazol-5-ylmethyl]-dimethyl- phenethyloxycarbonylmethyl-ammonium bromide

The title compound was prepared according to the method used to prepare Example 1 using Intermediate 10 in place of Intermediate 5.

LC-MS (Method 1 ): Rt 8.1 1 min, m/z 477 [M⁺]

¹H NMR (CDCI₃): δ 0.99-1.43 (m, 7H), 1.58-2.16 (m, 3H), 2.24-2.39 (m, 1 H), 2.96 (t, 2H), 3.40 (s, 6H), 4.42 (t, 2H), 4.82 (s, 2H), 5.16-5.39 (m, 2H), 7.10-7.43 (m, 9H), 7.55 (d, 2H). Example 8

f2-r2-fCvclohexyl-hvdroxy-phenyl-methyl)-oxazol-5-vn-ethyl}-dimethyl-(3- phenylsulfanyl-propyD-ammonium bromide, (from second elutinq enantiomer)

The title compound was prepared according to the method used to prepare Example 1 , using Intermediate 15 in place of Intermediate 18.

LC-MS (Method 5): Rt 8.27min, m/z 479 [M⁺]

¹H NMR (MeOD): δ 1.02-1.39 (m, 6H), 1.48-1.59 (m, 1 H), 1.60-1.81 (m, 3H), 1.97-2.10 (m, 2H), 2.31 -2.42 (m, 1 H), 3.01 (t, 2H), 3.07 (s, 6H), 3.14-3.24 (m, 2H), 3.47-3.62 (m, 4H), 6.93 (s, 1 H), 7.16-7.26 (m, 2H), 7.26-7.35 (m, 4H), 7.40 (d, 2H), 7.50 (d, 2H).

Example 9

(2-Benzoyloxy-ethyl)-f2-((R)-cvclohexyl-hvdroxy-phenyl-methyl)-oxazol-5-ylmethvn dimethyl-ammonium bromide

The title compound was prepared according to the method used to prepare Example 1 , using 2-bromoethyl benzoate in place of Intermediate 5.

LC-MS (Method 1 ): Rt 7.70 min, m/z 463 [M⁺]

¹H NMR (CDCI₃): δ 1.01-1.76 (m, 10H), 2.26-2.39 (m, 1 H), 3.39 (bs, 6H), 3.97 -4.04 (m, 2H), 4.79-4.82 (m, 2H), 5.18-5.29 (m, 2H), 7.10-7.16 (m, 2H), 7.22-7.26 (m, 2H), 7.36-7.40 (m, 2H), 7.51 -7.55 (m, 2H), 7.64 (s, 1 H), 7.92-7.95 (m, 2H). Example 10

r2-((R)-Cvclohexyl-hvdroxy-phenyl-methvπ-oxazol-5-ylmethvn-dimethyl-(4- methyl-benzyloxycarbonylmethyl-ammonium bromide.

The title compound was prepared according to the method used to prepare Example 1 , using bromoacetic acid 4-methyl-benzyl ester in place of Intermediate 5.

LC-MS (Method 1): Rt 8.59 min, m/z 478 [M⁺]

¹H NMR (CDCI₃): δλ .09-1.40 (m, 8H), 1.56-1.80 (m, 2H), 2.27 (m, 1 H), 2.35 (s, 3H), 3.43 (s, 6H)₁ 3.98 (s, 1 H), 4.82 (s, 2H), 5.17 (s, 2H), 5.22-5.30 (d, 1 H), 5.32-5.42 (d, 1 H), 7.15-7.30 (m, 7H), 7.35 (s, 1 H), 7.52 (d, 2H).

Example 11

r3-(4-Chloro-ben2ylsulfanvπ-propyI1-r2-f(R)-cvclohexyl-hvdroxy-phenyl-methyl)- oxazol-5-ylmethyll-dimethyl-ammonium bromide

A solution of (R)-cyclohexyl-(5-dimethylaminomethyl-oxazol-2-yl)-phenyl-methanol (Intermediate 18) (50 mg, 0.16 mmol) and 1-(3-Bromo-propylsulfanylmethyl)-4- chloro-benzene (Intermediate 19) (222 mg, 0.796 mmol) in 1.5 ml. CH₃CN/CHCI₃ (ratio 2/3) was heated to 35 ⁰C for 4Oh. The solvent was concentrated and the mixture was purified by column chromatography using DCM, then AcOEt then 10% MeOH/DCM as the eluent. The combined fractions were concentrated to afford the title compound as a white foam.

Yield: 102 mg (100%)

LC-MS (Method 5): Rt 8.77min, m/z 515 [M⁺]

¹H NMR (400 MHz, CDCI₃): δ 7.58-7.54 (m, 3 H), 7.30-7.27 (m, 6 H), 7.25-7.17 (m, 1 H), 5.23-5.03 (m, 2 H)₁ 4.23 (s, 1 H), 3.70 (s, 2 H), 3.43-3.33 (m, 2 H), 3.23 (d, 6 H), 2.44 (t, 2 H), 2.32 (s, 1 H), 2.00 (m, 4 H)₁ 1.74 (m, 3 H), 1.32 (m, 4 H), 1.19- 1.08 (m, 3 H).

Example 12

r2-((R)-Cvclohexyl-hvdroxy-phenyl-methyl)-oxazol-5-ylmethvn-dimethyl-(3-p- tolylsulfanyl-propyD-ammonium bromide

The title compound was prepared according to the method used to prepare Example 11 , using Intermediate 23 in place of Intermediate 5.

LC-MS (Method 5): Rt 8.55min, m/z 480 [M⁺]

¹H NMR (400 MHz, CDCI₃): δ 7.62-7.50 (m, 2 H), 7.50 (s, 1 H), 7.30 (t, 2 H), 7.24- 7.19 (m, 3 H), 7.11 (d, 2 H), 5.27-5.07 (m, 2 H), 4.17-4.08 (m, 1 H), 3.62-3.45 (m, 2 H), 3.23 (d, 6 H), 2.88 (t, 2 H), 2.32 (s, 4 H), 2.02 (p, 2 H), 1.74 (m, 3 H), 1.40-1.20 (m, 4 H), 1.19-1.10 (m, 3 H).

Example 13

r3-(4-Chloro-phenylsulfanyl)-propyn-f2-((R)-cvclohexyl-hydroxy-phenyl-methyl)- oxazol-5-ylmethyll-dimethyl-ammonium bromide

The title compound was prepared according to the method used to prepare Example 11 , using Intermediate 21 in place of Intermediate 5.

LC-MS (Method 5): Rt 8.65min, m/z 501 [M⁺]

¹H NMR (400 MHz, CDCI₃): δ 7.60-7.52 (m, 2 H), 7.52 (s, 1 H), 7.31 (t, 2 H), 7.28 (s, 4 H), 7.24 (d, 1 H)₁ 5.27-5.10 (m, 2 H), 3.97 (s, 1 H), 3.68-3.56 (m, 2 H), 3.24 (s, 6 H), 2.93 (t, 2 H), 2.33 (s, 1 H), 2.13-2.02 (m, 2 H), 1.79-1.62 (m, 3 H), 1.39-1.21 (m, 4 H), 1.21-1.07 (m, 3 H). Example 14

r3-(4-Chloro-phenylmethanesulfonyl)-propyn-f2-((R)-cvclohexyl-hydroxy-phenyl- methyl)-oxazol-5-ylmethyl1-dimethyl-ammonium bromide

The title compound was prepared according to the method used to prepare Example 11 , using Intermediate 20 in place of Intermediate 5.

LC-MS (Method 5): Rt 8.02min, m/z 546 [M⁺]

¹H NMR (400 MHz, CDCI₃): δ 7.53-7.49 (m, 2 H), 7.44-7.37 (m, 1 H), 7.35 (d, 2 H), 7.42-7.12 (m, 4 H), 7.20 (t, 1 H), 4.94 (m, 2 H), 4.42 (s, 1 H), 3.64 (m, 2 H), 3.17 (m, 8 H), 2.48-2.26 (m, 3 H), 1.67 (s, 4 H), 1.48-1.40 (m, 1 H), 1.29-1.21 (m, 4 H), 1.15-1.03 (m, 3 H).

Example 15

r3-(4-Chloro-benzenesulfonyl)-propyn-f2-((R)-cyclohexyl-hvdroxy-phenyl-methvπ- oxazol-5-ylmethyll-dimethyl-ammonium bromide

The title compound was prepared according to the method used to prepare Example 11 , using Intermediate 22 in place of Intermediate 5.

LC-MS (Method 5): Rt 7.93min, m/z 533 [M⁺]

¹H NMR (400 MHz, CDCI₃): δ 7.88 (d, 2 H), 7.59-7.49 (m, 5 H), 7.29 (d, 2 H), 7.19 (t, 1 H), 5.10-4.96 (m, 2 H), 4.42 <s, 1 H), 3.81-3.69 (m, 2 H), 3.26 (d, 8 H), 2.40-

2.31 (m, 3 H), 1.84-1.51 (m, 3 H), 1.43 (s, 1 H), 1.35-1.20 (m, 3 H), 1.13 (d, 3 H).

Example 16

r2-(fR)-Cvclohexyl-hvdroxy-phenyl-methyl)-oxazol-5-ylmethvn-dimethyl-r3-(toluene- 4-sulfonyl)-propyll-ammonium bromide

The title compound was prepared according to the method used to prepare Example 11 , using Intermediate 24 in place of Intermediate 5.

LC-MS (Method 5): Rt 7.68min, m/z 512 [M⁺]

¹H NMR (400 MHz, CDCI₃): δ 7.78 (d, 2 H), 7.53 (d, 3 H), 7.37 (d, 2 H), 7.31-7.25 (m, 2 H), 7.20 (d, 1 H), 5.14-4.98 (m, 2 H), 4.38 (s, 1 H), 3.82-3.63 (m, 2 H), 3.28 (d, 6 H), 3.25-3.12 (m, 2 H), 2.45 (s, 3 H), 2.37 (m, 3 H), 1.81 (s, 3 H), 1.49-1.35 (m, 1 H), 1.34-1.19 (m, 3 H), 1.17-1.05 (m, 3 H).

Example 17

r2-(Hvdroxy-diphenyl-methyl)-oxazol-5-ylmethvM-dimethyl-(3-phenylsulfanyl- propyD-ammonium bromide

A solution of (5-Dimethylaminomethyl-oxazol-2-yl)-diphenyl-methanol (Intermediate 27) (100 mg, 0.32 mmol) and (3-bromo-propylsulfanyl)-benzene (Intermediate 5) (113 mg, 0.487 mmol) in 430 μl_ CH₃CN/CHCI₃ (ratio 2/3) was heated to 50⁰C for 68h. The solvent was evaporated and the product was triturated with DCM and collected by filtration to afford the title compound as a white solid.

Yield: 109 mg (60%)

LC-MS (Method 1): Rt 7.92min, m/z 459 {M⁺]

¹H NMR (400 MHz, DMSO-dD): δ 7.52 (s, 1 H)₁ 7.39-7.30 (m, 11 H), 7.29-7.20 (m, 3 H), 7.13 (s, 1 H), 4.75 (S₁ 2 H), 3.30 (d, 3 H)₁ 2.99 (s, 6 H), 2.91 (t, 2 H)₁ 2.07-1.96 (m, 2 H). Example 18

f3-(4-Chloro-phenylsulfanyl)-propyll-r2-(hvdroxy-diphenyl-methyl)-oxazol-5- ylmethyll-dimethyl-ammonium bromide

The title compound was prepared according to the method used to prepare Example 17 , using Intermediate 21 in place of Intermediate 5.

Yield: 130 mg (81%)

LC-MS (Method 5): Rt 8.04min, m/z 493 [M⁺]

¹H NMR (400 MHz, DMSO-dD): δ 7.52 (s, 1 H), 7.40-7.24 (m, 14 H), 7.13 (s, 1 H), 4.73 (s, 2 H), 3.30-3.26 (m, 3 H), 2.98 (s, 6 H), 2.90 (t, 2 H), 2.06-1.96 (m, 2 H).

Example 19

[2-((R)-Cyclohexyl-hydroxy-phenyI-methyl)-oxazol-5-ylmethyI]-dimethyl-((S)-1- phenyl-ethoxycarbonylmethyl)-ammonium formate The title compound was prepared according to the method used to prepare Example 1 using bromoacetic acid (S)-1 -phenyl-ethyl ester (JACS, 2001 , 123(25), 5962-5973) in place of Intermediate 5.

Yield: 41 mg (46%)

LC-MS (Method 1 ): Rt 8.82min, m/z 477 [M⁺] 1H NMR (400 MHz, CDCI₃): δ 8.64 (s, 1 H)₁ 7.56-7.50 (m, 2 H), 7.39-7.26 (m, 7 H), 7.26-7.15 (m, 2 H), 5.88 (q, 1 H), 5.19 (d, 1 H), 5.08 (d, 1 H), 4.83 (d, 1 H), 4.44 (d, 1 H), 3.31 (s, 6 H), 2.91 (s, 4 H), 2.28 (d, 1 H), 1.73 (d, 3 H), 1.43 (d, 1 H), 1.32 (d, 3 H), 1.19-1.08 (m, 3 H). Example 20

[2-((R)-Cyclohexyl-hydroxy-phenyl-methyl)-oxazol-5-ylmethyl]-dimethyl-((R)-1- phenyl-ethoxycarbonylmethyl)-ammonium formate

Step 1. Bromoacetic acid (R)-1 -phenyl-ethyl ester was prepared according to the procedure described in JACS, 2001 , 123(25), 5962-5973 using (R)-1 -Phenyl-ethanol in place of (S)-1 -Phenyl-ethanol.

Yield: 1.29 g (81%) The title compound was prepared according to the method used to prepare Example 1 using Bromo-acetic acid (R)-1 -phenyl-ethyl ester in place of Intermediate 5. Yield: 43 mg (49%)

LC-MS (Method 6): Rt 8.26min, m/z 477 [M⁺]

¹H NMR (400 MHz, CDCI₃): δ 8.64 (s, 1 H), 7.53-7.48 (m, 2 H), 7.38-7.25 (m, 7 H), 7.23-7.15 (m, 1 H), 7.13 (s, 1 H), 5.87 (q, 1 H), 5.14 (d, 1 H), 5.02 (d, 1 H), 4.82 (d, 1 H), 4.44 (d, 1 H), 3.32 (d, 6 H), 2.72 (s, 4 H), 2.27 (s, 1 H), 1.73-1.57 (d, 3 H), 1.52- 1.42 (m, 1 H), 1.38-1.19 (m, 3 H), 1.18-1.08 (m, 3 H).

BIOLOGICAL EXAMPLES The inhibitory effects of compounds of the present invention at the M3 muscarinic receptor were determined by the following binding assays:

Muscarinic Receptor Radioligand Binding Assays

Radioligand binding studies utilising [³H]-N-methyl scopolamine ([³H]-NMS) and commercially available cell membranes expressing the human muscarinic receptors (M2 and M3) were used to assess the affinity of muscarinic antagonists for M2 and M3 receptors. Membranes in TRIS buffer were incubated in 96-well plates with [³H]- NMS and M3 antagonist at various concentrations for 3 hours. Membranes and bound radioligand were then harvested by filtration and allowed to dry overnight. Scintillation fluid was then added and the bound radioligand counted using a Canberra Packard Topcount scintillation counter The half-life of antagonists at each muscarinic receptor was measured using the alternative radioligand [³H]-QNB and an adaptation of the above affinity assay. Antagonists were incubated for 3 hours at a concentration 10-fold higher than their Ki, as determined with the [³H]-QNB ligand, with membranes expressing the human muscarinic receptors. At the end of this time, [³H]-QNB was added to a concentration 25-fold higher than its Kd for the receptor being studied and the incubation continued for various time periods from 15 minutes up to 180 minutes. Membranes and bound radioligand were then harvested by filtration and allowed to dry overnight. Scintillation fluid was then added and the bound radioligand counted using a Canberra Packard Topcount scintillation counter.

The rate at which [3H]-QNB is detected binding to the muscarinic receptors is related to the rate at which the antagonist dissociates from the receptor, ie. to the half life of the antagonists on the receptors.

Alternatively,

Recombinant human M3 receptor was expressed in CHO-K1 cells. Cell membranes were prepared and binding of [3H]-N-methyl scopolamine ([3H]-NMS) and compounds was assessed by a scintillation proximity assay (SPA). The incubation time was 16 hours at room temperature in the presence of 1 % (v/v) DMSO. The assay was performed in white 96 well clear-bottomed NBS plates (Corning). Prior to the assay, the CHO cell membranes containing M3 receptor were coated onto SPA WGA (Wheat germ agglutinin) beads (GE Healthcare). Non specific binding was determined in the presence of 1 μM Atropine.

Radioactivity was measured on a Microbeta scintillation counter (PerkinElmer) using a 3H protocol with a 2 minutes per well read time. Compound inhibition of [3H]-NMS binding was determined typically using concentrations in the range 0.03 nM to 1 μM and expressed as percent inhibition relative to the plate specific radioligand binding for the plate. Concentration dependent inhibition of [3H]-NMS binding by compounds was expressed as plC50.

M3 Binding Ki < 1 nM "+++"; Kj 1-10 nM "++", K; > 10 nM, "+".

As an additional illustration of the invention, Example 8 exhibited a binding Kj of

0.11 nM and Example 1 exhibited a binding Kj of 0.35nM against the M3 receptor.

All compounds tested in the M3 binding assays exhibited potencies greater than 25 nM. Analysis of Inhibition of M3 Receptor Activation via Calcium Mobilization

CHO cells expressing the human M3 receptor were seeded and incubated overnight in 96 well collagen coated plates (black-wall, clear bottom) at a density of 50000 / 75μl of medium in 3% serum. The following day, a calcium-sensitive dye (Molecular Devices, Cat # R8041) was prepared in HBSS buffer with the addition of 5mM probenecid (pH 7.4). An equal volume of the dye solution (75μl) was added to the cells and incubated for 45 minutes followed by addition of 50μl of muscarinic antagonists or vehicle. After a further 15 minutes the plate was read on a FLEXstation™ (excitation 488nm, emission 525nm) for 15 seconds to determine baseline fluorescence. The muscarinic agonist Carbachol was then added at an EC₈₀ concentration and the fluorescence measured for a further 60 seconds. The signal was calculated by subtracting the peak response from the mean of the baseline fluorescence in control wells in the absence of antagonist. The percentage of the maximum response in the presence of antagonist was then calculated in order to generate IC₅₀ curves.

Evaluation of potency and duration of action in Isolated Guinea Pig Trachea

Experiments were carried out at 37⁰C in modified Krebs-Henseleit solution, (114mM NaCI, 15mM NaHCO₃, 1 mM MgSO₄, 1.3mM CaCI₂, 4.7mM KCI, 11.5mM glucose and 1.2mM KH₂PO₄ , pH 7.4) gassed with 95% O₂/5% CO₂. lndomethacin was added to a final concentration of 3μM

Tracheae were removed from adult male Dunkin Hartley Guinea pigs and dissected free of adherent tissue before being cut open longitudinally in a line opposite the muscle. Individual strips of 2-3 cartilage rings in width were cut and suspended using cotton thread in 10mL water-jacketed organ baths and attached to a force transducer ensuring that the tissue is located between two platinum electrodes. Responses were recorded via a MPIOOW/Ackowledge data acquisition system connected to a PC. Tissues were equilibrated for one hour under a resting tone of 1 g and were then subjected to electrical field stimulation at a frequency of 80Hz with a pulse width of 0.1 ms, a unipolar pulse, triggered every 2 minutes. A "voltage-response" curve was generated for each tissue and a submaximal voltage then applied to every piece of tissue according to its own response to voltage. Tissues were washed with Krebs solution and allowed to stabilize under stimulation prior to addition of test compound. Concentration response curves were obtained by a cumulative addition of test compound in half-log increments. Once the response to each addition had reached a plateau the next addition was made. Percentage inhibition of EFS-stimulated contraction is calculated for each concentration of each compound added and dose response curves constructed using Graphpad Prism software and the EC₅₀ calculated for each compound.

Onset time and duration of action studies were performed by adding the previously determined EC₅₀ concentration of compound to EFS contracted tissues and the response allowed to plateau. The time taken to reach 50% of this response was determined to be the onset time. Tissues were then washed free of compound by flushing the tissue bath with fresh Krebs solution and the time taken for the contraction in response to EFS to return to 50% of the response in the presence of compound is measured. This is termed the duration of action.

Methacholine Induced Bronchoconstriction in vivo

Male Guinea pigs (Dunkin Hartley), weighing 500-60Og housed in groups of 5 were individually identified. Animals were allowed to acclimatize to their local surroundings for at least 5 days. Throughout this time and study time animals were allowed access to water and food ad libitum.

Guinea pigs were anaesthetized with the inhaled anaesthetic Halothane (5%). Test compound or vehicle (0.25 - 0.50 mlVkg) was administered intranasally. Animals were placed on a heated pad and allowed to recover before being returned to their home cages.

Up to 72hrs post dosing guinea pigs were terminally anaesthetized with Urethane

(250μg/mL, 2mL/kg). At the point of surgical anaesthesia, the jugular vein was cannulated with a portex i.v. cannula filled with heparinised phosphate buffered saline (hPBS) (10U/mL) for i.v. administration of methacholine. The trachea was exposed and cannulated with a rigid portex cannula and the oesophagus cannulated transorally with a flexible portex infant feeding tube.

The spontaneously breathing animal was then connected to a pulmonary measurement system (EMMS, Hants, UK) consisting of a flow pneumotach and a pressure transducer. The tracheal cannula was attached to a pneumotach and the oesophageal cannula attached to a pressure transducer.

The oesophageal cannula was positioned to give a baseline resistance of between

0.1 and 0.2cmH20/ml_/s. A 2 minute baseline reading was recorded before i.v. administration of methacholine (up to 30μg/kg, 0.5ml_/kg). A 2 minute recording of the induced constriction was taken from the point of i.v. administration.

The software calculated a peak resistance and a resistance area under the curve (AUC) during each 2 minute recording period which were used to analyse the bronchoprotective effects of test compounds.

Inhibition of pilocarpine induced salivation by Ln. administered compounds. Guinea pigs (450-55Og) supplied by Harlan UK or David Hall, Staffs UK and acclimatised to the in-house facilities for a minimum of three days before use. Guinea pigs were randomly assigned into treatment groups and weighed. Each animal was lightly anaesthetised (4% Halothane) and administered compound or vehicle intranasally (0.5ml_/kg) at up to 24 hours before challenge with pilocarpine. At the test time point, guinea pigs were terminally anaesthetised with urethane (25% solution in H20, 1.5g/kg). Once sufficient anaesthesia had developed (absence of toe pinch reflex) each animal had an absorbent pad placed in the mouth for 5 minutes to dry residual saliva, this pad was removed and replaced with a new pre-weighed pad for 5 minutes to establish a reading of baseline saliva production. At the end of this 5 minute period the pad was removed and weighed. A new pre-weighed pad was inserted into the mouth before each animal received s.c. pilocarpine administered under the skin at the back of the neck (0.6mg/kg @ 2ml_/kg). The pad was removed, weighed and replaced with a new pre-weighed pad every 5 minutes up to 15 minutes.

Saliva production was calculated by subtracting the pre-weighed weight of the pad from each 5 minute period post weighed pad and these numbers added together to produce an accumulation of saliva over 15 minutes. Each 5 minute period could be analysed in addition to the whole 15 minute recording period. Baseline production of saliva was assumed to be constant and multiplied by three to produce a reading for baseline saliva production over 15 minutes.

Inhibition of saliva produced by the compound could be calculated by using the following equation:

(1 -(Test-baseline)/(Veh-baseline))^*100.

Claims

1. A compound of formula (I):

wherein

(i) R¹ is CrCβ-alkyl or hydrogen; and R² is a group, -Z-Y-W-R⁷; and R³ is a lone pair or CrC₆-alkyl; or

(ii) R¹ and R³ together with the nitrogen to which they are attached form a heterocycloalkyl ring, and R² is a group -Z-Y-W-R⁷; or

(iii) R¹ and R² together with the nitrogen to which they are attached form a heterocycloalkyl ring, said ring being substituted by a group -Y-W-R⁷ or -Z-Y-W-R⁷; and R³ is a lone pair or d-Ce-alkyl;

R⁴ and R⁵ are independently selected from the group consisting of aryl, aryl-fused- heterocycloalkyl, heteroaryl, d-C₆-alkyl and cycloalkyl;

κ 9 10 R⁶ is OH, d-Ce-alkyl, C,-C₆-alkoxy, hydroxy-C_rC₆-alkyl, nitrile, a group CONR R or a hydrogen atom;

A is an oxygen or a sulfur atom;

X is a d-C₈-alkylene, C₂-C₈-alkenylene or C₂-C₈-alkynylene group;

W is a direct bond or a d-C₈-alkylene, C₂-C₈-alkenylene or C₂-C₈-alkynylene group;

R⁷ is an Ci-C₆-alkyl, aryl, aryl-fused-cycloalkyl, aryl-fused-heterocycloalkyl, heteroaryl, cycloalkyl or heterocycloalkyl group;

R⁸, R⁹, R¹⁰ and R¹¹ are each independently selected from C_rC₆-alkyl or a hydrogen atom;

Z is a C_rC₁₆-alkylene, C₂-C₁₆-alkenylene or C₂-C₁₆-alkynylene group; and

Y is -S-, -SO-, -SO₂-, -CO₂-, -OC(=O)-, -N(R¹¹)SO₂- or -SO₂N(R¹¹)-;

wherein, unless otherwise specified, each occurrence of alkyl, alkenyl, heterocycloalkyl, aryl, aryl-fused-heterocycloalkyl, heteroaryl, cycloalkyl, alkoxy, alkylene, alkenylene, alkynylene or aryl-fused-cycloalkyl, independently, may be optionally substituted; and wherein each alkenylene chain contains, where possible, up to 3 carbon-carbon double bonds and each alkynylene chain contains, where possible, up to 3 carbon- carbon triple bonds; or a pharmaceutically acceptable salt thereof.

2. A compound as claimed in claim 1 , or a pharmaceutically acceptable salt thereof, wherein R¹ is methyl or ethyl, or a hydrogen atom; R² is-Z- Y-W-R⁷, and R³ is a lone pair or C_rC₆-alkyl.

3. A compound as claimed in any one of claims 1 to 2, or a pharmaceutically acceptable salt thereof, wherein R⁷ is phenyl optionally substituted with 1 or 2 substituents independently selected from Ci-C₆-alkyl, CrCVhaloalkyl, C₁-C₆- haloalkoxy, CN, -N(R¹²)C(O)d-C₆alkyl and halo, wherein R¹² is selected from H and C_rC₆alkyl.

4. A compound as claimed in any one of claims 1 to 2, or a pharmaceutically acceptable salt thereof, wherein -W-R⁷ is a lipophilic group such as phenyl, benzyl, dihydrobenzofuryl or phenylethyl.

5. A compound as claimed in any of the preceding claims, or a pharmaceutically acceptable salt thereof, wherein (i) each of R⁴ and R⁵ is thienyl; or (ii) each of R⁴ and R⁵ is phenyl; or (iii) one of R⁴ and R⁵ is phenyl and the other is cyclopentyl or cyclohexyl; or (iv) one of R⁴ and R⁵ is thienyl, and the other is cyclopentyl or cyclohexyl.

6. A compound as claimed in claim 5, or a pharmaceutically acceptable salt thereof, wherein R⁶ is -OH.

7. A compound as claimed in any of the preceding claims, or a pharmaceutically acceptable salt thereof, wherein R⁸ is hydrogen.

8. A compound as claimed in any of the preceding claims, or a pharmaceutically acceptable salt thereof, wherein X is -CH₂- or

-CH₂CH₂-.

9. A compound as claimed in claim 1 , selected from the group consisting of

^-((RJ-cyclohexyl-hydroxy-phenyl-methylJ-oxazol-S-ylmethylJ-dimethyl-CS- phenylsulfanyl-propyl)-ammonium salt;

[2-((R)-cyclohexyl-hydroxy-phenyl-methyl)-oxazol-5-ylmethyl]-dimethyl-(3- benzenesulfonyl-propyl)-ammonium salt; (2-benzenesulfonylamino-ethyl)-[2-((R)-cyclohexyl-hydroxy-phenyl-methyl)-oxazol-5- ylmethyl]-dimethyl-ammonium salt;

(2-benzenesulfonylamino-propyl)-[2-((R)-cyclohexyl-hydroxy-phenyl-methyl)-oxazol-5- ylmethyl]-dimethyl-ammonium salt;

[3-(4-acetylamino-phenoxycarbonyI)-propyl]-[2-((R)-cyclohexyl-hydroxy-phenyl- methyl)-oxazol-5-ylmethyl]-dimethyl-ammonium salt;

(benzyloxycarbonylmethyl)-[2-((R)-cyclohexyl-hydroxy-phenyl-methyl)-oxazol-5- ylmethyl]-dimethyl-ammonium salt;

[2-((R)-cyclohexyl-hydroxy-phenyl-methyl)-oxazol-5-ylmethyl]-dimethyl- phenethyloxycarbonylmethyl-ammonium salt; {2-[2-(cyclohexyl-hydroxy-phenyl-methyl)-oxazol-5-yl]-ethyl}-dimethyl-(3- phenylsulfanyl-propyl)-ammonium salt;

{2-benzoyloxy-ethyl)-[2-((R)-cyclohexyl-hydroxy-phenyl-methyl)-oxazol-5-ylmethyl]- dimethyl-ammonium salt; and

[2-((R)-cyclohexyl-hydroxy-phenyl-methyl)-oxazol-5-ylmethyl]-dimethyl-(4-methyl- benzyloxycarbonylmethyl-ammonium salt; wherein each ammonium salt comprises a pharmaceutically acceptable anion.

10. A compound as claimed in any of the preceding claims, or a pharmaceutically acceptable salt thereof, for use in therapy.

11. A pharmaceutical composition comprising a compound as claimed in any of claims 1 to 9, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier or excipient.

12. A pharmaceutical composition as claimed in claim 11 , or a pharmaceutically acceptable salt thereof, in a form suitable for inhalation.

13. Use of a compound as claimed in any of claims 1 to 9, or a pharmaceutically acceptable salt thereof, for the manufacture of a medicament for use in the treatment of prevention of a disease or condition in which M3 muscarinic receptor activity is implicated.

14. A method of treatment of a disease or condition in which M3 muscarinic receptor activity is implicated comprising administration to a subject in need thereof of an effective amount of a compound as claimed in any of claims 1 to 9, or a pharmaceutically acceptable salt thereof.

15. Use as claimed in claim 13 or a method of treatment as claimed in claim 14, wherein the disease or condition is a respiratory-tract disorder.

16. Use as claimed in claim 13 or a method of treatment as claimed in claim 14, wherein the disease or condition is chronic obstructive lung disease, chronic bronchitis, asthma, chronic respiratory obstruction, bronchial hyperactivity, pulmonary fibrosis, pulmonary emphysema, or allergic rhinitis.