Bicyclic compounds and their use in medicine, process for their preparation and pharmaceutical compositions containing them

Compounds of formula (I) ##STR1## its tautomeric forms, its stereoisomers, its polymorphs, its pharmaceutically acceptable salts or its pharmaceutically acceptable solvates can be used to prevent or treat diabetes caused by insulin resistance or impaired glucose tolerance or complications of diabetes caused by insulin resistance or impaired glucose tolerance. The compounds can also be used to reduce cholesterol, body weight, blood glucose, triglycerides and free fatty acids in the blood.

If you were to search for Bicyclic compounds and their use in medicine, process for their preparation and pharmaceutical compositions containing them using relaxed search criteria, these patents would come up:

We claim:

1. A compound of formula (I) ##STR85##

its tautomeric forms, its stereoisomers, its polymorphs, its pharmaceutically acceptable salts, or its pharmaceutically acceptable solvates, wherein the groups R.sup.1, R.sup.2, R.sup.3, R.sup.4, and the groups R.sup.5 and R.sup.6 when attachedto a carbon atom, may be same or different and represent hydrogen, halogen, hydroxy, nitro, cyano, formyl or optionally substituted groups selected from alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aryloxy, aralkyl, aralkoxy, heterocyclyl selected fromaziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; heteroaralkyl group selectedfrom furanmethyl, pyridinemethyl, oxazolemethyl, or oxazolethyl; heteroaryloxy wherein the heteroaryl moiety is as defined above; heteroaralkoxy; wherein the heteroaralkyl moiety is as defined above; acyl selected from acetyl, propionyl or benzoyl; acyloxy, hydroxyalkyl, amino, acylamino, alkylamino, arylamino, aralkylamino, aminoalkyl, alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl, alkoxyalkyl, aryloxyalkyl, aralkoxyalkyl, alkylthio, thioalkyl, alkoxycarbonylamino, aryloxycarbonylamino,aralkoxycarbonylamino, carboxylic acid or its esters or amides, or sulfonic acid or its esters or amides; one or both of R.sup.5 and R.sup.6 may represent an oxo group when attached to a carbon atom; R.sup.5 and R.sup.6 when attached to a nitrogen atommay be the same or different and represent hydrogen, hydroxy, formyl or optionally substituted groups selected from alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aralkyl, heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl orpiperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl, oroxazolethyl; acyl selected from acetyl, propionyl or benzoyl; acyloxy, hydroxyalkyl, amino, acylamino, alkylamino, arylamino, aralkylamino, aminoalkyl, aryloxy, aralkoxy, heteroaryloxy wherein the heteroaryl moiety is as defined above; heteroaralkoxy,wherein the heteroaralkyl moiety is as defined above; alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl, alkoxyalkyl, aryloxyalkyl, aralkoxyalkyl, alkylthio, thioalkyl groups, esters or amides of carboxylic acid or esters or amides of sulfonic acid; Xrepresents oxygen or sulfur; Ar represents an optionally substituted divalent single aromatic or fused aromatic or heterocyclic group; R.sup.7 represents hydrogen atom, hydroxy, alkoxy, halogen, lower alkyl, optionally substituted aralkyl group orforms a bond together with R.sup.8 ; R.sup.8 represents hydrogen, hydroxy, alkoxy, halogen, lower alkyl group, acyl, or optionally substituted aralkyl or R.sup.8 forms a bond together with R.sup.7 ; R.sup.9 represents hydrogen, or optionallysubstituted groups selected from alkyl, cycloalkyl, aryl, aralkyl, alkoxyalkyl, alkoxycarbonyl, aryloxycarbonyl, alkylaminocarbonyl, arylaminocarbonyl, acyl selected from acetyl, propionyl or benzoyl; heterocyclyl selected from aziridinyl, pyrrolidinyl,morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; or heteroaralkyl group selected from furanmethyl,pyridinemethyl, oxazolemethyl, or oxazolethyl; R.sup.10 represents hydrogen or optionally substituted groups selected from alkyl, cycloalkyl, aryl, aralkyl, heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; or heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl or oxazolethyl; Yrepresents oxygen or NR.sup.12, where R.sup.12 represents hydrogen, alkyl, aryl, hydroxyalkyl, aralkyl, heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl,pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; or heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl or oxazolethyl; R.sup.10 and R.sup.12 together may form a 5 or 6 memberedcyclic structure containing carbon atoms, which may optionally contain one or more heteroatoms selected from oxygen, sulfur or nitrogen; the linking group represented by --(CH.sub.2).sub.n --(O).sub.m -- may be attached either through a nitrogen atom ora carbon atom; n is an integer ranging from 1-4 and m is an integer 0 or 1, with the proviso that when the linking group is attached through a carbon atom and either of R.sup.5 or R.sup.6 represents an oxo group and Y is an oxygen atom, R.sup.9 does notrepresent a hydrogen atom.

2. A compound according to claim 1, wherein when the groups represented by R.sup.1, R.sup.2, R.sup.3 and R.sup.4, and the groups R.sup.5 and R.sup.6 when attached to a carbon atom are substituted, the substituents are selected from halogen,hydroxy, or nitro or optionally substituted groups selected from alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aralkyl, aralkoxyalkyl, heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl groupselected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl, or oxazolethyl; acyl selected fromacetyl, propionyl or benzoyl; acyloxy, hydroxyalkyl, amino, acylamino, arylamino, aminoalkyl, aryloxy, alkoxycarbonyl, alkylamino, alkoxyalkyl, alkylthio, thioalkyl, carboxylic acid or its esters or amides, or sulfonic acid or its esters or amides.

3. A compound according to claim 1, wherein when the groups R.sup.5 and R.sup.6 attached to nitrogen are substituted, the substituents are selected from halogen atoms, hydroxy, acyl selected from acetyl, propionyl or benzoyl; acyloxy, or aminogroups.

4. A compound according to claim 1, wherein Ar represents optionally substituted divalent phenylene, naphthylene, pyridyl, quinolinyl, benzofuranyl, dihydrobenzofuryl, benzopyranyl, dihydrobenzopyranyl, indolyl, indolinyl, azaindolyl,azaindolinyl, pyrazolyl, benzothiazolyl, or benzoxazolyl groups.

5. A compound according to claim 1, wherein when the group represented by R.sup.9 is substituted, the substituents are selected from halogen, hydroxy, or nitro or optionally substituted groups selected from alkyl, cycloalkyl, alkoxy,cycloalkoxy, aryl, aralkyl, aralkoxyalkyl, heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl,tetrazolyl, benzopyranyl, or benzofuranyl; heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl, or oxazolethyl; acyl selected from acetyl, propionyl or benzoyl; acyloxy, hydroxyalkyl, amino, acylamino, arylamino, aminoalkyl,aryloxy, alkoxycarbonyl, alkylamino, alkoxyalkyl, alkylthio, thioalkyl groups, carboxylic acid or its esters or amides, or sulfonic acid or its esters or amides.

6. A compound selected from:

Ethyl (E/ Z)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropano ate;

(.+-.) Methyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate ;

(+) Methyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate ;

(-) Methyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate ;

Ethyl (E/ Z)-3-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypr opanoate;

Ethyl (E/ Z)-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropa noate;

(.+-.) Methyl 3-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropa noate;

(+) Methyl 3-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropa noate;

(-) Methyl 3-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropa noate;

(.+-.) Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxyp ropanoate;

(+) Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxyp ropanoate;

(-) Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxyp ropanoate;

(.+-.) Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxyp ropanoate;

(+) Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxyp ropanoate;

(-) Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxyp ropanoate;

(.+-.) Methyl 2-(2-fluorobenzyl)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl] -2-ethoxypropanoate;

(+) Methyl 2-(2-fluorobenzyl)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl] -2-ethoxypropanoate;

(-) Methyl 2-(2-fluorobenzyl)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl] -2-ethoxypropanoate;

Ethyl (E/ Z)-3-[4-[2-(3-oxo-2H-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate ;

(.+-.) Methyl 3-[4-[2-(3-oxo-2H-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate;

(+) Methyl 3-[4-[2-(3-oxo-2H-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate;

(-) Methyl 3-[4-[2-(3-oxo-2H-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoate;

Ethyl (E/ Z)-3-[6-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthyl]-2-ethoxypro panoate;

(.+-.) Methyl 3-[6-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthyl]-2-ethoxypropan oate;

(+) Methyl 3-[6-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthyl]-2-ethoxypropan oate;

(-) Methyl 3-[6-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthyl]-2-ethoxypropan oate;

(.+-.) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoat e;

(+) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoat e;

(-) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoat e;

(.+-.) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-hydroxypropano ate;

(+) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-hydroxypropano ate;

(-) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-hydroxypropano ate;

(.+-.) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-benzyloxypropano ate;

(+) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-benzyloxypropano ate

(-) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-benzyloxypropano ate

(.+-.) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-butoxypropanoate ;

(+) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-butoxypropanoate ;

(-) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-butoxypropanoate ;

(.+-.) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hexyloxy propanoate;

(+) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hexyloxy propanoate;

(-) Ethyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hexyloxy propanoate;

Ethyl (E/ Z)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropen oate;

(.+-.) Methyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoat e;

(+) Methyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoat e;

(-) Methyl 3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoat e;

Ethyl (E/ Z)-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxyprop enoate;

(.+-.) Methyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropano ate;

(+) Methyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropano ate;

(-) Methyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropano ate;

Ethyl (E/ Z)-3-[4-(4-methyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-etho xypropanoate;

(.+-.) Methyl 3-[4-(4-methyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxyp ropanoate;

(+) Methyl 3-[4-(4-methyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxyp ropanoate;

(-) Methyl 3-[4-(4-methyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxyp ropanoate;

Ethyl (E/ Z)-3-[4-(4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-etho xypropanoate;

(.+-.) Methyl 3-[4-(4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxyp ropanoate;

(+) Methyl 3-[4-(4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxyp ropanoate;

(-) Methyl 3-[4-(4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxyp ropanoate;

(.+-.) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts;

(+) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts;

(-) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts;

(.+-.) 3-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropa noic acid and its salts;

(+) 3-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropa noic acid and its salts;

(-) 3-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypropa noic acid and its salts;

(.+-.) 3-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypro panoic acid and its salts;

(+) 3-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypro panoic acid and its salts;

(-) 3-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)methylbenzofuran-5-yl]-2-ethoxypro panoic acid and its salts;

(.+-.) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoi c acid and its salts;

(+) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoi c acid and its salts;

(-) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoi c acid and its salts;

(.+-.) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanam ide;

(+) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanam ide;

(-) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanam ide;

(.+-.) N-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethox ypropanamide;

(+) N-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethox ypropanamide;

(-) N-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethox ypropanamide;

(.+-.) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamid e;

(+) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamid e;

(-) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanamid e;

(.+-.) N-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxyp ropanamide;

(+) N-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxyp ropanamide;

(-) N-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxyp ropanamide;

(.+-.) N-Benzyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxyp ropanamide;

(+) N-Benzyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxyp ropanamide;

(-) N-Benzyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxyp ropanamide;

(.+-.) N-Benzyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethox ypropanamide;

(+) N-Benzyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethox ypropanamide;

(-) N-Benzyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethox ypropanamide;

(.+-.) 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxyp ropanoic acid and its salts;

(+) 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxyp ropanoic acid and its salts;

(-) 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxyp ropanoic acid and its salts;

(.+-.) 2-(2-Fluorobenzyl)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl] -2-ethoxypropanoic acid and its salts;

(+) 2-(2-Fluorobenzyl)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl] -2-ethoxypropanoic acid and its salts;

(-) 2-(2-Fluorobenzyl)-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl] -2-ethoxypropanoic acid and its salts;

(.+-.) 3-[4-[2-(3-Oxo-2H-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts;

(+) 3-[4-[2-(3-Oxo-2H-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts;

(-) 3-[4-[2-(3-Oxo-2H-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts;

(.+-.) 3-[4-[2-(3-Oxo-2H-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts;

(+) 3-[4-[2-(3-Oxo-2H-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts;

(-) 3-[4-[2-(3-Oxo-2H-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid and its salts;

(.+-.) 3-[6-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]naphthyl]-2-ethoxypropanoi c acid and its salts;

(+) 3-[6-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]naphthyl]-2-ethoxypropanoi c acid and its salts;

(-) 3-[6-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]naphthyl]-2-ethoxypropanoi c acid and its salts;

(.+-.) 3-[6-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthyl]-2-ethoxypropan oic acid and its salts;

(+) 3-[6-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthyl]-2-ethoxypropan oic acid and its salts;

(-) 3-[6-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]naphthyl]-2-ethoxypropan oic acid and its salts;

(.+-.) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoic acid and its salts;

(+) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoic acid and its salts;

(-) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hydroxypropanoic acid and its salts;

(.+-.) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-hydroxypropano ic acid and its salts;

(+) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-hydroxypropano ic acid and its salts;

(-) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-hydroxypropano ic acid and its salts;

(.+-.) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-benzyloxypropano ic acid and its salts;

(+) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-benzyloxypropano ic acid and its salts;

(-) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-benzyloxypropano ic acid and its salts;

(.+-.) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-butoxypropanoic acid and its salts;

(+) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-butoxypropanoic acid and its salts;

(-) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-butoxypropanoic acid and its salts;

(.+-.) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hexyloxypropanoi c acid and its salts;

(+) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hexyloxypropanoi c acid and its salts;

(-) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-hexyloxypropanoi c acid and its salts;

(.+-.) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid and its salts;

(+) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid and its salts;

(-) 3-[4-[2-(2,3-Dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxypropanoic acid and its salts;

(.+-.) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropano ic acid and its salts;

(+) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropano ic acid and its salts;

(-) 3-[4-[2-(2,3-Dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-phenoxypropano ic acid and its salts;

(.+-.) Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxy propanoate;

(+) Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxy propanoate;

(-) Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxy propanoate;

(.+-.) 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxy propanoic acid and its salts;

(+) 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxy propanoic acid and its salts;

(-) 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzoxazin-4-yl)ethoxy]phenyl]-2-phenoxy propanoic acid and its salts;

(.+-.) Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-pheno xypropanoate;

(+) Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-pheno xypropanoate;

(-) Methyl 2-methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-pheno xypropanoate;

(.+-.) 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-pheno xy propanoic acid and its salts;

(+) 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-pheno xy propanoic acid and its salts;

(-) 2-Methyl-3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-pheno xy propanoic acid and its salts;

(.+-.) 4-Nitrophenyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxy propanoate;

(+) 4-Nitrophenyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxy propanoate;

(-) 4-Nitrophenyl 3-[4-[2-(2,3-dihydro-1,4-benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxy propanoate;

(.+-.) 3-[4-(4-Benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxyp ropanoic acid and its salts;

(+) 3-[4-(4-Benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxyp ropanoic acid and its salts;

(-) 3-[4-(4-Benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxyphenyl]-2-ethoxyp ropanoic acid and its salts;

(.+-.) 4-Nitrophenyl-3-[4-(4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxy phenyl]-2-ethoxypropanoate;

(+) 4-Nitrophenyl-3-[4-(4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxy phenyl]-2-ethoxypropanoate; and

(-) 4-Nitrophenyl-3-[4-(4-benzyl-3,4-dihydro-2H-1,4-benzoxazin-2-yl)methoxy phenyl]-2-ethoxypropanoate.

7. A process for the preparation of a compound of formula (I) ##STR86##

its tautomeric forms, its stereoisomers, its polymorphs, its pharmaceutically acceptable salts, or its pharmaceutically acceptable solvates, wherein the groups R.sup.1, R.sup.2, R.sup.3, R.sup.4, and the groups R.sup.5 and R.sup.6 when attachedto a carbon atom, may be same or different and represent hydrogen, halogen, hydroxy, nitro, cyano, formyl or optionally substituted groups selected from alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aryloxy, aralkyl, aralkoxy, heterocyclyl selected fromaziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; heteroaralkyl group selectedfrom furanmethyl, pyridinemethyl, oxazolemethyl, or oxazolethyl; heteroaryloxy wherein the heteroaryl moiety is as defined above; heteroaralkoxy; wherein the heteroaralkyl moiety is as defined above; acyl selected from acetyl, propionyl or benzoyl; acyloxy, hydroxyalkyl, amino, acylamino, alkylamino, arylamino, aralkylamino, aminoalkyl, alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl, alkoxyalkyl, aryloxyalkyl, aralkoxyalkyl, alkylthio, thioalkyl, alkoxycarbonylamino, aryloxycarbonylamino,aralkoxycarbonylamino, carboxylic acid or its esters or amides, or sulfonic acid or its esters or amides; one or both of R.sup.5 and R.sup.6 may represent an oxo group when attached to a carbon atom; R.sup.5 and R.sup.6 when attached to a nitrogen atommay be the same or different and represent hydrogen, hydroxy, formyl or optionally substituted groups selected from alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aralkyl, heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl orpiperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl, oroxazolethyl; acyl selected from acetyl, propionyl or benzoyl; acyloxy, hydroxyalkyl, amino, acylamino, alkylamino, arylamino, aralkylamino, aminoalkyl, aryloxy, aralkoxy, heteroaryloxy wherein the heteroaryl moiety is as defined above; heteroaralkoxy,wherein the heteroaralkyl moiety is as defined above; alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl, alkoxyalkyl, aryloxyalkyl, aralkoxyalkyl, alkylthio, thioalkyl groups, esters or amides of carboxylic acid or esters or amides of sulfonic acid; Xrepresents oxygen or sulfur; Ar represents an optionally substituted divalent single aromatic or fused aromatic or heterocyclic group; R.sup.7 represents hydrogen atom, hydroxy, alkoxy, halogen, lower alkyl, optionally substituted aralkyl group orforms a bond together with R.sup.8 ; R.sup.8 represents hydrogen, hydroxy, alkoxy, halogen, lower alkyl group, acyl, or optionally substituted aralkyl or R.sup.8 forms a bond together with R.sup.7 ; R.sup.9 represents hydrogen, or optionallysubstituted groups selected from alkyl, cycloalkyl, aryl, aralkyl, alkoxyalkyl, alkoxycarbonyl, aryloxycarbonyl, alkylaminocarbonyl, arylaminocarbonyl, acyl selected from acetyl, propionyl or benzoyl; heterocyclyl selected from aziridinyl, pyrrolidinyl,morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; or heteroaralkyl group selected from furanmethyl,pyridinemethyl, oxazolemethyl, or oxazolethyl; R.sup.10 represents hydrogen or optionally substituted groups selected from alkyl, cycloalkyl, aryl, aralkyl, helyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; or heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl or oxazolethyl; Yrepresents oxygen; the linking group represented by --(CH.sub.2).sub.n --(O).sub.m -- may be attached either through a nitrogen atom or a carbon atom; n is an integer ranging from 1-4 and m is an integer 0 or 1, with the proviso that when the linkinggroup is attached through a carbon atom and either of R.sup.5 or R.sup.6 represents an oxo group and Y is an oxygen atom, R.sup.9 does not represent a hydrogen atom which comprises:

a) reacting a compound of the formula (IIIa) ##STR87##

where all symbols are as defined above with a compound of formula (IIIb) ##STR88##

where R.sup.9 and R.sup.10 are as defined above and R.sup.14 represents (C.sub.1 -C.sub.6)alkyl, to yield compound of formula (IVa) ##STR89##

which represents a compound of formula (I) where R.sup.7 and R.sup.8 together represent a bond and Y represents an oxygen atom and all other symbols are as defined above, and (b) reducing the compound of formula (IVa) to yield a compound of theformula (I) where R.sup.7 and R.sup.8 each represent hydrogen atom and all symbols are as defined above.

8. An intermediate of formula (IVf) ##STR90##

where the groups R.sup.1, R.sup.2, R.sup.3, R.sup.4, and the groups R.sup.5 and R.sup.6 when attached to a carbon atom, may be same or different and represent hydrogen, halogen, hydroxy, nitro, cyano, formyl or optionally substituted groupsselected from alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aryloxy, aralkyl, aralkoxy, heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl,oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl, or oxazolethyl; heteroaryloxy wherein the heteroaryl moiety is as defined above; heteroaralkoxy, wherein the heteroaralkyl moiety is as defined above; acyl selected from acetyl, propionyl or benzoyl; acyloxy, hydroxyalkyl, amino, acylamino, alkylamino, arylamino, aralkylamino, aminoalkyl, alkoxycarbonyl, aryloxycarbonyl,aralkoxycarbonyl, alkoxyalkyl, aryloxyalkyl, aralkoxyalkyl, alkylthio, thioalkyl, alkoxycarbonylamino, aryloxycarbonylamino, aralkoxycarbonylamino, carboxylic acid or its esters or amides, or sulfonic acid or its esters or amides; one or both of R.sup.5and R.sup.6 may represent an oxo group when attached to a carbon atom; R.sup.5 and R.sup.6 when attached to nitrogen atom may be the same or different and represent hydrogen, hydroxy, formyl or optionally substituted groups selected from alkyl,cycloalkyl, alkoxy, cycloalkoxy, aryl, aralkyl, heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl,tetrazolyl, benzopyranyl, or benzofuranyl; heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl, or oxazolethyl; acyl selected from acetyl, propionyl or benzoyl; acyloxy, hydroxyalkyl, amino, acylamino, alkylamino, arylamino,aralkylamino, aminoalkyl, aryloxy, aralkoxy, heteroaryloxy wherein the heteroaryl moiety is as defined above; heteroaralkoxy wherein the heteroaralkyl moiety is as defined above; alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl, alkoxyalkyl,aryloxyalkyl, aralkoxyalkyl, alkylthio, thioalkyl groups, esters or amides of carboxylic acid, or esters or amides of sulfonic acid; X represents oxygen or sulfur; Ar represents an optionally substituted divalent single aromatic or fused aromatic orheterocyclic group; R.sup.7 represents hydrogen atom, hydroxy, alkoxy, halogen, lower alkyl, or optionally substituted aralkyl group; R.sup.8 represents hydrogen, hydroxy, alkoxy, halogen, lower alkyl group, acyl selected from acetyl, propionyl orbenzoyl; or optionally substituted aralkyl group; R.sup.9 represents hydrogen, or optionally substituted groups selected from alkyl, cycloalkyl, aryl, aralkyl, alkoxyalkyl, alkoxycarbonyl, aryloxycarbonyl, alkylaminocarbonyl, arylaminocarbonyl, acylselected from acetyl, propionyl or benzoyl; heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl,tetrazolyl, benzopyranyl, or benzofuranyl; heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl, or oxazolethyl; the linking group represented by --(CH.sub.2).sub.n --(O).sub.m -- may be attached either through a nitrogen atomor a carbon atom; n is an integer ranging from 1-4 and m is an integer 0 or 1.

9. A process for the preparation of compound of formula (IVf) as defined in claim 8 where R.sup.7 and R.sup.8 represent hydrogen atoms and all other symbols are as defined in claim 8 which comprises:

a) reacting a compound of formula (IIIa) ##STR91##

where all symbols are as defined above with a compound of formula (IVh)

where R.sup.9 represents optionally substituted groups selected from alkyl, cycloalkyl, aryl, aralkyl, alkoxyalkyl, alkoxycarbonyl, aryloxycarbonyl, alkylaminocarbonyl, arylaminocarbonyl, acyl selected from acetyl, propionyl or benzoyl; heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl, or oxazolethyl and Hal represents a halogen atom, to yield a compound of formula (IVi) ##STR92##

where all symbols are as defined above,

b) reacting a compound of formula (IVi) with an alcohol of the formula R.sup.9 OH where R.sup.9 is as defined above to yield a compound of formula (IVj), ##STR93##

where all symbols are as defined above,

c) reacting a compound of formula (IVj) obtained above where all symbols are as defined above with trialkylsilyl cyanide to produce a compound of formula (IVf) where all symbols are as defined above.

10. An intermediate of formula (IVg) ##STR94##

where the groups R.sup.1, R.sup.2, R.sup.3, R.sup.4, and the groups R.sup.5 and R.sup.6 when attached to a carbon atom, may be same or different and represent hydrogen, halogen, hydroxy, nitro, cyano, formyl or optionally substituted groupsselected from alkyl, cycloalkyl, alkoxy, cycloalkoxy, aryl, aryloxy, aralkyl, aralkoxy, heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl,oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl, or benzofuranyl; heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl, or oxazolethyl; heteroaryloxy, wherein the heteroaryl moiety is as defined above; heteroaralkoxy, wherein the heteroaralkyl moiety is as defined above; acyl selected from acetyl, propionyl or benzoyl, acyloxy, hydroxyalkyl, amino, acylamino, alkylamino, arylamino, aralkylamino, aminoalkyl, alkoxycarbonyl, aryloxycarbonyl,aralkoxycarbonyl, alkoxyalkyl, aryloxyalkyl, aralkoxyalkyl, alkylthio, thioalkyl, alkoxycarbonylamino, aryloxycarbonylamino, aralkoxycarbonylamino, carboxylic acid or its esters or amides, or sulfonic acid or its esters or amides; one or both of R.sup.5and R.sup.6 may represent an oxo group when attached to a carbon atom; R.sup.5 and R.sup.6 when attached to a nitrogen atom may be the same or different and represent hydrogen, hydroxy, formyl or optionally substituted groups selected from alkyl,cycloalkyl, alkoxy, cycloalkoxy, aryl, aralkyl, heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl,tetrazolyl, benzopyranyl, or benzofuranyl; heteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl, or oxazolethyl; acyl selected from acetyl, propionyl or benzoyl; acyloxy, hydroxyalkyl, amino, acylamino, alkylamino, arylamino,aralkylamino, aminoalkyl, aryloxy, aralkoxy, heteroaryloxy wherein the heteroaryl moiety is as defined above; heteroaralkoxy wherein the heteroalkyl moiety is as defined above; alkoxycarbonyl, aryloxycarbonyl, aralkoxycarbonyl, alkoxyalkyl,aryloxyalkyl, aralkoxyalkyl, alkylthio, thioalkyl groups, esters or amides of carboxylic acid, or esters or amides of sulfonic acid; X represents oxygen or sulfur; Ar represents an optionally substituted divalent single aromatic or fused aromatic orheterocyclic group; R.sup.7 represents hydrogen atom, hydroxy, alkoxy, halogen, lower alkyl, or optionally substituted aralkyl group; R.sup.10 represents hydrogen or optionally substituted groups selected from alkyl, cycloalkyl, aryl, aralkyl,heterocyclyl selected from aziridinyl, pyrrolidinyl, morpholinyl, piperidinyl or piperazinyl; heteroaryl group selected from pyridyl, thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, oxadiazolyl, tetrazolyl, benzopyranyl or benzofuranyl; orheteroaralkyl group selected from furanmethyl, pyridinemethyl, oxazolemethyl, or oxazolethyl; the linking group represented by --(CH.sub.2).sub.n --(O).sub.m -- may be attached either through a nitrogen atom or a carbon atom; n is an integer rangingfrom 1-4 and m is an integer 0 or 1.

11. A process for the preparation of compound of formula (IVg) defined in claim 10, which comprises:

a) reacting a compound of formula (IIIh) ##STR95##

where L.sup.1 is a leaving group and all other symbols are as defined in claim 10 with a compound of formula (IVl) ##STR96##

where R.sup.8 is a hydrogen atom and all other symbols are as defined in claim 10, to yield a compound of formula (IVk) ##STR97##

where R.sup.8 is a hydrogen atom and all other symbols are as defined above, and

b) reacting a compound of formula (IVk) obtained above with a diazotizing agent.

12. A pharmaceutical composition which comprises a compound of formula ##STR98##

as defined in claim 1 and a pharmaceutically acceptable carrier, diluent, excipient or solvent.

13. A pharmaceutical composition as claimed in claim 12, in the form of a tablet, capsule, powder, syrup, solution or suspension.

14. A pharmaceutical composition which comprises, a compound according to claim 6, as an active ingredient and a pharmaceutically acceptable carrier, diluent excipient or solvent.

15. A pharmaceutical composition as claimed in claim 14, in the form of a tablet, capsule, powder, syrup, solution or suspension.

16. 3-[4-[2-(2,3-Dihydro-1,4benzothiazin-4-yl)ethoxy]phenyl]-2-ethoxypropanoic acid of the formula: ##STR99##

17. A pharmaceutical composition which comprises a compound as defined in claim 16 and a pharmaceutically acceptable carrier, diluent, excipient or solvate.

18. A pharmaceutical composition as claimed in claim 17 in the form of a tablet, capsule, powder, syrup, solution or suspension.

19. A method of preventing or treating diabetes caused by insulin resistance or impaired glucose tolerance or complications of diabetes caused by insulin resistance or impaired glucose tolerance comprising administering a therapeuticallyeffective amount of a compound of formula (I) as defined in claim 1 and a pharmaceutically acceptable carrier diluent or excipient to a patient in need thereof.

20. The method according to claim 19, wherein the complication is dyslipidemia, hypertension, hyperglycemia, coronary heart disease, cardiovascular disorders, atherosclerosis , obesity, psoriasis, polycystic ovarian syndrome (PCOS),osteoporosis, hyperlipidemia, renal diseases, diabetic nephropathy, glomerulonephritis, glomerular sclerosis, nephrotic syndrome, hypertensive nephrosclerosis, end-stage renal disease, disorders related to endothelial cell division, microalbuminuria oreating disorders.

21. A method of preventing or treating diabetes caused by insulin resistance or impaired glucose tolerance or complications of diabetes caused by insulin resistance or impaired glucose tolerance comprising administering a therapeuticallyeffective amount of a compound of formula (I) as defined in claim 6, and a pharmaceutically acceptable carrier, diluent or excipient to a patient in need thereof.

22. The method according to claim 21, wherein the complication is dyslipidaemia, hypertension, hyperglycemia, coronary heart disease, cardiovascular disorders, atherosclerosis, obesity, psoriasis, polycystic ovarian syndrome (PCOS),osteoporosis, hyperlipidemia, renal diseases, diabetic nephropathy, glomerulonephritis, glomerular sclerosis, nephrotic syndrome, hypertensive nephrosclerosis, end-stage renal disease, disorders related to endothelial cell division, microalbuminuria oreating disorders.

23. A method of preventing or treating diabetes caused by insulin resistance or impaired glucose tolerance or complications of diabetes caused by insulin resistance or impaired glucose tolerance comprising administering a therapeuticallyeffective amount of a compound of formula (I) as defined in claim 16, and a pharmaceutically acceptable carrier, diluent or excipient to a patient in need thereof.

24. The method according to claim 23, wherein the complication is dyslipidaemia, hypertension, hyperglycemia, coronary heart disease, cardiovascular disorders, atherosclerosis, obesity, psoriasis, polycystic ovarian syndrome (PCOS),osteoporosis, hyperlipidemia, renal diseases diabetic nephropathy, glomerulonephritis, glomerular sclerosis, nephrotic syndrome, hypertensive nephrosclerosis, end-stage renal disease, disorders related to endothelial cell division, microalbuminuria oreating disorders.

25. A method of reducing LDL, VLDL cholesterol, body weight, blood glucose, triglycerides, and free fatty acids comprising administering a compound as defined in claim 16 and a pharmaceutically acceptable carrier, diluent or solvates orexcipient to a patient in need thereof.

26. A method of reducing total cholesterol, body weight, blood plasma glucose, triglycerides, LDL, VLDL and free fatty acids in the plasma comprising administering a compound of formula (1), as defined in claim 1 and a pharmaceuticallyacceptable carrier, diluent, solvent or excipient to a patient in need thereof.

27. A method of reducing total cholesterol, body weight, blood plasma glucose, triglycerides, LDL, VLDL and free fatty acids in the plasma comprising administering a compound of formula (1), as defined in claim 6 and a pharmaceuticallyacceptable carrier, diluent, solvent or excipient to a patient in need thereof.