PGD2 receptor antagonists for the treatment of inflammatory diseases

1. A compound represented by the following structural formula:

or a pharmaceutically acceptable salt thereof, wherein:

Ring A is an optionally substituted, fused 5-6 membered aryl or heteroaryl ring;

Y is >C(R x )—;

X 1 is —C(═O)—, —SO 2 —, —CONR—, —C(R) 2 —, or —CO 2 —,

R 1 is an optionally substituted group selected from a monocyclic or bicyclic aryl, a monocyclic or bicyclic heteroaryl, a monocyclic or bicyclic non-aromatic heterocyclic, or a monocyclic or bicyclic non-aromatic carbocylic group;

R 2 is a C 1 -C 3 alkyl group, a C 1 -C 3 haloalkyl group or C 3 -C 6 cycloalkyl group wherein the C 1 -C 3 alkyl group represented by R 2 is optionally substituted with R 5 ;

R 3 is hydrogen, C 1 -C 6 alkyl optionally substituted by R 6 , C 1 -C 6 fluoroalkyl, or an optionally substituted group selected from a C 3 -C 8 cycloalkyl, a monocyclic non-aromatic heterocyclic, a monocyclic aryl, or a monocyclic heteroaryl group;

R 4 is —[C(R 7 ) 2 ] m —B; or R 3 and R 4 may be taken together with the intervening nitrogen atom to form an optionally substituted monocyclic or bicyclic heteroaryl or non-aromatic heterocyclic group; or

R x and R 4 may be taken together with the intervening carbon and nitrogen atoms to form an optionally substituted monocyclic non-aromatic nitrogen-containing heterocyclic group;

R 5 is —OH, —O(C 1-4 aliphatic), —COOR′ or —N(R′) 2 ;

R 6 is —OH, —O(C 1-4 aliphatic), —N(R′) 2 , —C(O)R′, —COOR′, C(O)N(R′) 2 , or an optionally substituted group selected from a monocyclic cycloalkyl, a monocyclic aryl, a monocyclic heteroaryl, or a monocyclic non-aromatic heterocyclic group;

each R 7 is independently hydrogen, fluoro, or C 1 -C 3 alkyl;

each R, R x or R′ is independently hydrogen or a C 1 -C 4 aliphatic group or N(R′) 2 is a monocyclic non-aromatic nitrogen-containing heterocyclic group;

m is zero or one; and

B is —H, —C(R 7 ) 3 , —C(R 7 ) 2 —C(R 7 ) 3 , or an optionally substituted group selected from a monocyclic or bicyclic cycloalkyl, a monocyclic or bicyclic aryl, a monocyclic or bicyclic heteroaryl, or a monocyclic or bicyclic non-aromatic heterocyclic group.

2. The compound of claim 1 wherein the compound is represented by the following structural formula:

or a pharmaceutically acceptable salt thereof, wherein:

n is 0 or an integer from 1-4;

each R 8 is independently halo, —OR 9 , —SR 9 , —CN, —NO 2 , —N(R 10 ) 2 , —N(R 10 )C(O)R 9 , —N(R 10 )CO 2 R 9a , —N(R 10 )C(O)N(R 10 ) 2 , —C(O)N(R 10 ) 2 , —OC(O)R 9 , —OC(O)N(R 10 ) 2 , —C(O)R 9 , —CO 2 R 9 , —SO 2 R 9a , —S(O)R 9a , —SO 2 N(R 10 ) 2 , —N(R 10 )SO 2 R 9a or an optionally substituted group selected from a C 1-8 aliphatic, a monocyclic aryl, a monocyclic heteroaryl, or a monocyclic non-aromatic heterocyclic group;

each R 9 is independently hydrogen or an optionally substituted C 1-6 aliphatic group;

each R 9a is independently an optionally substituted C 1-6 aliphatic group; and

each R 10 is independently hydrogen, a C 1-6 aliphatic group, —CO 2 R 9a , —SO 2 R 9a , or —C(O)R 9 , or N(R 10 ) 2 is a monocyclic heteroaryl or a monocyclic non-aromatic heterocyclic group.

3. The compound of claim 2 wherein the compound is represented by the following structural formula:

or a pharmaceutically acceptable salt thereof.

4. The compound of claim 3 wherein:

R 1 is an optionally substituted monocyclic or bicyclic aryl or heteroaryl group optionally substituted at any one or more substitutable ring carbon atoms with R 11 ;

each R 11 is independently halo, —OR 12 , —SR 12 , —CN, —NO 2 , —N(R 12 R 13 ), —N(R 13 )C(O)R 12 , —N(R 13 )CO 2 R 12a , —N(R 13 )C(O)N(R 12 R 13 ), —C(O)N(R 12 R 13 ), —OC(O)R 12 , —OC(O)N(R 12 R 13 ), —C(O)R 12 , —CO 2 R 12 , —SO 2 R 12a , —S(O)R 12a , —SO 2 N(R 12 R 13 ), —N(R 13 )SO 2 R 12a , an optionally substituted group selected from a C 1-8 aliphatic, a monocyclic aryl, a monocyclic heteroaryl, or a monocyclic non-aromatic group;

each R 12 is independently hydrogen or an optionally substituted C 1-6 aliphatic group;

each R 12a is an optionally substituted C 1-6 aliphatic group; and

each R 13 is independently hydrogen, a C 1-6 aliphatic group, —CO 2 R 12a , —SO 2 R 12a , or —C(O)R 12 , or —N(R 12 R 13 ) is a monocyclic heteroaryl or non-aromatic heterocyclic group.

5. The compound of claim 4 wherein:

B is a monocyclic aryl or heteroaryl group, or a monocyclic cycloalkyl group, each optionally substituted at any one or more substitutable ring carbon atoms with R 14 ; and

each R 14 is independently C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 haloalkoxy, R 14a , R 14b , -T-R 14a , -T-R 14b , —V-T 1 -R b , —V-T-R 14a , —V 1 -T-R 14a or —V 1 -T 1 -R 14b ;

V is —O—, —N(R)—, —C(O)N(R)— or —S(O) 2 N(R)—;

V 1 is —S(O) 2 , —C(O)—, —N(R)C(O)— or —N(R)SO 2 —;

T is a C 1 -C 4 optionally substituted alkylene;

T 1 is a C 2 -C 4 optionally substituted alkylene;

each R 14a is independently selected from —OR 15a , —SR 15a , —C(O)N(R 16 ) 2 , —C(O)R 15 , —CO 2 R 15 , —SO 2 R 15a , —S(O)R 15a , —SO 2 N(R 16 ) 2 , an optionally substituted monocyclic aryl or heteroaryl group or an optionally substituted monocyclic non-aromatic heterocyclic group;

each R 14b is independently selected from halo, —OH, —SH, —CN, —NO 2 , —N(R 16 ) 2 , —N(R 16 )C(O)R 15 , —N(R 16 )CO 2 R 15a , —N(R 16 )C(O)N(R 16 ) 2 , —OC(O)R 15 , —OC(O)N(R 16 ) 2 or —N(R 16 )SO 2 R 15a ,

each R 15 is independently hydrogen or a C 1-6 aliphatic group;

each R 15a is a C 1-6 aliphatic group; and

each R 16 is independently selected from hydrogen, a C 1-6 aliphatic group, —CO 2 R 15a , —SO 2 R 15a , or —C(O)R 15 , or N(R 16 ) 2 is a monocyclic heteroaryl or a monocyclic non-aromatic heterocyclic group.

6. The compound of claim 5 wherein

R 2 is C 1 -C 2 alkyl or C 3 -C 6 cycloalkyl;

R 3 is a C 1 -C 4 alkyl group, and

R 4 is —(CH 2 ) m —B.

7. The compound of claim 6 wherein R 1 is a phenyl, pyridyl, pyrimidyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, furanyl, thiophenyl, imidazolyl, pyrazolyl, pylori, tetrazolyl, indolyl, benzotriazolyl, benzothiazolyl, benzimidazolyl, benzothienyl, benzofuranyl, benzmorpholinyl or benzpiperazinyl, each optionally substituted at any one or more substitutable ring carbon atoms with R 11 .

8. The compound of claim 7 wherein —C(O)NR 3 R 4 and —R 2 are trans relative to one another.

9. The compound of claim 8 wherein the compound is represented by the following structural formula:

or a pharmaceutically acceptable salt thereof, wherein s and t are independently 0, 1, 2, 3 or 4.

10. The compound of claim 9 wherein R 8 , R 11 and R 14 , when present, are independently, halo, CO 2 R 12 , CONR 12 R 13 , C 1-3 alkyl, C 1-3 haloalkyl, hydroxyl, C 1-3 alkoxy, C 1-3 haloalkoxy, —CN, amine, C 1-3 alkyl amine, C 1-3 dialkylamine, C 1-3 hydroxyalkyl or C 1-3 aminoalkyl.

11. The compound of claim 3 , wherein:

R 1 is a monocyclic aryl or heteroaryl group substituted with T 2 -V 2 -T 3 -M-R Y and is further optionally substituted at any one or more substitutable ring carbon atoms with R 11 ;

each R 11 is independently halo, —OR 12 , —SR 12 , —CN, —NO 2 , —N(R 12 R 13 ), —N(R 13 )C(O)R 12 , —N(R 13 )CO 2 R 12a , —N(R 13 )C(O)N(R 12 R 13 ), —C(O)N(R 12 R 13 ), —OC(O)R 12 , —OC(O)N(R 12 R 13 ), —C(O)R 12 , —CO 2 R 12 , —SO 2 R 12a , —S(O)R 12a , —SO 2 N(R 12 R 13 ), —N(R 13 )SO 2 R 12a , an optionally substituted group selected from a C 1-8 aliphatic, a monocyclic aryl, a monocyclic heteroaryl, or a monocyclic non-aromatic group;

each R 12 is independently hydrogen or an optionally substituted C 1-6 aliphatic group;

each R 12a is an optionally substituted C 1-6 aliphatic group; and

each R 13 is independently hydrogen, a C 1-6 aliphatic group, —CO 2 R 12a , —SO 2 R 12a , or —C(O)R 12 , or —N(R 12 R 13 ) is a monocyclic heteroaryl or non-aromatic heterocyclic group;

R Y is —C(O)OR 18 , —C(O)R 18 , —OC(O)R 18 , —C(O)N(R 19 ) 2 , —NR 19 C(O)R 18 , —NR 19 C(O)OR 18a , —S(O) 2 R 18a , —S(O) 2 COR 18 , —S(O) 2 N(R 19 ) 2 , —NR 19 S(O) 2 R 18a , —NR 19 S(O) 2 R 18a , S(O) 2 OR 18 , —S(O)OR 18 , —S(O)R 18a , —SR 18 , —C(O)NR 19 S(O) 2 R 18a , —CN, —NR 19 C(O)N(R 19 ) 2 , —OC(O)N(R 19 ) 2 , —N(R 19 ) 2 , —OR 18 , an optionally substituted non-aromatic heterocyclic group or an optionally substituted heteroaryl group;

M is absent or an optionally substituted monocyclic arylene, an optionally substituted monocyclic non-aromatic carbocyclene or an optionally substituted monocyclic non-aromatic heterocyclene;

V 2 is absent, —O—, —C(O)—, —N(R 19 )—, —S—, —S(O)—, —C(O)NR 19 —, —NR 19 C(O)—, —S(O) 2 NR 19 —, —NR 19 S(O) 2 —, or —S(O) 2 —;

T 2 is absent, or a C 1-10 straight chain alkylene;

T 3 is C 1-10 is a straight chain alkylene; provided that T 3 is a C 2-10 straight chained alkylene when M is absent and V 2 is —O—, —S—, —N(R 19 )—, —C(O)N(R 19 )— or —S(O) 2 N(R 19 )— and R Y is —NR 19 S(O) 2 R 18a , —NR 19 S(O) 2 R 18a , —NR 19 C(O)R 18 , —NR 19 C(O)OR 18a , —NR 19 C(O)NR 19 2 , —CN, —OH, —SH, —N(R 19 ) 2 ;

wherein T 2 and T 3 together contain no more than 10 carbon atoms, and wherein T 2 and T 3 are optionally and independently substituted at any one or more substitutable carbon atoms with halide, alkyl, gem dialkyl, gem dihalo, haloalkyl, alkoxy, haloalkoxy, spiro cycloalkyl, optionally N-substituted nitrogen containing spiro non-aromatic heterocyclic group, oxygen-containing spiro non-aromatic heterocyclic group, amine, alkylamine, dialkylamine, or hydroxyl;

each R 18 is independently hydrogen or C 1-6 aliphatic group;

each R 18a is independently C 1-6 aliphatic group; and

each R 19 is independently selected from hydrogen, a C 1-6 aliphatic group, —CO 2 R 18 , —SO 2 R 18 , or —C(O)R 18 , or —NR 19 is a monocyclic heteroaryl or a monocyclic non-aromatic heterocyclic group.

12. The compound of claim 11 wherein T 2 and M are absent.

13. The compound of claim 12 wherein:

B is a monocyclic aryl or heteroaryl group or a monocyclic cycloalkyl group, each optionally substituted at any one or more substitutable ring carbon atoms with R 14 ;

each R 14 is independently C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 haloalkoxy, R 14a , R 14b , -T-R 14a , -T-R 14b , —V-T-R 14a , —V-T 1 -R 14b , —V 1 -T-R 14a or —V 1 -T 1 -R 14b ;

V is —O—, —N(R)—, —C(O)N(R)— or —S(O) 2 N(R)—;

V 1 is —S(O) 2 , —C(O)—, —N(R)C(O)— or —N(R)SO 2 —;

T is a C 1 -C 4 optionally substituted alkylene;

T 1 is a C 2 -C 4 optionally substituted alkylene;

each R 14a is independently selected from −OR 15a , —SR 15a , —C(O)N(R 16 ) 2 , —CO 2 R 15 , —SO 2 R 15a , —S(O)R 15a , —SO 2 N(R 16 ) 2 , an optionally substituted monocyclic aromatic group or an optionally substituted monocyclic non-aromatic heterocyclic group;

each R 14b is independently selected from halo, —OH, —SH, —CN, —NO 2 , —N(R 16 ) 2 , —N(R 16 )C(O)R 15 , —N(R 16 )CO 2 R 15a or —N(R 16 )C(O)N(R 16 ) 2 , —OC(O)R 15 , —OC(O)N(R 16 ) 2 or —N(R 16 )SO 2 R 15a ;

each R 15 is independently hydrogen or a C 1-6 aliphatic group;

each R 15a is a C 1-6 aliphatic group; and

each R 16 is independently selected from hydrogen, a C 1-6 aliphatic group, —CO 2 R 15a , —SO 2 R 15a , or —C(O)R 15 , or N(R 16 ) 2 is a monocyclic heteroaryl or a monocyclic non-aromatic heterocyclic group.

14. The compound of claim 13 wherein:

R 2 is C 1 -C 2 alkyl or C 3 -C 6 cycloalkyl;

R 3 is a C 1 -C 4 alkyl group, and

R 4 is —(CH 2 ) m —B.

15. The compound of claim 14 wherein R 1 is a phenyl, pyridyl, pyrimidyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, furanyl, thiophenyl, imidazolyl, pyrazolyl, pyrollyl, tetrazolyl, indolyl, benzotriazolyl, benzothiazolyl, benzimidazolyl, benzothienyl, benzofuranyl, benzmorpholinyl or benzpiperazinyl, each substituted with —V 2 -T 3 -R Y , and each optionally substituted at any one or more substitutable ring carbon atoms with R 11 .

16. The compound of claim 15 wherein the compound is represented by structural formula:

or a pharmaceutically acceptable salt thereof, wherein s is 0, 1, 2, 3, or 4.

17. The compound of claim 16 wherein —C(O)NR 3 R 4 and —R 2 are trans relative to one another.

18. The compound of claim 17 wherein the compound is represented by the following structural formula:

or a pharmaceutically acceptable salt thereof.

19. The compound of claim 18 wherein:

V 2 is a covalent bond or —O—;

T 3 is C 1-6 is a straight chain alkylene optionally substituted at any one or more substitutable carbon atoms with halide, alkyl, gem dialkyl, gem dihalo, haloalkyl, spiro cycloalkyl, optionally N-substituted nitrogen containing spiro non-aromatic heterocyclic group, oxygen-containing spiro non-aromatic heterocyclic group, amine, alkylamine, dialkylamine, or hydroxyl;

R Y is —C(O)OR 18 , —C(O)N(R 19 ) 2 , —NR 19 C(O)R 18 , —NR 19 C(O)OR 18a , —S(O) 2 N(R 19 ) 2 , —NR 19 S(O) 2 R 18a , —NR 19 C(O)N(R 19 ) 2 ,) an optionally substituted non-aromatic heterocyclic group represented by R 20 or an optionally substituted heteroaryl group represented by R 21 ;

each R 18 is independently H or C 1 -C 3 alkyl;

each R 18a is independently C 1 -C 3 alkyl;

each R 19 is H or alkyl or N(R 19 ) 2 is a nitrogen-containing non-aromatic heterocyclic group;

R 20 is an optionally substituted piperidinonyl, oxazolidinyl, oxazolidinonyl, thiazolidinyl, tetrahydrofuranyl, tetrahydropyranyl, thiazolidinyl, tetrahydrothiophene, morpholinyl, thiomorpholinyl, imidazolidinyl, imidazolidinonyl, dioxanyl, dioxolanyl, dithiolanyl, pyrrolidinyl, pyrrolidinonyl, piperazinyl, or piperidinyl; and

R 21 is an optionally substituted furanyl, tetrazolyl, oxazolyl, isoxazolyl, oxadiazolyl, pyrrolyl, pyrazolyl, pyridinyl, pyrimidyl, thiazolyl, thienyl, or imidazolyl.

20. The compound of claim 19 wherein the compound is represented by the following structural formula:

or a pharmaceutically acceptable salt thereof, wherein t is 0, 1, 2, 3 or 4.

21. The compound of claim 20 wherein:

R Y is —C(O)OR 18 , —C(O)N(R 19 ) 2 , optionally N-substituted tetrazolyl or optionally N-substituted imidazolyl; and

R 18 and each R 19 are independently —H, methyl, or ethyl.

22. The compound of claim 21 wherein R 8 , R 11 and R 14 , when present, are independently, halo, CO 2 R 12 , CONR 12 R 13 , C 1-3 alkyl, C 1-3 haloalkyl, hydroxyl, C 1-3 alkoxy, C 1-3 haloalkoxy, —CN, amine, C 1-3 alkyl amine, C 1-3 dialkylamine.

23. The compound of claim 3 wherein:

R 1 is a monocyclic aryl or heteroaryl group, substituted by —V 3 —R 22 and wherein the aryl or heteroaryl group represented by R 1 optionally is further substituted at any one or more substitutable carbon atoms represented by R 11 ;

V 3 is a covalent bond, —O—, —C(O)—, —N(R 13 )—, —S—, —S(O)—, —C(O)NR 13 —, —NR 13 C(O)—, —S(O) 2 NR 13 —, —NR 13 S(O) 2 —, or —S(O) 2 —;

each R 11 is independently halo, —OR 12 , —SR 12 , —CN, —NO 2 , —N(R 12 R 13 ), —N(R 13 )C(O)R 12 , —N(R 13 )CO 2 R 12a , —N(R 13 )C(O)N(R 12 R 13 ), —C(O)N(R 12 R 13 ), —OC(O)R 12 , —OC(O)N(R 12 R 13 ), —C(O)R 12 , —CO 2 R 12 , —SO 2 R 12a , —S(O)R 12a , —SO 2 N(R 12 R 13 ), —N(R 13 )SO 2 R 12a , or an optionally substituted group selected from a C 1-8 aliphatic, a monocyclic aryl, a monocyclic heteroaryl, or a monocyclic non-aromatic group;

each R 12 is independently hydrogen or an optionally substituted C 1-6 aliphatic group;

each R 12a is an optionally substituted C 1-6 aliphatic group; and

each R 13 is independently hydrogen, a C 1-6 aliphatic group, —CO 2 R 12a , —SO 2 R 12a , or —C(O)R 12 , or —N(R 12 R 13 ) is an optionally substituted monocyclic heteroaryl or non-aromatic heterocyclic group; and

R 22 is an optionally substituted monocyclic or bicyclic non-aromatic carbocyclic or an optionally substituted monocyclic or bicyclic non-aromatic heterocyclic group.

24. The compound of claim 23 wherein:

B is a monocyclic aryl or heteroaryl group or a monocyclic cycloalkyl group, each optionally substituted at any one or more substitutable ring carbon atoms with R 14 ;

each R 14 is independently C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 haloalkoxy, R 14a , R 14b , -T-R 14a , -T-R 14b , —V-T-R 14a , —V-T 1 -R 14b , —V 1 -T-R 14a or —V 1 -T 1 -R 14b ;

V is —O—, —N(R)—, —C(O)N(R)— or —S(O) 2 N(R)—;

V 1 is —S(O) 2 , —C(O)—, —N(R)C(O)— or —N(R)SO 2 —;

T is a C 1 -C 4 optionally substituted alkylene;

T 1 is a C 2 -C 4 optionally substituted alkylene;

each R 14a is independently selected from —OR 15a , —SR 15a , —C(O)N(R 16 ) 2 , —CO 2 R 15 , —SO 2 R 15a , —S(O)R 15a , —SO 2 N(R 16 ) 2 , an optionally substituted monocyclic aryl or heteroaryl group or an optionally substituted monocyclic non-aromatic heterocyclic group;

each R 14b is independently selected from halo, —OH, —SH, —CN, —NO 2 , —N(R 16 ) 2 , —N(R 16 )C(O)R 15 , —N(R 16 )CO 2 R 15a , —N(R 16 )C(O)N(R 16 ) 2 , —OC(O)R 15 , —OC(O)N(R 16 ) 2 or —N(R 16 )SO 2 R 15a ;

each R 15 is independently hydrogen or a C 1-6 aliphatic group;

each R 15a is a C 1-6 aliphatic group; and

each R 16 is independently selected from hydrogen, a C 1-6 aliphatic group, —CO 2 R 15a , —SO 2 R 15a , or —C(O)R 15 , or N(R 16 ) 2 is a monocyclic heteroaryl or a monocyclic non-aromatic heterocyclic group.

25. The compound of claim 24 wherein:

R 2 is C 1 -C 2 alkyl or C 3 -C 6 cycloalkyl;

R 3 is a C 1 -C 4 alkyl group, and

R 4 is —(CH 2 ) m —B.

26. The compound of claim 25 wherein R 22 is an optionally substituted monocyclic non-aromatic heterocyclic group.

27. The compound of claim 26 wherein the compound is represented by the following structural formula:

or a pharmaceutically acceptable salt thereof, wherein s is 0, 1, 2, 3, or 4.

28. The compound of claim 27 wherein —C(O)NR 3 R 4 and —R 2 are trans relative to one another.

29. The compound of claim 28 wherein R 22 is an optionally substituted cyclohexanyl, oxazolidinyl, oxazolidinonyl, thiazolidinyl, tetrahydrofuranyl, tetrahydropyranyl, thiazolidinyl, tetrahydrothienyl, morpholinyl, thiomorpholinyl, imidazolidinyl, imidazolidinonyl, dioxanyl, dioxolanyl, dithiolanyl, pyrrolidinyl, pyrrolidinonyl, piperazinyl, isothiazolidinyl S,S, dioxide, or piperidinyl.

30. The compound of claim 29 wherein the compound is represented by the following structural formula:

or a pharmaceutically acceptable salt thereof.

31. The compound of claim 30 wherein V 3 is absent.

32. The compound of claim 31 wherein R 22 is oxazolidinyl, thiazolidinyl, tetrahydrofuranyl, morpholinyl, imidazolidinyl, imidazolidinonyl, pyrrolidinyl, pyrrolidinonyl, piperazinyl, or piperidinyl, each optionally substituted at any substitutable carbon atom by alkyl, halide, haloalkyl, hydroxyalkyl, —C(O)OR 23 , —C(O)R 23 , —OC(O)R 23 , or —C(O)N(R 23 ) 2 , and each optionally substituted at any substitutable nitrogen atom with alkyl, haloalkyl, hydroxyalkyl, —C(O)OR 23 , —C(O)R 23 , —(CH 2 ) q CO 2 H, —(CH 2 ) q C(O)N(R 23 ) 2 , —(CH 2 ) q CH(CH 3 )CON(R 23 ) 2 ; —(CH 2 ) q C(CH 3 ) 2 CON(R 23 ) 2 ; —(CH 2 ) q C(CH 3 ) 2 CO 2 R 23 or —(CH 2 ) q CH(CH 3 )CO 2 R 23 ;

q is an integer from 1-4; and

each R 23 is independently —H, alkyl, haloalkyl, or hydroxyalkyl.

33. The compound of claim 32 wherein the compound is represented by the following structural formula:

or a pharmaceutically acceptable salt thereof, wherein t is 0, 1, 2, 3 or 4.

34. The compound of claim 33 wherein R 8 , R 11 and R 14 , when present, are independently, halo, C 1-3 alkyl, C 1-3 haloalkyl, hydroxyl, C 1-3 alkoxy, C 1-3 haloalkoxy, —CN, amine, C 1-3 alkyl amine, C 1-3 dialkylamine.

35. A pharmaceutical composition comprising a pharmaceutically acceptable carrier or diluent and an effective amount of a compound represented by the compound of claim 1 .

36. A method of treating an inflammatory disease in a subject, comprising the step of administering to the subject an effective amount of a compound represented by the compound of claim 1 .

37. The method of claim 36 , where the inflammatory disease is atopic dermatitis, allergic rhinitis, rheumatoid arthritis, multiple sclerosis, chronic obstructive pulmonary disorder (COPD), COPD exacerbations, or allergic asthma.

38. The method of claim 37 , where the inflammatory disease, disorder or symptom is atopic dermatitis, chronic obstructive pulmonary disorder (COPD), COPD exacerbations, allergic rhinitis, or allergic asthma.

39. A method of inhibiting CRTH2 activity in: (a) a subject; or (b) a biological sample; which method comprises administering to said subject, or contacting said biological sample with a compound represented by claim 1 .