1-phenyl-substituted heterocyclyl derivatives and their use as prostaglandin D2 receptor modulators

1. A compound of formula (I):

wherein

Y represents —NH—, —O— or a bond;

Z represents O or S;

R 1 represents

(C 3 -C 6 )alkyl which is unsubstituted, mono-substituted with (C 1 -C 4 )alkoxy, or mono-, di- or tri-substituted with fluoro;

(C 1 -C 4 )alkyl which is mono-substituted with (C 4 -C 6 )cycloalkyl, optionally substituted cyclopropyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted heterocyclyl, optionally substituted aryloxy, optionally substituted heteroaryloxy, or optionally substituted aryl-(C 1 -C 2 )alkoxy;

(C 2 -C 4 )alkenyl which is mono-substituted with optionally substituted aryl; or

(C 3 -C 6 )cycloalkyl which is unsubstituted, mono-substituted with optionally substituted aryl or mono- or di-substituted with (C 1 -C 4 )alkyl;

R 2 represents halogen or cyano;

R 3 represents hydrogen or methyl;

R 4 represents hydrogen, (C 1 -C 4 )alkyl, (C 3 -C 6 )cycloalkyl, halogen, phenyl, (C 1 -C 2 )fluoroalkyl, or —NR 5 R 6 ;

R 5 represents hydrogen or methyl; and

R 6 represents hydrogen, (C 1 -C 4 )alkyl, (C 1 -C 4 )alkyl-carbonyl, (C 1 -C 4 )alkyl-sulfonyl, (C 3 -C 6 )cycloalkyl-carbonyl, or (C 3 -C 6 )cycloalkyl-sulfonyl;

or a salt thereof.

2. The compound according to claim 1 , wherein

Y represents —O— or a bond;

Z represents O;

R 1 represents

(C 3 -C 6 )alkyl which is unsubstituted, mono-substituted with (C 1 -C 4 )alkoxy, or mono-, substituted with fluoro;

(C 1 -C 4 )alkyl which is mono-substituted with (C 4 -C 6 )cycloalkyl, optionally substituted aryl, optionally substituted heteroaryl, or optionally substituted aryl-(C 1 -C 2 )alkoxy;

(C 2 -C 4 )alkenyl which is mono-substituted with optionally substituted aryl; or

(C 3 -C 6 )cycloalkyl which is mono-substituted with optionally substituted aryl;

R 2 represents halogen or cyano;

R 3 represents hydrogen; and

R 4 represents hydrogen, methyl, bromo, trifluoromethyl, or —NH 2 ;

or a salt thereof.

3. The compound according to claim 1 , wherein

Y represents —O—;

Z represents O;

R 1 represents

(C 3 -C 6 )alkyl which is unsubstituted, mono-substituted with (C 1 -C 4 )alkoxy, or mono-, substituted with fluoro; or

(C 1 -C 4 )alkyl which is mono-substituted with (C 4 -C 6 )cycloalkyl, optionally substituted aryl, or optionally substituted heteroaryl;

R 2 represents halogen or cyano;

R 3 represents hydrogen or methyl;

R 4 represents hydrogen, (C 1 -C 4 )alkyl, (C 3 -C 6 )cycloalkyl, halogen, phenyl, (C 1 -C 2 )fluoroalkyl, or —NR 5 R 6 ;

R 5 represents hydrogen or methyl; and

R 6 represents hydrogen, (C 1 -C 4 )alkyl, (C 1 -C 4 )alkyl-carbonyl, (C 1 -C 4 )alkyl-sulfonyl, (C 3 -C 6 ) cycloalkyl-carbonyl, or (C 3 -C 6 )cycloalkyl-sulfonyl;

or a salt thereof.

4. The compound according to claim 1 , wherein Y represents —O—;

or a salt thereof.

5. The compound according to claim 1 , wherein Y represents a bond;

or a salt thereof.

6. The compound according to claim 1 , wherein Z represents O; or a salt thereof.

7. The compound according to claim 1 , wherein R 1 represents

(C 1 -C 4 )alkyl which is mono-substituted with (C 4 -C 6 )cycloalkyl, optionally substituted aryl, or optionally substituted aryl-(C 1 -C 2 )alkoxy;

(C 2 -C 4 )alkenyl which is mono-substituted with optionally substituted aryl; or

(C 3 -C 6 )cycloalkyl which is mono-substituted with optionally substituted aryl;

or a salt thereof.

8. The compound according to claim 1 , wherein R 1 represents

(C 3 -C 6 )alkyl which is unsubstituted, mono-substituted with (C 1 -C 4 )alkoxy, or mono-substituted with fluoro; or

(C 1 -C 4 )alkyl which is mono-substituted with (C 4 -C 6 )cycloalkyl, optionally substituted aryl, or optionally substituted heteroaryl;

or a salt thereof.

9. The compound according to claim 1 , wherein R 3 represents hydrogen; or a salt thereof.

10. The compound according to claim 1 , wherein R 4 represents hydrogen, (C 1 -C 4 )alkyl, halogen, trifluoromethyl, or —NH 2 ;

or a salt thereof.

11. The compound according to claim 1 , wherein the compound is:

{4-Chloro-2-[5-(2-fluoro-benzylcarbamoyl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

{4-Chloro-2-[5-(3-fluoro-benzylcarbamoyl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

{4-Chloro-2-[5-(4-fluoro-benzylcarbamoyl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

[2-(5-Benzylcarbamoyl-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl)-4-chloro-phenoxy]-acetic acid;

{4-Chloro-2-[(R)-5-((1R,2R)-2-phenyl-cyclopropanecarbonyl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

{4-Chloro-2-[(R)-5(1S,2S)-2-phenyl-cyclopropanecarbonyl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

(4-Chloro-2- (R)-5- [(1R,2R)-2-(3-fluoro-phenyl)-cyclopropanecarbonyl]-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl)-phenoxy)-acetic acid;

(4-Chloro-2-{(R)-5-[(1R,2R)-2-(4-fluoro-phenyl)-cyclopropanecarbonyl]-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl}-phenoxy)-acetic acid;

(4-Chloro-2-{(R)-5-[(1S,2S)-2-(4-fluoro-phenyl)-cyclopropanecarbonyl]-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl}-phenoxy)-acetic acid;

{4-Chloro-2-[(R)-2-methyl-5-((1R,2R)-2-phenyl-cyclopropanecarbonyl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

{4-Chloro-2-[(S)-2-methyl-5-((1R,2R)-2-phenyl-cyclopropanecarbonyl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

4-(2-Carboxymethoxy-5-chloro-phenyl)-2-trifluoromethyl-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid benzyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-2-isopropyl-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid benzyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-2-cyclopropyl-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid benzyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-2-methyl-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid benzyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-2-ethyl-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid benzyl ester;

2-Amino-4-(2-carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid benzyl ester;

(S)-4-(2-Carboxymethoxy-5-chloro-phenyl)-2-methyl-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid benzyl ester;

(R)-4-(2-Carboxymethoxy-5-chloro-phenyl)-2-methyl-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid benzyl ester;

2-Bromo-4-(2-carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid benzyl ester;

(4-Chloro-2-{5-[3-(4-fluoro-phenoxy)-propionyl]-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl}-phenoxy)-acetic acid;

{4-Chloro-2-[trans-5-(2-phenyl-cyclopropanecarbonyl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

(4-Chloro-2-{trans-5-[2-(2-trifluoromethyl-phenyl)-cyclopropanecarbonyl]-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl}-phenoxy)-acetic acid;

(4-Chloro-2-{trans-5-[2-(2-chloro-phenyl)-cyclopropanecarbonyl]-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl}-phenoxy)-acetic acid;

{4-Chloro-2-[trans-5-(2-o-tolyl-cyclopropanecarbonyl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

(4-Chloro-2-{5-[3-(5-methoxy-1H-indol-3-yl)-propionyl]-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl}-phenoxy)-acetic acid;

(4-Chloro-2-{5-[3-(2-methyl-1H-indol-3-yl)-propionyl]-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl}-phenoxy)-acetic acid;

(4-Chloro-2-{5-[3-(1-methyl-1H-indol-3-yl)-propionyl]-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl}-phenoxy)-acetic acid;

{4-Chloro-2-[5-(3-o-tolyl-propionyl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

(4-Chloro-2-{5-[4-(2-fluoro-phenyl)-butyryl]-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl}-phenoxy)-acetic acid;

(4-Chloro-2-{5-[2-(2-chloro-benzyloxy)-acetyl]-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl}-phenoxy)-acetic acid;

(4-Chloro-2-{5-[2-(2,6-dimethyl-pyridin-3-yloxy)-acetyl]-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl}-phenoxy)-acetic acid;

(4-Chloro-2-[5-(3-indazol-1-yl-propionyl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy)-acetic acid;

{4-Chloro-2-[5-(2-phenoxy-acetyl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

{4-Chloro-2-[5-((S)-3-phenyl-butyryl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

{4-Chloro-2-[5-(indane-2-carbonyl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

(4-Chloro-2-{5-[2-(1-phenyl-cyclopropyl)-acetyl]-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl}-phenoxy)-acetic acid;

{4-Chloro-2-[5-((R)-3-phenyl-butyryl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

{4-Chloro-2-[5-(2-isochroman-1-yl-acetyl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

{4-Chloro-2-[5-(3,3-dimethyl-butyryl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

{4-Chloro-2-[5-(2-cyclopropyl-acetyl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

(4-Chloro-2-{5-[3-(3,5-dimethyl-isoxazol-4-yl)-propionyl]-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl}-phenoxy)-acetic acid;

[4-Chloro-2-(5-cyclopropanecarbonyl-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl)-phenoxy]-acetic acid;

{4-Chloro-2-[5-(2-1H-indazol-3-yl-acetyl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

(4-Chloro-2-{5-[(E)-(3-phenyl-acryloyl)]-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl}-phenoxy)-acetic acid;

{4-Chloro-2-[5-(2-indan-2-yl-acetyl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

{4-Chloro-2-[5-(2,2-dimethyl-cyclopropanecarbonyl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

{4-Chloro-2-[5-(2-cyclohexyl-acetyl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

{4-Chloro-2-[5-(2-naphthalen-2-yl-acetyl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

{4-Chloro-2-[5-(2-naphthalen-1-yl-acetyl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

(4-Chloro-2-{5-[4-(4-fluoro-phenyl)-butyryl]-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl}-phenoxy)-acetic acid;

{4-Chloro-2-[5-(3-2,3-dihydro-indol-1-yl-propionyl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

{4-Chloro-2-[5-(3-3,4-dihydro-2H-quinolin-1-yl-propionyl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

(4-Chloro-2-{5-[(E)-3-(4-methoxy-phenyl)-acryloyl]-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl}-phenoxy)-acetic acid;

(4-Chloro-2-{5-[(E)-3-(4-fluoro-phenyl)-acryloyl]-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl}-phenoxy)-acetic acid;

{4-Chloro-2-[5-((E)-3-p-tolyl-acryloyl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

(4-Chloro-2-{5-[(E)-3-(2,4-difluoro-phenyl)-acryloyl]-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl}-phenoxy)-acetic acid;

(R)-4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 2,5-difluoro-benzyl ester;

(R)-4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 2,4-difluoro-benzyl ester;

(R)-4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 2,2-dimethyl-butyl ester;

(R)-4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 4-fluoro-benzyl ester;

(R)-4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 3-methoxy-3-methyl-butyl ester;

(R)-4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 2,4-dimethyl-benzyl ester;

(R)-4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 2-chloro-5-fluoro-benzyl ester;

(R)-4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 3,3-dimethyl-butyl ester;

(R)-4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid cyclohexylmethyl ester;

(R)-4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 3-methyl-butyl ester;

(R)-4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 5-chloro-2-fluoro-benzyl ester;

(R)-4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid cyclobutylmethyl ester;

(R)-4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 2-methyl-butyl ester;

(R)-4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 2,3-difluoro-benzyl ester;

(R)-4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 2,3-dimethyl-benzyl ester;

(R)-4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 2,6-difluoro-benzyl ester;

(R)-4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 3-fluoro-propyl ester;

(R)-4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 2-fluoro-benzyl ester;

(R)-4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 3-fluoro-benzyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 2-(3-fluoro-phenyl)-ethyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 3-fluoro-benzyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 2-fluoro-benzyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 4-fluoro-benzyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 2,3-dichloro-benzyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 2,3-difluoro-benzyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 2,4-difluoro-benzyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 2-chloro-benzyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 3-chloro-benzyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 4-chloro-benzyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 2,6-dichloro-benzyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid phenethyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 2,6-difluoro-benzyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid indazol-1-ylmethyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 2-(2-ethyl-5-methyl-2H-pyrazol-3-yl)-ethyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 2-chloro-5-fluoro-benzyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 2,5-difluoro-benzyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 2,4-dichloro-benzyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid pyrazin-2-ylmethyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid cyclohexylmethyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid benzooxazol-2-ylmethyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid isobutyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid butyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 2,4-dimethyl-benzyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 2,3-dimethyl-benzyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid 5-chloro-2-fluoro-benzyl ester;

(R)-4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid benzyl ester;

(S)-4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid benzyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid benzyl ester;

4-(2-Carboxymethoxy-5-cyano-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid benzyl ester;

[4-Chloro-2-(5-phenethylcarbamoyl-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl)-phenoxy]-acetic acid;

{4-Chloro-2-[5-(2-chloro-benzylcarbamoyl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

{4-Chloro-2-[5-(2-methoxy-benzylcarbamoyl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

{4-Chloro-2-[5-(2-methoxy-benzylthiocarbamoyl)-4,5,6,7-tetrahydro-thiazolo[5,4-c]pyridin-4-yl]-phenoxy}-acetic acid;

4-(2-Carboxymethoxy-5-chloro-phenyl)-2-propyl-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid benzyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-2-phenyl-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid benzyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-2-methanesulfonylamino-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid benzyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-2-cyclopropanesulfonylamino-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid benzyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-2-(cyclopropanecarbonyl-amino)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid benzyl ester;

2-Acetylamino-4-(2-carboxymethoxy-5-chloro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid benzyl ester;

4-(2-Carboxymethoxy-5-chloro-phenyl)-2-dimethylamino-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid benzyl ester;

4-(2-Carboxymethoxy-5-fluoro-phenyl)-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid benzyl ester;

4-[2-((R)-1-Carboxy-ethoxy)-5-chloro-phenyl]-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid benzyl ester; or

4-[2-((S)-1-Carboxy-ethoxy)-5-chloro-phenyl]-6,7-dihydro-4H-thiazolo[5,4-c]pyridine-5-carboxylic acid benzyl ester;

or a salt thereof.

12. A pharmaceutical composition comprising a compound according to claim 1 , or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier.

13. A method of treating a disease comprising administering to a subject in need thereof a therapeutically effective amount of the compound according to claim 1 , wherein the disease is asthma, allergic asthma eosinophilic asthma, severe asthma, rhinitis, allergic rhinitis, angioedema, insect venom allergy, drug allergies, allergic sinusitis, allergic nephritis, allergic conjunctivitis, atopic dermatitis, bronchial asthma, food allergy, systemic mast cell disorders, anaphylactic shock, urticaria, eczema, ulcerative colitis, chronic obstructive pulmonary disease (COPD), inflammatory bowel disease, rheumatoid arthritis, Churg-Stauss syndrome, Wegener's granulomatosis, microscopic polyangiitis or organ-specific subsets of the latter, eosinophilic pneumonia, eosinophilic esophagitis, reflux esophagitis, eosinohilic endocarditis (Loeffler's endocarditis), eosinophilia-myalgia syndrome, eosinophilic fasciitis, eosinohilic pustular folliculitis (Ofuji's disease), eosinophilic ulcers, angiolymphoid hyperplasia with eosinophilia (ALHE), eosinophilic cellulitis (Wells syndrome), chronic eosinophilic leukemia, DRESS syndrome (Drug Rash with Eosinophilia and Systemic Symptoms), basophilic leukemia or basophilic leukocytosis.

14. The method according to claim 13 , wherein the disease is asthma, allergic asthma, eosinophilic asthma, severe asthma, rhinitis, allergic rhinitis, angioedema, insect venom allergy, drug allergies, allergic sinusitis, allergic nephritis, allergic conjunctivitis, atopic dermatitis, bronchial asthma, food allergy, systemic mast cell disorders, anaphylactic shock, urticaria, eczema, ulcerative colitis, chronic obstructive pulmonary disease (COPD), inflammatory bowel disease and rheumatoid arthritis.

15. The method according to claim 13 , wherein the disease is Churg-Stauss syndrome Wegener's granulomatosis, microscopic polyangiitis or organ-specific subsets of the latter.

16. The method according to claim 13 , wherein the disease is eosinophilic pneumonia, eosinophilic esophagitis, reflux esophagitis, eosinohilic endocarditis (Loeffler's endocarditis), eosinophilia-myalgia syndrome, eosinophilic fasciitis, eosinohilic pustular folliculitis (Ofuji's disease), eosinophilic ulcers, angiolymphoid hyperplasia with eosinophilia (ALHE), eosinophilic cellulitis (Wells syndrome), chronic eosinophilic leukemia and DRESS syndrome (Drug Rash with Eosinophilia and Systemic Symptoms).

17. The method according to claim 14 , wherein the disease is basophilic leukemia or basophilic leukocytosis.