Immuno inhibitory heterocyclic compounds

1. A compound of formula (I) or a pharmaceutically or veterinarily acceptable salt thereof:

wherein

Y is —CH 2 —, —CH 2 CH 2 —, or —CH 2 CH 2 CH 2 —;

R 1 represents H; F; methyl, trifluoromethyl, methoxy or trifluoromethoxy;

R 3 represents H; F; Cl; Br; —NO 2 ; —CN; C 1 -C 6 alkyl optionally substituted by F or Cl; or C 1 -C 6 alkoxy optionally substituted by F;

R 4 represents a carboxylic acid group (—COOH) or an ester group of formula COOR wherein R is methyl, ethyl, n- or iso-propyl, n-, sec-, or tert-butyl or benzyl, or —C(═O)NR 6 R 7 , —NR 7 C(═O)R 6 , —NR 7 C(═O)OR 6 , —NHC(═O)NR 7 R 6 or —NHC(═S)NR 7 R 6 wherein

R 6 represents H, or a radical of formula -(Alk) m -Q wherein

m is 0 or 1

Alk is an optionally substituted divalent straight or branched C 1 -C 12 alkylene, or C 2 -C 12 alkenylene, or C 2 -C 12 alkynylene radical or a divalent C 3 -C 12 carbocyclic radical, any of which radicals may be interrupted by one or more —O—, —S— or —N(R 8 )- radicals wherein R 8 represents H or C 1 -C 4 alkyl, C 3 -C 4 alkenyl, C 3 -C 4 alkynyl, or C 3 -C 6 cycloalkyl, and

Q represents H; —NR 8 R 8 wherein each R 8 independently represents H; C 1 -C 4 alkyl; C 3 -C 4 alkenyl; C 3 -C 4 alkynyl; C 3 -C 6 cycloalkyl; an ester group of formula COOR wherein R is methyl, ethyl, n- or iso-propyl, n-, sec-, or tert-butyl or benzyl; an optionally substituted carbocyclic or heterocyclic group; or form a ring when taken together with the nitrogen to which they are attached, which ring is optionally substituted; and

R 7 represents H or C 1 -C 6 alkyl; or when taken together with the atom or atoms to which they are attached R 6 and R 7 form an optionally substituted monocyclic heterocyclic ring having 5, 6 or 7 ring atoms; and

X represents a bond or a divalent radical of formula -(Z) n -(Alk)- or -(Alk)-(Z) n - wherein Z represents —O—, —S— or —NH—, Alk is as defined in relation to R 6 and n is 0 or 1.

2. A compound as claimed in claim 1 wherein Y is —CH 2 CH 2 —.

3. A compound as claimed in claim 1 wherein the radical R 4 X— is in the 4-position of the phenyl ring.

4. A compound as claimed in claim 1 wherein X is a bond.

5. A compound as claimed in claim 1 wherein R 3 is hydrogen.

6. A compound as claimed in claim 1 wherein R 1 is hydrogen or fluoro.

7. A compound as claimed in claim 1 wherein R 4 represents —C(═O)NR 6 R 7 .

8. A compound as claimed in claim 1 wherein R 4 represents —NHC(═O)NR 7 R 6 .

9. A compound as claimed in claim 1 wherein R 6 represents a radical of formula -(Alk) m -Q wherein m is 1 and the divalent radical Alk contains 3 or 4 carbon atoms and is unsubstituted, and Q represents —NR 8 R 8 wherein each R 8 independently represents H; C 1 -C 4 alkyl; C 3 -C 4 alkenyl; C 3 -C 4 alkynyl; C 3 -C 6 cycloalkyl; an ester group of formula COOR wherein R is methyl, ethyl, n- or iso-propyl, n-, sec-, or tert-butyl of benzyl; an optionally substituted carbocyclic or heterocyclic group; or form a ring when taken together with the nitrogen to which they are attached, which ring is optionally substituted.

10. A compound as claimed in claim 9 wherein Q is a quinuclidine radical.

11. A compound as claimed in claim 7 wherein R 7 is hydrogen.

12. A compound as claimed in claim 1 wherein R 6 represents a radical of formula -(Alk) m -Q wherein m is 1, Alk is —CH 2 —, —CH 2 CH 2 , —CH 2 CH 2 CH 2 —, or —CH 2 CH(CH 3 )CH 2 —, or a divalent cyclopropylene, cyclopentylene or cyclohexylene radical, optionally substituted by OH, oxo, CF 3 , methoxy or ethoxy, and Q represents hydrogen; —NR 8 R 8 wherein each R 8 may be the same or different and selected from hydrogen, methyl, ethyl, n- or isopropyl or tert-butyl; a methyl, ethyl or benzyl ester; or an optionally substituted phenyl, phenoxy, cyclopentyl, cyclohexyl, furyl, thienyl, piperidyl, or piperazinyl group.

13. A compound as claimed in claim 1 wherein R 7 represents methyl, ethyl, n- or iso-propyl, n-, sec- or tert-butyl; or when taken together with the atom or atoms to which they are attached R 6 and R 7 form a monocyclic heterocyclic ring having 5, 6 or 7 ring atoms.

14. A compound as claimed in claim 1 wherein R 1 is F, in the 6-position of the 3-oxo-1,3-dihydro-2H-pyrazolo[4,3-c]cinnolin-2-yl ring system.

15. A compound as claimed in claim 1 wherein X is a bond, or a —CH 2 — or —CH 2 CH 2 — radical.

16. A compound of formula (IC) or a pharmaceutically or veterinarily acceptable salt thereof:

wherein X is a bond, or a —CH 2 — or —CH 2 CH 2 — radical and R 4 represents a carboxylic acid group (—COOH) or an ester group of formula COOR wherein R is methyl, ethyl, n- or iso-propyl, n-, sec- or tert-butyl or benzyl, or —C(═O)NR 6 R 7 , —NR 7 C(═O)R 6 , —NR 7 C(═O)OR 6 , —NHC(═O)NR 7 R 6 or

—NHC(═S)NR 7 R 6 wherein

R 6 represents a radical of formula -(Alk) m -Q wherein m is 1 and

the divalent radical Alk contains 3 or 4 carbon atoms and is unsubstituted, and Q represents —NR 8 R 8 wherein each R 8 independently represents H; C 1 -C 4 alkyl; C 1 -C 4 alkenyl, C 3 -C 4 alkynyl; C 3 -C 6 cycloalkyl; an ester group; an optionally substituted carbocyclic or heterocyclic group; or form a ring when taken together with the nitrogen to which they are attached, which ring is optionally substituted; or

Alk is —CH 2 —, —CH 2 CH 2 , —CH 2 CH 2 CH 2 —, or —CH 2 CH(CH 3 )CH 2 —, or a divalent cyclopropylene, cyclopentylene or cyclohexylene radical, optionally substituted by OH, oxo, CF 3 , methoxy or ethoxy, and Q represents hydrogen; —NR 8 R 8 wherein each R 8 may be the same or different and selected from hydrogen, methyl, ethyl n- or isopropyl or tert-butyl; a methyl, ethyl or benzyl ester; or an optionally substituted phenyl, phenoxy, cyclopentyl, cyclohexyl, furyl, thienyl, piperidyl, or piperazinyl group; and

R 7 represents H or C 1 -C 6 alkyl; or when taken together with the atom or atoms to which they are attached R 6 and R 7 form an optionally substituted monocyclic heterocyclic ring having 5, 6 or 7 ring atoms.

17. A compound as claimed in claim 15 wherein the radical R 4 X— is in the 4-position of the phenyl ring.

18. A compound as claimed in claim 16 wherein X is a bond and R 4 is —C(═O)NR 6 R 7 wherein R 6 represents a radical of formula —(Alk) m -Q wherein m is 1 Alk is —CH 2 —, —CH 2 CH 2 , —CH 2 CH 2 CH 2 —, or —CH 2 CH(CH 3 )CH 2 —, or a divalent cyclopropylene, cyclopentylene or cyclohexylene radical, optionally substituted by OH, oxo, CF 3 , methoxy or ethoxy, and Q represents hydrogen and R 7 represents H or C 1 -C 6 alkyl; or when taken together with the atom or atoms to which they are attached R 6 and R 7 form a monocyclic heterocyclic ring having 5, 6 or 7 ring atoms.

19. A pharmaceutical or veterinary composition comprising a compound as claimed in claim 1 together with a pharmaceutically or veterinarily acceptable excipient or carrier.