Guanidine derivatives as inhibitors of DDAH

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

wherein:

R 1 is -L-Het-L′, -L-Y-L′, -L-Het-A or -L-Y-A; wherein:

L is C 1 -C 6 alkyl, C 2 -C 6 alkenyl or C 2 -C 6 alkynyl;

L′ is C 1 -C 6 alkyl, C 2 -C 6 alkenyl or C 2 -C 6 alkynyl;

A is C 6 -C 10 aryl, C 3 -C 8 carbocyclyl, 5- to 10-membered heterocyclyl or 5- to 10-membered heteroaryl;

Het is —O—, —S— or —NR′—, wherein R′ is hydrogen, C 1 -C 6 alkyl, C 2 -C 6 alkenyl, or C 2 -C 6 alkynyl;

Y is —CO—, —SO—, —SO 2 —, —CO—O—, —CO—NR′—, —O—CO— or —NR′-CO—, wherein R′ is defined as above;

R 2 is hydrogen, C 1 -C 6 alkyl, C 2 -C 6 alkenyl or C 2 -C 6 alkynyl; and

R 3 is hydrogen, C 1 -C 6 alkyl, C 2 -C 6 alkenyl or C 2 -C 6 alkynyl;

R 4 is hydrogen, C 1 -C 6 alkyl, C 2 -C 6 alkenyl or C 2 -C 6 alkynyl;

B is C 1 -C 6 alkyl, C 2 -C 6 alkenyl, —O-L-, —S-L- or -L-Het-L′-; wherein L, L′ and Het are as defined above;

X is —O—, —S— or —NR'-; wherein R′ is as defined above;

R 5 is hydrogen, C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, aryl, C 3 -C 8 carbocyclyl, 5- to 10-membered heterocyclyl, 5- to 10-membered heteroaryl, -L-A, -L-Het-L′, -L-Y-L′, -L-Het-A, -L-Y-A, -L-A-Het-A, -L-A-L′-A or -L-A-Het-L′-A; wherein L, L′, Het and Y are as defined above and wherein each A is the same or different and is as defined above;

R 6 is hydrogen, C 1 -C 6 alkyl, C 2 -C 6 alkenyl or C 2 -C 6 alkynyl;

R 7 is hydrogen, C 1 -C 6 alkyl, C 2 -C 6 alkenyl or C 2 -C 6 alkynyl; and

R 8 is hydrogen, C 1 -C 6 alkyl, C 2 -C 6 alkenyl or C 2 -C 6 alkynyl;

wherein:

the alkyl, alkenyl and alkynyl groups and moieties in the substituents R 1 to R 7 , X and B are unsubstituted or substituted by one, two or three substituents which are the same or different and are independently selected from the group consisting of halogen, hydroxy, amino and thio substituents; and

the aryl, carbocyclyl, heterocyclyl and heteroaryl groups and moieties in the substituents R 1 and R 5 are unsubstituted or substituted by one, two or three substituents independently-selected from the group consisting of halogen, hydroxy, amino, thio, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 1 -C 6 alkylthio, nitro, cyano, C 1 -C 6 alkylamino, di-(C 1 -C 6 alkyl)amino, C 1 -C 6 haloalkyl, C 1 -C 6 haloalkoxy and C 1 -C 6 haloalkylthio substituents.

2. A compound according to claim 1 wherein the compound of formula (I) is a compound of formula (II)

wherein:

R 11 is —(C 1 -C 2 alkyl)-O-phenyl, —(C 1 -C 2 alkyl)-O—(C 1 -C 4 alkyl), —(C 1 -C 2 alkyl)-S(C 1 -C 2 alkyl) or —(C 1 -C 2 alkyl)-NMe-(C 1 -C 2 alkyl);

R 21 is hydrogen, methyl or ethyl;

B 1 is a 1,2-ethyl or 1,3-propyl moiety; and

R 51 is hydrogen, C 1 -C 4 alkyl, —(C 1 -C 2 alkyl)-phenyl, —(C 1 -C 2 alkyl)-O—(C 1 -C 2 alkyl) or —(C 1 -C 2 alkyl)-phenyl-O-phenyl;

wherein:

the alkyl groups and moieties in the substituents R 11 , R 21 , B and R 51 are unsubstituted or substituted by a single fluoro substituent; and the phenyl group in R 11 is unsubstituted and the phenyl groups in R 51 are unsubstituted or substituted by one or two substituents selected from fluorine, C 1 -C 2 alkyl, C 1 -C 2 alkoxy and C 1 -C 2 haloalkyl substituents.

3. A compound according to claim 2 wherein R 11 is —(C 1 -C 2 alkyl)-O—(C 1 -C 4 alkyl).

4. A compound according to claim 2 wherein R 51 is C 1 -C 4 alkyl or —(C 1 -C 2 alkyl)-phenyl.

5. A compound according to claim 1 wherein A is phenyl, C 3 -C 6 carbocyclyl, 5- to 6-membered heterocyclyl or 5- to 6-membered heteroaryl.

6. A compound according to claim 1 wherein L and L′ are the same or different and are C 1 -C 6 alkyl.

7. A compound according to claim 1 wherein B is C 2 -C 6 alkyl.

8. A compound according to claim 1 wherein R 5 is hydrogen, C 1 -C 6 alkyl, C 2 -C 6 alkenyl, phenyl, C 3 -C 6 carbocyclyl, 5- to 6-membered heterocyclyl, 5- to 6-membered heteroaryl, -L-A, -L-Het-L′, -L-Y-L′, -L-Het-A, -L-Y-A or -L-A-Het-A.

9. A compound according to claim 1 which is N G -(2-methoxyethyl)-L-arginine or N G -(2-methoxyethyl)-L-arginine methyl ester, or a pharmaceutically acceptable salt thereof.

10. A pharmaceutical composition comprising a compound of formula (I), as defined in claim 1 , or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier or diluent.

11. A method of treating a patient suffering from ischaemia-reperfusion injury of the brain or heart, asthma, pain, peritonitis or sepsis, which method comprises administering to said patient an effective amount of a compound of formula (I) or a pharmaceutically acceptable salt thereof,

wherein:

R 1 is -L-Het-L′, -L-Y-L′, -L-Het-A or -L-Y-A; wherein:

L is C 1 -C 6 alkyl, C 2 -C 6 alkenyl or C 2 -C 6 alkynyl;

L′ is C 1 -C 6 alkyl, C 2 -C 6 alkenyl or C 2 -C 6 alkynyl;

A is C 6 -C 10 aryl, C 3 -C 8 carbocyclyl, 5- to 10-membered heterocyclyl or 5- to 10-membered heteroaryl;

Het is —O—, —S— or —NR′—, wherein R′ is hydrogen, C 1 -C 6 alkyl, C 2 -C 6 alkenyl, or C 2 -C 6 alkynyl;

Y is —CO—, —SO—, —SO 2 —, —CO—O—, —CO—NR′—, —O—CO— or —NR′—CO—, wherein R′ is defined as above;

R 2 is hydrogen, C 1 -C 6 alkyl, C 2 -C 6 alkenyl or C 2 -C 6 alkynyl; and

R 3 is hydrogen, C 1 -C 6 alkyl, C 2 -C 6 alkenyl or C 2 -C 6 alkynyl;

R 4 is hydrogen, C 1 -C 6 alkyl, C 2 -C 6 alkenyl or C 2 -C 6 alkynyl;

B is C 1 -C 6 alkyl, C 2 -C 6 alkenyl, —O-L-, —S-L- or -L-Het-L′-; wherein L, L′ and Het are as defined above;

X is —O—, —S— or —NR′—; wherein R′ is as defined above;

R 5 is hydrogen, C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, aryl, C 3 -C 8 carbocyclyl, 5- to 10-membered heterocyclyl, 5- to 10-membered heteroaryl, -L-A, -L-Het-L′, -L-Y-L′, -L-Het-A, -L-Y-A, -L-A-Het-A, -L-A-L′-A or -L-A-Het-L′-A; wherein L, L′, Het and Y are as defined above and wherein each A is the same or different and is as defined above;

R 6 is hydrogen, C 1 -C 6 alkyl, C 2 -C 6 alkenyl or C 2 -C 6 alkynyl;

R 7 is hydrogen, C 1 -C 6 alkyl, C 2 -C 6 alkenyl or C 2 -C 6 alkynyl; and

R 8 is hydrogen, C 1 -C 6 alkyl, C 2 -C 6 alkenyl or C 2 -C 6 alkynyl;

wherein:

the alkyl, alkenyl and alkynyl groups and moieties in the substituents R 1 to R 7 , X and B are unsubstituted or substituted by one, two or three substituents which are the same or different and are independently selected from the group consisting of halogen, hydroxy, amino and thio substituents; and

the aryl, carbocyclyl, heterocyclyl and heteroaryl groups and moieties in the substituents R 1 and R 5 are unsubstituted or substituted by one, two or three substituents independently-selected from the group consisting of halogen, hydroxy, amino, thio, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 1 -C 6 alkylthio, nitro, cyano, C 1 -C 6 alkylamino, di-(C 1 -C 6 alkyl)amino, C 1 -C 6 haloalkyl, C 1 -C 6 haloalkoxy and C 1 -C 6 haloalkylthio substituents.

12. The method according to claim 11 wherein the disease is peritonitis or sepsis.

13. The method according to claim 11 wherein the compound of formula (I) is a compound of formula (II),

wherein:

R 11 is —(C 1 -C 2 alkyl)-O-phenyl, —(C 1 -C 2 alkyl)-O—(C 1 -C 4 alkyl), —(C 1 -C 2 alkyl)-S(C 1 -C 2 alkyl) or —(C 1 -C 2 alkyl)-NMe-(C 1 -C 2 alkyl);

R 21 is hydrogen, methyl or ethyl;

B 1 is a 1,2-ethyl or 1,3-propyl moiety; and

R 51 is hydrogen, C 1 -C 4 alkyl, —(C 1 -C 2 alkyl)-phenyl, —(C 1 -C 2 alkyl)-O—(C 1 -C 2 alkyl) or —(C 1 -C 2 alkyl)-phenyl-O-phenyl;

wherein:

the alkyl groups and moieties in the substituents R 11 , R 21 , B and R 51 are unsubstituted or substituted by a single fluoro substituent; and the phenyl group in R 11 is unsubstituted and the phenyl groups in R 51 are unsubstituted or substituted by one or two substituents selected from fluorine, C 1 -C 2 alkyl, C 1 -C 2 alkoxy and C 1 -C 2 haloalkyl substituents.

14. The method of claim 11 wherein the compound is N G -(2-methoxyethyl)-L-arginine, N G -(2-methoxyethyl)-L-arginine methyl ester, or a pharmaceutically acceptable salt thereof.