Tetrahydronaphthalene derivatives, process for their production and their use as anti-inflammatory agents

1. Compounds of general formula (I),

in which

R 1 and R 2 , independently of one another, mean a hydrogen atom, a hydroxy group, a halogen atom, an optionally substituted (C 1 -C 10 )-alkyl group, an optionally substituted (C 1 -C 10 )-alkoxy group, a (C 1 -C 10 )-alkylthio group, a (C 1 -C 5 )-perfluoroalkyl group, a cyano group, a nitro group, or R 1 and R 2 together mean —O—(CH 2 ) n —O—, —O—(CH 2 ) n —CH 2 —, —O—CH═CH—, —(CH 2 ) n+2 —, —NH—(CH 2 ) n+1 , —N(C 1 -C 3 -alkyl)-(CH 2 ) n+1 , and —NH—N═CH—,

wherein n=1 or 2, and the terminal oxygen atoms and/or carbon atoms and/or nitrogen atoms are linked to directly adjacent ring-carbon atoms, or NR 8 R 9 ,

R 8 and R 9 , independently of one another, mean hydrogen, C 1 -C 5 -alkyl or (CO)—C 1 -C 5 -alkyl,

R 11 means a hydrogen atom, a hydroxy group, a halogen atom, a cyano group, an optionally substituted (C 1 -C 10 )-alkyl group, a (C 1 -C 10 )-alkoxy group, a (C 1 -C 10 )-alkylthio group, or a (C 1 -C 5 )-perfluoroalkyl group,

R 12 means a hydrogen atom, a hydroxy group, a halogen atom, a cyano group, an optionally substituted (C 1 -C 10 )-alkyl group, or a (C 1 -C 10 )-alkoxy group,

R 3 is indazole that is optionally substituted, independently of one another, by one or more

(C 1 -C 5 )-alkyl groups, which are optionally substituted by 1-3 hydroxy or 1-3 COOR 13 groups, wherein R 13 means hydrogen or (C 1 -C 5 )-alkyl,

(C 1 -C 5 )-alkoxy groups,

halogen atoms,

hydroxy groups,

NR 8 R 9 groups,

exomethylene groups, or

oxygen,

wherein this group is linked via any position to the amine of the tetrahydronaphthalene system and optionally is hydrogenated at one or more sites,

R 4 means a hydroxy group, a group OR 10 or an O(CO)R 10 group, whereby R 10 means a hydroxy protective group or a C 1 -C 10 -alkyl group,

R 5 means a (C 1 -C 10 )-alkyl group or an optionally partially or completely fluorinated (C 1 -C 10 )-alkyl group, a (C 3 -C 7 )cycloalkyl group, a (C 1 -C 8 )alkyl(C 3 -C 7 )cycloalkyl group, a (C 2 -C 8 )alkenyl(C 3 -C 7 )cycloalkyl group, a heterocyclyl group, a (C 1 -C 8 )alkylheterocyclyl group, a (C 2 -C 8 )-alkenylheterocyclyl group, an aryl group, a (C 1 -C 8 )alkylaryl group, a (C 2 -C 8 )alkenylaryl group, (C 2 -C 8 )alkinylaryl groups, a monocyclic or bicyclic heteroaryl group that optionally is substituted by 1-2 keto groups, 1-2 (C 1 -C 5 )-alkyl groups, 1-2 (C 1 -C 5 )-alkoxy groups, 1-3 halogen atoms, or 1-2 exomethylene groups and that contains 1-3 nitrogen atoms and/or 1-2 oxygen atoms and/or 1-2 sulfur atoms, a (C 1 -C 8 )alkenylheteroaryl group or a (C 2 -C 8 )alkenylheteroaryl group, or a (C 2 -C 8 )alkinylheteroaryl group, wherein this group is linked via any position to the tetrahydronaphthalene system and optionally is hydrogenated at one or more sites, and

R 6 and R 7 , independently of one another, mean a hydrogen atom, a methyl or ethyl group or, together with the carbon atom of the tetrahydronaphthalene system, a (C 3 -C 6 )-cycloalkyl ring.

2. A stereoisomer of formula (I)

in which

R 1 and R 2 , independently of one another, mean a hydrogen atom, a hydroxy group, a halogen atom, an optionally substituted (C 1 -C 10 )-alkyl group, a (C 1 -C 10 )-alkoxy group, a (C 1 -C 10 )-alkylthio group, a (C 1 -C 5 )-perfluoroalkyl group, a cyano group, or a nitro group,

or R 1 and R 2 together mean —O—(CH 2 ) n —O—, —O—(CH 2 ) n —CH 2 —, —O—CH═CH—, —(CH 2 ) n+2 —, —NH—(CH 2 ) n+1 , —N(C 1 -C 3 -alkyl)-(CH 2 ) n+1 , or —NH—N═CH—,

wherein n=1 or 2, and the terminal oxygen atoms and/or carbon atoms and/or nitrogen atoms are linked to directly adjacent ring-carbon atoms, or NR 8 R 9 ,

R 8 and R 9 , independently of one another, are hydrogen, C 1 -C 5 -alkyl or (CO)-C 1 -C 5 -alkyl,

R 11 means a hydrogen atom, a hydroxy group, a halogen atom, a cyano group, an optionally substituted (C 1 -C 10 )-alkyl group, a (C 1 -C 10 )-alkoxy group, a (C 1 -C 10 )-alkylthio group, or a (C 1 -C 5 )-perfluoroalkyl group,

R 12 means a hydrogen atom, a hydroxy group, a halogen atom, a cyano group, an optionally substituted (C 1 -C 10 )-alkyl group, or a (C 1 -C 10 )-alkoxy group,

R 3 is indazole that optionally is substituted by one or more

(C 1 -C 5 )-alkyl groups, which are optionally substituted by 1-3 hydroxy or 1-3 COOR 13 groups, wherein R 13 means hydrogen or (C 1 -C 5 )-alkyl,

(C 1 -C 5 )-alkoxy groups,

halogen atoms, or

exomethylene groups,

wherein this group is linked via any position to the amine of the tetrahydronaphthalene system and is optionally hydrogenated at one or more sites,

R 4 means a hydroxy group, a group OR 10 or an 0 (CO)R 10 group, wherein R 10 means a hydroxy protective group or a C 1 -C 10 -alkyl group,

R 5 means a (C 1 -C 5 )-alkyl group or an optionally partially or completely fluorinated (C 1 -C 5 )-alkyl group, a (C 3 -C 7 )cycloalkyl group, a (C 1 -C 8 )alkyl(C 3 -C 7 )cycloalkyl group, a (C 2 -C 8 )alkenyl(C 3 -C 7 )cycloalkyl group, a heterocyclyl group, a (C 1 -C 8 )alkylheterocyclyl group, a (C 2 -C 8 )-alkenylheterocyclyl group, an aryl group, a (C 1 -C 8 )alkylaryl group, a (C 2 -C 8 )alkenylaryl group, a (C 2 -C 8 )alkinylaryl group,

a monocyclic or bicyclic heteroaryl group that optionally is substituted by 1-2 keto groups, 1-2 (C 1 -C 5 )-alkyl groups, 1-2 (C 1 -C 5 )-alkoxy groups, 1-3 halogen atoms, 1-2 exomethylene groups or that contains 1-3 nitrogen atoms and/or 1-2 oxygen atoms and/or 1-2 sulfur atoms, a (C 1 -C 8 )alkylheteroaryl group or a (C 2 -C 8 )alkenylheteroaryl group, wherein this group is linked via any position to the tetrahydronaphthalene system and optionally is hydrogenated at one or more sites, and

R 6 and R 7 , independently of one another, mean a hydrogen atom, a methyl or ethyl group or together with the carbon atom of the tetrahydronaphthalene system mean a (C 3 -C 6 )-cycloalkyl ring,

provided that at least three of radicals R 1 , R 2 , R 11 and R 12 are not hydrogen.

3. A compound of formula (I),

in which

R 1 and R 2 , independently of one another, mean a hydrogen atom, a hydroxy group, a halogen atom, an optionally substituted (C 1 -C 10 )-alkyl group, an optionally substituted (C 1 -C 10 )-alkoxy group, a (C 1 -C 10 )-alkylthio group, a (C 1 -C 5 )-perfluoralkyl group, a cyano group, or a nitro group or R 1 and R 2 together mean —O—(CH 2 ) n —O—, —O—(CH 2 ) n —CH 2 —, —O—CH═CH—, —(CH 2 ) n+2 —, —NH—(CH 2 ) n+1 , —N(C 1 -C 3 -alkyl)-(CH 2 ) n+1 , and —NH—N═CH—,

wherein n=1 or 2, and the terminal oxygen atoms and/or carbon atoms and/or nitrogen atoms are linked to directly adjacent ring-carbon atoms, or NR 8 R 9 ,

R 8 and R 9 , independently of one another, are hydrogen, C 1 -C 5 -alkyl or (CO)-C 1 -C 5 -alkyl,

R 11 means a hydrogen atom, a hydroxy group, a halogen atom, a cyano group, an optionally substituted (C 1 -C 10 )-alkyl group, a (C 1 -C 10 )-alkoxy group, a (C 1 -C 10 )-alkylthio group, or a (C 1 -C 5 )-perfluoroalkyl group,

R 12 means a hydrogen atom, a hydroxy group, a halogen atom, a cyano group, an optionally substituted (C 1 -C 10 )-alkyl group, or a (C 1 -C 10 )-alkoxy group,

R 3 is indazole that is optionally substituted, independently of one another, by one or more

(C 1 -C 5 )-alkyl groups, which are optionally substituted by 1-3 hydroxy or 1-3 COOR 13 groups, wherein R 13 means hydrogen or (C 1 -C 5 )-alkyl,

(C 1 -C 5 )-alkoxy groups,

halogen atoms,

hydroxy group,

NR 8 R 9 groups,

exomethylene groups, or

oxygen,

wherein this group is linked via any position to the amine of the tetrahydronaphthalene system and optionally is hydrogenated at one or more sites,

R 4 means a hydroxy group, a group OR 10 or an O(CO)R 10 group, wherein R 10 means a hydroxy protective group or a C 1 -C 10 -alkyl group,

R 5 means a (C 1 -C 10 )-alkyl group or an optionally partially or completely fluorinated (C 1 -C 10 )-alkyl group, and

R 6 and R 7 , independently of one another, mean a hydrogen atom, a methyl or ethyl group, or, together with the carbon atom of the tetrahydronaphthalene system, mean a (C 3 -C 6 )-cycloalkyl ring.

4. A compound of formula (I),

in which

R 1 and R 2 , independently of one another, mean a hydrogen atom, a hydroxy group, a halogen atom, an optionally substituted (C 1 -C 10 )-alkyl group, an optionally substituted (C 1 -C 10 )-alkoxy group, a (C 1 -C 10 )-alkylthio group, a (C 1 -C 5 )-perfluoralkyl group, a cyano group, or a nitro group, or R 1 and R 2 together mean —O—(CH 2 ) n —O—, —O—(CH 2 ) n —CH 2 —, —O—CH═CH—, —(CH 2 ) n+2 —, —NH—(CH 2 ) n+1 , —N(C 1 -C 3 -alkyl)-(CH 2 ) n+1 , and —NH—N═CH—,

wherein n=1 or 2, and the terminal oxygen atoms and/or carbon atoms and/or nitrogen atoms are linked to directly adjacent ring-carbon atoms, or NR 8 R 9 ,

R 8 and R 9 , independently of one another, are hydrogen, C 1 -C 5 -alkyl or (CO)-C 1 -C 5 -alkyl,

R 11 means a hydrogen atom, a hydroxy group, a halogen atom, a cyano group, an optionally substituted (C 1 -C 10 )-alkyl group, a (C 1 -C 10 )-alkoxy group, a (C 1 -C 10 )-alkylthio group, or a (C 1 -C 5 )-perfluoralkyl group,

R 12 means a hydrogen atom, a hydroxy group, a halogen atom, a cyano group, an optionally substituted (C 1 -C 10 )-alkyl group, or a (C 1 -C 10 )-alkoxy group,

R 3 is indazole that is optionally substituted, independently of one another, by one or more

(C 1 -C 5 )-alkyl groups, which are optionally substituted by 1-3 hydroxy or 1-3 COOR 13 groups, wherein R 13 means hydrogen or (C 1 -C 5 )-alkyl),

(C 1 -C 5 )-alkoxy groups,

halogen atoms,

exomethylene groups, or

oxygen,

wherein this group is linked via any position to the amine of the tetrahydronaphthalene system and optionally is hydrogenated at one or more sites,

R 4 means a hydroxy group, or a group OR 10 , wherein R 10 means a C 1 -C 10 -alkyl group,

R 5 means a (C 1 -C 5 )-alkyl group or an optionally partially or completely fluorinated (C 1 -C 5 )-alkyl group, and

R 6 and R 7 , independently of one another, mean a hydrogen atom, a methyl or ethyl group, or, together with the carbon atom of the tetrahydronaphthalene system, a (C 3 -C 6 )-cycloalkyl ring.

5. A stereoisomer of formula (II),

in which

R 1 and R 2 , independently of one another, mean a hydrogen atom, a hydroxy group, a halogen atom, a (C 1 -C 10 )-alkyl group, a (C 1 -C 10 )-alkoxy group, a (C 1 -C 10 )-alkylthio group, a (C 1 -C 5 )-perfluoroalkyl group, a cyano group, or a nitro group, or R 1 and R 2 together mean —O—(CH 2 ) n —O—, —O—(CH 2 ) n —CH 2 —, —O—CH═CH—, or —(CH 2 ) n+2 —,

wherein n=1 or 2, and the terminal oxygen atoms and/or carbon atoms are linked to directly adjacent ring-carbon atoms, or NR 8 R 9 ,

R 8 and R 9 , independently of one another, are hydrogen, C 1 -C 5 -alkyl or (CO)-C 1 -C 5 -alkyl,

R 3 is indazole that is optionally substituted by 1-2 keto groups, 1-2 (C 1 -C 5 )-alkyl groups, 1-2 (C 1 -C 5 )-alkoxy groups, 1-3 halogen atoms, or 1-2 exomethylene groups, wherein this group is linked via any position to the amine of the tetrahydronaphthalene system and optionally is hydrogenated at one or more sites,

R 4 means a hydroxy group,

R 5 means a (C 1 -C 5 )-alkyl group or an optionally partially or completely fluorinated (C 1 -C 5 )-alkyl group, an aryl group, a (C 1 -C 8 )alkylaryl group, a (C 2 -C 8 )alkenylaryl group, a (C 3 -C 7 )cycloalkyl group, a (C 1 -C 8 )alkyl(C 3 -C 7 )cycloalkyl group, or a (C 2 -C 8 )alkenyl(C 3 -C 7 )cycloalkyl group, and

R 6 and R 7 , independently of one another, mean a hydrogen atom, a methyl or ethyl group, or, together with the carbon atom of the tetrahydronaphthalene system, mean a (C 3 -C 6 )-cycloalkyl ring.

6. A compound of formula (II),

in which

R 1 and R 2 , independently of one another, mean a hydrogen atom, a hydroxy group, a halogen atom, a (C 1 -C 10 )-alkyl group, a (C 1 -C10)-alkoxy group, a (C 1 -C 10 )-alkylthio group, a (C 1 -C 5 )-perfluoroalkyl group, a cyano group, or a nitro group, or R 1 and R 2 together mean —O—(CH 2 ) n —O—, —O—(CH 2 ) n —CH 2 —, —O—CH═CH—, —(CH 2 ) n+2 —, —NH—(CH 2 ) n+1 , N(C 1 -C 3 -alkyl)-(CH 2 ) n+1 , or —NH—N═CH—,

wherein n=1 or 2, and the terminal oxygen atoms and/or carbon atoms are linked to directly adjacent ring-carbon atoms, or NR 8 R 9 ,

R 8 and R 9 , independently of one another, are hydrogen, C 1 -C 5 -alkyl or (CO)-C 1 -C 5 -alkyl,

R 3 is indazole that is optionally substituted by one or more

(C 1 -C 5 )-alkyl groups, which are optionally substituted by 1-3 hydroxy or 1-3 COOR 13 groups, wherein R 13 is hydrogen or (C 1 -C 5 )-alkyl,

(C 1 -C 5 )-alkoxy groups,

halogen atoms, or

exomethylene groups,

wherein this group is linked via any position to the amine of the tetrahydronaphthalene system and optionally is hydrogenated at one or more sites,

R 4 means a hydroxy group, or a group OR 10 , wherein R 10 means a C 1 -C 10 -alkyl group,

R 5 means a (C 1 -C 5 )-alkyl group or an optionally partially or completely fluorinated (C 1 -C 5 )-alkyl group,

R 6 and R 7 , independently of one another, mean a hydrogen atom, a methyl or ethyl group, or, together with the carbon atom of the tetrahydronaphthalene system, a (C 3 -C 6 )-cycloalkyl ring.

7. A compound of formula I according to claim 1 , wherein R 5 is a trifluoromethyl group or a pentafluoroethyl group.

8. A compound of formula I according to claim 1 , which is in the form of a salt with a physiologically compatible anion.

9. A pharmaceutical composition comprising a compound according to claim 1 and a pharmaceutically compatible vehicle.

10. A process for preparing a compound of formula I according to claim 1 , comprising cyclizing a compound of formula III

in which radicals R 1 , R 11 , R 12 , R 3 , R 4 , R 5 , R 6 , and R 7 have the meanings as in the compound of formula I,

to form a compound of formula I with the addition of an organic or inorganic acid or Lewis acid.

11. A compound, which is

(+)-6-Fluoro-1-[(1H-indazol-4-yl)amino]-4,4-dimethyl-2-(trifluoromethyl)-1,2,3,4-tetrahydronaphthalene-2,5-diol;

(−)-6-Fluoro-1-[(1H-indazol-4-yl)amino]-4,4-dimethyl-2-(trifluoromethyl)-1,2,3,4-tetrahydronaphthalene-2,5-diol;

8-Bromo-1-[(1H-indazol-4-yl)amino]-4,4-dimethyl-2-(trifluoromethyl)-1,2,3,4-tetrahydronaphthalene-2,5-diol);

1-[(1H-indazol-4-yl)amino]-4,4-dimethyl-2-(trifluoromethyl)-1,2,3,4-tetrahydronaphthalen-2-ol;

6-[(1H-indazol-4-yl)amino]-9,9-dimethyl-7-(trifluoromethyl)-6,7,8,9-tetrahydro-naphtho[1,2-d]-1,3-dioxol-7-ol;

5-Bromo-1-[(1H-indazol-4-yl)amino]-4,4-dimethyl-2-(trifluoromethyl)-1,2,3,4-tetrahydronaphthalen-2-ol;

6-Chloro-1-[(1H-indazol-4-yl)amino]-4,4-dimethyl-2-(trifluoromethyl)1,2,3,4-tetrahydronaphthalene-2,5-diol;

7-Chloro-1-[(1H-indazo-4-yl)amino]-4,4-dimethyl-2-(trifluoromethyl)-1,2,3,4-tetrahydronaphthalene-2,5-diol;

(−)-7-Chloro-1-[(1H-indazol-4-yl)amino]-4,4-dimethyl-2-(trifluoromethyl)-1,2,3,4-tetrahydronaphthalene-2,5-diol;

(+)-7-Chloro-1-[(1H-indazol-4-yl)amino]-4,4-dimethyl-2-(trifluoromethyl)-1,2,3,4-tetrahyclronaphthalene-2,5-diol;

7-Fluoro-1-[(1H-indazol-4-yl)amino]-4,4-dimethyl-5-methoxy-2-(trifluoromethyl)-1,2,3,4-tetrahydronaphthalen-2-ol;

7-Fluoro-1-[(1H-indazol-4-yl)amino]-4,4-dimethyl-2-(trifluoromethyl)-1,2,3,4-tetrahydronaphthalene-2,5-diol;

(−)-7-Fluoro-1-[(1H-indazol-4-yl)amino]-4,4-dimethyl-2-(trifluoromethyl)-1,2,3,4-tetrahydronaphthalene-2,5-diol;

(+)-7-Fluoro-1-[(1H-indazol-4-yl)amino]-4,4-dimethyl-2-(trifluoromethyl)-1,2,3,4-tetrahydronaphthalene-2,5-diol;

5-Fluoro-1-[(1H-indazol-4-yl)amino]-4,4-dimethyl-2-(trifluoromethyl)-1,2,3,4-tetrahydronaphthalene-2,5-diol;

5-Fluoro-1-[(1H-indazol-4-yl)amino]-4,4-dimethyl-2-(trifluoromethyl)-1,2,3,4-tetrahydronaphthalene-2,5-diol;

1-[(1H-indazol-4-yl)amino]4,4-dimethyl-5-methoxy-2-(trifluoromethyl)-1,2,3,4-tetrahydronaphthalen-2-ol;

1-[(1H-indazol-4-yl)amino]-4,4-dimethyl-5-methoxy-2-(trifluoromethyl)-1,2,3,4-tetrahydronaphthalen-2-ol;

1-[(1H-indazol-4-yl)amino]-4,4-dimethyl-2-(trifluoromethyl)-1,2,3,4-tetrahydronaphthalene-2,5-diol;

7-Chloro-1-[(1H-indazol-4-yl)amino]-4,4-dimethyl-2-(trifluoromethyl)-1,2,3,4-tetrahydronaphthalen-2-ol;

1-[(1-Methyl-indazol-4-yl)amino]-4,4-dimethyl-5-methoxy-2-(trifluoromethyl)-1,2,3,4-tetrahydronaphthalen-2-ol;

7-Ethyl-1-[(1H-indazol-4-yl)amino]-4,4-dimethyl-5-methoxy-2-(trifluoromethyl)-1,2,3,4-tetrahydronaphthalen-2-ol;

7-Ethyl-1-[(1H-indazol-4-yl)amino]-4,4-dimethyl-2-(trifluoromethyl)-1,2,3,4-tetrahydronaphthalen-2-ol;

1-[(1-Methyl-indazol-4-yl)amino]-4,4-dimethyl-2-(trifluoromethyl)-1,2,3,4-tetrahydronaphthalene-2,5-diol;

Rac.-5,8-Difluoro-1-[(1H-indazol-4-yl)amino]-4,4-dimethyl-2-(trifluoromethyl)-1,2,3,4-tetrahydronaphthalen-2-ol;

1-[(5-Chloro-1H-indazol-4-yl)amino]-6-fluoro-5 -methoxy-4,4-dimethyl-2-(trifluoromethyl)-1,2,3,4-tetrahydronaphthalen-2-ol;

1-(5-Methyl-1H-indazol-4-ylamino)-6-fluoro-4,4-dimethyl-2-trifluoromethyl-1,2,3,4-tetrahydro-naphthalene-2,5-diol;

7-Bromo-1[(1H-indazol-4-yl)amino]-5-methoxy-4,4-dimethyl-2-(trifluoromethyl)-1,2,3,4-tetrahydronaphthalen-2-ol;

4-{[6-Chloro-2-hydroxy-4,4-dimethyl-5-methoxy-2-(trifluoromethyl)-1,2,3,4-tetrahydronaphthalen-1-yl]amino}-indazole;

(−)-2-Chloro-5-(1H-indazol-4-ylamino)-8,8-dimethyl-6-(trifluoromethyl)-5,6,7,8,-tetrahydro-naphthalene-1,6-diol;

(+)-2-Chloro-5-(1H-indazol-4-ylamino)-8,8-dimethyl-6-(trifluoromethyl)-5,6,7,8,-tetrahydro-naphthalene-1,6-diol;

3-Fluoro-4,7-dihydroxy-8-(1H-indazol-4-ylamino)-5,5-dimethyl-7-(trifluoromethyl)-5,6,7,8-tetrahydronaphthalene-2-carbonitrile;

3-Chloro-2-fluoro-5-(1H-indazol-4-ylamino)-8,8-dimethyl-6-(trifluoromethyl)-5,6,7,8-tetrahydronaphthalene-1,6-diol;

3-Chloro-2-fluoro-5-(5-chloro-1H-indazol-4-ylamino)-8,8-dimethyl-6-(trifluoromethyl)-5,6,7,8-tetrahydronaphthalene-1,6-diol;

1,6-Dihydroxy-5-(1H-indazolyl-4-ylamino)-3,8,8,-trimethyl-6-(triftuoromethyl)-5,6,7,8-tetrahydronaphthalene-2-carbonitrile;

1,6-Dihydroxy-5-(5-chloro-1H-indazolyl-4-ylamino)-3,8,8,-trimethyl-6-(trifluoromethyl)-5,6,7,8-tetrahydronaphthalene-2-carbonitrile;

2-Chloro-5-(1H-indazol-4-ylamino)-3,8,8-trimethyl-6-(trifluoromethyl)-5,6,7,8-tetrahydronaphthalene-1,6-diol; or

2-Fluoro-5-(1H-indazol-4-ylamino)-3,8,8-trimethyl-6-(trifluoromethyl)-5,6,7,8-tetrahydronaphthalene-1,6-diol.

12. A pharmaceutical composition comprising a compound according to claim 11 and a pharmaceutically compatable vehicle.