Patent ID: 7704960

Claim:
A compound of formula wherein R is a hydrogen atom or a methyl group; R 1 is a hydrogen atom, an N,N-di(C 1 -C 3 )alkylamino group, an N,N-di(C 1 -C 3 )alkylamino-N-oxide group, an N—(C 1 -C 3 )alkyl-N-benzyl-amino group, an N—(C 1 -C 4 )acyl-N—(C 1 -C 3 )alkylamino group, an N—[N,N-dimethylamino(C 1 -C 4 )alkylamino]acetyl-N—(C 1 -C 3 )alkylamino group or a chain of formula wherein A is a hydrogen atom, a phenyl or a five- or six-membered heteroaryl ring having from one to three hetero atoms selected from nitrogen, oxygen and sulphur; X is O, S, SO, SO 2 or NR 6 , where R 6 is a hydrogen atom, a linear or branched C 1 -C 3 alkyl, a C 1 -C 3 alkoxycarbonyl group or a benzyloxycarbonyl group; Y is a C 6 H 4 group, a five- or six-membered heteroaryl ring having from one to three hetero atoms selected from nitrogen, oxygen and sulphur or is O, S, SO, SO 2 or NR 6 where R 6 has the meanings given above; r is an integer from 1 to 3; m is an integer from 1 to 6; n is an integer from 0 to 2; or R 1 forms a bond together with R 2 ; R 2 is a hydrogen atom or forms a bond together with R 1 ; R 3 is a hydroxy group or forms a group ═N—O—R 5 together with R 4 , and R 5 is a hydrogen atom, a linear or branched C 1 -C 5 alkyl, a benzyl optionally substituted with one or two substituents selected from nitro, hydroxy, carboxy, amino, linear or branched C 1 -C 5 alkyl, C 1 -C 4 alkoxycarbonyl groups, aminocarbonyl groups or cyano groups or a chain of formula —(CH 2 )r-X—(CH 2 )m-Y—(CH 2 )n-A wherein r, m, n, X, Y and A have the meanings given above; R 4 is a hydrogen atom or forms a group ═N—O—R 5 together with R 3 , and R 5 has the meanings given above; and the pharmaceutically acceptable salts thereof, provided, however, that R 1 is not a dimethylamino group when R 3 is hydroxy, and both R 2 and R 4 are a hydrogen atom; R 1 is not a dimethylamino group when in the substituent ═N—O—R 5 in the 9 position, R 5 is a hydrogen atom, a linear or branched C 1 -C 5 alkyl, an unsubstituted benzyl group, or a chain —(CH 2 )r-X—(CH 2 )m-Y—(CH 2 )n-A where r is 1, X is O, m is 2, Y is O, n is 1, and A is H; R 1 is not a methylethylamino group when in the substituent ═N—O—R 5 in the 9 position, R 5 is a linear or branched C 1 -C 5 alkyl, or an unsubstituted benzyl group.