Patent ID: 7488811

Claim:
A compound of formula wherein R is a hydrogen atom or a methyl group; R 1 is a hydrogen atom, an N,N-dimethylamino-N-oxide group, an N-benzyl-N-methylamino group, an N-acetyl-N-methylamino group, an N-[N,N-dimethylamino(C 1 -C 2 )alkylamino]acetyl-N-methylamino group or a chain of formula wherein A is a hydrogen atom, a phenyl or a five- or six-membered heteroaryl ring selected from pyrrole, thiophene, furan, imidazole, oxazole, thiazole, pyridine, pyrimidine, triazole and thiadiazole; X is O or NR 6 and R 6 is a hydrogen atom; Y is, when n is 0, a C 6 H 4 group or a five- or six-membered heteroaryl ring selected from pyrrole, thiophene, furan, imidazole, oxazole, thiazole, pyridine, pyrimidine, triazole and thiadiazole; or, when n is 1, NR 6 and R 6 is a hydrogen atom; r is an integer from 1 to 3; m is the integer 1 or 2; n is the integer 0 or 1; 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.