A compound of general formula (I) ** Formula ** where: Z is selected from the group consisting of (CH2) m where m>； = 0, 1 or 2； and CR4R5 wherein R4 is independently selected from H or a linear or branched alkyl (from 1 to 4 carbon atoms), preferably methyl, optionally substituted by a cycloalkyl (from 1 to 4 carbon atoms) and R5 is independently selected from the group consisting of linear or branched alkyl (1 to 4 carbon atoms), preferably methyl； - phenyl； - benzyl； - NH2； and - HNCOOR ', wherein R' is straight or branched alkyl (1 to 4 carbon atoms), preferably t-butyl. R1 and R2 are different or equal and are independently selected from the group consisting of - H； - linear or branched alkyl (1 to 6 carbon atoms), optionally substituted by one or more substituents selected from halogen atoms, cycloalkyl (3 to 7 carbon atoms) or cycloalkenyl (5 to 7 carbon atoms)； - cycloalkyl (from 3 to 7 carbon atoms)； - cycloalkenyl (from 5 to 7 carbon atoms)； - linear or branched alkenyl (2 to 6 carbon atoms)； and - linear or branched alkynyl (2 to 6 carbon atoms). R3 is one or more substituents independently selected from the group consisting of H, CN, NO2, CF3 and halogen atoms. A is a phenyl optionally substituted with one or more Rx groups, or A is a ring system, which is a mono or bicyclic ring that may be saturated, partially unsaturated or unsaturated, such as aryl, cycloalkyl (from 3 to 8 atoms of carbon) or a heteroaryl ring optionally substituted with one or more Rx groups, wherein A is a heteroaryl ring selected from the group consisting of pyrrole, pyrazole, furan, thiophene, imidazole, oxazole, isoxazole, thiazole, pyridine, pyrimidine, pyrazine, pyridazine and pyran, in which the optional substituent Rx in the ring A system may be one or more, may be the same or different, and is independently selected from the group consisting of: - alkyl (from 1 to 6 carbon atoms) linear or branched, optionally substituted by one or more halogen or cycloalkyl atoms (from 3
