A compound of formula (I): ** Formula ** where A is a group - (CH2) 1-3-X-R1； R1 is hydrogen, halogen, or a group selected from linear or branched C1-C6 alkyl, C3-C7 cycloalkyl, cycloalkyl-alkyl, arylalkyl, heterocyclyl and heterocyclylalkyl； R2 is a group selected from C2-C6 alkynyl, aryl, and heterocyclyl； R3 and R4 are each independently hydrogen, halogen, cyano, or a group selected from C3-C7 cycloalkyl, cycloalkyl-alkyl, C2-C6 alkenyl, C2-C6 alkynyl, aryl, arylalkyl, heterocyclyl and heterocyclylalkyl； X is a single bond or a divalent radical selected from -NR ', and -O-, where R' is hydrogen, COR5, C (NH) R5, S (O) 2R9, or an optionally substituted group selected from C1- alkyl C6 linear or branched, C3-C7 cycloalkyl, cycloalkyl-alkyl, aryl, arylalkyl, heterocyclyl and heterocyclylalkyl or, together with the nitrogen atom to which they are attached, R 'and R1 can form a 5- to 7-membered heteroaryl or heterocyclyl group which optionally contains an additional heteroatom selected from N, O and S； where: R5 is OR6, NR7R8 or a group selected from linear or branched C1-C6 alkyl, C3-C7 cycloalkyl, C2-C6 cycloalkyl, C2-C6 alkynyl, aryl, arylalkyl, heterocyclyl and heterocyclylalkyl； where: R6 is a group selected from linear or branched C1-C6 alkyl, C3-C7 cycloalkyl, aryl and heterocyclyl； R7 and R8 are each independently hydrogen or a group selected from straight or branched C1-C6 alkyl, C3-C7 cycloalkyl, aryl and heterocyclyl； R9 is a group selected from linear or branched C1-C6 alkyl, C3-C7 cycloalkyl, aryl and heterocyclyl； where any of the groups R1-R9 and R 'can optionally be substituted, in any of their free positions, by 1 to 6 groups, independently selected from: halogen atom, nitro, oxo groups (>； = O), cyano, alkyl C1-C6 hydroxyalkyl, polyfluorinated alkyl, polyfluorinated alkoxy, alkenyl, alkynyl, aryl, arylalkyl, heterocyclyl, C3-C7 cycloalkyl, hydroxy, alkoxy, aryloxy, heterocyclyloxy, methylenedioxy, alkylcarbonyloxy, arylcarbonyloxy, cycloalkenyloxy,
