| abstract |
A compound of formula (I): ** Formula * + wherein R1 is an optionally substituted group selected from linear or branched C1-C6 alkyl, aryl, arylalkyl, heterocyclyl and heterocyclyl alkyl; R2 is a group selected from -NR''R '' 'and -OR' ', where R' 'and R' '' are each independently hydrogen or an optionally substituted group selected from linear or branched C1-C6 alkyl , C3-C7 cycloalkyl, cycloalkyl-alkyl, aryl, arylalkyl; R3 is hydrogen or an optionally substituted group selected from linear or branched C1-C6 alkyl, C3-C7 cycloalkyl, cycloalkyl-alkyl, arylalkyl, heterocyclyl and heterocyclylalkyl; R4 is hydrogen or a linear or branched C1-C6 alkyl group; X is a single bond or a divalent radical selected from -NR'-, -O- and -S-, where R 'is hydrogen or an optionally substituted group selected from linear or branched C1-C6 alkyl, aryl, arylalkyl, heterocyclyl and heterocyclylalkyl; A is a group selected from - (CH2) 2-, - (CH2) 3-, -CH> = CH-, -C (CH3) 2-CH2- and -CH2-C (CH3) 2; or a pharmaceutically acceptable salt thereof. |