Patent ID: 8598172

Claim:
A compound of formula (I): wherein R 1 is an optionally substituted group selected from straight or branched C 1 -C 3 alkyl, C 1 -C 3 alkoxy, C 1 -C 3 polyfluorinated alkyl, C 1 -C 3 polyfluorinated alkoxy and —COR′ wherein R′ is an optionally substituted C 1 -C 6 alkyl; R 2 is a —NR″R″′ group wherein R″ and R″′ are, each independently, hydrogen or an optionally substituted group selected from straight or branched C 1 -C 6 alkyl, C 3 -C 6 cycloalkyl and heterocyclyl or taken together with the nitrogen atom to which they are bonded, R″ and R″′ may form an optionally substituted heterocyclyl ring optionally containing one additional heteroatom selected from N, O or S; R 3 and R 4 are, each independently, hydrogen or an optionally substituted group selected from straight or branched C 1 -C 6 alkyl, C 3 -C 6 cycloalkyl and heterocyclyl, and pharmaceutically acceptable salts thereof, wherein when R 1 is C 1 -C 3 alkyl or is alkoxy, R″ and R″′ are not hydrogen and are not C 1 -C 6 alkyl.