Patent ID: 8546413

Claim:
A compound of formula (I): wherein: R1 is hydrogen or R1′, wherein R 1 ′ is R2 is hydrogen or R2′, wherein R2′ is R3 is NH2 or R3′, wherein R3′ is L 3 -R5, wherein L 1 is direct bond, CH 2 , CH═CH, O, NH or N(CH 3 ); L 2 is CH 2 CH 2 , CH═CH or C≡C; L 3 is NHCO, NHCH 2 , NHCONH, CH═CH or C≡C; A is direct bond, O, OCH 2 , OCO, CON(Y), CON(Y)O, CON(Y)N(Y), CON(Y)SO 2 , N(Y), N(Y)CO, N(Y)SO 2 —, N(Y)CON(Y), N(Y)CSN(Y), N(Y)CON(Y)N(Y), N(Y)COO, N(Y)CON(Y)SO 2 or N(Y)SO 2 N(Y); Y is hydrogen or an optionally substituted straight or branched (C 1 -C 3 ) alkyl; R5 is hydrogen or an optionally substituted group selected from straight or branched (C 1 -C 8 ) alkyl, (C 2 -C 8 ) alkenyl, (C 2 -C 8 ) alkynyl, (C 3 -C 8 ) cycloalkyl, heterocyclyl, aryl and heteroaryl; R6 is selected from hydrogen, halogen, trifluoromethyl, (C 1 -C 3 ) alkyl and (C 1 -C 3 ) alkoxy; R4 is an optionally substituted group selected from straight or branched C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 3 -C 6 cycloalkyl and heterocyclyl; with the proviso that only one of R1, R2 and R3 is respectively R1′, R2′ or R3′ as defined above, and pharmaceutically acceptable salts.