Patent ID: 8101591

Claim:
A compound of formula (I): wherein: R represents hydrogen or NRaRb; R 1 represents hydrogen or C 1-6 alkyl; R 2 represents hydrogen or hydroxy; R 3 represents hydrogen; R 4 represents hydrogen; R 5 represents hydrogen, C 1-6 alkyl or C 1-6 alkoxycarbonyl; X represents NRxRy; Ra and Rb independently represent hydrogen or C 1-6 alkyl; and Rx and Ry independently represent hydrogen, benzyl, C 3-6 cycloalkyl, C 3-6 alkenyl, C 3-6 alkynyl, C 1-6 alkyl optionally substituted by one or more groups selected from hydroxy, methoxy, halogen, NRaRb and trifluoromethyl, —C 1-6 alkylcycloalkyl, —C 1-6 alkylheterocycle, C 1-6 alkylamino and C 1-6 alkylthio or together Rx and Ry form a heterocycle; or a pharmaceutically acceptable salt thereof.