Patent ID: 8420684

Claim:
A compound of formula (I) or a pharmaceutically acceptable salt thereof, including all tautomers and stereoisomers thereof wherein: R 1 represents heteroaryl; -carbocyclyl-heteroaryl; -alkenylheteroaryl or -alkylheteroaryl; R 2 represents alkyl, which may optionally be substituted by hydroxy; carbocyclyl, which may optionally be substituted by one or more groups selected from alkyl and hydroxy; aryl; -aryl-heteroaryl; -heteroaryl-aryl; -aryl-heterocyclyl; H; heteroaryl; or heterocyclyl, which may optionally be substituted by one or more groups selected from alkyl, oxo and hydroxy; aryl or heteroaryl of R 2 may be optionally substituted with one or more of alkyl, alkenyl, alkynyl, haloalkyl, -thioalkyl, -thiomethyl, SOalkyl, —SO 2 alkyl, SOcycloalkyl, alkoxy-, cycloalkyl, fluoroalkyl, —SO 2 cycloalkyl, alkenyloxy-, alkynyloxy-, —C(O)-alkyl, alkoxyalkyl-, nitro, halogen, cyano, hydroxyl, oxo, —C(O)OH, —C(O)Oalkyl, —NH 2 , —NHalkyl, —N(alkyl) 2 , —C(O)N(alkyl) 2 , —C(O)NH 2 or —C(O)NH(alkyl); R 3 represents heteroaryl; alkyl, which may optionally be substituted by one of more groups selected from alkoxy, amine, hydroxy and —C(O)Oalkyl; carbocyclyl, which may optionally be substituted by one or more groups selected from alkyl, haloalkyl, alkoxy, amine, hydroxy and —C(O)Oalkyl; -alkyl-aryl; -alkyl(aryl) 2 ; -alkyl-heteroaryl; -alkyl(heteroaryl) 2 ; -alkyl(heteroaryl)(aryl); -aryl-O-aryl; aryl; heterocyclyl, -alkyl-C(O)-heterocyclyl, -alkyl-heterocyclyl, -alkyl-C(O)—NR 5 -heterocyclyl or -alkyl(heterocyclyl) 2 in any of which groups heterocyclyl may be optionally substituted by one or more groups selected from alkyl, hydroxy and oxo; -heteroaryl; or -hydroxyalkylaryl; R 4 represents H or C 1-3 alkyl; R 5 represents H or C 1-3 alkyl; and X represents O or S.