Compounds of formula (I) have checkpoint kinase 1 (CHK1) inhibitory activity: wherein R1, R2, R5 and R6 are independently selected from hydrogen, hydroxy, methyl, trifluoromethyl, hydroxymethyl, methoxy, trifluoromethoxy, methylamino and dimethylamino; R3, and R4 are independently selected from hydrogen, hydroxy, C1-C3 alkyl, fluoro-(C1-C3)-alkyl, hydroxy-(C1-C3)-alkyl, C1-C3 alkoxy, fluoro-(C1-C3)-alkoxy, hydroxy-(C1-C3)-alkoxy, —N(R11)—R12, -Alk-N(R11)—R12, —O-Alk-N(R11)—R12, —C(═O)OH, carboxy-(C1-C3)-alkyl, or —C(═O)—NH—R13; Alk is a straight or branched chain divalent C1-C6 alkylene radical; R7 and R8 are independently selected from hydrogen, hydroxy, or C1-C3 alkoxy; X is a straight chain divalent C1-C3 alkylene radical, optionally substituted on one or more carbons by R9 and/or R10; W is selected from —C(═O)—N(—R16)— or —N(—R17)—C(═O)—; Y is hydrogen, C1-C3 alkyl, C1-C3 alkoxy, or halo; and Q is selected from optionally substituted phenyl, optionally substituted cyclohexyl, or an optionally substituted 6-membered monocyclic heteroaryl ring.