| abstract |
A novel protein kinase and an inhibitor thereof are provided. A compound of formula I, or a pharmaceutically acceptable salt or solvate thereof. [Wherein R1 is hydrogen or an optionally substituted alkyl group, cycloalkyl group, etc .; R2 is hydrogen or an optionally substituted alkyl group; X is —NH—; R4 is substituted. R5 is hydrogen; R6 is an optionally substituted phenyl group, acyl group, or heteroaryl group. ] [Selection figure] None |