A compound represented by the following general formula (I), wherein R1, R2, R3, R4 and R5 represent hydrogen atom, a halogen atom, a lower alkyl group and the like, R6 represents an alkyl group, a cycloalkyl group and the like, R7 and R8 represent hydrogen atom, a lower alkyl group, a (lower cycloalkyl)(lower alkyl) group and the like, R9 represents hydrogen atom, a halogen atom, a lower alkoxy group and the like, R10 and R11 represent hydrogen atom, a lower alkyl group, a lower alkoxy group, a halo(lower alkyl) group and the like, and A represents a heterocyclic ring constituted by 6 to 10 atoms, which has potent inhibitory activity on cholesterol ester transfer protein (CETP).