A compound represented by the following general formula (I), wherein R 1 , R 2 , R 3 , R 4 and R 5 represent hydrogen atom, a halo(lower alkyl) group, cyano group and the like, R 6 represents an alkyl group, a cycloalkyl group and the like, R 7 , R 8 , R 9 and R 10 represent hydrogen atom, a halogen atom, a lower alkyl group, a halo(lower alkyl) group and the like, R 11 and R 12 represent hydrogen atom, a lower alkyl group, a (lower cycloalkyl)(lower alkyl) group and the like, and R 13 represents hydrogen atom, a halogen atom, a lower alkoxy group and the like, which has potent inhibitory activity on cholesterol ester transfer protein (CETP).