PURPOSE: To obtain a new compound useful in the treatment or prevention of atherosclerosis by inhibiting the esterification and intestinal absorption of cholesterol.

CONSTITUTION: The compound of formula I [R1 is 10-25C alkyl chain or the like, R2 is hydroxy, lower alkyl, lower alkoxy, halogeno, amino or the like; R3 to R5 are each H, -(CH2)n-Ar (Ar is phenyl, heteroaryl or the like; n is 0 to 2); m is 0 to 2], e.g. N-(6,7-dimethoxy-l-phenyl-1,2,3,4-tetrahydroisoquinoline)-9- Z-octadeceneamide. The compound of formula I is obtained by reacting an amine of formula II with an acid chloride of formula R1COCl in the presence of a tertiary amine base (e.g. trietylamine) in a solvent (e.g. dichloromethane).