Processes for production of (r)-3- 4-(trifluoromethyl)- phen ylamino pentanamide derivatives

The present invention provides a method for easily producing an (R)-3-[4-(trifluoromethyl)phenylamino]-pentanoic acid amide derivative useful for an intermediate for pharmaceutical products, particularly an inhibitor of a cholesteryl ester transfer protein (CETP) from easily available raw materials. In the present invention, (S)-N-[4-(trifluoromethyl)phenyl]-3-hydroxypentanoic acid amide prepared from easily available raw materials leads a production of (R)-4-ethyl-1-[4-(trifluoromethyl)phenyl]-2-azetidinone to give (R)-3-[4-(trifluoromethyl)phenylamino]-pentanoic acid amide. Furthermore, (R)-4-ethyl-1-[4-(trifluoromethyl)phenyl]-2-azetidinone is reacted with a carbamic acid ester to give an (R)-3-[4-(trifluoromethyl)phenylamino]-pentanoic acid amide derivative.