N-propionyl-4-(2,6-dimethylanilino)butyric acid 、
ethyl-4-(benzylamino)butanoate 以produces ethyl N-[N-propionyl-4-(2,6-dimethylanilino)butyryl]-4-(benzylamino)butyrate (oil), saponification of which and processing of the reaction product的产率得到ethyl N-[N-propionyl-4-(2,6-dimethylanilino)butyryl]-4-(benzylamino)butyrate