An Efficient Synthesis Of Optical Isomers Of Vasopressin V-2 Receptor Antagonist Opc-41061 By Lipase-Catalyzed Enantioselective Transesterification

The optically active enantiomers of 7-chloro-5-hydroxy-1-[2-methyl-4-(2-methylbenzoylamino)benzoyl] -2,3,4,5-tetrahydro-1H-1-benzazepine (OPC-41061, 1) were enantioselectively synthesized. The chiral acetate ((R)-(-)-3) and the chiral alcohol ((S)-(+)-2) were prepared via the resolution of the racemic alcohol ((+/-)-2) using the lipase-mediated transesterification with vinyl acetate. Compounds ((R)-(-)-3) and ((S)-(+)-2) were converted to optically active 1.