An Improved Process for the Enantioselective Synthesis of HCV NS5A Inhibitor Elbasvir (MK-8742) Chiral Amine Intermediate

Abstract Large-scale enantioselective synthesis of the chiral amine unit of HCV NS5A inhibitor Elbasvir has been accomplished in six steps, with 55% overall yield. The process includes a highly enantioselective reduction of the NH imine using R-(+)-diphenylprolinol with NaBH4. This target chiral synthesis requires simple starting materials and inexpensive catalysts.