AN IMPROVED PROCESS FOR PREPARATION OF (2E)-2-CYANO-3-(3,4- DIHYDROXY-5-NITROPHENYL)N,N-DIETHYL-2-PROPENAMIDE POLYMORPHIC FORM A

摘要

The present invention relates to an improved, cost effective, eco-friendly and easy t handle process to manufacture substantially pure form of (2E)-2-Cyano-3-(3,4-dihydroxy-5 nitrophenyl)-N,N-diethyl-2-propenamide or (E)- N,N-diethyl-2-cyano-3-(3,4-dihyroxy-5 nitro?henyl)-acrylamide polymorphic form A commonly known as (E)-Entacapone represente by Formula I, using ammonium acetate as a base.