Non-Infringing Efficient One-Pot Process for the Preparation of Pure Entacapone

Abstract

A new and non-infringing efficient one-pot process for the preparation of catechol-O- methyltransferase (COMT) enzyme inhibitors, entacapone 1 under mild condition, initially reaction of 3-methoxy-4-hydroxy-5-nitro-benzaldehyde 5 with 2-cyano acetic acid 13 in presence of new organic base benzyl Trimethyl ammonium hydroxide, i.e. Triton-B which undergo Knoevenagel condensation to get intermediate 22 which is then react with SOCl2 to get chloride intermediate 23 and which undergo condensation with diethylamine to get 6 and finally deprotection in presence of HBr-AcOH to get economically efficient and industrially feasible entacapone 1 with higher purity and yield without isolation of any intermediate as compared to conventional batch wise process.