A PROCESS FOR THE PREPARATION OF AN IMPURITY OF ENTACAPONE

摘要

The present invention provides a process for the preparation of an impurity present in Entacapone. The invention also provide a process for the preparation of 1-(Cyanoacetyl) Piperidine, used for the preparation of impurity 1-[2-cyano-3-(3,4-dihydroxy-5-nitrophenyl)-1-oxo-2-propenyl]- Piperidine.