A NOVEL PROCESS FOR THE SYNTHESIS OF LAMOTRIGINE AND ITS INTERMEDIATE

摘要

This invention discloses a process for the preparation of 3,5-Diamino-6-(2,3-dichlorophenyl)-1,2,4-triazine of a formula (I), commonly known as Lamotrigine which comprises the step of reacting aminoguanidine bicarbonarte and 2,3- dichlorobenzocynide with a reagent prepared by dissolving phosphorus pentoxide and methane sulfonic acid, to produce a novel intermediate 2-(2,3-dichlorophenyl)-2-(aminoguanidine)-acetonitrile monomesylate which is further cyclized to lamotrigine without basification.