PROCESS FOR THE PREPARATION OF 6-CHLORO-2,3,4,9-TETRAHYDRO-1H-CARBAZOLE-1-CARBOXAMIDE AND INTERMEDIATES THEREOF

摘要

The invention relates to a novel process for the preparation of rac-6-Chloro-2,3,4,9-tetrahydro-1H-carbazole-1-carboxamide (I) in pharmaceutically acceptable polymorphic form, through the conversion of a 3-bromo-2-oxo-cyclohexanecarboxylic acid alkyl ester into 6-chloro-2,3,4,9-tetrahydro-1H-carbazole-1-carboxylic acid alkyl ester, which in turn is processed to yield the final product.

主权项

1. A process for the preparation of compound (I′-b) according to the following scheme: wherein R is C1-C6 linear, branched or cyclic alkyl chain and preferably ethyl, said process being characterised in that the reaction between (I′-a) and 4-chloroaniline is performed under heating in a solvent which forms an azeotropic mixture with water.