PROCESS FOR PREPARING BENZOFURAN-2-CARBOXAMIDE DERIVATIVES

摘要

Provided herein are novel, commercially viable and industrially advantageous processes for the preparation of benzofuran-2-carboxamide derivatives and their intermediates, or a pharmaceutically acceptable salt thereof, in high yield and purity. Provided particularly herein are novel, commercially viable and industrially advantageous processes for the preparation of vilazodone or a pharmaceutically acceptable salt thereof in high yield and purity. Provided also herein is an improved and commercially viable process for the preparation of 3-(4-hydroxybutyl)-1H-indole-5-carbonitrile, in high yield and purity, using novel intermediate compound 3-(4-hydroxybutyryl)-1H-indole-5-carbonitrile.

主权项

1. A process for preparing an alkyl 5-(1-piperazinyl)benzofuran-2-carboxylate compound of formula II(i): or an acid addition salt thereof, wherein R2 is an alkyl group having 1 to 4 carbon atoms, comprising: a) reacting an alkyl 5-aminobenzofuran-2-carboxylate compound of formula III: or an acid addition salt thereof, wherein R2 is as defined in formula II(i);with a sulfonamide compound of formula IV: wherein G is selected from alkyl, cycloalkyl, and a phenyl radical which is unsubstituted or substituted by alkyl, alkoxy, halo, nitro, amino or acetyl amino group;in the presence of a base to produce a sulfonyl piperazine compound of formula V: wherein G and R2 are as defined above; and b) deprotecting the compound of formula V to produce the alkyl 5-(1-piperazinyl)benzofuran-2-carboxylate compound of formula II(i), and optionally converting the compound of formula II(i) obtained into an acid addition salt thereof.