Patent ID: 6635763
Filing Date: 2003-10-21
Classification: C07D

Abstract:
A process for the preparation of compound of formula (I), where X represents either hydrogen, fluoro, chloro, bromo or iodo atom which comprises:i) reacting a compound of formula (V) or its salt, â€ƒwith a cyanide of general formula (VII) where M represents alkali metal, trimethysilyl, Cu, or hydrogen, followed by addition of compound of general formula (VI), where X is as defined earlier, to obtain a racemic compound of general formula (IV), where X is as defined earlier; ii) reacting a compound of general formula (IV), in (Â±) form or any of its optically active (+), or (âˆ’) forms, â€ƒwith acidic or basic reagents to obtain a compound of formula (II) or its salt with retention of configuration; iii) reacting a compound of general formula (II), in either (Â±) form or its optically active (+) or (âˆ’) forms; â€ƒwith acidic reagents in presence of methanol to obtain a compound of formula (I) or its salt, with retention of configuration; and iv) resolving the (Â±) form of the compound of formula (I) or its salt if formed into its optical isomers.