AN IMPROVED PROCESS FOR THE PREPARATION OF INTERMEDIATE OF LEUKOTRIENE RECEPTOR ANTAGONIST

摘要

ABSTRACT: The present invention relates to a process synthetic process for preparing the side-chain precursor l- (mercaptomethyl)cyclopropancacctic acid, Which is useful in the synthesis of leukotriene receptor antagonist such as Montelukast and salts thereof. Preferably the present invention relates to a process for the prepartion of 1- (bromomethyl) Cyclopropane-acetonitrile starting from 1- (hydroxymethyl)cyclopropaneacetonitrile. Preferably, the present invention relates to avoiding the use of toxic solvent such as DMF and additional component such asr sodium iodide in the preparation ofl-(hydroxymethyl)cyclopropaneacetonitrile. Preferably, the present invention relates avoding the use of reagents PBr3 or Ph3P/Br2in the preparation of l-(bromomethyl) Cyclopropane-acetonitrile.