Un procedimiento mejorado para la preparación de Montelukast y sus sales

摘要

A method for the preparation of montelukast and salts thereof has been described. The method comprises of following steps: (a) (S)-1-(3-((E)-2-(7-chloroquinolin-2-yl)vinyl)phenyl)-3-(2-isopropenylphenyl)propyl methane sulphonate (styrene mesylate salt) (b) coupling with 1-(mercapto methyl)cyclopropane acetic acid followed by salification with an amine gives styrene amine salt (c) Converting styrene amine salt to Montelukast amine salt (d) Converting Montelukast amine salt to Montelukast free acid and or its required alkali/alkaline salt.