PROCESS FOR PREPARING MONTELUKAST AND SALTS THEREOF USING OPTICALLY IMPURE 2-(2-(3(S)-(3-(7-CHLORO-2-QUINOLINYL)ETHENYL)PHENYL)-3-HYDROXYPROPYL)PHENYL-2-PROPANOL

摘要

A process for preparing montelukast and salts thereof using an optically impure 2-(2-(3(S)-(3-(7-chloro-2-quinolinyl)-ethenyl)-phenyl)-3-(hydroxylpropyl)phenyl)-2 propanol as starting material, which contains the (R)-enantiomer impurity in the range of greater than 0.5% to about 8.0% by weight, is disclosed. The process described herein using an optically impure material results in the final product, montelukast sodium, in optical purity of greater than 99.7% enantiomeric excess.