PROCESS FOR THE PREPARATION OF A LEUKOTRIENE ANTAGONIST AND INTERMEDIATES THEREOF

摘要

It comprises a preparation process of Montelukast from a new intermediate compound of formula (VI), which is previously prepared by reaction of the corresponding sulfonate with 1-(mercaptomethyl)cyclopropyl)methanol. Compound (VI) is reacted with a Grignard reactant to convert the ester group into a tertiary alcohol, followed by conversion of the primary alcohol into a sulfonate, substitution of the sulfonate group by a cyano group, and finally transforming the cyano compound to the carboxilic acid compound by a hydrolysis reaction to afford Montelukast. Montelukast can also be prepared by a hydrolysis reaction of the corresponding amide. It also comprises new intermediate compounds useful in such preparation process.