PROCESS FOR THE PREPARATION OF A LEUKOTRIENE ANTAGONIST AND INTERMEDIATES THEREOF

摘要

It comprises a preparation process of Montelukast from an intermediate compound of formula (Vl), which is previously prepared by reaction of the corresponding sulfonate with i-fmercaptomethyljcyclopropyljmethanol. Compound (Vl) 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 intermediate compounds useful in such preparation process.