Process for cyclooxygenase-2 selective inhibitor

摘要

The present invention describes a process for preparing a cyclooxygenase-2 selective inhibitor. It provides a synthetic procedure for the said substance namely 5-chloro-3-(4-methylsulphonyl)phenyl-2-(2-methyl-5-pyridinyl)pyridine of formula (I). The invention also relates to preparation of a new intermediate of formula (IV) and a process to prepare it. Furthermore, the invention describes a process for preparing another key intermediate of formula (II). Compounds of formula (IV) and formula (II) are useful intermediates in synthesis of the said cyclooxygenase-2 inhibitor.

主权项

1. A process for the preparation of etoricoxib comprising subjecting 5-Chloro-3-(4-methylthio)phenyl-2-(2-methyl-5-pyridinyl)pyridine (IV) to oxidation in presence of an oxidation catalyst, a phase transfer catalyst, and a halogenated hydrocarbon solvent to obtain etoricoxib of formula-(I); wherein the oxidation catalyst is selected from the group consisting of molybdenum, vanadium, and tungsten catalysts; and wherein the phase transfer catalyst is selected from the group consisting of quatenary ammonium chloride salts.