PROCESS FOR THE PREPARATION OF CETYLTRIMETHYLAMMONIUM NAPROXENATE.

摘要

A process for the prepn. of cetyltrimethyl ammonium d-2-(6'- methoxy-2'-naphthyl) propionate of formula (I) (cetyltrimethyl ammonium naproxenate, ''Naprocet'') is new. The process comprises (a) treating an aq. soln. of cetyltrimethyl ammonium halide with an ion-exchange resin in OH form; (b) reacting the resulting cetyltrimethyl ammonium hydroxide with d-(2-(6'-methoxy-2'-naphthyl) propionic acid; (c) evaporating the water; (d) opt. purifying the obtd. prod.. The process in which the ion exchange resin is Amberlite IRA400, analytical grade and the process in which the cetyltrimethyl ammonium halide is the bromide. The ion-exchange resin is initially in its Cl(-) form and is converted to the OH(-) form using pref. NaOH or KOH. The soln. is then neutralised with Naproxen and evaporated to give a waxy solid. The prod. can be recrystallised from organic solvents.