PROCESS FOR THE PREPARATION OF CITALOPRAM

摘要

This invention discloses an improved process for the preparation of citalopram of the formula III which comprises (i) preparing the compound of the formula VIII by reducing an unisolable magnesium salt of a benzophenone derivative of the formula V using sodium borohydride in the presence of a protic solvent, (ii) reacting the compound of the formula VIII obtained in step (i) with an acid catalyst in a non-polar solvent to obtain a compound of the formula I, (iii) reacting the compound of the formula I obtained in step (ii) with copper (I) cyanide in a polar solvent medium and isolating the resulting cyano compound, by recrystallization by using polar and/or alcoholic solvents to obtain the compound of the formula II and (III) reacting the resulting compound of the formula II by conventional methods to form citalopram of the formula III. Citalopram is widely used as an antidepressant.