Patent ID: 7511161

Claim:
A process of purifying citalopram, either in racemic or enantiomeric form, which process comprises: (i) providing a crude mixture comprising citalopram, either in racemic or enantiomeric form, dissolved in a water immiscible organic solvent, and which mixture also includes one or more citalopram derivatives which are present as citalopram impurities; (ii) washing said crude mixture with at least one dilute aqueous solution of a polybasic acid of editic acid, either in free form or as a partial alkali metal salt, so as to separate said citalopram from citalopram impurities present in said crude mixture, said solution having a strength in the range of 0.5% to 6%; and (iii) where required converting citalopram free base, separated from citalopram impurities further to step (ii), to a pharmaceutically acceptable salt.