IMPROVED PROCESS FOR THE MANUFACTURE OF CITALOPRAM HYDROBROMIDE

摘要

The present invention describes an improved process for the preparation of pure 1-(4'-Fluorophenyl)-1-(3-dimethylaminopropyl)-5-phthalanecarbonitrile and its bromide salt (citalopram hydrobromide), which is a well known antidepressant. Another aspect of the invention is isolation of crystalline (4-Bromo-2-hydroxymethyl)phenyl-(4-fluorophenyl)-3-(dimethylaminopropyl)methanol (Bromodiol) and conversion of desmethylcitalopram which is formed during the cyanide exchange reaction, to citalopram by heating with a mixture of formaldehyde and formic acid in chloroform. The resulting citalopram is purified using conventionally extraction methodology.