Process for the preparation of pure citalopram (5-cyano-1-(3-dimethylaminopropyl)-1-(4-fluorophenyl)phthalane) by reacting 5-substituted-1-(3-dimethylaminopropyl)-1-(4-fluorophenyl)phthalane with a cyanide source, then subjecting the crude citalopram product to a film distillation process

摘要

Process for the preparation of citalopram of formula I in which a compound of formula II is subjected to a cyanide exchange reaction in which the group Z is exchanged with cyanide by reaction with a cyanide source. The resultant crude citalopram product is optionally subjected to some initial purification. The crude citalopram base is then subjected to a film distillation process. The resulting citalopram product is then optionally further purified and worked up and isolated as the base or a pharmaceutically acceptable salt thereof. In the compound of formula II, Z is I, Br, Cl or CF3-(CF2)n-SO2-O-, where n is 0, 1, 2, 3, 4, 5, 6, 7 or 8. Also described is citalopram whenever prepared by the above-described process.