Method for the prevention of citalopram.

摘要

A method for the preparation of citalopram or any of its enantiomers and its acid addition salts comprising treating a compound of formula IV ** (Formula) ** wherein X is O or S; R1-R2 are each independently selected from hydrogen and C1-6 alkyl, or R1 and R2 together form a C2-5 alkylene chain thereby forming a spiro ring; R3 is selected from hydrogen and C1-6 alkyl, R4 is selected from hydrogen, C1-6 alkyl, a carboxy group or a precursor group thereto, or R3 and R4 together form a C2-5 alkylene chain thereby forming a spiro ring; with a dehydrating agent or alternatively when X is S, subject the thiazoline ring to thermal dissociation or treat it in the presence of a radical initiator, to form citalopram having the formula ** (Formula) ** and then optionally convert the free base or its acid addition salt thus obtained in its pharmaceutically acceptable salt.