A METHOD FOR THE PREPARATION OF CITALOPRAM ACID ADDITION SALTS

摘要

The present invention discloses a simple in situ method for the purification of citalopram acid addition salts without isolating crystalline citalopram base as a solid, wherein citalopram base is treated with metal hydrides in solvent medium followed by acid addition, to remove structurally similar impurities by filtration to get crude citalopram acid addition salts. The resulting citalopram salts are subjected to simple purification to get pharmaceutically acceptable acid addition salts. The said citalopram base is prepared by subjecting 5-cyanophthalane to an eco-friendly and safe C-alkylation reaction with 3,N,N dimethylaminopropyl chloride in the presence of strong base in a mixture of dimethylsulfoxide and toluene.