Preparation of high purity citalopram comprises a cyanide exchange reaction followed by thin film distillation and recrystallization from methanol and water

摘要

Preparation of citalopram (I) by subjecting a corresponding compound (II) to a cyanide exchange reaction, is new. Preparation of citalopram (1-(3-(dimethylamino)propyl)-1-(4-fluorophenyl)-1,3-dihydro-5-isobenzofuran-carbonitrile) of formula (I) by subjecting a corresponding compound of formula (II) to a cyanide exchange reaction, followed by initial purification to give crude citalopram base, subjecting the crude product to film distillation and optionally further purifying, working up and isolating pure citalopram, is new. Z = I, Br, Cl or CF3(CF2)nSO2O-; and n = 0-8.