| 摘要 |
Preparation of citalopram involves removal of the desmethyl-citalopram impurity by reaction with an amide or an amide-like group forming agent; removing the amides, and further purifying the crude product to isolate the base citalopram. Preparation of citalopram (I) by subjecting a compound of formula (II) to a cyanide exchange reaction with a cyanide source involves: optionally subjecting the resultant crude (I) to initial purification; subsequently treating with an amide or an amide-like group forming agent (a) R-CO-X; Hal-C(Y')-W'-R or R'-SO2-Hal; subjecting the reaction mixture to an acid/base wash and/or crystallization and recrystallization to remove the amides formed from the crude mixture; optionally purifying the resulting product of (I), working up and isolating (I) as a base or a salt. Z = I, Br, Cl, CF3-(CF2)nSO2-O-; n = 0 - 8; X = halogen or O-CO-R'; Y' = O or S; W' = O, N or S; and R, R', R and R' = H, alkyl or optionally substituted aryl or aralkyl. |
