METHOD FOR THE PREPARATION OF CITALOPRAM

摘要

A method for the preparation of citalopram is described comprising reduction of the oxo group of a compound of formula (IV), wherein R1 is CN, C1-6 alkyloxycarbonyl or C1-6 alkylaminocarbonyl, ring closure of the resulting hydroxy compound thereby obtaining the corresponding 1-(4-fluorophenyl)-1,3- dihydroisobenzofuran, then if R1 is cyano using it directly in the next step and if R1 is C1-6 alkyloxycarbonyl or C1-6 alkylaminocarbonyl, conversion of the compound to the corresponding compound wherein R1 is cyano; and alkylati on of the resulting 5-cyano compound with 3-dimethyl-aminopropylhalogenid in basic conditions thereby obtaining citalopram.