Patent ID: 6762308
Filing Date: 2004-07-13
Classification: A61P,C07D

Abstract:
A method for the preparation of citalopram comprising reacting a compound of formula (I) wherein Y is a group which may be converted to cyano, with a compound having the formula wherein X is a suitable leaving group and R is â€”CH2â€”Oâ€”Pg, â€”CH2â€”NPg1Pg2, â€”CH2â€”NMePg1, â€”COâ€”N(CH3)2, â€”CH(A1R1)(A2R2), â€”COOR3, â€”CH2â€”COâ€”NH2, â€”CH&boxH;CHâ€”R7 or â€”CONHR8, wherein Pg is a protection group for an alcohol group, Pg1 and Pg2 are protection groups for an amino group, R1 and R2 are independently selected from alkyl, alkenyl, alkynyl and optionally alkyl substituted aryl or aralkyl groups or R1 and R2 together form a chain of 2 to 4 carbon atoms, each of R3 and R7 are independently selected from alkyl, alkenyl, alkynyl and optionally alkyl substituted aryl or aralkyl, R8 is hydrogen or methyl and A1 and A2 are selected from O and S; to form a compound of formula wherein R and Y are as defined above, followed by, in either order, converting R to a dimethylaminomethyl group and converting Y to a cyano group, followed by isolating citalopram base or a pharmaceutically acceptable acid addition salt thereof.