US 2001/0027256 A1 · Method for the preparation of citalopram

Abstract

The present invention relates to a method for the preparation of citalopram comprising reaction a compound of formula (I) 1 with a compound having the formula 2 wherein X is a suitable leaving group and R is —CH2—O—Pg, —CH2—NPg1Pg2, —CH—N(CH3)2, —CH(OR1)(OR2) —C(OR4)(OR5)(OR6), —COOR3, —CH2—CO—NH2, —CH═CHR7 and —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, R4, R5, R6 and R7 are independently selected from alkyl, alkenyl, alkynyl and optionally alkyl substituted aryl or aralkyl and R8 is hydrogen or methyl; to form a compound of the formula 3 wherein R is as defined above; followed by conversion of the group R to form a dimethylaminomethyl group and isolation of citalopram base or a pharmaceutically acceptable salt thereof.

Claims18

Dependent claims

A method for the preparation of citalopram comprising reacting a compound of formula (I) 20

with a compound having the formula 21
wherein X is a suitable leaving group and R is —CH2—O—Pg, —CH2—NPg1Pg2, —CH2—NMePg1, —CO—N(CH3)2, —CH(OR1)(OR2), —C(OR4)(OR5)(OR6), —COOR3, —CH2—CO—NH2, —CH═CHR7 or —CO—NHR8, 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, R4, R5, R6 and R7 are independently selected from alkyl, alkenyl, alkynyl and optionally alkyl substituted aryl or aralkyl and R8 is hydrogen or methyl;
to form a compound of the formula 22
wherein R is as defined above;
followed by conversion of the group R to form a dimethylaminomethyl group and isolation of citalopram base or a pharmaceutically acceptable salt thereof.

2 more elements

Dependencies are inferred from the claim text.

Method for the preparation of citalopram

Life of this patent

Method for the preparation of citalopram

Life of this patent

Abstract

Claims18