Process for the preparation of 2-(2-(4((4-chlorophenyl)phenylmethyl)-1-piperazinyl)ethoxy)-acetic acid and their salts

摘要

Preparation of cetirizine (2-Ä2-Ä4-Ä(4-chlorophenyl)phenylmethylÜ-1-piperazinylÜethoxyÜacetic acid) (I) comprises reacting 1-Ä(4-chlorophenyl)phenylmethylÜ-piperazine (II) with 2-chloroethoxyacetic acid in the presence of an acid acceptor and in an inert solvent. Acid acceptors are preferably selected from alkali metal carbonates and hydroxides, triethylamine, ethyl diisopropylamine, N-ethylmorpholine and 2,4,6-trimethyl-pyridine. The molar ratio of (I):(II) is 3:1-1:3 and an alkali metal iodide may also be present.