Cetirizine dihydrochloride synthesis

Yield:83881-52-1 87.9%

Reaction Conditions:

with hydrogenchloride in water;acetone at 20 - 50; for 2 h;

Steps:

1.C

2-{2-[4-[(4-chlorophenyl)phenylmethyl]-1-piperazinyl]-ethoxy}acetic acid from B above (13.4 g, 0.034 mol) was suspended in acetone (150 ml), heated to 50 °C and concentrated hydrochloric acid (6.2 ml, 0.078 mol) was added with vigorous stirring. The resulting almost clear solution was stirred at room temperature for 2 hours after which a fine white precipitate of 2-{2-[4-[(4-chlorophenyl)phenylmethyl]-1-piperazinyl]ethoxy}acetic acid dihydrochloride had formed. The solution was filtered, washed with acetone (50 ml) and dried in vacuo leaving 13.8 g (87.9 %) of 2-{2-[4-[(4-chlorophenyl)phenylmethyl]-1-piperazinyl]ethoxy}acetic acid dihydrochloride. M. P. 224-226 °C.

References:

EP1157016,2003,B1 Location in patent:Page/Page column 5