METHOD FOR PREPARING {2-[4-(ALPHA-PHENYL-PARA-CHLOROBENZYL)PIPERAZINE-1-YL]ETHOXY}-ACETIC ACID AND NEW INTERMEDIATE COMPOUNDS

FIELD: organic chemistry, chemical technology, medicine, pharmacy. ^ SUBSTANCE: invention relates to a method for preparing {2-[4-(alpha-phenyl-p-chlorobenzyl)piperazine-1-yl]ethoxy}acetic acid (cetirizine) of the formula (I): (I). ^ Method involves hydrolysis of compound of the formula (II): (II) ^ wherein R1 and R2 represent independently (C1-C4)-alkyl that can be substituted with phenyl, (C2-C4)-alkenyl or cyclohexyl; or R1 and R2 in common with adjacent nitrogen atom form morpholine group. Hydrolysis is carried if necessary in the presence of interphase catalyst. Cetirizine is used as a component in anti-allergic pharmaceutical compositions. Also, invention describes a method for preparing intermediate compounds of the formula (II). ^ EFFECT: improved preparing method, valuable medicinal properties of compound. ^ 5 cl, 25 ex