| 摘要 |
<p>The invention enables the procedure of preparation of esters of (2-(4-((4-chlorophenyl)phenylmethyl)-1-piperazinyl)etoxy) acetic acid having a formula (I), where X represents a halogen atom and R a lower alkyl group, comprising the reaction of: (a) a compound according to the formula (II), (b) a compound according to the formula (III), and (c) a tertiary amine as a solvent and acid remover at the temperature of at least 100 degrees Celsius, where X is a halogen atom, X' is chosen from a group containing bromide and chloride, and R is a lower alkyl group. The above mentioned compounds are the principal intermediate steps in the preparation of cetirizine dihydrochloride, a non-sedative antihistamine drug.</p> |
