左旋盐酸西替利嗪的合成工艺改进

目的研究左旋盐酸西替利嗪的合成工艺。方法以氯代苯和苯甲酰氯为起始原料。经傅克酰化、还原胺化得到左旋盐酸西替利嗪的关键中间体4-氯双苯胺（4），4再经拆分、成环、缩合制得左旋盐酸西替利嗪。结果与结论目标化合物的结构经红外光谱、元素分析确证，总收率为9．96％。该工艺操作简便，适用于工业化生产。

Improved synthesis of levocetirizine dihydrochloride

Abstract: Aim To improve the synthetic process of levocetirizine dihydrochloride. Methods 4-chloro -phenylphenylmethylamine(4), a key intermediate of cetirizine, was obtained via Friedel-Crafts reaction from 1-chlorobenzene with benzoyl chloride, followed by separating with L-(+)tartaric acid to give R enantiomer(5) of 4. Cyclization of 5 with bis(2-Chloroethyl)amine hydrochloride to afford (R)-4-chlorophenylphenylmethyl piperazine (6), then 6 was subsequently condensed to levocetirizine dihydrochloride(1). Results and conclusion The structure of target compound was confirmed by IR, elemental analysis, and the overall yield was 9.96%. The improved method was easy for synthesis and suitable for industrial manufactur -ing.