Rac- and<i>R</i>-(+)-[4,4′,5,5′-<sup>2</sup>H<sub>4</sub>]-2-(1′-[2′′,6′′-dichlorophenoxy]-ethyl)-Δ<sup>2</sup>-imidazoline (lofexidine)
作者:Ashish P. Vartak、Vijayakumar Sonar、Peter A. Crooks
DOI:10.1002/jlcr.1655
日期:2009.8
The synthesis of the d4-forms of rac- and R-lofexidine was accomplished. Two methods are described; one method is a two-step synthesis of rac-d4-lofexidine from 2-chloropropionitrile, the second method is a three-step preparation of R-d4-lofexidine in absolute enantiomeric purity from S-methyl lactate. The commercial availability of R-methyl lactate makes this latter enantioselective synthesis applicable also to the synthesis of S-d4- lofexidine. These procedures also conserve the utilization of the relatively expensive [1,1′,2,2′-2H4]ethylene diamine precursor. The availability of S- and R-d4-lofexidines will enable pharmacokinetic studies to be carried out to determine if differential in vivo metabolism of the two enantiomers of lofexidine occurs. Copyright © 2009 John Wiley & Sons, Ltd.
合成rac-和R-洛非昔丁的d4-形式已完成。描述了两种方法;一种方法是从2-氯丙腈经过两步合成rac-d4-洛非昔丁,第二种方法是从S-甲基乳酸经过三步制备具有绝对对映体纯度的R-d4-洛非昔丁。商业上可获得的R-甲基乳酸使得后者的对映选择性合成同样适用于S-d4-洛非昔丁的合成。这些程序还节省了相对昂贵的[1,1′,2,2′-2H4]乙二胺前体的使用。S-和R-d4-洛非昔丁的可用性将使药代动力学研究得以进行,以确定洛非昔丁的两种对映体是否存在不同的体内代谢。版权 © 2009 John Wiley & Sons, Ltd.