通过微波辅助聚磷酸乙酯(PPE)促进的ω-硫代酰胺醇的闭环反应,开发了一种高效且通用的合成2-取代的噻唑啉和5,6-二氢-4 H -1,3-噻嗪的方法。环化反应涉及S N 2型机理,具有反应时间短,产率高和可预测的立体化学结果的优点。无环前体是通过改进的二酰化-硫磺化-皂化顺序,从市售的ω-氨基醇中以高收率制备的。整个过程无金属且操作简单。
Thionation ofN-(?-Halogenoalkyl)-Substituted Amides withLawesson's Reagent: Facile Synthesis of 4,5-Dihydro-1,3-thiazoles and 5,6-Dihydro-4H-1,3-thiazines
作者:Yasuhiro Kodama、Mayuko Ori、Takehiko Nishio
DOI:10.1002/hlca.200590000
日期:2005.2
The thionation and cyclization of N-(ω-halogenoalkyl)-substitutedamides (and related compounds) with Lawesson's reagent (LR=2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane 2,4-disulfide) has been investigated. Treatment of the amides 1 with LR gave the corresponding thioamides 2 in moderate to good yields (Table). The latter, upon treatment with base, afforded, either in a separate step or in