A Novel General Route for the Preparation of Enantiopure Imidazolines

Abstract

A novel procedure for the preparation of enantiopure 1,4-disubstituted 2-imidazolines is reported. Enantiopure beta-amino alcohols are converted into N-hydroxyethylamides, which are reacted with excess thionyl chloride, or with thionyl chloride followed by phosphorus pentachloride to yield N-chloroethylimidoyl chlorides. These intermediates are treated with amines and anilines to produce N-chloroethylamidines, which are converted into imidazolines upon workup with aqueous hydroxide. The method is simple and efficient and has been used to prepare a wide variety of enantiopure imidazolines, in a modular fashion, from readily available amino alcohols.

Synthesis of Cyclopalladated Phenyl Imidazoline-Carbene Complexes and Catalytic Study in Suzuki Reaction

“…然后将酰氨基醇在亚硫酰氯中回流, 蒸去过量的亚硫酰 氯, 将其溶于乙醚, 过滤除去不溶物, 再加入三乙胺和 对甲苯胺, 室温搅拌后, 加入氢氧化钠的水溶液, 萃取, 干燥, 浓缩, 薄层层析分离即得苯基咪唑啉化合物 2a 和 2b [12] .…”

Five‐Membered Heterocycles: 1,3‐Azoles

“…N-hydroxyethylamides are treated with excess thionyl chlorides, or thionyl chlorides followed by PCl 5 , to afford N-chloroethylimidoyl chlorides 219. These intermediates are treated with amines and anilines to produce N-chloroethylamidines 220, which are converted into imidazolines upon workup with aqueous sodium hydroxide (Scheme 10.119) [345].…”

Thionyl Chloride - A Versatile Reagent

“…5 (C) Chlorination of amino alcohols with thionyl chloride gives chloroethyl amides; if excess thionyl chloride is used, the reaction yields chloroethyl imidoyl chlorides. 6 (E) In the presence of a Lewis acid catalyst, 2-methylanisole reacts with SOCl 2 in a Friedel-Crafts reaction, which yields the corresponding aryl sulfinyl chloride. 8 (F) Thionyl chloride can also be used as a chlorinating agent through its oxidation and partial dehydrogenation of organic compounds.…”