Stereoselective synthesis of (E)-4-alkoxy-2-aryl-5-chloro-2-thiazolines

The first synthesis of the title compounds has been achieved starting from chloralamides by a route involving chemical and electrochemical steps. N-(1-Alkoxy-2,2,2-trichloroethyl)benzamides were efficiently prepared from chloralbenzamides and were electrochemically converted into N-(1-alkoxy-2,2-dichloroethyl)benzamides in high yields by cathodic reduction in a protic medium. Thionation of these compounds with Lawesson's reagent followed by basic treatment gave novel (E)-4-alkoxy-2-aryl-5-chloro-2-thiazolines in fair to quantitative yields.