Preparation of S-Vinylsulfilimines

For the preparation of S-vinylsulfilimines (1), mainly S-phenyl-N-tosyl-S-vinylsulfilimine, three routes were examined, viz., (A) the reaction of vinyl sulfide with chloramine T, (B) that of 2-haloethyl phenyl sulfide with chloramine T followed by dehydrohalogenation, and (C) that of 2-hydroxyethyl sulfide with chloramine T followed by acetylation of the hydroxyl group and deacetoxylation. Route A has disadvantages of troublesome preparation of vinyl sulfides and low yield. Route B gives the precursor sulfilimine to 1 in good yield only by use of anhydrous chloramine T. Route C gives the best results in view of starting material and yield.