Selenium heterocycles. XXXV . Synthesis and pyrrolysis of aryloxy‐, arylthio‐, and arylseleno‐1,2,3‐selenadiazoles

A series of 4‐substituted‐5‐arylthio‐1,2,3‐selenadiazoles, 4‐substituted‐5‐arylseleno‐1,2,3‐selenadiazoles and 4‐aryloxymethyl‐1,2,3‐selenadiazoles were synthesized. Pyrrolysis of these compounds afforded the corresponding acetylenes XI, XIII (X = S, Se) and XII, respectively. Oxidation of 4‐substituted‐5‐arylthio‐1,2,3‐selenadiazoles (XIV) with m ‐chloroperbenzoic acid gave 4‐substituted‐5‐arylsulfinyl‐1,2,3‐selenadiazoles (XV) and 4‐substituted‐5‐arylsulfonyl‐1,2,3‐selenadiazoles (XVI).