Cyclization of Semicarbazones to 1,2,3-Selenadiazoles By Selenium Dioxide

Abstract In the present work some of 1,2,3-selenadiazole compounds derived from corresponding semicabazones have been prepared. The reaction of substituted chalcone compounds (1a-c) and 4-methoxy benzyl cyanide give compounds (2a-c) which were converted through the reaction with semicarbazide hydrochloride into the corresponding semicarbazones (3a-d(. The treatment of these compounds with selenium dioxide leads to ring closure of semicarbazones to give the 1,2,3-selenadiazole compounds. The structures of the synthesized compounds were established by physical and spectral methods.