However, there is no report on the synthesis of 1 from simple aldehyde hydrazones 2. It is well known that the reaction of sterically crowded ketone hydrazones with disulfur dichloride in the presence of bases afforded thiones in good yields. [7] Recently, we have reported the synthesis of 1,3,4-selenadiazolines by the reaction of ketone hydrazones with diselenium dibromide, suggesting that the intermediates were not only selenoketones but also diazoalkanes. [8] These ...
