Reactions of Monohalomethyl Aryl Ketoximes with Tetrasulfur Tetranitride: Much Improved Synthesis of 3-Aryl-1,2,5-thiadiazoles

Article abstract of DOI:10.3987/COM-94-6755

Reactions of chloromethyl aryl ketoximes (1, X = Cl) with tetrasulfur tetranitride in p-dioxane at reflux for 4 h afforded 3-aryl-1,2,5-thiadiazoles (2) in 37-92percent yields, whereas those of bromo analogs under the same conditions gave 2 and 3-aryl-4-bromo-1,2,5-thiadiazoles 3 in 48-81percent and 17-31percent yields, respectively.However, the compounds (3) were not formed in the presence of pyridine. α-Nitrosostyrene and its ring-substituted derivatives (4) are proposed as intermediates for the formations of 2.