Halo-heterocyclization of trans-5-phenyl-3-cinnamylsulfanyl[1,2,4]triazine into [1,3]thiazino[3,2-b][1,2,4]triazin-9-ium systems

Treatment of trans-5-phenyl-3-cinnamylsulfanyl[1,2,4]triazine with bromine or iodine in dichloromethane leads to haloannulation onto the thiazine moiety with formation of (7r,8t)-7-halo-3,8-diphenyl-7,8-dihydro-6H-[1,3]thiazino[3,2-b][1,2,4]-triazin-9-ium salts. The product structure was confirmed by X-ray study.