Halo-heterocyclization of butenyl(prenyl)thioethers of 4,5-diphenyl-1,2,4-triazol-3-thiole into triazolo[5,1-b] [1,3]thiazinium systems: experimental and theoretical evolution

摘要

A facile and highly efficient regioselective synthesis of partially saturated triazolo[5,1-b][1,3]thiazinium salts by the electrophilic heterocyclization of the butenyl thioethers of 4,5-diphenyl-1,2,4-triazol-3-thiol with halogens was developed. Under developed conditions, electrophilic cyclization reactions proceeded smoothly and cleanly and the corresponding fused products were obtained in high yields in all cases examined. Herein, we also report the studying of the regiochemistry of this process using computer simulation methods, XDR, and spectral investigations for explaining of electrophilic cyclization mechanism and solving of final products structure. Graphic abstract