Fluorinated 2‐Amino‐5‐phenyl‐1,3,4‐thiadiazines: Synthesis and Structures.

Fluorinated 2-amino-5-phenyl-1,3,4-thiadiazines were obtained for the first time. A study of their tautomeric structures revealed that trifluoromethyl-containing 1,3,4-thiadiazines exist as the 4H-tautomer in both solutions and the solid state, while their monofluoroaryl analogs exist as the 6H-tautomer.