Synthesis of Novel 4-Chloro-5-methyl-2-(R-thio)-N-(2,3-dihydro-1,3,4-thiadiazol-2-ylidene)benzenesulfonamide Derivatives

Two series of novel 4-chloro-5-methyl-2-(R-thio)-N-(2,3-dihydro-1,3,4-thiadiazol-2- ylidene)benzenesulfonamide derivatives 5-14 were synthesized by the reaction of potassium 6-chloro-1,1-dioxo-7-methyl-1,4,2-benzodithiazine-3-thiolate (1) or 6-chloro-3- mercapto-7-methyl-1,4,2-benzodithiazine 1,1-dioxide (2) with hydrazonyl bromides 3a-g. Suggested mechanisms of the investigated reaction were discussed. Themolecular orbital calculation of the possible tautomeric forms of 3-mercaptobenzodithiazine 2 were also presented.