Synthesis of 2,5-Diaryltetrazoles fromN-Phenylsulfonylbenzhydrazidoyl Chlorides and Arylhydrazines

A new synthesis of 2,5-diaryltetrazoles is given by the reaction of N-phenylsulfonylbenzhydrazidoyl chlorides with arylhydrazines and the action of potassium carbonate on the intermediate product formed in the initial reaction. Thirty tetrazoles carrying H, CH3, Cl, Br, or NO2 as the para-substituent of the 2-phenyl group, and H, CH3, Cl, CH3O, CN, or NO2 as that of the 5-phenyl group, were synthesized in 70–16% yields, respectively. The reaction may proceed via the concerted elimination of benzenesulfinate ion from the intermediate 1,3-diaryl-5-phenylsulfonylformazanide anion taking a quasi-aromatic configuration.