An efficient and simple method for the preparation of 5-arylamino-1H-tetrazole and 1-aryl-5- amino-1H-tetrazole derivatives is reported using aluminum (III) hydrogensulfate (Al (HSO4) 3) as an effective heterogeneous catalyst from secondary arylcyanamides. Generally, when the substitution in arylcyanamide is strongly electron-withdrawing the position of equilibrium would shift toward the isomer of 1-aryl-5-amino-1H-tetrazole (B) and as the electron- ...
