One-pot synthesis of tetrazolo[1,5-a]pyrimidines under solvent-free conditions

A series of 5,7-diaryl-4,7-dihydrotetrazolo [1,5-a]pyrimidines and 5-methyl-7-aryl-4,7-dihydrotetrazolo [1,5-a]pyrimidine-6-carboxylates were obtained from aryl aldehydes, 2-aminotetrazole, substituted acetophenones, or ethyl acetoacetate in good to excellent yields by proceeding through a simple, mild, and efficient procedure utilizing N,N,N,N-tetrabromobenzene-1,3-disulfonamide as catalyst.