Utility of Pyrazolylchalcone Synthon to Synthesize Azolopyrimidines under Grindstone Technology

A series of pyrazolyl-triazolo[1,5-a]pyrimidines, pyrazolyl-tetrazolo[1,5-a]pyrimidines, pyrazolyl-benzo[4,5]imidazo[1,2-a]pyrimidines and bis-azolopyrimidines were prepared by reaction of pyrazolyl-chalcones or its bis-pyrazolyl-chalcones with the appropriate heterocyclic amines as aminotriazole, aminotetrazole, 2-aminobenzimidazole and 4,6-dimethyl-1H-pyrazolo[3,4-b]pyridin-3-amine by grinding method. The newly synthesized compounds have been characterized on the basis of elemental analysis and spectral data (IR, ¹H- and ¹³C-NMR, Mass). Moreover, the newly synthesized products were screened for their in vitro antibacterial activities and the results showed that compounds 5f and 11d exhibited excellent activities compared with penicillin G and streptomycin as reference drugs.