Microwave Assisted Improved Synthesis of Some Novel Heterofused Pyrazolopyrimidines Derivatives and Their Antimicrobial Activity

Heterofused pyrazolopyrimidines possesses various biological activities such as CNS depressant, neuroleptic, tuberculostatic, antimicrobial, adenosine receptor antagonistic, antinociceptive, anti-inflammatory, non-narcotic analgesic, anticancer and leishmanicidal activity.

Therefore, in this work, we have synthesized some new Heterofused containing disubstitued Pyrazolopyrimidines employing microwave techniques and have been evaluated for their antimicrobial activity. Substituted 5-amino-1- Phenyl Pyrazole-4-Carboxamide was reacted with appropriate amount of Ethyl formate in the presence of Sodium ethoxide solution to furnish titled compounds. Neat reactants were cyclocondensed under microwaves to afford, in good yield, the desired product in less irradiation times as compared to the classical technique.

All the synthesized compounds were characterized by melting point, R_f value and further confirmed by UV, IR, H1NMR and Mass spectroscopy.

The title compounds were screened for antibacterial activity by cup plate method using Streptomycin as the standard drug against Klebsiella (Gram -ve), Escherichia coli (Gram -ve), Staphylococcus aureus (Gram +ve) and Bacillus subtillis (Gram +ve). All the compounds showed weak to moderate activity against all four microorganisms.