Microwave assisted the short time clean synthesis of 1,3-Diketones as Building Blocks in Heterocyclic Synthesis: A Facile Synthesis and Antimicrobial Evaluation of New Dihydropyridine, 4H-Pyrane, Dihydropyridazine, Pyrimidine and Pyrazole derivatives

Abstract Background: According to literature survey, the compounds bearing naphthalene moiety can be used as medical preparations because of their wide spectrum of biological activity and low toxicity. In this study, a new series of azoles or azines were synthesized from the reaction of the key intermediate 1-(1-hydroxynaphthalen-2-yl)-3-phenylpropane-1,3-dione 3 with a variety of electrophilic and nucleophilic reagents under a variety of mild conditions. Results: The chemical structures of these compounds were confirmed by various spectroscopic methods such as (IR, 1H-NMR, 13C-NMR, mass spectral data and elemental analyses). Conclusions: The prepared compounds were screened in vitro for their antimicrobial activity against some species of Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis) and Gram-negative bacteria (Escherichia coli and Pseudomonas aeuroginosa). Anti-fungal activities of the compounds were tested against yeast and mycelial fungi,Candida albicans and Aspergillus flavus. The antimicrobial activity of this series was showed either weak or moderate activities.