CONVENTIONAL AND MICROWAVE ASSISTED SYNTHESIS OF SOME NEW DERIVATIVES OF COUMARIN CONTAINING PYRAZOLINE AND INVESTIGATION OF THEIR ANTIBACTERIAL AND ANTIFUNGAL ACTIVITIESAbstract
Pyrazoline derivatives, being used as potential medicinal agents, 3-Acetyl-2H-chromen-2one (I) was prepared by Knoevenagel condensation of salicyladehyde with ethylacetoacetate in presence of piperidine. A series of 3-[(2E)-3-substituted-prop-2-enoyl]-2H-chro men-2-one derivatives (II a-h) were prepared by Claisen-Schmidt condensation of 3-acetyl coumarin with aromatic aldehydes. Treatment of 3-substituted cinnamoylcoumarin with hydrazine hydrate in the presence of ethanol gave [5-substitutedphenyl]-4, 5-dihydro-1H-pyrazol-3-yl]-2H-chromen-2-one (III a-h). Title compound were synthesized by conventional as well as by microwave assisted method. The structures of the newly synthesized compounds were confirmed by IR and 1H-NMR spectroscopy. All the synthesized compounds were tested for their antibacterial and antifungal activities using cup-plate-agar-diffusion method. The antibacterial activity screening revels that the compound III b has comparable activity and compound III c shows moderate activity as that of standard ampicillin against gram positive and gram negative bacteria. All synthesized compounds were found to be inactive as antifungal against Candida albicans.
A. S. Lunkad * and R. L. Sawant
SCSSS’s Sitabai Thite College of Pharmacy, Pune-Nagar Bypass, Pune, Maharashtra, India.
28 September, 2017
20 December, 2017
25 December, 2017
01 July, 2018