G. Thirunarayanan, K. Sekar
Nov 1, 2016
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Influential Citations
8
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Journal
Journal of Saudi Chemical Society
Abstract
Abstract One-pot synthesis of some 1 N -acetyl pyrazoles including 1-(3-(3,4-dimethylphenyl)-5-(substituted phenyl)-4,5-dihydro- 1 H -pyrazole-1-yl) ethanones has been achieved via solvent-free microwave irradiation using substituted chalcones, hydrazine hydrate and acetic anhydride in the presence of catalytic amount of fly-ash: PTS catalyst. The yield of these 1 N -acetyl pyrazole derivatives is more than 75%. The synthesized 1 N -acetyl pyrazoline derivatives were characterized by their physical constants and spectral data. The infrared spectral νC N and C O (cm −1 ) frequencies, NMR chemical shifts (δ, ppm) of H a , H b , H c , CH 3 protons, C N, C O and CH 3 carbons of 1-(3-(3,4-dimethylphenyl)-5-(substituted phenyl)-4,5-dihydro- 1 H -pyrazole-1-yl) ethanones have been assigned and correlated with Hammett substituent constants and Swain-Lupton’s parameters using single and multi-regression analysis. From the results of statistical analyses, the effect of substituents on the above group frequencies and chemical shifts of the acetylated pyrazoles were discussed.