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Synthesis and spectral studies of some N-[(E)-phenylmethylidene]benzenesulfonamides

Sekar K. G., Thirunarayanan G.

International Letters of Chemistry, Physics and Astronomy

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2013

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Vol. 8, iss. 3

249-258

EN

A series of some N-[(E)-phenylmethylidene]benzenesulfonamide derivatives have been synthesised using solid SiO2-H3PO4 catalyst under solvent free conditions in microwave irradiation. The synthesised E-N-benzene sulfonilimines purities have been verified by their physical constants and spectroscopic data. The spectral frequencies are correlated with Hammett substituent constants, F and R parameters using linear regression analysis. From the results of statistical analysis the effect of substituents on the group frequencies will be discussed.

2

Synthesis and spectral correlation study of some 3-(3,4-dichlorophenyl)-5-(substituted phenyl)-4,5-dihydro-1H-pyrazole-1-yl-ethanones

Thirunarayanan G., Ravi K.

International Letters of Chemistry, Physics and Astronomy

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2013

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Vol. 14

44--57

EN

Some N-acetyl pyrazoles including 3-(3,4-dichlorophenyl)-5-(substituted phenyl)-4,5-dihydro-1H-pyrazole-1-yl-ethanones have been synthesised by solvent free cyclization cum acetylation of chalcones including substituted styryl 3,4-dichlorophenyl ketones using hydrazine hydrate and acetic anhydride in presence of catalytic amount of fly-ash: H2SO4 catalyst. The yield of these N-acetyl pyrazole derivatives are more than 75 %. The synthesised 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 Ha, Hb, Hc, CH3 protons, C=N, C=O and CH3 carbons of 1-(3-(3,4-dichlorophenyl)-5-(substitutedphenyl)-4,5-dihydro-1H-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.

3

Solvent-free synthesis and spectral linearity of some (E)-2-(substituted benzylideneamino)-N-(3-chloro-4-fluorophenyl)-hexahydro-2H cyclopenta[b]thiophene-3-carboxamides

Thirunarayanan G., Sekar K. G.

International Letters of Chemistry, Physics and Astronomy

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2013

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Vol. 8, iss. 2

160-174

EN

Some (E)-2-(substituted benzylideneamino)-N-(3-chloro-4-fluorophenyl)-hexahydro-2H-cyclopenta[b]thiophene-3-carboxamide derivatives have been synthesized by SiO2:H3PO4 catalyzed solvent-free condensation of 2-amino-N-(3-chloro-4-fluorophenyl)-hexahydro-2H-cyclopenta [b]thiophene-3-carboxamide and various substituted benzaldehydes in microwave irradiation. The yield of the imine-carboximido derivatives has been found to be more than 85 %. The purity of all imine-carboximido derivatives has been checked using their physical constants and spectral data. The spectral data of the imine-carboximido derivatives such as infrared ? (cm-1) of CO, NH, C-N, C-Cl, C-F, C=N, and the NMR chemical shifts (?, ppm) of NH, CH, CO and C=N have been correlated with Hammett substituent constants, F and R parameters. From the results of statistical analysis, the effects of substituent on the above spectral group absorptions have been discussed.

4

Preheated fly-ash catalyzed cyclization ofchalcones: Synthesis of some substituted pyrazole-1-carbothioamides and spectral correlations in 3-(3,4-dichlorophenyl)-5-(substituted phenyl)-4,5-dihydro-1H-pyrazole-1 carbothioamides

Thirunarayanan G., Sekar K. G.

International Letters of Chemistry, Physics and Astronomy

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2013

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Vol. 10, iss. 1

18-34

EN

Some substituted 1-thiocarbomyl pyrazolines including 3-(3,4-dichlorophenyl)-5-(substituted phenyl)-4,5-dihydro-1H-pyrazole-1-carbothioamides using solvent-free preheated fly-ash catalyzed cyclization between chalcones and thiosemicarbazide microwave irradiation. The yields of these thiocarbomyl pyrazolines are more than 80 %. The purities of these synthesised pyrazoline derivatives are checked by their physical constants and spectral data earlier reported in the literature The spectral data of these 3-(3,4-dichlorophenyl)-5-(substituted phenyl)-4,5-dihydro-1H-pyrazole-1-carbothioamides had been correlated, using single and multi-linear regression analysis.