Ganesamoorthy Thirunarayanan

Synthesis, spectral studies and antimicrobial activities of some 2-naphthyl pyrazoline derivatives

A series of 2-naphthyl pyrazolines were synthesized by the cyclization of 2-naphthyl chalcones and phenylhydrazine hydrochloride in the presence of sodium acetate. The yields of pyrazoline derivatives are more than 80%. The synthesized pyrazolines were characterized by their physical constants, IR, (1)H, (13)C and MS spectra. From the IR and NMR spectra the C=N (cm(-1)) stretches, the pyrazoline ring proton chemical shifts (ppm) of δ(Ha), H(b) and H(c) and also the carbon chemical shifts (ppm) of δC=N are correlated with Hammett substituent constants, F and R, and Swain-Luptons parameters using single and multi-regression analyses. From the results of linear regression analysis, the effect of substituents on the group frequencies has been predicted. The antimicrobial activities of all synthesized pyrazolines have been studied.

Fly-ash:H2SO4 catalyzed solvent free efficient synthesis of some aryl chalcones under microwave irradiation

Some 2E aryl chalcones have been synthesized using greener catalyst Fly-ash:H(2)SO(4) assisted solvent free environmentally benign Crossed-Aldol reaction. The yields of chalcones are more than 90%. The synthesized chalcones are characterized by their physical constants and spectral data.

Synthesis and insect antifeedant activities of some substituted styryl 3,4-dichlorophenyl ketones

Sixteen substituted styryl 3,4-dichlorophenyl ketones [(2E)-1-(3,4-dichlorophenyl)-3-phenyl-2-propen-1-ones] were synthesized using eco-friendly benign stereoselective crossed-aldol reaction. They are characterized by their analytical, infrared, NMR and mass spectral data. The insect antifeedant activities of these chalcones were evaluated using Caster semilooper and Achoea janata L.

Solvent-free synthesis, spectral correlations and antimicrobial activities of some aryl imines.

A series of aryl imines have been synthesized by Fly-ash: H2SO4 catalyzed microwave assisted process under solvent-free conditions. The yields of the imines have been found to be more than 87%. The purity of all imines has been checked using their physical constants and spectral data as published earlier in literature. The UV λmaxCN(nm), infrared νCN(cm(-1)), NMR δ(ppm) of CH and CN spectral data have been correlated with Hammett substituent constants and F and R parameters using single and multi-linear regression analysis. From the results of statistical analysis, the effect of substituents on the above spectral data has been studied. The antimicrobial activities of All synthesised imines have been studied using Bauer-Kirby method.

Hydroxyapatite catalyzed aldol condensation: synthesis, spectral linearity, antimicrobial and insect antifeedant activities of some 2,5-dimethyl-3-furyl chalcones.

A series of 2,5-dimethyl-3-furyl chalcones [2E-1-(2,5-dimethyl-3-furyl)-3-(substituted phenyl)-2-propen-1-ones] have been synthesized by Hydrotalcite catalyzed aldol condensation between 3-acetyl-2,5-dimethylfuron and substituted benzaldehydes. Yields of chalcones are more than 80%. These chalcones were characterized by their physical constants and spectral data. The group frequencies of infrared ν(cm(-1)) of CO s-cis and s-trans, CH in-plane and out of plane, CH=CH out of plane, C=C out of plane modes, NMR chemical shifts δ(ppm) of Hα, Hβ, CO, Cα and Cβ of these chalcones were correlated with Hammett substituent constants, F and R parameters using single and multi-regression analyses. From the results of statistical analyses, the effects of substituents on the group frequencies are explained. Antibacterial, antifungal and insect antifeedant activities of these chalcones have been studied.

Synthesis, spectral studies, antimicrobial, antioxidant and insect antifeedant activities of some 9H-fluorene-2-yl keto-oxiranes

Thirteen ee (αS, βR) 9H-fluorene-2-yl keto-oxiranes (2-(9H)-fluorene-4-yl[3-(substituted phenyl)oxiran-2-yl]methanones) have been synthesized by phase transfer catalysed epoxidation of 9H-fluorene-2-yl chalcones. The yields of oxiranes are more than 95%. The synthesized oxiranes have been characterized by IR, (1)H, (13)C and GC-MS spectral data. The spectral data are correlated with Hammett substituent constants and Swain-Lupton parameters. From the regression analysis, the effect of substituents on the group frequencies has been predicted. The antimicrobial, antioxidant and insect antifeedant activities of all the synthesized oxiranes have been studied.

Solvent-free synthesis, spectral correlations and antimicrobial activities of some aryl E 2-propen-1-ones.

Totally 38 aryl E 2-propen-1-ones including nine substituted styryl 4-iodophenyl ketones have been synthesised using solvent-free SiO2-H3PO4 catalyzed Aldol condensation between respective methyl ketones and substituted benzaldehydes under microwave irradiation. The yields of the ketones are more than 80%. The synthesised chalcones were characterized by their analytical, physical and spectroscopic data. The spectral frequencies of synthesised substituted styryl 4-iodophenyl ketones have been correlated with Hammett substituent constants, F and R parameters using single and multi-linear regression analysis. The antimicrobial activities of 4-iodophenyl chalcones have been studied using Bauer-Kirby method.

Eco-friendly synthesis and antimicrobial activities of some 1-phenyl-3(5-bromothiophen-2-yl)-5-(substituted phenyl)-2-pyrazolines

Background Green catalyst fly ash: H2SO4 was prepared by mixing fly ash and sulphuric acid. Microwave irradiations are applied for solid phase cyclization of 5-bromo-2-thienyl chalcones and phenyl hydrazine hydrate in the presence of fly ash: H2SO4 yields, 1-phenyl-3(5-bromothiophen-2-yl)-5-(substituted phenyl)-2-pyrazolines. These pyrazolines were characterized by their physical constants and spectral data. The antimicrobial activities of all synthesized pyrazolines have been studied. Results Scanning electron microscopy (SEM) analysis shows the morphology changes between fly ash and the catalyst fly ash: H2SO4. The SEM photographs with the scale of 1 and 50 μm show the fly-ash particle is corroded by H2SO4 (indicated by arrow mark), and this may be due to dissolution of fly ash by H2SO4. The yields of 1-phenyl-3(5-bromothiophen-2-yl)-5-(substituted phenyl)-2-pyrazolines is more than 75% using this catalyst under microwave heating. All pyrazolines showed moderate activities against antimicrobial strains. Conclusion We have developed an efficient catalytic method for synthesis of 1-phenyl-3(5-bromothiophen-2-yl)-5-(substituted phenyl)-2-pyrazolines by solid phase cyclization using a solvent-free environmentally greener catalyst fly ash: H2SO4 under microwave irradiation between aryl chalcones and hydrazine hydrate. This reaction protocol offers a simple, economical, environment friendly, non-hazardous, easier work-up procedure, and good yields. All synthesized pyrazoline derivatives showed moderate antimicrobial activities against bacterial and fungal strains.

PREHEATED FLY-ASH CATALYZED ALDOL CONDENSATION: EFFICIENT SYNTHESIS OF CHALCONES AND ANTIMICROBIAL ACTIVITIES OF SOME 3-THIENYL CHALCONES

In the present study we have prepared a series of some chalcones using solvent - free Aldol - condensation by microwave irradiation. The yields of the ketones are more than 60%. The synthesised chalcones were characterized by their analytical, physical and spectral data. The antimicrobial activities of substituted styryl 3-thienyl ketones have been studied using Bauer-Kirby method.

A facilely designed, highly efficient green synthetic strategy of a peony flower-like SO42−–SnO2-fly ash nano-catalyst for the three component synthesis of a serendipitous product with dimedone in water

For the first time we have successfully found a serendipitous product 2-((2-((9-ethyl-9H-carbazol-3-yl)amino)-4,4-dimethyl-6-oxocyclohex-1-en-1-yl)(phenyl)methyl)-5,5-dimethylcyclohexane-1,3-dione and its derivatives by utilizing a SO42−–SnO2-fly ash nano-catalyst in water. We have designed a SO42−–SnO2-fly ash nano-catalyst which is easily separable, has good catalytic activity, good reusability and notable industrial applications. The catalytic role of Sn–O involves its high affinity with the carbonyl group of dimedone. The major component of fly ash (SiO2) may enhance the catalytic activity of oxidation processes. With these properties, the conversion of product could be rapid and high yielding. The facilely designed, SO42−–SnO2-fly ash nano-catalyst was characterized by Fourier transform infrared spectroscopy (FT-IR), confocal Raman spectroscopy, powder X-ray diffraction (PXRD), field emission electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS and elemental color mapping), high resolution transmission electron microscopy (HR-TEM) and UV-Visible diffuse reflectance spectroscopy (UV-Vis DRS) techniques. The nano-cube and peony flower like morphologies were found in the FE-SEM and HR-TEM images. The flower like SO42−–SnO2-fly ash catalyst’s highly stable nature is favorable for organic reactions. The crystalline nature, surface morphology, chemical composition and morphology of the reused SO42−–SnO2-fly ash nano-catalyst were proved by PXRD, FE-SEM, EDAX and HR-TEM analyses respectively. The facilely designed SO42−–SnO2-fly ash nano-catalyst is versatile from both environmental and economical points of view. The synthesized serendipitous product derivatives and byproducts were characterized by FT-IR, nuclear magnetic resonance (NMR) and high resolution-mass spectrometry (HR-MS).