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1

Synthesis, Pharmacological and Insect Antifeedant Activities of some 3-(2-naphthyl)-5-(substituted phenyl)-4,5-dihydroisoxazoles

Thirunarayanan G., Sathiyendiran V.

International Letters of Chemistry, Physics and Astronomy

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2015

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Vol. 49

1--14

EN

Totally thirty one 3,5-substituted aryl 4,5-dihydro isoxazole derivatives including 3-(2-naphthyl)-5-(substituted phenyl)-4,5-dihydroisoxazole have been synthesized by fly-ash:H2SO4 catalyzed cyclization of hydroxylamine hydrochloride and aryl chalcones under solvent-free conditions. The yields of the isoxazoles are more than 94%. The synthesized isoxazole were characterized by their physical constants and spectral data. The antimicrobial, antioxidant and insect antifeedant activities of the synthesized isoxazoles have been evaluated using a variety of bacterial and fungal species, DPPH radical scavenging and castor-leaf disc bioassay of 4th instar larvae Achoea Janata L methods.

2

Insect antifeedant potent quinoxalines

Lakshmanan K., Sekar K. G., Sathiyendiran V., Muthuvel I.

International Letters of Chemistry, Physics and Astronomy

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2015

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Vol. 41

82--87

EN

Some 6-substituted aryl quinoxalines have been prepared and their purities were checked by their physical constants and spectroscopic data reported earlier. The insect antifeedant activities of these quinolones were studied by leaf-discs bio assay method using 4th instar larvae Achoea Janata L.

3

(E)-N-substitutedbenzylidene-4-methoxyanilines as Insect Antifeedants

Lakshmanan K., Sekar K. G., Sathiyendiran V., Suresh R.

International Letters of Chemistry, Physics and Astronomy

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2015

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Vol. 41

118--123

EN

Some substituted aryl Schiff’s bases[(E)-N-substitutedbenzylidene-4-methoxyanilines] have been prepared and their purities were checked by their physical constants and spectroscopic data reported earlier. The insect antifeedant activities of these Schiff’s bases have been studied by leafdiscs bio assay method using 4th instar larvae Achoea Janata L.

4

Effect of Substituents on Phenazine Derivatives by Spectral Studies

Thirunarayanan G., Muthuvel I., Sathiyendiran V.

International Letters of Chemistry, Physics and Astronomy

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2015

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Vol. 48

114--122

EN

A series of eleven substituted dipyrido[3,2-a; 2′,3′-c]phenazine derivatives have been synthesized and examined their purities by literature method. The infrared and 13C NMR spectral data of prepared phenazines were correlated with Hammett substituent constants, F and R parameters using single and multi-regression analysis. From the results of statistical analysis, the effect of substituents on the infrared frequencies (ν, cm-1) and 13C nmr chemical shifts(δ, ppm) has been studied.

5

Structure parameter correlation of some quinoxaline derivatives through IR and 13C NMR spectra

Thirunarayanan G., Muthuvel I., Sathiyendiran V.

International Letters of Chemistry, Physics and Astronomy

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2014

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Vol. 19, iss. 2

198--207

EN

A series of 6-substituted quanoxaline derivatives have been synthesized and examined their purities by literature method. The infrared and 13>/Sup>C NMR spectral data of these quinoxalines were correlated with Hammett substituent constants, F and R parameters using single and multi-regression analysis. From the results of statistical analysis, the effect of substituents on the spectral frequencies has been studied.

6

Spectral correlations in some substituted styryl (E)-4-((2-oxopropyl) diazenyl) benzoic acids

Sathiyendiran V., Sekar K. G., Thirunarayanan G., Arulkumaran R., Sundararajan R., Kamalakkannan D., Suresh R., Manikanadan V., Vijayakumar R., Vanangamudi G.

International Letters of Chemistry, Physics and Astronomy

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2014

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Vol. 11, iss. 1

33-43

EN

A series of titled compounds were prepared and analyzed their purities by literature method. The infrared and NMR spectral group frequencies of the compounds were assigned and correlated with Hammett substituent constants, F and R constants using single and multi linear regression analysis. From the results of statistical analysis, the effect of substituents on the above spectral frequencies was discussed.

7

IR and 1H NMR spectral studies of some 2-Amino-4-isopropyl-6-methoxy-N-phenylpyrimidine-5-carboxamides: Assessment of substituent effects

Arulkumaran R., Sundararajan R., Manikandan V., Sathiyendiran V., Pazhamalai S., Thirunarayanan G.

International Letters of Chemistry, Physics and Astronomy

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2014

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Vol. 19, iss. 1

15--25

EN

A series of 2-Amino-4-isopropyl-6-methoxy-N-phenylpyrimidine-5-carboxamide compounds have been synthesized from various substituted dithioacetal and guanidine. The purities of these compounds were checked by their physical constants, UV, IR, NMR and MASS spectral data. The IR and 1HNMR spectral data of these compounds have been correlated with Hammett sigma constants, F and R parameters using single and multi-linear regression analysis. From the results of statistical analysis, the effects of substituents on the spectral group frequencies have been discussed.

8

Mechanistic studies on the oxidation of some organic sulphides with quinolinium fluorochromate in nonaqueous medium

Meenakshisundaram S., Sathiyendiran V.

Bulletin of the Polish Academy of Sciences. Chemistry

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1999

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Vol. 47, No. 2

167-174

EN

The oxidation kinetics of diphenyl, dialkyl and methyl phenyl sulphides has been investigated under pseudo-first-order conditions with quinolinium fluorochromate (QFC), a newly developed Cr(VI) reagent in acetonitrile medium. p- Toluene sulphonic acid (TsOH) is used for catalyzing the reaction. Initial-rate methods are used for determining the orders with respect to reactants in dialkyl sulphides. The oxidation is first-order with respect to [QFC] and second-order dependence is observed on [TsOH]. [Sulphide] has no effect on the reaction rate. Diphenyl sulphide (DPS) oxidation follows the rate law, v = k2Rrl [S][Ox][TsOH]. Acrylonitrile retards the rate of oxidation significantly in diphenyl sulphides indicating the involvement of free radical cation sulphur intermediate in the rate-limiting step. The Michaelis-Menten dependence each on [sulphide] and [TsOH] can be well explained by a two-pathway mechanism in methyl phenyl sulphide oxidation. The derived rate law, v = k1[Ox][TsOH] -+ k3[OX][S] is consistent with experimental observations.

9

Quinolinium fluorochromate oxidation of alpha-hydroxy acids in perchloric acid medium

Meenakshisundaram Subbiah, Sathiyendiran V.

Polish Journal of Chemistry

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1998

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Vol. 72, nr 10

2261-2266

EN

The kinetics of oxidation of alpha-hydroxy acids (mandelic, lactic and glycolic) with a recently developed new mild Cr(VI) regent quinolinium fluorochromate (QFC) has been investigated in perchloric acid medium. First-order depedence with respect to [oxidant] is observed. Increase in [substrate] increases the rate proportionally. The acidity dependence is fractional order throughout the entire range of acidities studied. Decrease in dielectric constant of the medium increases the oxidation rate considerably. Kinetic solvent isotope effect studies indicate a pre-equilibrium fast proton transfer. Absence of polymerization with acrylonitrile rules out a free radical mechanism. An intermediate formed between protonated oxidant and substrate decomposes in a slow rate-limiting step giving the products.