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A series containing ten (E)-2-(1-phenylethylidene)-1-tosylhydrazines have been synthesized by thionyl chloride catalyst assisted condensation between 1-tosylhydrazine and substituted acetophenones. These benzylidenes have been characterized by their physical constants, UV-Vis, IR, ¹H and 13C NMR spectral techniques. The antibacterial and antifungal activities of the synthesized benzylidene have been evaluated. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to synthesise some substituted styryl 3,4-dimethoxy phenyl ketones using solvent-free SiO2-H2SO4 catalyzed aldol condensation between 3,4- dimethoxy acetophenone and substituted benzaldehydes under microwave irradiation. Then to characterize them by their analytical, physical and spectroscopic data, and also to study their the spectral correlation and antimicrobial activities. Methods: Solvent free microwave assisted aldol condensation method was used for synthesising 3,4-dimethoxyphenyl chalcones. They were characterised by ultraviolet (UV), infrared (IR), nuclear magnetic resonance (NMR) and mass spectroscopic data. The UV, IR, NMR spectral data were correlated with substituent constants, F and R parameters, using Hammett equation, to study the effect of substituents. The Bauer-Kirby method was used for evaluation of antimicrobial activities of the synthesised chalcones. Results: Yields of synthesised chalcones were more than 85%. The spectral data of these ketones had been correlated, using single and multi-linear regression analysis. These gave a satisfactory degree of correlations with some parameters and a fair degree of correlations with other parameters. Few chalcones gave excellent antimicrobial activities, whereas others gave poor antimicrobial activities. Conclusion: Easy handling, non-hazardous and environmentally benign aldol condensation method had been adopted for synthesising chalcones with better yields. Some of the Hammett spectral correlations were found to be satisfactory with the observed spectroscopic data. Halo, methoxy, methyl and nitro substituted compounds had shown excellent antimicrobial activities based on their zone of inhibitions. [ABSTRACT FROM AUTHOR]

A series of substituted styryl 2,4-dichlorophenyl ketones have been synthesized by crossed aldol condensation reaction. These ketones are characterized by their physical constants, IR and NMR data. The IR carbonyl stretching frequencies and 1H NMR spectral data of ethylenic protons are correlated with various Hammett sigma constants, field, resonance and Swain-Lupton parameters by single and multi regression analyses. From the statistical analysis, the effect of substituents on the group frequencies is studied. [ABSTRACT FROM AUTHOR]

Good yields of three series 39 ee (αS, βR) epoxy ketones were synthesized from their E-conformers of substituted styryl ketones using chiral quaternary ammonium bromide-PF6 catalyst. The yields of epoxides were more than 96%. These compounds have been characterized using the microanalytical technique, spectral data and physical constants. [ABSTRACT FROM AUTHOR]

Three series of styryl aryl ketones (E-2-propen-1-ones) are synthesized by solvent free method carried out by grinding the benzaldehydes and the aryl methyl ketones in the presence of solid sodium hydroxide. They are characterized by physical constants and spectral data. From infrared spectral data, the deformation modes of C-H in-plane/outof- plane, -CH=CH- and >C=C< out-of-plane of the vinyl parts are assigned. With the help of regression analysis, the deformation modes have been correlated with Hammett substituent constants. From the results of statistical analysis the effects of substituent on the above deformation modes have been explained. The anti-plasmoidal potential is evaluated for the synthesized chalcones. [ABSTRACT FROM AUTHOR]

The kinetics of oxidation of cinnamic acids by pyridinium bromochromate (PBC) in the presence of oxalic acid has been studied in acetic acid-water (60:40%) medium. The reaction shows unit order dependence each with respect to oxidant as well as oxalic acid [OX], the order with respect to [H+] and [CA] are fractional. The reaction is acid catalyzed and a low dielectric constant favours the reaction. Increase the ionic strength has no effect on the reaction rate. In the case of substituted cinnamic acids the order with respect to substrate vary depending upon the nature of the substituent present in the ring. In general, the electron withdrawing substituents retard the rate while the electron releasing substituents enhance the rate of reaction. From the kinetic data obtained the activation parameters have been computed and a suitable mechanism has been proposed. [ABSTRACT FROM AUTHOR]