Abstract The one‐bond nucleophilic reactivities of seven cyclic α‐diazo carbonyl compounds in dichloromethane were determined by analyzing the kinetics their reactions with benzhydrylium ions (one‐bond reference electrophiles) at 20 °C according to Mayr‐Patz equation. Though not calibrated for pericyclic reactions, identified nucleophilicities also reflect relative 1,3‐dipolar cycloadditions di...

Direct arylation of most five-membered ring heterocycles are generally easily accessible and strongly favored at the ?-position using classical palladium-catalysis. Conversely, regioselective functionalization such concurrent ?-position remains currently very challenging. Herein, we report general conditions for direct pyrazoles, while C?H is free. By aryl bromides as source a judicious choice ...

The vaporization enthalpies of 1-methyl-, 1-ethyl-, 1-phenyl-, and 1-benzylimidazole, 1-methyl- and 1-phenylpyrazole, and trans-azobenzene are evaluated by correlation-gas chromatography (C-GC) using a variety of azines and diazines as standards. The vaporization enthalpies obtained by C-GC when compared to literature values are approximately 14 kJ·mol(-1) smaller for the imidazoles and 6 kJ·mo...

A series of 1-phenyl-3-aryl-5-(4-(3-propanoloxy) phenyl)-1H-pyrazoles were synthesized from chalcones and studied for their in vitro antibacterial activity. Chalcones i.e.,1-aryl-3-(4hydroxyphenyl) prop-2-en-1-ones (1) on reaction with phenyl hydrazine in presence of acetic acid and few drops of HCl yielded the corresponding 1-phenyl-3-aryl-5-(4-hydroxyphenyl)-1H-pyrazoles (2) which on further ...

The development of a mild, general, and green method for the C-H arylation pyrazoles with relatively unreactive aryl halides is an ongoing challenge in organic synthesis. We describe herein novel sonophotoreactor based on ultrasonic cleaning bath blue LED light (visible light) that induce copper-catalyzed monoarylation pharmacologically relevant pyrazoles. hybrid effect irradiation discussed to...

In vitro antimicrobial activity of seventeen heterocyclic nitrogen compounds {2-substituted pyrido [1,2-a] pyrimidin -4-oxo-1 [4]-3-Carbonitriles and ethyl 5-amino-3-(substituted) - pyrazole-3-Carboxylates} was tested against Escherichia coli, Bacillus subtilis and candida albicans strains, Antimicrobial activity was measured using standard two -fold serial dilution method and the minimum inhib...