Synthesis and plant growth activity of 2-(4-oxochromen-3-yl)benzothiazolium and -benzoxazolium bromides

A facile synthesis of novel 2-(4-oxochromen-3-yl) benzothiazolium bromides 4 and benzoxazolium bromide 5 using the one-pot condensation of substituted 4-oxochromene-3-carboxaldehydes 1 with 2-methylbenzothiazole (2a) or 2-methylbenzoxazole (2b) and benzyl bromide is described. The effects of benzothiazolium bromides 4 on the growth stimulation of the cucumber and retardant activity on corn seedlings were investigated. They inhibited growth of cucumber (root and hypocotyl) and shoots of corn at the range of 10 – 100 ppm and stimulated at 0.1 – 1 ppm concentrations.

Ag2O/GO/TiO2 Composite Nanostructure: an efficient heterogeneous catalyst for one pot synthesis of Bis (dihydropyrimidinone) and tetrahydro-4H-chromenes derivatives

The simple and efficient synthesis reaction was used for preparing Bis (dihydropyrimidinone) derivatives through Biginelli condensation reaction of terephthalic aldehyde, 1, 3-dicarbonyl compounds and (thio) urea or guanidine and tetrahydro-4H-chromenes via one pot condensation of aromatic aldehydes, malononitrile and dimedone with Ag2O/GO/TiO2 composite nanostructures as a catalyst. The structural functionalities and morphological observations of catalyst were obtained using characterization techniques of field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Fourier transfer infrared (FT-IR) spectroscopy and transmission electron microscope (TEM). The structures of Bis (dihydropyrimidinone) and tetrahydro-4H-chromenes confirmed by FT- IR, NMR and mass spectroscopy. Excellent yields of the products, simple reaction process and simple work-up are attractive features of these effective synthesis methods.

Ag2O/GO/TiO2 Composite Nanostructure: An Efficient Heterogeneous Catalyst for one Pot Synthesis of Bis (Dihydropyrimidinone) and Tetrahydro-4H-chromenes Derivatives

The simple and efficient synthesis reaction was used for preparing Bis (dihydropyrimidinone) derivatives through Biginelli condensation reaction of terephthalic aldehyde, 1, 3-dicarbonyl compounds and (thio) urea or guanidine and tetrahydro-4H-chromenes via one pot condensation of aromatic aldehydes, malononitrile and dimedone with Ag2O/GO/TiO2 composite nanostructures as a catalyst. The structural functionalities and morphological observations of catalyst were obtained using characterization techniques of field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Fourier transfer infrared (FT-IR) spectroscopy and transmission electron microscope (TEM). The structures of Bis (dihydropyrimidinone) and tetrahydro-4H-chromenes confirmed by FT- IR, NMR and mass spectroscopy. Excellent yields of the products, simple reaction process and simple work-up are attractive features of these effective synthesis methods.

Synthesis, Characterization and in vitro Antimicrobial Screening of Some Novel Series of 2-Azetidinone Derivatives Integrated with Quinoline, Pyrazole and Benzofuran Moieties

A series of 5-(benzofuran-2-yl)-N-(3-chloro-4-(2-(p-tolyloxy) substituted quinolin-3-yl)-2-oxoazetidin-1-yl)-1-phenyl-1H-pyrazole-3-carboxamide derivatives (4a-f) were synthesized with excellent yields by cyclocondensation reaction of 5-(benzofuran-2-yl)-N′-(2-(p-tolyloxy) substituted quinolin-3-yl)methylene)-1-phenyl-1H-pyrazole-3-carbohydrazide (3a-f) with chloroacetyl chloride in presence of triethylamine in DMF. One pot condensation of 5-(benzofuran-2-yl)-1-phenyl-1H-pyrazole-3-carbohydrazide (1) with 2-(p-tolyloxy) substituted quinoline-3-carbaldehyde (2a-f) in ethanol solvent in presence of catalytic amount of acetic acid gave intermediate compounds (3a-f). The structures of newly synthesized compounds have been substantiated through elemental analysis and spectral studies viz. 1H NMR, 13C NMR, IR and mass spectra. All the synthesized compounds were screened for their in vitro antibacterial activity against pathogenic bacteria such as S. aureus and E. coli at different concentrations.