Rajeswar Rao Vedula

Synthesis, biological activity evaluation and molecular docking studies of novel coumarin substituted thiazolyl-3-aryl-pyrazole-4-carbaldehydes.

A novel series of coumarin substituted thiazolyl-3-aryl-pyrazole-4-carbaldehydes (4a-o) were synthesized via an efficient, one-pot multicomponent approach involving 3-(2-bromoacetyl)coumarins (1a-g), thiosemicarbazide (2) and substituted acetophenones (3a-c) utilizing Vilsmeier-Haack reaction condition with good yields. The title compounds structure was elucidated by spectroscopic data (IR, NMR and Mass) and elemental analysis. All the synthesized compounds were screened for their in vitro cytotoxic activity against MCF-7, DU-145 and HeLa cell lines and studied detailed about molecular interaction of probable target protein human microsomal cytochrome CYP450 2A6 using docking simulation. These coumarin derivatives were exhibiting moderate to appreciable cytotoxic activities. The compounds 4m and 4n exhibited significant cytotoxic activity with IC50 values having 5.75 and 6.25μM against HeLa cell line. Similarly compound 4n also exhibiting good anti cancer property and antibacterial activity against DU-145 cell line and Gram negative bacterial strains.

A facile one-pot synthesis of 1,3,4-thiadiazine-5-yl-pyran-2-one derivatives via a multicomponent reaction

A facile synthesis of 1,3,4-thiadiazine-5-yl-pyran-2-one derivatives is achieved via a three-component reaction involving 3-(2-bromoacetyl)-4-hydroxy-6-methyl-2H-pyran-2-one, thiocarbohydrazide with various carbonyl compounds in one-pot under stirring. The main advantage of this procedure is the short reaction time, high yields, simple workup, and purification of products by non-chromatographic methods, i.e. by simple recrystallization from ethanol. The structures of newly prepared compounds have been established by elemental analysis and spectral data.

New, Convenient, One-Pot Method for the Synthesis of Thiazolyl-pyrazolones from Dehydroacetic Acid Derivative via a Multicomponent Approach

Abstract A convenient one-pot method for the synthesis of thiazolyl-pyrazolones was described in excellent yields. Reaction of 3-(2-bromoacetyl)-4-hydroxy-6-methyl-2H-pyran-2-one with thiosemicarbazide and ethyl 2-(2-arylhydrazono)-3-oxobutanoates in anhydrous ethanol under reflux conditions afforded the corresponding 4-(2-arylhydrazono)-1-(4-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)thiazol-2-yl)-3-methyl-1H-pyrazol-5(4H)-one in good yields. The structures of newly synthesized compounds were established on the basis of elemental analysis, infrared, 1H NMR, and mass spectroscopic studies. GRAPHICAL ABSTRACT

Synthesis of 4-aryl-2-pyranyl-7,8-dihydroquinolin-5(6 H )-ones catalyzed by cerium ammonium nitrate via Hantzsch multicomponent reaction and their antibacterial activity

4-Aryl-2-pyranyl-7,8-dihydroquinolin-5(6H)-one derivatives were obtained in excellent yields from 3-acetyl-4-hydroxy-6-methyl-2Hpyran-2-one, aromatic aldehydes, 5,5-dimethylcyclohexane-1,3-dione, and ammonium acetate by a one-pot multicomponent Hantzsch synthesis in the presence of cerium ammonium nitrate in water. In vitro antibacterial activity of all the newly synthesized compounds was evaluated. Some of the tested compounds showed a promising antibacterial activity against both Gram-positive and Gram-negative bacterial strains.

Synthesis of 3-(2-(4,5-Dihydro-3,5-diphenylpyrazol-1-yl)thiazol-4-yl)-2H-chromen-2-one Derivatives via Multicomponent Approach

Abstract An efficient synthesis of 3-(2-(4,5-dihydro-3,5-diphenylpyrazol-1-yl)thiazol-4-yl)-2H-chromen-2-one derivatives by a simple, atom-economical, and multicomponent reaction of chalcones, thiosemicarbazide, and 3-(2-bromoacetyl) coumarins in the presence of aqueous sodium hydroxide in refluxing ethanol is reported. The structures of newly prepared compounds have been confirmed by their analytical and spectral (IR, 1HNMR, 13CNMR and mass) data. [Supplementary materials are available for this article. Go to the publishers online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.] GRAPHICAL ABSTRACT

Novel One-Pot Multicomponent Synthesis of Substituted 2,3-Dihydro-2-(6-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-3-yl)phthalazine-1,4-diones and Substituted 3-[3-(N′-Benzylidene-hydrazino)-7H-[1,2,4] triazolo[3,4-b][1,3,4]thiadiazin-6-yl]-4-hydroxy-6-methyl-pyran-2-ones

Abstract A one-pot procedure has been developed for the synthesis of substituted 2,3-dihydro-2-(6-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)-7H-[1,2,4]triazolo[3,4-b] [1,3,4]thiadiazin-3-yl)phthalazine-1,4-diones by reaction of 3-(2-bromoacetyl)-4-hydroxy-6-methyl-2H-pyran-2-one, 4-amino-5-hydrazino-4H-[1,2,4]triazole-3-thiol, and phthalic anhydrides in acetic acid medium. Similarly, a one-pot, three-component synthetic procedure has been developed for substituted 3-[3-(N1-benzylidene-hydrazino)-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-6-yl]-4-hydroxy-6-methyl-pyran-2-ones from 3-(2-bromoacetyl)-4-hydroxy-6-methyl-2H-pyran-2-one, 4-amino-5-hydrazino-4H-[1,2,4]triazole-3-thiol, and various aromatic aldehydes in absolute ethanol and a few drops of glacial acetic acid. [Supplementary materials are available for this article. Go to the publishers online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.] GRAPHICAL ABSTRACT

Facile One-Pot Synthesis of Aryl, Heteryl Substituted Hydrazono Thiazolyl-Pyrazolone Derivatives via Three-Component Reaction

Abstract A facile, one-pot, three-component bis heterocyclized reaction for the synthesis of hydrazonothiazolyl-pyrazolones has been described. Reaction of phenacyl bromides or 3-(2-bromoacetyl)coumarins, with thiosemicarbazide and ethyl 2-(2-arylhydrazono)-3-oxobutanoates in AcOH/NaOAc, gave the corresponding products in good yields. All the synthesized compounds were characterized by their analytical and spectral data. GRAPHICAL ABSTRACT

One-Pot Synthesis of 1,3,4-Thiadiazin-5-yl-chromen-2-one Derivatives via Three-Component Reaction

Abstract An expeditious, one-pot reaction has been described for the preparation of 1,3,4-thiadiazin-5-yl-chromen-2-one derivatives. These compounds were synthesized by the reaction of 3-(2-bromoacetyl)coumarin with thiocarbohydrazide and various carbonyl compounds. The newly synthesized compounds were characterized by infrared, 1H NMR, and mass spectra. GRAPHICAL ABSTRACT

Synthesis of 3-(2-(4-Chlorophenylimino)-3-(4-chlorophenyl)-2,3-dihydrothiazol-4-yl)-2 h-Chromen-2-one via Multicomponent Approach

A simple and highly efficient one-pot, three-component synthesis of 3-(2-(4-chlorophenylimino)-3-(4-chlorophenyl)-2,3-dihydrothiazol-4-yl)-2H-chromen-2-ones has been reported by the reaction of 3-(2-bromoacetyl)-2H-chromen-2-one, primary amines, and phenyl isothiocyanates in presence of dimethylformamide as a solvent. The structures of newly synthesized compounds were confirmed by their analytical and spectral data. GRAPHICAL ABSTRACT

One-pot multicomponent synthesis of functionalized 2,5-disubstituted-1,3,4-thiadiazine derivatives

ABSTRACT An atom-efficient and environmentally friendly approach to the synthesis of 2,5-disubstituted-1,3,4-thidiazine derivatives has been developed. These compounds were synthesized by a reaction of 2-(2-bromoacetyl)benzofuran and thiocarbohydrazide with various aryl aldehydes, acetylacetones, and pthalic anhydrides in good yields. The advantages of this methodology are mild reaction conditions, easy workup procedure, clean reaction profile, shorter reaction time, and a wide range of substrate applicability. The structures of all synthesized compounds were confirmed from their analytical and spectral data. GRAPHICAL ABSTRACT