Cerium(IV) ammonium nitrate catalyzed green synthesis of 2-substituted 2,3-dihydro- quinazolin-4(1<Emphasis Type=Italic>H</Emphasis>)-ones using a grinding technique

An efficient and facile method for the synthesis of 2-substituted 2,3-dihydro-quinazolin-4(1H)-ones from anthranilamide with aldehydes or ketones in the presence of cerium(IV) ammonium nitrate in water by a grinding technique has been developed. The structures of the new products were proved by IR, ¹H NMR, MS, and elemental analysis. A plausible mechanism for the formation of these products is proposed.     

Regiospecific O-alkylation of 4-polyfluoroalkyl-1<Emphasis Type=Italic>H</Emphasis>-pyrimidin-2-ones

The alkylation of 4-polyfluoroalkylpyrimidin-2-ones with iodomethane, 4-bromobutyl acetate, and epichlorhydrin occurs regiospecifically to form O-regioisomers.     

Ultrasound-accelerated one-pot synthesis of <Emphasis Type=Italic>N</Emphasis>-acetyl-2-aryl-1,2-dihydro-4<Emphasis Type=Italic>H</Emphasis>-3,1-benzoxazin-4-ones

The one-pot synthesis of N-acetyl-2-aryl-1,2-dihydro-4H-3,1-benzoxazin-4-one derivatives from the condensation reaction of anthranilic acids with heteroaromatic aldehydes in the presence of excess amount of acetic anhydride has been explored. The reactions proceed smoothly under ultrasound irradiation and without catalyst at 35 − 40 °C to afford the title products in high yields.     

Synthesis of isobornylphenol-containing 3-aryl-1,2,4-triazin-5(4<Emphasis Type=Italic>H</Emphasis>)-ones

A method for modification of 3-aryl-1,2,4-triazin-5(4H)-ones with isobornylphenols was proposed. The influence of various acylating agents on the reaction pathway was studied.     

Transformations of 3-nitropyridin-4(1<Emphasis Type=Italic>H</Emphasis>)-one and 1-Methyl-3-nitropyridin-4(1<Emphasis Type=Italic>H</Emphasis>)-one in reaction with hydrazine

Hydrazinolysis of 3-nitropyridin-4(1H)-one and its N-methyl derivative leads to the formation of 1-(1H-pyrazol-3-yl)ethanone hydrazone whose structure was confirmed by independent synthesis from authentic 3-acetyl-1H-pyrazole and comparison of the IR and ¹H NMR spectra. Oxidation of 1-(1H-pyrazol-3- yl)ethanone hydrazone with potassium permanganate gave 1H-pyrazole-3-carboxylic acid.     

One-pot,Simple, and Convenient Synthesis of 2-Thioxo-2,3-dihydroquinazolin-4(1<Emphasis Type="Italic">H</Emphasis>)-ones

Summary. A simple and convenient method for the synthesis of diverse 2-thioxo-2,3-dihydroquinazolin-4(1H)-ones was developed as one-pot reaction of anthranilic acid esters, primary amines, and bis(benzotriazolyl)methanethione in presence of the amidine base DBU.