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.     

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.     

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.     

Experimental and computational studies on (<Emphasis Type=Italic>Z</Emphasis>)-1-((4-phenylamino)phenylamino)-methylene)naphthalen-2(1<Emphasis Type=Italic>H</Emphasis>)-one

The Schiff base compound (Z)-1-((4-phenylamino)phenylamino)methylene)naphthalen-2(1H)-one has been synthesized and characterized by IR, UV–Vis, and X-ray single-crystal determination. Molecular geometry from X-ray experiment of the title compound in the ground state have been compared using the Hartree–Fock (HF) and density functional method (B3LYP) with 6−31G(d,p) basis set. Calculated results show that density functional theory DFT and HF can well reproduce the structure of the title compound. Using the time-dependent density functional theory (TD-DFT) and Hartree–Fock (TD-HF) methods, electronic absorption spectra of the title compound have been predicted and a good agreement with the TD-DFT method and experimental ones is determined. The energetic behavior of the title compound in solvent media has been examined using B3LYP method with the 6−31G(d,p) basis set by applying the polarizable continuum model (PCM). The total energy of the title compound decreases with increasing polarity of the solvent. In addition, DFT calculations of the title compound, molecular electrostatic potential (MEP), natural bond orbital analysis (NBO), and non-linear optical (NLO) properties were performed at B3LYP/6−31G(d,p) level of theory.     

1-(Pyrimidin-4-yl)pyrazol-5(4<Emphasis Type=Italic>H</Emphasis>)-one derivatives: II. Electrophilic substitution in 5-hydroxy-3-methyl-1-(6-methyl-2-methylsulfanylpyrimidin-4-yl)-1<Emphasis Type=Italic>H</Emphasis>-pyrazole

Electrophilic substitution of hydrogen in bicyclic 5-hydroxy-3-methyl-1-(6-methyl-2-methylsulfanylpyrimidin-4-yl)-1H-pyrazole occurs exclusively at the C⁴ atom of the five-membered heteroring. Unstable electrophilic substitution products are stabilized via addition of the second substrate molecule with formation of bridged adducts.     

Synthesis of regioisomeric naphtho-furans <Emphasis Type=Italic>via</Emphasis> naphthyloxyalkanals

A new route to the regioisomeric 2-alkylnaphtho[2,1-b]- and 2-alkylnaphtho[1,2-b]furans via acid-catalyzed cyclization of the corresponding 2-naphthyloxyalkanals under mild conditions over Amberlyst 15 resin has been described. The 2-naphthyloxyalkanals were obtained by palladium-catalyzed reduction of 2-naphthyloxyalkanoyl chlorides.     

Synthesis and some transformations of <Emphasis Type=Italic>N</Emphasis>,2,2-trimethyltetrahydro-2<Emphasis Type=Italic>H</Emphasis>-pyran-4-amine

Reaction of 2,2-dimethyltetrahydro-2H-pyran-4-one with aqueous methanamine, followed by reduction of the Schiff base thus obtained with sodium tetrahydridoborate gave N,2,2-trimethyltetrahydro-2H-pyran-4-amine which was subjected to cyanoethylation with acrylonitrile. The resulting 3-(2,2-dimethyltetrahydro-2H-pyran-4-ylmethylamino)propanenitrile was reduced with lithium tetrahydridoaluminate to N-(2,2-dimethyltetrahydro-2H-pyran-4-yl)-N-methylpropane-1,3-diamine, and some chemical transformations of the latter were studied.