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.     

Nitration kinetics of 6-hydroxy-2-methylpyrimidin-4(3<Emphasis Type="Italic">H</Emphasis>)-one and 2-methoxy-2-methylimidazolidine-4,5-dione

Possibility of synthesizing sulfo- and aminomethyl derivatives of 4-isononylphenol (I) was examined and the anticorrosion activity of the compounds obtained was determined.     

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 and Functionalization of 3-Ethylquinoxalin-2(1<Emphasis Type="Italic">H</Emphasis>)-one

A new and effective procedure was developed for the synthesis of 3-ethylquinoxalin-2(1H)-one from o-phenylenediamine and ethyl 2-oxobutanoate. The latter was prepared by the Grignard reaction of diethyl oxalate with ethylmagnesium bromide or iodide. The ethyl group in 3-ethylquinoxalin-2(1H)-one can readily be converted into various functional groups: α-bromoethyl, α-thiocyanato, α-azidoethyl, α-phenylaminoethyl, acetyl, and bromoacetyl. The reaction of 3-(bromoacetyl)quinoxalin-2(1H)-one with thiourea and hydrazine-1,2-dicarbothioamide gives the corresponding 3-(2-amino-4-thiazolyl) derivatives.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 4, 2005, pp. 609–616.Original Russian Text Copyright © 2005 by Mamedov, Kalinin, Gubaidullin, Isaikina, Litvinov.     

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.     

Structure and photochromism of 2-(<Emphasis Type="Italic">N</Emphasis>-acyl-<Emphasis Type="Italic">N</Emphasis>-arylaminomethylene)benzo[<Emphasis Type="Italic">b</Emphasis>]thiophen-3(2<Emphasis Type="Italic">H</Emphasis>)-ones

It was shown by electron absorption spectroscopy and X-ray diffraction analysis that steric strains in photochromic 2-(N-acyl-N-arylaminomethylene) benzo[b]thiophen-3(2H)-one molecules ortho-substituted in the N-phenyl ring increase the quantum yield of the N→O photoinduced rearrangement in accord with an increase in the steric constant of the ortho-substituent.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2151–2155, October, 2004.     

Polyfunctional Derivatives of Isocytosine. Effect of Hydration on Prototropic Tautomerism of 2-(2-Hydroxyethyl)amino-6-methylpyrimidin-4(3<Emphasis Type="Italic">H</Emphasis>)-one

Hydration of 2-(2-hydroxyethyl)amino-6-methylpyrimidin-4(3H)-one forms an equilibrium mixture of 4-oxo-3,4-dihydro and 4-hydroxy tautomers. The intermediate in mutual transitions of these tautomers has a zwitter ionic structure. The equilibrium shifts to the 4-oxo-3,4-dihydro form as the polarity of the medium decreases.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 4, 2005, pp. 677–682.Original Russian Text Copyright © 2005 by Erkin, Krutikov.     

Synthesis of isomeric 2-oxazolidinones from (1<Emphasis Type="Italic">R</Emphasis>,2<Emphasis Type="Italic">R</Emphasis>)-and (1<Emphasis Type="Italic">S</Emphasis>,2<Emphasis Type="Italic">S</Emphasis>)-2-amino-1-(4-nitrophenyl)-1,3-propanediols

A synthesis is reported for (4R,5R)-and (4S,5S)-4-hydroxymethyl-5-(4-nitrophenyl)oxazolidin-2-ones and (1′R,4R)-and (1′S,4S)-4-[hydroxy(4-nitrophenyl)methyl]oxazolidin-2-ones from (1R,2R)-and (1S,2S)-2-amino-1-(4-nitrophenyl)-1,3-propanediols. The effect of the experimental conditions on the formation of these compounds was studied. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1562–1570, October, 2007.