Experimental and Theoretical Studies on (<Emphasis Type="Italic">p</Emphasis>-methoxyphenyl)thiosemicarbazide

The title compound, (p-methoxyphenyl)thiosemicarbazide, has been characterized by elemental analysis, IR, electronic spectroscopy, and single-crystal X-ray diffraction. Ab initio calculations of the structure, atomic charges, natural bond orbital, topological analysis, and thermodynamic functions of the title compound were performed at HF/6-311G^** and B3LYP/6-311G^** levels of theory. The calculated results show that the sulfur atom and nitrogen atoms have bigger negative charges, which result in that they are the potential sites to react with the metallic ions. Electronic absorption spectra were calculated by the time-dependent density functional theory (TD-DFT) and configuration interaction single-excitation (CIS) methods and they are corresponding to the experimental values. The calculation of the second-order optical nonlinearity was carried out, and the molecular hyperpolarizability was 2.592×10⁻³⁰ esu, indicating it is a potential candidate as second-order nonlinear optical material.     

3-Arylazo-2-thioxo-2,3-dihydro-1<Emphasis Type="Italic">H</Emphasis>-quinazolin-4-ones as Azodisperse Dyes for Dyeing Polyester Fabrics

Summary. Diazotized 3-amino-2-thioxo-2,3-dihydro-1H-quinazolin-4-one was coupled with various hydroxy aromatics to give the corresponding 3-arylazo-2-thioxo-2,3-dihydro-1H-quinazolin-4-ones in reasonable yields. The dyes produced were applied to polyesters as disperse dyes and their fastness properties were elevated.     

Reaction of 2-methoxy-1,3,2-dioxaphosphorino[4,5-<Emphasis Type="Italic">b</Emphasis>]pyridin-4(4<Emphasis Type="Italic">H</Emphasis>)-one with hexafluoroacetone

The reaction of the di-O-trimethylsilyl derivative of 2-hydroxynicotinic acid with methyl phosphodichloridite afforded 2-methoxy-1,3,2-dioxaphosphorino[4,5-b]pyridin-4(4H )-one. The NMR spectrkscopic data suggest that the reaction of the latter with hexafluoroacetone produces unstable 2-methoxy-2,5-dioxo-4,4-bis(trifluoromethyl)-4,5-dihydro-1,3,2-dioxaphosphepino[4,5-b]pyridine, which is readily transformed into 9-methyl-2,5-dioxo-4,4- bis(trifluoromethyl)-4,5-dihydro-1,3,2-dioxaphosphepino[4,5-b]pyrid-9-inium-2-oate. The structure of the hydrolysis product of the latter, viz., 1-methyl-3-(2-hydroxy-3,3,3-trifluoro-2- trifluoromethylpropanoyl)pyridin-2-one, was established by X-ray diffraction analysis.Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1640–1646, August, 2004.     

Stereoselective synthesis of spiro derivatives of 2,4-dimethyl-2,3,4,4a,5,6-hexahydro-6<Emphasis Type="Italic">H</Emphasis>-benzo[<Emphasis Type="Italic">c</Emphasis>]quinolizine

The reactions of 2-(3,5-dimethylpiperidino)benzaldehyde with Meldrum's acid and cyclohexane-1,3-dione occur as a tandem of the Knoevenagel condensation and cyclization promoted by the tert-amino effect. The cyclization yields only one isomer with the axial hydrogen atoms in positions 4 and 4a of the benzoquinolizine ring. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1492–1494, June, 2005.     

1-Acyl-and 1,2-dihydro-1<Emphasis Type="Italic">H</Emphasis>(acyl)deoxyvasicinones. Synthesis and chemical transformations

1-Acyl-and 1,2-dihydro-1H(methyl, acyl)deoxyvasicinones were synthesized. Their PMR and ¹³C NMR spectra were investigated. The chemical shifts and SSCC were determined. 1-Acyl derivatives were produced by acylation of 1,2-dihydrodeoxyvascinone with caprylyl-and chloroacetylchlorides. It was shown that the Cl atom of 1-chloroacetyldeoxyvasicinone was labile and underwent nucleophilic substitution by amines. In contrast with this, it reacted with cyanide, hydroselenide, methoxide, phenoxide, and anions of compounds with an activated methylene group in a completely different direction to cleave the chloroacetyl group and form 1,2-dihydrodeoxyvasicinone. It was found that addition of 1,2-dihydrodeoxyvasicinone to phenylacetylene occurred regio-and stereoselectively to form the cis-isomer of 1-(2-phenylvinyl)-1,2-dihydrodeoxyvasicinone. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 353–359, July–August, 2007.     

A one-pot synthesis of 8-amino-1-methoxy-6<Emphasis Type="Italic">H</Emphasis>-dibenzo[<Emphasis Type="Italic">b,d</Emphasis>]pyran-6-one

8-Amino-1-methoxy-6H-dibenzo[b,d]pyran-6-one was synthesized in a one-pot reaction of 2′,6′-dimethoxy-4-nitro-1,1′-biphenyl-2-carboxylic acid methyl ester using hydroiodic acid as a reagent to effect O-demethylation, lactonization, and nitro reduction to amine. This new reaction represents an improved alternative to the previously reported three-step reactions for this transformation.     

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.     

Synthesis of 4<Emphasis Type="Italic">E</Emphasis>,7<Emphasis Type="Italic">Z</Emphasis>-tridecadien-1-ylacetate,a component of the <Emphasis Type="Italic">Phthorimaea opercucella</Emphasis> sex pheromone

A new synthetic approach to 4E,7Z-tridecadien-1-ylacetate, a component of the Phthorimaea opercucella (Zeller) potato moth sex pheromone, was developed using a highly stereoselective Claisen rearrangement and Wittig reaction. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 235–236, May–June, 2007.     

Ionic Liquid Promoted One-Pot Synthesis of Furo[2,3-<Emphasis Type="Italic">d</Emphasis>]pyrimidine-2,4(1<Emphasis Type="Italic">H</Emphasis>,3<Emphasis Type="Italic">H</Emphasis>)-diones

Summary. The three-component condensation of aldehyde, N,N′-dimethylbarbituric acid and alkyl or aryl isocyanide afforded the corresponding furo[2,3-d]pyrimidine-2,4(1H,3H)-diones in 1-butyl-3-methylimidazolium bromide as an ionic liquid in high yields at room temperature within several minutes.     

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.     

Quantum-chemical modeling of photoelectron spectra and electronic structure of <Emphasis Type="Italic">tris</Emphasis>-β-diketonates of 3<Emphasis Type="Italic">d</Emphasis>-metals Sc,Ti, V

The electronic structure and ionization energies of chelate complexes were calculated for transition metals Sc, Ti, and V using the Hartree-Fock (HF)SCF ab initio approximations. As the number of d electrons increases in the series of these compounds, the sequence of HF orbitals does not agree any longer with the PES bands and with the data obtained in the density functional theory approximation. Using the configuration interaction (CI) method considerably improves agreement with experiment. For the vanadium complex containing an odd d electron in the ionized state, the HF orbitals become a rough approximation for the CI decomposition, hindering the interpretation of the ionic states.Original Russian Text Copyright © 2004 by V. I. Vovna and I. S. OsmushkoTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 4, pp. 651–659, July–August, 2004.This revised version was published online in April 2005 with a corrected cover date.     

Proton affinities of fluoro derivatives of benzene,toluene, and<Emphasis Type="Italic">m</Emphasis>-xylene from<Emphasis Type="Italic">ab initio</Emphasis> MP2 calculations

The proton affinity (PA) energies of fluoro derivatives of benzene, toluene, andm-xylene were obtained fromab initio MP2-FC/6-31G^* calculations and compared with experimental results. Protonated forms of the molecules, resulting from different ways of proton addition, were studied. Relative concentrations of isomeric arenonium ions were calculated and compared with the results of NMR studies on arenonium ions in solutions. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1847–1849, November, 2000.     

Reaction sites of <Emphasis Type="Italic">N,N′</Emphasis>-substituted <Emphasis Type="Italic">p</Emphasis>-phenylenediamine antioxidants

The geometries of N,N′-diphenylbenzene-1,4-diamine (DPPD), N-phenyl-N′-(1-phenylethyl)benzene-1,4-diamine (SPPD), N-(4-methylpentan-2-yl)-N′-phenylbenzene-1,4-diamine (6PPD), N-propan-2-yl-N′-phenylbenzene-1,4-diamine (IPPD), N-(2-methoxybenzyl)-N′-phenylbenzene-1,4-diamine (MBPPD), and N-phenyl-N′-(2-phenylpropan-2-yl)benzene-1,4-diamine (CPPD) as well as of their dehydrogenation products were optimized by the semiempirical AM1 method. The results support the idea of stable N_B=C_X structures formation during the consecutive dehydrogenation of SPPD, 6PPD, IPPD, and MBPPD antioxidants. The biradicals formed during the second step of dehydrogenation of substituted phenylenediamines might be important for their antioxidant effectiveness. Dedicated to Professor Vladimír Kvasnička, DrSc., in honour of his 65th birthday     

Aryltetralin Lignans from <Emphasis Type="Italic">Linum mucronatum</Emphasis> Bertol. ssp. <Emphasis Type="Italic">mucronatum</Emphasis>

The dried and aerial part of Linum mucronatum ssp. mucronatum was analyzed by gas chromatography-mass spectrometry (GC-MS). Two aryltetralin lignans, podophylloyoxin, 6-methoxypodophylloyoxin, and β-peltatin, were identified. This is the first report of the analysis of L. mucronatum ssp. mucronatum.__________Published in Khimiya Prirodnykh Soedinenii, No. 1, pp. 24–25, January–February, 2005.     

<Emphasis Type="Italic">O</Emphasis>- and <Emphasis Type="Italic">N</Emphasis>-Alkylation of <Emphasis Type="Italic">N</Emphasis>-halosuccinimides in ionic reactions with 1-phenyltricyclo [4.1.0.0<Superscript>2,7</Superscript>]heptane

N-Bromo and N-chlorosuccinimides add to 1-phenyltricyclo[4.1.0.0^2,7]heptane in CH₂Cl₂ with cleavage of the C(1)-C(7) bond to give isomeric 1 : 1 Markownikoff-type endo, anti-adducts of the norpinane structure in a ∼3 :7 ratio corresponding to N and O alkylation of succinimide.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No.2, pp. 457–460, February, 2005     

Synthesis of 2-aryl-6-nitro-4-(<Emphasis Type="Italic">vic</Emphasis>-triazol-1-yl)-1<Emphasis Type="Italic">H</Emphasis>-indoles from <Emphasis Type="Italic">E</Emphasis>-2,4,6-trinitrostilbenes

A method is developed for the preparation of 4-(vic-triazol-1-yl)indoles that involves replacement of the ortho-NO₂ group in E-2,4,6-trinitrostilbenes by an azido group, condensation of E-2-azido-4,6-dinitrostilbenes with acetylacetone, replacement of the second ortho-NO₂ group in the resulting stilbenes by N₃, and subsequent thermolysis of the azide into the target indole. The reactions of E-2-azido-4,6-dinitrostilbenes with cyclohexane-1,3-dione gave E-2-amino-4,6-dinitrostilbenes, which can be used for selective transformation of the ortho-NO₂ group into an amino group in E-2,4,6-trinitrostilbenes. Dedicated to Academician N. K. Kochetkov on the occasion of his 90th birthday. __________ Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1293–1296, May, 2005.     

Pyrano[4,3-<Emphasis Type="Italic">d</Emphasis>]pyrimidinium salts

5-Aroyl-1,3,6-trimethyluracils were converted to pyrano[4,3-d]pyrimidinium salts. Reactions of the salts obtained with ammonia, primary amines, and hydrazine were studied. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2251–2257, November, 2007.     

Synthesis of 5-alkyl-4-polyfluoroacylpyrrole-2,3(1<Emphasis Type="Italic">H</Emphasis>)-diones

Diacylation of fluoroalkyl-containing α-aminovinyl ketones with oxalyl chloride afforded 5-alkyl-4-polyfluoroacylpyrrole-2,3(1H)-diones.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2240–2242, October, 2004.