4-Phosphoranylidene-5(4H)-oxazolones — A novel synthesis and properties

Summary 4-Phosphoranylidene-5(4H)-oxazolones (2), a hardly known class of phosphorus ylides, were readily prepared from 4-unsubstituted-5-(4H)-oxazolones (1) by treatment with Ph₃P-Br₂, Bu₃P-Br₂, Ph₃P-CCl₄, or Ph₃P-CBr₄ adducts in the presence of triethylamine in CH₂Cl₂ at room temperature in a novel, efficient one-pot procedure. The spectroscopic properties of the ylides are reported and discussed.

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4-Phosphoranyliden-5(4H)-oxazolone — Eine neue Synthese und Eigenschaften

Zusammenfassung 4-Phosphoranyliden-5(4H)-oxazolone, eine sehr wenig bekannte Gruppe der Phosphor-ylide, wurden auf einfache Weise nach einem neuen Eintopfverfahren mit guten Ausbeuten hergestellt. Als Ausgangsverbindungen wurden 4-unsubtituierte-5-(4H)-Oxazolone (1) eingesetzt, die unter der Einwirkung von Addukten wie Ph₃P-Br₂, Bu₃P-Br₂, Ph₃P-CCl₄ oder Ph₃P-CBr₄ in Anwesenheit von Triethylamin in CH₂Cl₂ bei Zimmertemperatur die Titelverbindungen liefern. Die spektroskopischen Eigenschaften der Ylide werden berichtet und diskutiert.

     

2-Trif luoromethyl-4H-thiochromen-4-one and 2-trif luoromethyl-4H-thiochromene-4-thione: Synthesis and reactivities

2-Trifluoromethyl-4H-thiochromene-4-thione obtained from 2-trifluoromethyl-4H-thiochromen-4-one and P₂S₅ reacts with aromatic amines, hydrazine hydrate, phenylhydrazine, and hydroxylamine at the C(4) atom of the chromene ring to give the corresponding anils, azine, hydrazones, and oxime of thiochromone. 2-Trifluoromethyl-4H-thiochromen-4-one is oxidized by hydrogen peroxide in AcOH into 4-oxo-2-trifluoromethyl-4H-thiochromene 1,1-dioxide and reduced by NaBH₄ to 2-trifluoromethyl-4H-thiochromen-4-ol or cis-2-(trifluoromethyl)thiochroman-4-ol. When treated with hydrazine hydrate, thiochromen-4-one gives 3(5)-(2-mercaptophenyl)-5(3)-trifluoromethylpyrazole. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 504–509, March, 2006.     

Synthesis of pyrido[3,4-<Emphasis Type="Italic">d</Emphasis>]pyrimidines by condensation of ethyl 1-benzyl-3-oxopiperidine-4-carboxylate with morpholine-4-carboxamidine

A method has been developed for the synthesis of 4-amino-substituted 7-benzyl-2-morpholin-4-yl-5,6,7,8-tetrahydropyrido[3,4-d]pyrimidines by condensation of ethyl 1-benzyl-3-oxopiperidine-4-carboxylate with morpholine-4-carboxamidine and subsequent reaction of the 7-benzyl-2-morpholin-4-yl-5,6,7,8-tetrahydro-3H-pyrido[3,4-d]pyrimidin-4-one with trifluoromethanesulfonic anhydride and secondary amines. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 762–768, May, 2007.     

Synthesis and reactivity of 2-polyfluoroalkylchromene-4(4<Emphasis Type="Italic">H</Emphasis>)-thiones

2-Polyfluoroalkylchromene-4(4H)-thiones, synthesized from 2-polyfluoroalkylchromones and P₂S₅, react with aniline, phenylhydrazines, and hydroxylamine at the C(4) atom and afford corresponding anils, phenylhydrazones, and oximes of chromones. On heating in alcohol in the presence of concentrated HCl, chromone phenylhydrazones and oximes undergo ring closure to form 3-(2-hydroxyaryl)-1-phenyl-5-polyfluoroalkylpyrazoles and 5-hydroxy-3-(2-hydroxyaryl)-5-polyfluoroalkyl-Δ²-isoxazolines.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2188–2195, October, 2004.     

Chemical transformations of reaction products of 2-methyl-3-(4-tolyl)-4(3<Emphasis Type="Italic">H</Emphasis>)-quinazolone with benzil and its 4,4′-derivatives

The reaction of 2-methyl-3-(4-tolyl)-4(3H)-quinazolone with benzil produces 2-[(Z)-3-oxo-2,3-diphenylprop-1-enyl]-3-(4-tolyl)-4(3H)-quinazolone, which is readily transformed into 2-(3,3-diphenylsuccinimido)-N-(4-tolyl)benzamide on dissolution in organic water-containing solvents. The rearrangement mechanism was suggested and investigated by the quantum chemical PM3 method. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 146–151, January, 2007.     

Selection of adsorbents for <Emphasis Type="Italic">in-situ</Emphasis> coupling technology of adsorptive desulfurization and biodesulfurization

In-situ coupling of adsorptive desulfurization and biodesulfurization is a new desulfurization technology for fossil oil. It has the merits of high-selectivity of biodesulfurization and high-rate of adsorptive desulfurization. It is carried out by assembling nano-adsorbents onto surfaces of microbial cells. In this work, In-situ coupling desulfurization technology of widely used desulfurization adsorbents of γ-Al₂O₃, Na-Y molecular sieves, and active carbon with Pseudomonas delafieldii R-8 were studied. Results show that Na-Y molecular sieves restrain the activity of R-8 cells and active carbon cannot desorb the substrate dibenzothiophene (DBT). Thus, they are not applicable to in-situ coupling desulfurization technology. Gamma-Al₂O₃ can adsorb DBT from oil phase quickly, and then desorb it and transfer it to R-8 cells for biodegradation, thus increasing desulfurization rate. It is also found that nano-sized γ-Al₂O₃ increases desulfurization rate more than regular-sized γ-Al₂O₃. Therefore, nano-γ-Al₂O₃ is regarded as the better adsorbent for this in-situ coupling desulfurization technology. Supported by National Basic Research Program of China (Grant No: 2006CB202507) and National High-tech R&D Program (Grant No: 2006AA02Z209)     

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.     

Synthesis and stereoisomerism of derivatives of <Emphasis Type="Italic">tert</Emphasis>-butyl 7-alkylideneceph-3-em-4-carboxylate

By condensation of tert-butyl 3-methyl-7-oxoceph-3-em-4-carboxylate and its 3-acetoxymethyl analog with acetylmethylenetriphenylphosphorane and 3-trimethylsilylpropyn-2-ylindenetriphenylphosphorane tert-butyl 7Z-acetylmethylene-3-methylceph-3-em-4-carboxylate and also 7Z-and 7E-isomers of tert-butyl 3-acetoxymethyl-7-(3-trimethylsilylpropyn-2-ylidene)ceph-3-em-4-carboxylates were synthesized. Oxidation of these compounds with 1 equivalent of meta-chloroperbenzoic acid gave their 1R-and 1S-sulfoxides, and oxidation with 2 equivalents gave the corresponding sulfones. According to data from ¹H NMR spectroscopy, the carbonyl of the β-lactam descreens proton H-9 of the alkylidene group in the 7Z-isomers more strongly than in the 7E-isomers, shifting their signals to weaker field. Analogous shifts of the H-6 signal to weaker field was observed in the 1R-sulfoxides in comparison with that for the 1S-sulfoxide. These results were confirmed by X-ray crystallography of tert-butyl 7Z-acetylmethylene-3-methyl-1S-oxoceph-3-em-4-carboxylate and tert-butyl 7Z-acetylmethylene-3-methyl-1,1-dioxoceph-3-em-4-carboxy-late. In memory of Professor A.A. Potekhin __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, 618–626, April, 2008.     

Orthorhombic–orthorhombic phase transitions in Nd2NiO4+δ (0.067≤δ≤0.224)

Variation of the phases of Nd₂NiO_4+δ with the excess oxygen concentration δ has been examined at room temperature in the range 0.067≤δ≤0.224 using the X-ray powder diffraction technique. The phases observed at room temperature are orthorhombic-I (0.21<δ≤0.224), orthorhombic-IV (0.175<δ≤0.21), orthorhombic-II (0.15<δ≤0.175), orthorhombic-II+quasi-tetragonal-I (0.10<δ≤0.15), and quasi-tetragonal-I (0.067<δ≤0.10).     

Synthese von 4H-Pyrano[2,3-d]pyrimidinen

Summary Good yields of substituted 5-(5R-2-furyl)-4H-pyrano[2,3-d]pyrimidines4 were obtained in the reaction of 2-ethoxymethyleneamino-3-cyano-4H-pyranes2 with ammonia. Compounds2 were prepared by the condensation of the starting 2-amino-5-acetyl-3-cyano-6-methyl-4H-pyranes1 with ethyl orthoformate. Spectral properties of the bicyclic system4 in relation to compounds3 are discussed.

     

4-Hydroxy-2-quinolones 143. Synthesis,structure, and spectroscopic characteristics of ethyl 2-hydroxy-4-oxo-4H-pyrazino[1,2-<Emphasis Type="Italic">a</Emphasis>]pyrimidine-3-carboxylate

Condensation of aminopyrazine with triethyl methanetricarboxylate gave ethyl 2-hydroxy-4-oxo-4H-pyrazino[1,2-a]pyrimidine-3-carboxylate. According to X-ray analytical data the compound exists in the 2-hydroxy-4-oxo form in the crystal. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 411–419, March, 2008.     

<Emphasis Type="Italic">N</Emphasis>-bridged heterocycles: regiospecific synthesis of 2-methyl-4H-pyrimido[2,1-<Emphasis Type="Italic">b</Emphasis>]benzothiazol-4-ones

N-bridged heterocycles, 2-methyl-4H-pyrimido[2,1-b]benzothiazol-4-ones, have been synthesized in quantitative yield by the reaction of 2-aminobenzothiazoles with ethylacetoacetate in the presence of polyphosphoric acid involving dehydrative condensation followed by cyclization. The possibility of the formation of 4-methyl-2H-pyrimido[2,1-b]benzothiazol-2-ones has been excluded on the basis of spectral studies.     

Zur Chemie der 4-Aminothiazolin-2-thione

4-Aminothiazolin-2-one-hydrazones3 are obtained by succesive treatment of the title compound1 with dimethyl sulfate and hydrazinehydrate. The rearrangement of 4-aminothiazolin-2-ylidenmalononitrile7 derived from1 yields the 2,4-diamino-thiophene derivatives8. Analogously, the 4-aminothiazolin-2-yliden-cyanamides10 react to form the substituted 2,4-diaminothiazoles11. Succesive reaction of the ethyl (4-amino-2-thioxo-thiazolinyl-3)-acetates12 with dimethyl sulfate and malononitrile yields the 3,6-diamino-pyrrolo[2,1-b]-thiazoles14.

     

Reaction of 1,5-diaryl-3-hydroxy-4-methylsulfonyl-3-pyrrolin-2-ones with urea,hydrazine, ethylenediamine,and <Emphasis Type="Italic">o</Emphasis>-phenylenediamine

With urea 1,5-diaryl-3-hydroxy-4-methylsulfonyl-3-pyrrolin-2-ones form the 3-amino derivatives of pyrrolones. In reactions with hydrazine hydrate and ethylenediamine the corresponding salts are formed. With ethylenediamine at 180–185°C the double salt of 3-hydroxy-4-methylsulfonyl-1,5-diphenyl-3-pyrrolin-2-one forms N,N′-di(4-methylsulfonyl-1,5-diphenyl-3-pyrrolin-2-on-3-yl)-ethylenediamine. The reaction with o-phenylenediamine gives 2,3-diaryl-4-methylsulfonylpyrrolo-[2,3-b]quinoxalines. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, 1631–1636, November, 2007.     

Synthesis and rearrangement of 4-imino-4H-3,1-benzoxazines

Summary N-Acylanthranilamides react with dibromotriphenylphosphorane in the presence of triethylamine as HBr captor to give 4-imino-4H-3,1-benzoxazines in good yields. If the reaction is carried out without acid acceptor, N-acetylanthranilamides yield 2-methyl-4-quinazolones, whereas N-benzoylanthranilamides give 2-phenyl-4-imino-4H-3,1-benzoxazines. It has also been found that 2-methyl-4-imino-4H-3,1-benzoxazines rearrange under the influence of HCl or HBr into the respective 2-methyl-4-quinazolones; 2-phenyl-4-imino-4H-3,1-benzoxazines, however, do not undergo such a rearrangement.

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Synthese und Umlagerung von 4-Imino-4H-3,1-benzoxazinen

Zusammenfassung Die Umsetzung von N-Acyl-anthranilsäure-amiden mit Triphenyldibromphosphoran in Gegenwart von Triethylamin als HBr-Akzeptor führt mit guten Ausbeuten zu 4-Imino-4H-3,1-benzoxazinen. Wird die Reaktion ohne säurebindendes Mittel durchgeführt, dann entstehen aus N-Acetyl-anthranilsäure-amiden 2-Methylchinazolone-4, jedoch erhält man aus N-Benzoylanthranilsäure-amiden 2-Phenyl-4-imino-4H-3,1-benzoxazine. 2-Methyl-4-imino-4H-3,1-benzoxazine erleiden unter dem Einfluß von HBr oder HCl eine Umlagerung in entsprechende 2-Methylchinazolone-4, während 2-Phenyl-4-imino-4H-3,1-benzoxazine zu einer solchen Umlagerung nicht befähigt sind.

     

Synthesis of 4-aryloxy-7-nitrobenzofurazan derivatives from 4-chloro-7-nitrobenzofurazan and various phenoxide anions (including pharmaceuticals) in the presence of crown ethers

4-Chloro-7-nitrobenzofurazan reacts by nucleophilic substitution with phenoxide anions derived from estriol (2c), ethynylestradiol (2d), phenol (3e), guaiacol (3f), 2,6-dimethoxyphenol (3g), eugenol (3h), isoeugenol (3i), the cytostatic Etoposide (4), and Reichardt’s betaine (5) in the presence of crown ethers affording the corresponding 4-aryloxy-7-nitrobenzofurazan derivatives 6c, 6d, 7e-7i, 8, and 9. The structure of these compounds was confirmed by NMR spectra. Hydrophobicity/hydrophilicity parameters were investigated by reverse phase thin-layer chromatography.     

One-step synthesis of 5-acetyl-2-amino-4-aryl-3-cyano-4H-pyrano[3,2-b]indoles. Molecular and crystal structure of 5-acetyl-2-amino-4-(4"-chloro-3"-nitrophenyl)-3-cyano-4H-pyrano[3,2-b]indole

A one-step procedure was developed for the synthesis of 5-acetyl-2-amino-4-aryl-3-cyano-4H-pyrano[3,2-b]indoles involving the three-component reaction of 1-acetylindol-3(2H)-one with aromatic aldehydes and malononitrile in ethanol in the presence of triethylamine as the catalyst. The structure of 5-acetyl-2-amino-4-(4"-chloro-3"-nitrophenyl)-3-cyano-4H-pyrano[3,2-b]indole was established by X-ray diffraction analysis.     

Synthesis of 4<Emphasis Type="Italic">H</Emphasis>-imidazole-5-carbaldoxime 3-oxides and 4<Emphasis Type="Italic">H</Emphasis>-imidazole-5-carbonitrile 3-oxides

The condensation of 3-hydroxyamino-3-methylbutan-2-one or 3-ethyl-3-hydroxyamino-pentan-2-one with aldehydes and ammonia afforded a series of new 1-hydroxy-4-methyl-2,5-dihydroimidazoles, whose oxidation gave rise to the corresponding 5-methyl-4H-imidazole 3-oxides. The latter, like 1-hydroxy-4-methyl-2,5-dihydroimidazoles, react with PrⁱONO in the presence of bases to form 4H-imidazole-5-carbaldoxime 3-oxides, which are transformed into 4H-imidazole-5-carbonitrile 3-oxides in the reaction with TsCl in the presence of Et₃N. The by-products produced in different steps of the synthesis were isolated and characterized. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1487–1503, July, 2008.     

Interaction of esters of β-aroylacrylic acids with <Emphasis Type="Italic">o</Emphasis>-phenylenediamines and 1,2-diamino-4-phenylimidazole

3-Phenacylquinoxalin-2-ones were synthesized by the reaction of the ethyl esters of β-aroylacrylic acids with o-phenylenediamines, while interaction with 1,2-diamino-4-phenylimidazole gave ethyl 7-amino-2-aryl-5-phenyl-3,4-dihydroimidazolo[1,5-b]pyridazine-4-carboxylates. Their chemical properties have been investigated. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1646–1654, November, 2007.     

4-Hydroxy-2-quinolones 129. Synthesis and structure of 2-bromomethyl-4-carboxy-5-methyl-1,2-dihydrooxazolo-[3,2-<Emphasis Type="Italic">a</Emphasis>]quinolinium bromide

By analogy with the 4-hydroxy derivatives, the bromination of N-allyl-4-methyl-2-oxo-1,2-dihydroquinoline-3-carboxylic acid leads to the closure of a five membered oxazole ring but, in contrast, it forms the 2-bromomethyl-4-carboxy-5-methyl-1,2-dihydrooxazolo[3,2-a]quinolinium bromide salt. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1496–1502, October, 2007.