Oxidative ammonolysis of 3- and 4-methylpyridines on vanadium oxide catalysts modified with titanium and tin oxides

Catalytic properties of vanadium-titanium-tin oxides catalysts of various compositions were studied in oxidative ammonolysis of 3- and 4-methylpyridines.     

Oxidative ammonolysis of 3-picoline on mixed oxide catalysts

The oxidative ammonolysis of 3-picoline has been studied on the following catalysts: V₂O₅ on corundum, V₂O₅ with the addition of 1% of H₂WO₄ on corundum, V₂O₅ + MoO₃ + P₂O₅ (10.350.35) on silica gel, V₂O₅ + Al₂O₃, and a melt of V₂O₅ + TiO₂ (10.22). Mixed catalysts of vanadium and titanium oxides exhibited the highest activity and selectivity. With the passage of 25–45 moles of oxygen (in the form of air), 5–10 moles of ammonia, and 50–70 moles of water per mole of 3-picoline at a temperature of 390–410° C, the amount of nicotinonitrile formed on these catalysts amounted to 85–90% of the theoretically possible amount.Part LXIII of the series Oxidation of organic compounds; for part LXII, see [1].     

Oxidative ammonolysis of 3-picoline on mixed oxide catalysts

The oxidative ammonolysis of 3-picoline has been studied on the following catalysts: V₂O₅ on corundum, V₂O₅ with the addition of 1% of H₂WO₄ on corundum, V₂O₅ + MoO₃ + P₂O₅ (1∶0.35∶0.35) on silica gel, V₂O₅ + Al₂O₃, and a melt of V₂O₅ + TiO₂ (1∶0.22). Mixed catalysts of vanadium and titanium oxides exhibited the highest activity and selectivity. With the passage of 25–45 moles of oxygen (in the form of air), 5–10 moles of ammonia, and 50–70 moles of water per mole of 3-picoline at a temperature of 390–410° C, the amount of nicotinonitrile formed on these catalysts amounted to 85–90% of the theoretically possible amount.     

Oxidation of 3- and 4-methylpyridines on modified vanadium oxide catalysts

The partial oxidation of 3- and 4-methylpyridines on V₂O₅ and vanadium oxide catalysts doped with TiO₂, Al₂O₃, and ZrO₂ was studied. The catalytic activities of the studied catalysts were correlated with the calculated proton affinities of the vanadyl oxygen. A possible mechanism of the surface stages of the partial oxidation of 3- and 4-methylpyridines on the vanadium oxide catalysts was discussed.     

Oxidative ammonolysis of 2-methylquinoxaline on vanadium-titanium oxide catalyst

The behavior of 2-methylquinoxaline in the course of oxidative ammonolysis on V-Ti oxide catalyst in a wide range of conditions was studied, and this reaction was examined as a route to 2-quinoxalinecarbonitrile.     

Oxidation of n-propanol over vanadium oxide catalysts

The kinetics of catalytic oxidation of n-propanol on V₂O₅ and V₂O₅ modified with BeO, MgO, CaO and SrO has been investigated. A high selectivity of the oxidation to propionaldehyde was observed. The activation energies of the reaction and of the exchange of oxygen in these catalysts with molecular oxygen and CO₂ were found to change in parallel.

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- V₂O₅ V₂O₅ BeO, CaO, MgO SrO. . .

     

Physico-chemical properties of silica-supported vanadium oxide catalysts

- . TiO₂ ZnO. - CO₂ H₂O. — .

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The effect of visible light on propane and n-butane oxidation has been sutied on a seires of metal oxides. TiO₂ and ZnO have been found to exert a photocatalytic effect. On TiO₂, propane and n-butane are oxidized to CO₂ and H₂O. On ZnO as catalyst, partial oxidation products, aldehydes and ketones, are formed.

     

Conversions of methyl esters of (6-methyl-2-methylthio-4-pyrimidinyloxy)- and (3,4-dihydro-6-methyl-2-methylthio-4-oxo-3-pyrimidinyl)acetic acids

A study has been made of nucleophilic reactions (hydrolysis, hydrazinolysis, ammonolysis, reduction) and electrophilic reactions (bromination, nitration) of isomeric methyl esters of (6-methyl-2-methylthio-4-pyrimidinyloxy) acetic acid and (3,4-dihydro-6-methyl-2-methylthio-4-oxo-3-pyrimidinyl)acetic acid. Carboxyl-group derivatives and also derivatives with substituents in position 5 of the pyrimidine ring have been synthesized.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1655–1659, December 1992.     

Enantioseparation of 3,4-dihydroxyphenylalanine and 2-hydrazino-2-methyl-3-(3,4-dihydroxyphenyl)propanoic acid by capillary electrophoresis using cyclodextrins

The enantiomeric separations of 3,4-dihydroxyphenylalanine (dopa) and 2-hydrazino-2-methyl-3-(3,4-dihydroxyphenyl)propanoic acid (carbidopa) by capillary electrophoresis were studied using several native, neutral and anionic cyclodextrins as chiral additives and uncoated fused-silica capillaries. The effect of the type and concentration of the cyclodextrin added to 20 mM phosphate buffer (pH 2.5) on enantioseparation and migration times was studied. A high resolution value of 15.63 was obtained for dopa enantiomers with a buffer containing 20 mM single isomer, heptakis(2,3-diacetyl-6-sulfato)-beta-cyclodextrin. The enantiomers of carbidopa were separated using 20 mM carboxymethyl-beta-cyclodextrin as a chiral resolving agent. Both methods allowed the determination of 0.1% of the D-enantiomer (second migrating) in the presence of the L-enantiomer (first migrating) of dopa and carbidopa with a good precision. These methods also gave good results in terms of precision for both peak area, migration time, linearity and accuracy.     

Synthesis of (R)-3,4-diaminobutanoic acid by desymmetrization of dimethyl 3-(benzylamino)glutarate through enzymatic ammonolysis

Lipase B from Candida antarctica is shown to be a highly efficient catalyst for the desymmetrization of dimethyl 3-(benzylamino)glutarate (1) through aminolysis and ammonolysis reactions. Using this procedure, enantiopure monoamides are obtained in high yield. The synthetic value of these compounds is demonstrated by the preparation of an enantiopure nonnatural amino acid, i.e. (R)-3,4-diaminobutanoic acid [(+)-12].     

Supported dichlorobis(3-hydroxi-2-methyl-4-pyrone)Ti(IV) catalysts: Evaluation on ethylene polymerization

Dichlorobis(3-hydroxi-2-methyl-4-pyrone)Ti(IV) complex was grafted on different inorganic supports, namely different kinds of SiO₂, MAO-modified silica, MCM-41, Al₂O₃, ZrO₂ and MgO. The resulting supported catalysts were shown to be active in ethylene polymerization using methylaluminoxane (MAO) as cocatalyst, most of them being even more active that the homogeneous complex. The highest catalyst activities were observed for the Ti complex supported on SiO₂ 948 activated at 450 °C, MCM-41 and Al₂O₃.     

Synthesis of 6-(1-Aryl-5-methyl-1,2,3-triazol-4-yl)-3-(4-Pyridyl)-s-Triazolo[3,4-b]-l,3,4-Thiadiazoles

A survey of literature¹ revealed that s-triazolo[3,4-b]-1,3,4-thiadiazole, an interesting fused system of s-triazole and 1,3,4-thiadiazole rings, has received much attention during recent years on account of its prominent utilizations as antifungal, antiinflammatory, antiviral, analgesic and anthelmintic agents probably resulting from its planner and compact structure. Our earlier work on the synthesis of this class of heterocycles showed antibacterial, herbicidal and plant growth regulative properties^2-3 for the compounds. 1,2,3-Triazole derivatives have found their wide use in medicine, agriculture and industry^4-5. Incorporation of 1,2,3-triazole moiety into the 6-position of this ring system may lead to achieving compounds of better biological activities. In view of the above findings coupled with scanty reports on these condensed compounds carrying 6-heterocyclic groups, we wish to report here the condensation of 4-amino-5-mercapto-3-(4-pyridyl)-l,2,4-triazole(2) with 1-aryl-4-carboxy-5-methyl-1,2,3-triazoles(1_a-j) as a part of our continuing interest in this area.     

Crystal Structure and Thermal Property of 4-(3-Chlorophenyl)-3-isopropyl-1-methyl-3,4-dihydroquinolin-2(1H)-one

The target compound(C_(19)H_(20)ClNO) was structurally determined by single-crystal X-ray diffraction. The crystal is in monoclinic system, space group P2_1/n with a = 9.2365(2), b = 12.1241(3), c = 14.9960(4) ?, β = 106.589(3)°, C_(19)H_(20)ClNO, M_r = 313.81, D_c = 1.295 g/cm~3, V = 1609.42(7) ?~3, Z = 4, F(000) = 664, μ(MoKa) = 2.097 mm~(-1), T = 200(10) K, 2813 independent reflections with 2533 observed ones(I 2σ(I)), R = 0.0389 and wR = 0.1057 with GOF = 1.043(R = 0.0423 and wR = 0.1083 for all data). The 3,4-dihydroquinolin-2(1 H)-one moiety maintains thermodynamically stable trans configuration. The decomposition mechanism of compound 3 is complex by thermal analysis.     

Colorimetric determination of gold(III) using 3-methyl-4-vanillidine isoxazolone-5

Summary A new color reaction for the determination of gold(III) has been developed. Gold reacts with 3-methyl-4-vanillidine isoxazolone-5 in basic media at 90° to produce a pink color which is specific. Cobalt and nickel do not interfere when present upto 4 folds. Maximum tolerable amounts of other metal ions have also been studied.

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Zusammenfassung Eine neue Farbreaktion zur Goldbestimmung mit 3-Methyl-4-vanillidinisoxazolon-5 in basischem Milieu bei 90° führt zu einer spezifischen Rosafärbung. Kobalt und Nickel stören bis zur vierfachen Menge nicht. Außerdem wurden auch die tolerierbaren Mengen anderer Fremdionen bestimmt.

     

Synthesis and properties of 5-acetyl-3-cyano-4-isobutyl-6-methyl-3,4-dihydropyridine-2(1H)-thione

Condensation of isovaleric aldehyde with cyanothioacetamide and acetylacetone or its enamine produces 5-acetyl-3-cyano-4-isobutyl-6-methyl-3,4-dihydropyridine-2(1H)-thione, from which 5-acetyl-3-cyano-4-isobutyl-6-methylpyridine-2(1H)-thione and the corresponding substituted 2-alkylthio-1,4-dihydropyridines are prepared. T. G. Shevchenko Lugansk State Pedagogical Institute, Lugansk 348011, Ukraine; e-mail: kgb@lgpi.lugansk.ua; N. D. Zelinskii Institute of Organic Chemistry of the Russian Academy of Sciences, Moscow 117913, Russia; Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 516–519, April, 1999.