Showing papers on "Benzaldehyde published in 1982"

Heterogeneous Photocatalytic Reactions on Semiconductor Materials. III. Effect of pH and Cu2+ Ions on the Photo-Fenton Type Reaction

Abstract: The effect of pH and Cu2+ ions on the heterogeneous photocatalytic oxidation of toluenes by H2O2 formed from dissolved O2 in the presence of illuminated TiO2 powders, i.e. “the photo-Fenton type reaction,” was investigated. At low and high pH, a total amount of products increased drastically compared with that of the additive free system (pH 7). In the acidic region (aqueous H2SO4), side-chain oxidation prevailed over cresol formation and benzaldehyde was formed quite selectively at pH 1. Oxidation of the side chain in preference to hydroxylation of aromatic ring was also observed in the alkaline region (aqueous NaOH). By adding Cu2+ ion to the aqueous H2SO4 (pH 1 and 2), the yield of benzaldehyde increased further and cresols, benzyl alcohol, and bibenzyl were formed newly in high yields. At high Cu2+ concentrations (pH 2), the cresol formation in preference to the side-chain oxidation was attained. The observation was in good agreement with the Fenton reaction reported in which Cu2+ and Fe3+ ions are ad...

Production of an aromatic aldehyde oxidase by Streptomyces viridosporus

Abstract: Streptomyces viridosporus strain T7A, when grown in liquid media containing yeast extract and aromatic aldehydes, oxidized the aromatic aldehydes to the corresponding aromatic acids. Benzaldehyde, m-hydroxybenzaldehyde, p-hydroxybenzaldehyde, and protocatechualdehyde were catabolized further via the β-ketoadipate and gentisate pathways. Dehydrodivanillin, isophthalaldehyde, salicylaldehyde, syringaldehyde, terephthalaldehyde, vanillin, and veratraldehyde were oxidized only as far as the corresponding aromatic acids. Phthalaldehyde and aliphatic aldehydes were not oxidized. The aromatic aldehyde oxidase, which was produced by cultures grown in either the presence or absence of aromatic aldehydes, was partially purified by ammonium sulfate precipitation and ion-exchange chromatography. It consumed molecular oxygen, oxidized aromatic aldehydes to aromatic acids, and produced hydrogen peroxide all in equimolar amounts.

Asymmetric cyanohydrin synthesis catalyzed by synthetic dipeptides, 2

Abstract: In the asymmetric addition of hydrogen cyanide to benzaldehyde to give mandelonitrile, a cyanohydrin, the highest enantiomeric excess (e.e.) ever reported (90%) was obtained with (2d) whereas the corresponding linear dipeptide gave a very low e. e. This high e. e. decreased with the reaction time, because of the racemization of the product. All cyclic dipeptides used containing an (S)-histidine residue preferred the (R)-product. A scheme for the interaction between the catalyst and the reactants to give the (R)-product is proposed.

Phototochemistry of cation radicals in solution; photoinduced electron-transfer reactions between alcholos and the N,N,N′,N′,-tetraphenyl-p-phenylenediamine cation radical

Abstract: Irradiation of the N,N,N′,N′-tetraphenyl-p-phenylanediamine cation radical (TPPD·+) with benzyl alchohol causes its reduction to TPPD and oxidation of the alcohol into benzaldehyde; with benzhydrol and 1-phenylethanol the corresponding symmetrical ethers are formed in a photocatalytic process in which TPPD·+ is recycled via two successive electron transfers.

A spectroscopic study of the solvent dependent processes of the anils of benzaldehyde and salicylaldehyde

Abstract: The ultraviolet–visible, infrared, and Raman spectral characteristics of some anils of benzaldehyde and salicylaldehyde in several solvents have been investigated. The ultraviolet–visible absorptio...

Arenes disubstituted with primary alkyl groups from xylylene dianions

Abstract: 4198-15-6; NaBH4, 16940-66-2; 4-bromophenacyl bromide, 99-73-0; 2-bromocholestan-3-one, 22164-15-4; a-bromophenylacetic acid, 4870-65-9; sodium 2-thiophenetellurolate, 82093-40-1; thiophene, 110-02-1; butyllithium, 109-72-8; tellurium, 13494-80-9; phenacyl chloride, 532-27-4; phenacyl bromide, 70-11-1; phenacyl iodide, 4636-16-2; phenacyl acetate, 2243-35-8; phenacyl mesylate, 2018761-5; desyl chloride, 447-31-4; a-bromo-1-naphthylacetic acid, 72191-56-1; acetophenone, 98-86-2; p-bromoacetophenone, 99-90-1; desoxybenzoin, 451-40-1; cholestan-3-one, 15600-08-5; 3-methyl-lindanone, 6072-57-7; acetanilide, 103-84-4; phenylacetic acid, 10382-2; 1-naphthylacetic acid, 86-87-3; diphenylacetic acid, 117-34-0; benzaldehyde, 100-52-7. 82093-38-7; 5,16222-10-9; 7,5326-87-4; 8,82093-39-8; 11,94-41-7; 12,

Mechanism of the Cannizzaro reaction: possible involvement of radical intermediates

Abstract: The Cannizzaro reaction of [α-2H]benzaldehyde in alkaline aqueous dioxan or dioxan alone produces a substantial amount of [α-2H]benzyl alcohol together with the normal product, [α-2H2]benzyl alcohol, suggesting a possible partial involvement of radical intermediates.

Electrolytic synthesis of aryl alcohols, aryl aldehydes, and aryl acids

Abstract: Disclosed is a method of synthesizing compounds chosen from the group consisting of benzyl alcohol, benzaldehyde, benzoic acid, phenoxy benzyl alcohol, phenoxy benzaldehyde, phenoxy benzoic acid, and mixtures thereof by providing a composition of a current carrying component, such as a fluoroborate salt or a tetraethylammonium salt, a solvent, and a methyl aryl compound in contact with an anode and cathode. The solvent is reduced at the cathode and the methyl substituted aryl at the anode whereby to form product. According to an alternative exemplification of the invention, the anode and cathode are separated by a permionic membrane and a source of oxygen is provided in contact with the cathode and the permionic membrane.

Isochinolino[4,3-c]chinolone aus Phenylmalonylheterocyclen

Abstract: The reaction of 3-Phenyl-4-hydroxy-2-quinolones (1) and benzylammonium chloride yields the 4-aminocompounds2 as main products. The isoquinocondensed quinolones3 are formed as by-products. Thermolysis of 4-benzylamino-2-quinolones (4) affords also3. Better yields of3 are obtained by condensing the 4-aminoquinolones2 with benzaldehyde followed by thermal cyclodehydrogenation of the benzylidenamino compound6.

Hydrogen transfer reactions of model compounds typical of coal

Abstract: The hydrogen transfer reactions involving some model compounds, representing the bonds and functional groups typically found in coals, namely dibenzyl, dibenzyl ether, benzyl phenyl sulfide, acetophenone, and benzaldehyde, have been studied. The hydrogen donating capabilities of tetralin, tetrahydroquinoline, and molecular hydrogen, and the catalytic effect of SRC residue have been examined. Hydrogen can be abstracted more easily from tetrahydroquinoline than from tetralin. Hydrogen pressure has a marked effect on the rates of conversion of dibenzyl ether, benzyl phenyl sulfide, acetephenone, and benzaldehyde. SRC residue catalyzes the hydrogenation of carbonyl groups to a significant degree and the conversion of dibenzyl ether and benzyl phenyl sulfide to a lesser degree. The rate of cracking of dibenzyl is not affected by the presence of SRC residue.

Resonance-enhanced Raman identification of a ternary chemical intermediate during the equine liver alcohol dehydrogenase reduction of p-(dimethylamino)benzaldehyde.

Abstract: The nature of the binding of aromatic aldehyde and aromatic alcohol substrates to the catalytic zinc of equine liver alcohol dehydrogenase has been studied by using resonance-enhanced Raman spectroscopy. When an excess of both enzyme and coenzyme to substrate is used, a stable ternary chemical intermediate is formed between liver alcohol dehydrogenase and the reduced coenzyme, nicotinamide adenine dinucleotide, and the aldehyde, p-(dimethylamino)benzaldehyde, in the pH range 8.5-0.6. Resonance-enhanced Raman spectra clearly show that this same intermediate is formed between the excess enzyme, oxidized coenzyme, and the corresponding alcohol, p-(dimethylamino)benzyl alcohol. Thus, in the presence of excess enzyme and coenzyme, this specific ternary complex is a stable intermediate for both forward and reverse reactions. As a model for this enzyme-substrate intermediate, a complex between the aldehyde and Zn2+ in diethyl ether was made which showed a resonance-enhanced Raman spectrum essentially identical with that of the enzyme-coenzyme-substrate intermediate and completely different from that of the substrate. Most striking in this spectrum is the total absence of the carbonyl vibration which indicates that the C = O no longer exists in either the enzyme-substrate-coenzyme intermediate or the model complex, most probably due to the presence of a zinc-oxygen bond. The assignments are aided by 18O isotopic substitution in the substrate. The Raman spectra of crystals of the ternary complex and the dynamics of the complex are also discussed.

Process for the preparation of substituted benzaldehydes

Abstract: Substituted benzaldehydes are prepared by reaction of the substituted benzenes from which they are derived with carbon monoxide and hydrogen chloride in the presence of metal halides, the process being performed in the presence of 0.5 to 10 mols of hydrogen chloride per mol of metal halide at a partial pressure of carbon monoxide from 1 to 100 bars and a temperature from -20° C. to +100° C. and, if desired, in the presence of an inert diluent. The substituted benzaldehyde which contains, as a substituent, alkyl with at least 2 carbon atoms, cycloalkyl or optionally substituted benzyl, is prepared by reacting the appropriately substituted benzene with the additional presence of a benzene which does not contain the substituents mentioned, but which is identical in respect of further substituents which are optionally present with the benzene from which it is derived.

Oxidation of aromatic aldehydes and aliphatic secondary alcohols by Hyphomicrobium spp.

Abstract: Two of six tested strains of Hyphomicrobium respired on benzaldehyde with higher rates than on formaldehyde, and three strains with equal or lower rates, whereas one strain, Hyphomicrobium X, showed almost negligible respiration on benzaldehyde. Various substituted benzaldehydes stimulated oxygen consumption to lower rates than benzaldehyde itself in active strains. All strains contained multiple forms of dye-linked aldehyde dehydrogenase, as evident from polyacrylamide gel electropherograms of cell-free extracts and activity tests on the gels with nitroblue tetrazolium. All bands of this enzyme reacted more strongly with benzaldehyde than with formaldehyde in all strains. On gels of some strains additional bands appeared with benzaldehyde as the enzyme substrate. Hyphomicrobium X again displayed the lowest activity of this enzyme on the gels. A new band of this enzyme appeared on gels of strain ZV 580 after growth on methylamine, when tested in this respect. NAD-dependent secondary alcohol dehydrogenase ...

Reaction of 1-Lithio-1-arylthio(or alkylthio)methyltrimethylsilane with Acid Derivatives. A Novel Synthesis of Functionalized Vinyl Sulfides

Abstract: Reactions of 1-lithio-1-phenylthiomethyl- (1a) and 1-lithio-1-methylthiomethyltrimethylsilane (1b) with amides, an ester, acid anhydrides, a urea, and a carbonate are described which provide useful routes to functionalized vinyl sulfides. The reaction of 1 with amides gave β-functionalized vinyl sulfides, 1-dialkylamino-2-phenylthio (or methylthio)ethylenes, in 40–95% yields and the reaction could be extended to the sulfonyl derivatives of 1 to afford 1-dialkylamino-2-phenylsulfonyl(or methylsulfonyl)ethylenes. Although ethyl benzoate and some acid anhydrides were not good substrates for this reaction, tetramethylurea and diethyl carbonate gave α-functionalized vinyl sulfides, 1-amidovinyl- and 1-(ethoxycarbonyl)vinyl sulfides, in moderate yields when treated with 1a followed by addition of benzaldehyde.

Catalytic activity of polynuclear platinum carbonyl anions in homogeneous hydrogenation reactions

Abstract: The homogeneous hydrogenation of benzaldehyde, heptanal, cyclohexanone, cyclohexene, acetonitrile, and benzonitrile has been studied using [NBun4]2[{Pt3(CO)6}5](1) as the catalyst over a range of temperature (40– 80 °C) and pressure (20–64 lbf in–2). Infrared spectroscopic studies suggest the formation of a common intermediate in reactions carried out at 60 °C. Benzaldehyde is the most readily hydrogenated; the nature of the products depends on the pressure of hydrogen used and is selective to either benzyl alcohol or a mixture of benzene and methanol. Kinetic studies on the rate of benzyl alcohol formation indicate a first-order dependence of the rate on the concentration of (1). While the rate shows a Michaelis–Menten type of dependence on the PhCHO concentration, it seems to be independent of Hz pressure in the range 20–25 lbf in–2. Under these conditions, a value of 63.81 kJ mol–1 for the activation energy is obtained from the Arrhenius plot. A tentative mechanism for PhCHO hydrogenation is discussed.

Nuclear analogs of β-lactam antibiotics. XV. Synthesis of 6-substituted 2-methylpenem-3-carboxylic acids

Abstract: The synthesis of 6-substituted 2-methylpenem-3-carboxylic acids is described. The dianion 6 was prepared insitu from 2-methylpenem-3-carboxylic acid (5) by the addition of two equivalents of n-butyllithium in THF at −78 °C. This dianion reacted with deuterated acetic acid, acetone, acetaldehyde, benzaldehyde, and methyl thiomethylsulfonate to give 6-deuterio-, 6-(2′-hydroxy-2′-propyl)-, 6-(1′-hydroxyethyl)-, 6-(1′-hydroxybenzyl)-, 6-methylthio-2-methylpenem-3-carboxylic acids and their sodium or potassium salts, 7–11, respectively. The stereochemistry of the products is also discussed.

Synthesis of 1,2-diamino imidazole derivatives by the reaction of benzaldehyde guanylhydrazone with α-haloalkyl aryl ketones

Abstract: 2-Amino-1-benzylideneamino-4-arylimidazoles were obtained by the reaction of benzaldehyde guanylhydrazone with 4-alkyl- and 4-aryl-Ω-haloacetophenones. Side products of this reaction were cis- and trans-1,1′-bis(benzylideneamino)-4,4′-diaryl-2,2′-azoimidazoles. The corresponding 2-amino-1-benzylideneaminoimidazole and 1-benzyl-ideneaminoimidazo[l,2-a]imidazole were obtained in the reaction of α-bromopropiophenone with benzaldehyde guanylhydrazone. The 2-amino-1-benzylideneamino-4-arylimidazoles were converted by successive reactions to 1,2-diatnino-4-arylimidazoles and then to imidazo[1,2-b]-1,2,4-triazine derivatives —dyes for liquid crystals with positive dichroism.