Showing papers on "Benzaldehyde published in 1980"

Aldol Condensations with Metal(II) Complex Catalysts

Abstract: Aldol condensations of aldehydes with ketones catalyzed by the first-row transition metal(II) complexes have been widely studied. Complexes of Co(II), Ni(II), Cu(II), and Zn(II) acetates with 2,2′-bipyridine were effective catalysts to afford cross-aldol condensation products, α,β,-unsaturated ketones, in high yields without any self-condensation products. The reaction of 2-butanone, unsymmetrical aliphatic ketone, with benzaldehyde took place regioselectively to give base-catalyzed-type products.

Base induced cyclization of some quinolines. Formation of fused nitrogen heterocyclic ring system

Abstract: Condensation of 3,5-dinitro-4-chloro-6-methoxy-2-methylquinoline (1) with benzylamine, ethanolamine and/or thioglycolic acid afforded the quinoline derivatives4 a-c. Cyclization of4 a and4 b with alkali and condensation of1 with glycine in sodium carbonate solution furnish 2H-imidazo[4,5-c]quinoline derivatives5 a-c, respectively. Treatment of5 b with benzaldehyde in presence of zinc chloride gave the styryl derivative6. 1 reacted with sodium azide to give the azido derivative4 d, which upon treatment with phenylhydrazine or sodium borohydride yielded the 4-amino derivative4 3. Moreover,1 was treated with phenylhydrazine to give4 f, which cyclized in 10% sodium hydroxide solution to the corresponding v-triazolo[4,5-c]quinoline 3-oxide derivative7. When however4 f was treated with dilute hydrochloric acid, the corresponding phenylpyrazolo[3,4,5-de]quinoline derivative8 was obtained.

Method for producing a di-acetal of sorbitol and an aromatic aldehyde

Abstract: A method is provided for producing a di-acetal of sorbitol and an aromatic aldehyde wherein an aqueous solution containing a catalytic amount of a mineral acid and sorbitol is formed. Thereafter, an effective amount of an aromatic aldehyde such as benzaldehyde is incrementally admixed into the homogeneous aqueous admixture containing the sorbitol at a rate sufficient to allow a substantially spontaneous reaction to occur between the D-sorbitol and aromatic aldehyde; thus, forming an aqueous slurry containing crude di-acetal, e.g., dibenzylidene sorbitol. The amount of aromatic aldehyde employed is that amount sufficient to provide a molar ratio of D-sorbitol to aromatic aldehyde of from about 1:0.75 to about 1:1.75. Thereafter, the aqueous slurry is neutralized, and crude di-acetal is removed from the liquid phase and washed with water to remove mono-acetal impurities, e.g., monobenzylidene sorbitol. The washed di-acetal may then be dried to provide dried di-acetal, and the dried di-acetal may be further purified by washing with a relatively non-polar solvent.

SYNTHESIS OF 2H-CHROMENO[2,3-d]PYRIMIDINE-2,4(3H)-DIONES (5-DEAZA-10-OXAFLAVINS) AS AN AUTORECYCLING OXIDIZING AGENT

Abstract: Treatment of 3-methyl-6-phenoxyuracils with the Vilsmeier reagent gave the corresponding 5-formyl-3-methyl-6-phenoxyuracils. Dehydrative cyclization of the above 5-formyluracils with polyphosphoric acid gave 3-methyl-2H-chromeno[2,3-d]pyrimidine-2,4(3H)-diones (3-methyl-5-deaza-10-oxaflavins). These 5-deaza-10-oxaflavins showed strong oxidizing power in oxidizing benzyl alcohol even under neutral conditions to give benzaldehyde, while they were hydrogenated to 1,5-dihydro-5-deaza-10-oxaflavins.

Intramolecular cycloaddition reactions of N-sulfonyl nitrile imides bearing alkenyl groups.

Abstract: The reaction of the p-tolyl(or phenyl)sulfonylhydrazones of some 2-(alkenyloxy)benzaldehydes with lead tetraacetate leads, via the nitrile imide intermediates, Ar–\overset+C=N–\overset−N–SO2–C6H4–X-p, to intramolecular 1,3-dipolar cycloadducts and 1-acetyl-2-aroyl-1-[p-tolyl(or phenyl)sulfonyl]hydrazines in 20–65% and 7–70% yields respectively, while the intermolecular reactions of the benzaldehyde p-tolylsulfonylhydrazone with a dipolarophile such as acrylonitrile or styrene in the presence of lead tetraacetate gives only 1-acetyl-2-benzoyl-1-(p-tolylsulfonyl)hydrazine. The treatment of the N-(p-tolylsulfonyl)-o-(allyloxy)benzohydrazonoyl chloride (10) with triethylamine or by refluxing a benzene solution of 10 also gives an intramolecular 1,3-dipolar cycloadduct in a good yield.

Comparison of the phase transfer oxidation of benzyl alcohol in a pump cell and stirred-tank reactor

Abstract: The oxidation of benzyl alcohol by electrogenerated hypobromite in a two-phase emulsion has been studied using a quaternary ammonium salt as a phase transfer agent. The performances of a stirred-tank batch reactor and a bipolar electrochemical pump cell have been compared and the differences found are discussed in terms of the different mixing/transport/reaction regimes of the two cells. Benzaldehyde can be produced at a rate of 0.2 mol h−1 dm−2 of electrode area for 4.20 kWh kg−1.

Studies on Pyrimidine Derivatives. XVIII. Reaction of Active Methyl Groups on Pyrimidine N-Oxides

Abstract: Knoevenagel-type condensation and the Mannich reaction were investigated with various pyridine N-oxides having an active methyl group For example, 6-methyl-4-phenylpyrimidine 1-oxide (Va) readily reacted with benzaldehyde in an aqueous ethanolic solution of potassium hydroxide, while 4-methyl-6-phenylpyrimidine (IVa) failed to react with benzaldehyde under the same conditions When Va was treated with piperidine hydrochloride and paraformaldehyde, bis piperidinomethylation occurred at the 6-methyl group The product was transformed into 4-phenyl-6-(2-piperidinoethyl) pyrimidine 1-oxide (XXIIa) by treatment with 5% sulfuric acid at 90°

Synthesis of 10-Arylpyrimido [4, 5-b] quinoline-2, 4 (3H, 10H) diones (10-Aryl-5-deazaflavins) and Their Use in Oxidations of Alcohols and Amines

Abstract: Treatment of aryl-bis (6-anilino-3-methyluracil-5-yl) methanes, which were prepared by the condensation of 6-anilino-3-methyluracils with arylaldehydes, with diethyl azodicarboxylate (DAD) in the presence of sulfolane led to the formation of the corresponding 10-arylprimido [4, 5-b] quinoline-2, 4 (3H, 10H)-diones (10-aryl-5-deazaflavins). Heating of the methanes alone in sulfolane without DAD gave the corresponding 5-aryl-5-deazaalloxazines. The oxidizing abilities of the 10-aryl-5-deazaflavins thus obtained were examined from both kinetic and synthetic viewpoints. The oxidations of benzyl alcohol and benzylamine by these 5-deazaflavins have been shown to recycle automatically, and more than 100% yield of benzaldehyde (based on the 5-deazaflavins) was obtained.

Regio- and stereo-selectivity in the reactions of anions of aryl allyl sulfides with benzaldehyde

Abstract: Addition reactions of anions of aryl allyl sulfides to benzaldehyde proceed readily and in good yields and afford mixtures of products resulting from α- and γ-attack on the allyl anion. γ-Products pre- dominate, and the ratio of (E) : (Z) isomers usually surrounds unity, although in the case of the reaction involving 3-(phenylthio)but-1-ene the ratio is 10 : 1. The ratio of diastereoisomers formed in products resulting from α-attack ranges from 3 : 1 to 1.3 : 1 (starting from 3- (2,4,6-trimethyl-phenylthio)prop-1-ene and 2-methyl-3-(phenylthio)prop- 1-ene respectively).

6,6-dimethyl-6-silafulvene. generation and trapping reactions

Abstract: 6,6-Dimethyl-6-silafulvene generated from (allyl)(cyclopentadienyl)dimethylsilane reacts with a trapping reagent such as methanol, benzaldehyde, and benzophenone to give (cyclopentadienyl)(methoxy)dimethylsilane, 6-phenylfulvene, and 6,6-diphenylfulvene, respectively. Without a trapping reagent, the silafulvene undergoes dimerization.

Synthesis of cannabinoid model compounds. Part 2: (3R, 4R)-Δ1(6)-Tetrahydrocannabinol-5″-oic acid and 4″(R, S)-Methyl-(3R, 4R)-Δ1(6)-tetrahydrocannabinol-5″-oic Acid†

Abstract: Two novel cannabinoid model compounds, (3R, 4R)-Δ1(6)-tetrahydrocannabinol-5″-oic acid (22) and 4″(R, S)-methyl-(3R, 4R)-Δ1(6)-tetrahydrocannabinol-5″-oic acid (23) were synthesized by acid-catalyzed condensation of (+)-trans-p-mentha-2, 8-dien-l-ol (1) with the substituted resorcinols 18 and 19 obtained by a Wittig reaction between 3, 5-bis(benzyloxy)benzaldehyde (7) and methyl 4-bromobutanoate (10) or methyl 4-bromo-2(R, S)-methylbutanoate (11) resp. with subsequent hydrogenation. The resulting methyl esters 20 and 21 were hydrolyzed to give acids 22 and 23.

The conversion of aldehydes and ketones via their 2,4,6-tri-isopropylbenzenesulphonyl hydrazones into nitrites containing one additional carbon atom

Abstract: 2,4,6-Tri-isopropylbenzenesulphonyl hydrazones of aliphatic and alicyclic aldehydes and ketones react readily with potassium cyanide in boiling methanol solution to give the corresponding nitriles (containing one more carbon atom than the original aldehyde or ketone) in satisfactory yields Under the same conditions, benzaldehyde 2,4,6-tri-isopropylbenzenesulphonyl hydrazone gives phenylacetonitrile in very low yield In some cases, the arenesulphonyl hydrazones may be generated in situ, in methanol solution, from the carbonyl compounds and 2,4,6-tri-isopropylbenzenesulphonohydrazide (11a), thereby constituting a one-pot preparation of the nitriles

Kinetics of the Tungstate-catalyzed H2O2 Oxidation of Amines in Aqueous Methanol. Acidity Effect

Abstract: Oxidation of N,N-dimethylaniline and benzylamine with H2O2 catalyzed by Na2WO4 has been kinetically studied in buffered 50% aqueous methanol at 25 °C. The rates with a catalytic amount of Na2WO4fit Eq.: v=k[amine]t[Na2WO4]t[H2O2]0 and the pH profile of rate constant shows no dissociation of peroxotungstate at pH 5–10. N,N-Dimethylaniline gives N-oxide (73%) and benzylamine gives benzaldehyde oxime (65%) under the present kinetic conditions.

Determination of the equilibrium distribution between alcohol and aldehyde substrates when bound to horse liver alcohol dehydrogenase using magnetic resonance

Abstract: The interactions of horse liver alcohol dehydrogenase (LADH) with the rho-trifluoromethyl derivatives of benzyl alcohol, benzaldehyde, and benzoic acid have been investigated by use of 19F nuclear magnetic resonance. The aldehyde and alcohol are good substrates for the enzyme and display kinetic characteristics similar to other alcohol/aldehyde pairs. In single-turnover experiments with NADH, rho-(trifluoromethyl)benzaldehyde shows biphasic kinetics similar to those shown by other aromatic aldehydes, which led Bernhard and co-workers [Bernard, S. A., Dunn, M. F., Luisi, P. L., & Shack, P. (1970) Biochemistry 9, 185] to propose half-of-the-sites reactivity for this enzyme. Fluorine magnetic resonance demonstrates that under equilibrium conditions at 4 degrees C and pH 8.75 rho-(trifluoromethyl)benzyl alcohol binds to LADH with a dissociation constant of 1 x 10(-3) M. Addition of 1 equiv of NAD to a stoichiometric complex of LADH and the alcohol generates a discrete resonance. This resonance corresponds to the ternary complex of LADH, NAD, and alcohol with little contribution from the NADH and aldehyde ternary complex. Quantitation shows that the bound NAD-alcohol pair is favored by at least a factor of 20 over the bound NADH-aldehyde pair at equililbrium. These results are consistent with explanations for the biphasic kinetics which involve half-of-the-sites reactivity of multiple steps in the reaction of each catalytic site. These results eliminate explanations for the biphasic kinetics of this system which require this equilibrium constant to have a value near unity or those which give greatest thermodynamic stability to the heterodimer LADH [(NAD-alcohol)(NADH-aldehyde)].

New olefin and oxiran syntheses from carbonyl compounds, and diethyl sodiophosphonate anions and 1-aminophosphonate amino-anions

Abstract: Reaction of aromatic aldehydes, and phthalic and thiophthalic anhydrides, with diethyl sodiophosphonate (1) gives the trans-stilbenes (3), 3,3′-biphthalidylidene (30), and 3,3′-bis-(2-thiophthalidylidene)(33). Similar treatment of fluorenone (8) and xanthone (17) with (1) leads to 9,9′-bis(fluororenylidene)(9) and 9,10-dihydro-9-oxophenanthrene-10-spiro-9′-fluorene (10), and to 9,9′-bixanthenylidene (18) and 9,9′-bixanthenyl (19), respectively, but the reaction using anthrone (11) as a carbonyl reagent yields only anthraquinone (12) and anthracene (13). Similar treatment using N-methylisatoic anhydride (34) and N-methylisatin (36) produces NN′dimethylisoindigo (35). Reaction of benzaldehyde and p-chlorobenzaldehyde with diethyl 1-[(N-sodio)anilino]cyclohexylphosphonate (40) gives mainly corresponding mixtures of trans-(41a, b) and cis-stilbene epoxides (42a, b), while similar treatment of p-nitrobenzaldehyde with (40) produces 4,4′-dinitrostilbene (3e). Reaction of (8) with (40), as well as with (1), gives (9) and (10). The mechanism of formation of these products is discussed.

Chemistry of O-alkyl selenoesters. Reaction with triethylphosphine

Abstract: The reactions between triethylphosphine and a number of aliphatic and aromatic selenoesters under oxygen-free conditions have been investigated. The purple intermediate formed in the reaction with the aliphatic selenoesters was quenched with atmospheric oxygen and gave the corresponding esters, whereas quenching with methyl iodide gave the corresponding 1-alkoxy-1-iodoalkyltriethylphosphonium iodides (13)–(16). The 1-alkoxy-1-iodoalkyltriethyiphosphonium iodides gave the 1-alkoxyalkyltriethylphosphonium iodides (17)–(20) upon treatment with methanol, and treatment with benzaldehyde at –70 °C gave α-alkoxyalkyl phenyl ketones (22)–(25). The reaction between the selenobenzoates and triethylphosphine gave α-dialkoxy-stilbenes and -dibenzyls. When the reaction was carried out in cyclohexene 7-alkoxy-7-phenylbicyclo[4.1.0]heptanes were formed. The presence of benzaldehyde in the reaction mixture led to α-alkoxystilbenes. An explanation for these different reactions is presented.

Aldol condensations with metal(ii) complex catalysts

Abstract: Aldol condensations of aldehydes with ketones catalyzed by the first-row transition metal(II) complexes have been widely studied. Complexes of Co(II), Ni(II), Cu(II), and Zn(II) acetates with 2,2′-bipyridine were effective catalysts to afford cross-aldol condensation products, α,β,-unsaturated ketones, in high yields without any self-condensation products. The reaction of 2-butanone, unsymmetrical aliphatic ketone, with benzaldehyde took place regioselectively to give base-catalyzed-type products.

Untersuchungen über die Autoxidation von cis- und trans-β-Methylstyren

Abstract: Studies on the Autoxidation of cis- und trans-β-Methyl Styrene In the autoxidation of cis- and trans-β-methyl styrene at temperatures between 80 and 120°C the CC-double bond is preferably attacked: 35–60% of epoxides and their consecutive products and 25–50% of benzaldehyde are obtained. Products of allylic oxidation are formed only with yields lower than 1%; high-boiling or polymeric products, respectively, which could not be detected gaschromatographically are formed with yields lower than 20%. The ratio of cis- to trans-epoxides in the case of cis-β-methyl styrene oxidation amounts to about 0.04, in the case of trans-β-methyl styrene oxidation this ratio is about 0.01.