Showing papers on "Hydrazone published in 1973"
TL;DR: A quick and easily reproducible procedure for determining the catecholase activity of tyrosinase is described and the absorbance of the condensation compound is read at 500 nm.
43 citations
TL;DR: Spectrophotometric titration with hydrazines established that benzylamine oxidase contains one mole of reactive pyridoxal phosphate per mole of protein, whereas the copper content is at least two atoms per protein molecule.
Abstract: The interaction between pig plasma benzylamine oxidase and hydrazine derivatives has been investigated kinetically and spectrophotometrically. The hydrazines tested combine irreversibly to the enzyme and there is a one-to-one correspondence between inactivation of the enzyme and hydrazone formation with enzyme-bound pyridoxal phosphate. Spectrophotometric titration with hydrazines established that benzylamine oxidase contains one mole of reactive pyridoxal phosphate per mole of protein, whereas the copper content is at least two atoms per protein molecule.
38 citations
Patent•
01 Mar 1973TL;DR: In this paper, the preparation of 1,5-bis-substituted-1,4-pentadien-3-one, substituted amidinohydrazone salts are described.
Abstract: The preparation of 1,5-bis-substituted-1,4-pentadien-3-one, substituted amidinohydrazone salts are described. They are prepared by the reaction of a 1,5-bis(substituted)-1,4-pentadiene-3-one with a substituted aminoguanidine salt. These compounds are useful as anti-malarial and anti-tubercular agents in warm-blooded animals.
26 citations
TL;DR: Rat liver glutamine transaminase activity suggests that the enzyme has binding sites for glutamine and α-keto acids which overlap, and studies of the albizziinglyoxylate transamination reaction indicated that the enzymes exhibits ping-pong kinetics.
21 citations
TL;DR: In this article, 3-acetyl-5-6-dihydro-2-methyl-1,4-oxathiin-3-carboxylic acid hydrazide rearrange was found to undergo ring cleavage by nucleophilic nitrogen attack on C-2.
Abstract: Acid hydrolysis of 5,6-dihydro-2-methyl-1,4-oxathiin-3-carboxanilide gives 2-(2-hydroxyethylthio)-acetoacetanilide enol. 3-Carbonyl-substituted 5,6-dihydro-1,4-oxathiins were found to undergo ring cleavage by nucleophilic nitrogen attack on C-2. Thus the following reactions were observed: 3-acetyl-5,6-dihydro-2-methyl-1,4-oxathiin on treatment with hydrazine gives 4-(2-hydroxyethylthio)-3,5-di-methylpyrazole, instead of the hydrazone. The 1,4-oxathiins, N-(5,6-dihydro-2-methyl-1,4-oxathiin-3-ylcarbonyl)-N′-phenylurea and 5,6-dihydro-2-methyl-1,4-oxathiin-3-carboxylic acid hydrazide rearrange to give 5-(2-hydroxyethylthio)-6-methyl-1-phenyluracil and 4-(2-hydroxyethylthio)-3-methyl-2-pyrazolin-5-one, respectively. Finally, treatment of 5,6-dihydro-2-methyl-1,4-oxathiin-3-carbonyl chloride with 2-aminopyridine and with 2-aminopyrimidine affords 4H-3-(2-hydroxyethylthio)-2-methyl-pyrido[1,2-a]pyrimidin-4-one and 4H-3-(2-hydroxyethylthio)-2-methylpyrimido[1,2-a]pyrimidin-4-one, respectively, as the predominan...
16 citations
14 citations
TL;DR: In this paper, the complex formation of o-hydroxybenzaldehyde benzoyl hydrazone with Zn(II), and Mn(II) was investigated and the same complexes are soluble in organic solvents and studies on their extraction with chloroform, 1-pentanol and 1-octanol, for possible analytical application, are reported.
12 citations
TL;DR: In this article, N-Aryl- and N-alkylhexafluoroisopropylideneimines (2) were prepared from the hexafluorsothioacetone dimer by treatment with either aryl or alkylamines.
Abstract: N-Aryl- and N-alkylhexafluoroisopropylideneimines (2) were prepared from the hexafluorothioacetone dimer (1) by treatment with either aryl- or alkylamines. These imines reacted with alcohols and thiols to give three addition products, 7, 8, and 9. Phenylhydrazone (3), semicarbazone (4), hydrazone (5), and azine (6) of hexafluoroacetone were also obtained directly from 1 and the corresponding carbonyl reagents.
10 citations
TL;DR: Some Novel Reactions of 2-hydroxyacetophenone derivatives with N-Dimethoxymethyl-dimethylamine are discussed in this paper, where the behavior of 3 towards sodium hydroxide and sulfuric acid has been investigated.
7 citations
TL;DR: In this paper, 8-azapurine and its 2-oxo-and 2-thioxo-derivatives were cleaved by 1,1-dimethylhydrazine to yield 4-dimethioxonomethylamino-(7a), 4-ureido-(5a), and 4-thioureido(5b) 1,2,3-triazole-5-carbaldehyde hydrazone.
Abstract: 8-Azapurine and its 2-oxo- and 2-thioxo-derivatives were cleaved by 1,1-dimethylhydrazine to yield 4-dimethylhydrazonomethylamino-(7a), 4-ureido-(5a), and 4-thioureido-(5b) 1,2,3-triazole-5-carbaldehyde dimethylhydrazone, respectively, and by hydrazine to give 4-amino-(9a), 4-ureido-(9b), and 4-thioureido-(9c) 1,2,3-triazole-5-carbaldehyde azine, respectively. 2-Amino-8-azapurine gave 4-hydrazonomethylamino-1,2,3-triazole-5-carbaldehyde hydrazone (7d).With hydroxylamine, 8-azapurine and its 2-amino and 2-thioxo-derivatives yielded, respectively, 4-hydroxyiminomethylamino-(7b), 4-diaminomethyleneamino-(4a), and 4-thioureido-(5c) 1,2,3-triazole-5-carbaldehyde oxime, whereas the reaction with 8-azapurin-2(3H)-one stopped at the addition product 1,6-dihydro-6-hydroxyamino-8-azapurin-2(3H)-one (3a). Similarly 8-azapurine and methoxyamine yielded 5-methoxyiminomethyl-4-methoxyiminomethylamino-1,2,3-triazole (7c), whereas its 2-oxo-derivative gave 1,6-dihydro-6-methoxyamino-8-azapurin-2(3H)-one (3b).
1
H N.m.r. and u.v. spectra, and some pKa values, are reported; their bearing upon the structures of the products and the reaction mechanisms is discussed.
6 citations
TL;DR: Azo dyes have been prepared by coupling phenols with diazotized C- amino-1,2,4-triazole and p-aminophenyl-1 2,4,5 triazoles as discussed by the authors.
Abstract: Azo dyes have been prepared by coupling phenols with diazotized C- amino-1,2,4-triazole and p-aminophenyl-1,2,4-triazoles. Spectroscopic proofs of structure establish preferential para-coupling. The dyes exist in the azo form without evidence for quinone hydrazone tautomers. Spectroscopic evidence and chelation not involving the phenolic hydroxyl group suggest trans-configuration.
TL;DR: Condensation of 1-benzoyl-1-phenylhydrazine (I) with β-ketoesters and β-diketones was investigated as mentioned in this paper.
Abstract: Condensation of 1-benzoyl-1-phenylhydrazine (I) with β-ketoesters and β-diketones was investigated. Reaction of I with ethyl acetoacetate, ethyl benzoylacetate and diethyl acetonedicarboxylate in the presence of phosphorus pentoxide afforded the corresponding hydrazones which were easily cyclized by sodium hydroxide to give pyrazole derivatives. Reaction of I with acetylacetone proceeded to give hydrazone without condensing agent. 4-Carboxy-1,5-diphenylpyrazol-3-ylacetic acid and its mono- and diester were also prepared.
TL;DR: Aldehyde and 1.2-disubstituierte hydrazine werden zu 1,3,4-oxadiazolidinen (A) and Hexahydro-1.4.3.2.
Abstract: Aldehyde und 1.2-disubstituierte Hydrazine werden zu 1,3,4-Oxadiazolidinen (A) und Hexahydro-1.2.4.5-tetrazinen (B) umgesetzt. A lassen sich durch Eliminierung einer der beiden Aldehyd-Komponenten vermittels Hydrazon- oder Oxim-Bildung in B uberfuhren.
Cyclic Hydrazine-Acetals
Aldehydes and 1.2-disubstituted hydrazines react to 1.3.4-oxadiazolidines (A) and hexahydro-1.2.4.5-tetrazines (B). A were converted into B by elimination of one of the two aldehyde-components via hydrazone- or oxime-formation.
TL;DR: In this paper, the reaction path was studied on the basis of isolated compounds, and Picryl derivative of phenol gave 2,6-di-t-butyl-p-benzoquinone-picrylanil (X) instead of hydrazone (V).
Abstract: Alkaline ferricyanide oxidation of 4-arylazo-2,6-di-t-butylphenols (I) gave molecular nitrogen, diphenyl derivatives (VI), 2,6-di-t-butyl-p-benzoquinone-N-(3′,5′-di-t-butyl-4′-hydroxyphenyl)arylhydrazone (V) and red tarry compounds. Picryl derivative of phenol (I) gave 2,6-di-t-butyl-p-benzoquinone-picrylanil (X) instead of hydrazone (V). The reaction path was studied on the basis of isolated compounds.
TL;DR: In this article, Naphthoquinone aldehyde was hydrogenated to yield quinone imine 4 and further reactions were described, and the reaction mixtures with acyl hydrazides (e g isonicotic hydrazide) were isolated and their structures determined.
TL;DR: The long wavelength bands of the anions exhibit an opposite substituent effect to that observed for the hydrazones, and the shifts due to ionisation are approximately proportional to the Hammett σ constants of substituents in the aryl ring as mentioned in this paper.
Abstract: Several arenediazonium salts have been coupled to 1,2,3,4-tetrachlorocyclopentadiene and the products have been shown by i.r. spectroscopy to exist exclusively as hydrazones in the solid state. The visible absorption spectra show that the same situation exists in solution, and the effect of substituents on the spectra can be interpreted most readily in terms of the hydrazone structures. In the presence of bases the hydrazones readily form anions which absorb at longer wavelengths than the parent compounds. The long wavelength bands of the anions exhibit an opposite substituent effect to that observed for the hydrazones, and the shifts of the hydrazone bands due to ionisation are approximately proportional to the Hammett σ constants of substituents in the aryl ring.
TL;DR: Monohydrazones of N-(2-acetyl-1,3-indandione)trialkylammonium iodides have been synthesized and used as reagents for the carbonyl group and can be identified by the absorption spectrum of their derivatives with these reagents.
TL;DR: In this article, the reaction path was studied on the basis of isolated compounds, and Picryl derivative of phenol gave 2,6-di-t-butyl-p-benzoquinone-picrylanil (X) instead of hydrazone (V).
Abstract: Alkaline ferricyanide oxidation of 4-arylazo-2,6-di-t-butylphenols (I) gave molecular nitrogen, diphenyl derivatives (VI), 2,6-di-t-butyl-p-benzoquinone-N-(3′,5′-di-t-butyl-4′-hydroxyphenyl)arylhydrazone (V) and red tarry compounds. Picryl derivative of phenol (I) gave 2,6-di-t-butyl-p-benzoquinone-picrylanil (X) instead of hydrazone (V). The reaction path was studied on the basis of isolated compounds.
TL;DR: In this paper, the Fischer reaction was applied to 2,6-dichloro-4-pyridyl (2.6-dimethylpoly(2.4)-poly(1.5)-methylpyrazoline and 2, 6-dicloro4-poly(4)-aminopyridine, the ratio between which depends on the temperature and duration of the reaction.
Abstract: Instead of the usual indolization, when acetaldehyde (2,6-dichloro-4-pyridyl)hydrazone is heated with zinc chloride under the conditions of the Fischer reaction one observes the formation of acetone (2,6-dichloro-4-pyridyl)hydrazone, 1-(2,6-dichloro-4-pyridyl)-5-methylpyrazoline, and 2,6-dichloro-4-aminopyridine, the ratio between which depends on the temperature and duration of the reaction.
TL;DR: Azo dyes have been prepared by coupling phenols with diazotized C- amino-1,2,4-triazole and p-aminophenyl-1 2,4,5 triazoles as discussed by the authors.
Abstract: Azo dyes have been prepared by coupling phenols with diazotized C- amino-1,2,4-triazole and p-aminophenyl-1,2,4-triazoles. Spectroscopic proofs of structure establish preferential para-coupling. The dyes exist in the azo form without evidence for quinone hydrazone tautomers. Spectroscopic evidence and chelation not involving the phenolic hydroxyl group suggest trans-configuration.
TL;DR: Aldehyde and 1.2-disubstituierte hydrazine werden zu 1,3,4-oxadiazolidinen (A) and Hexahydro-1.4.3.2.
Abstract: Aldehyde und 1.2-disubstituierte Hydrazine werden zu 1,3,4-Oxadiazolidinen (A) und Hexahydro-1.2.4.5-tetrazinen (B) umgesetzt. A lassen sich durch Eliminierung einer der beiden Aldehyd-Komponenten vermittels Hydrazon- oder Oxim-Bildung in B uberfuhren.
Cyclic Hydrazine-Acetals
Aldehydes and 1.2-disubstituted hydrazines react to 1.3.4-oxadiazolidines (A) and hexahydro-1.2.4.5-tetrazines (B). A were converted into B by elimination of one of the two aldehyde-components via hydrazone- or oxime-formation.
TL;DR: In this paper, a study was made of the electrochemical reduction of some phenyl-substituted arhylhydrazones of methylglyoxal, diketobutyric acid and its ethyl ester in dimethylformamide.
Abstract: 1.
Employing classical and cyclic polarography, and polarography with a Kalousek switch, a study was made of the electrochemical reduction of some phenyl-substituted arhylhydrazones of methylglyoxal, diketobutyric acid and its ethyl ester in dimethylformamide.
2.
The nitro derivatives of the arylhydrazones form the most stable anion-radicals.
3.
It is postulated that an intramolecular hydrogen bond is present in theo-nitro-substituted arylhydrazones, which is formed by the hydrazone proton and the nitro group.