Showing papers on "Hydrazone published in 1986"
TL;DR: The stability of protein-Hydrazone conjugates was found to be significantly greater than that of the model compound, the N-acetylhydrazone of p-carboxybenzaldehyde, believed to result from the presence of multiple hydrazone linkages in protein conjugate.
Abstract: Proteins can be modified at their amino groups under gentle conditions to contain an average of three to six aryl aldehyde or acyl hydrazide groups. These two types of modified proteins at about 10 microM concentration condense with each other at pH approximately 5 to form conjugates linked by hydrazone bonds. Under proper conditions conjugates mainly of dimers and trimers in size or, if desired, higher oligomers can be obtained. The conjugates can be dissociated to their individual protein components by an exchange reaction with an excess of acetyl hydrazide. The reversible hydrazone bonds of conjugates can be reduced with NaCNBH3 to give stable hydrazide bonds. The stability of protein-hydrazone conjugates was found to be significantly greater than that of the model compound, the N-acetylhydrazone of p-carboxybenzaldehyde. This difference is believed to result from the presence of multiple hydrazone linkages in protein conjugates.
181 citations
TL;DR: Porcine kidney diamine oxidase is the second mammalian enzyme shown to have PQQ as its prosthetic group and it is incorrect to assume that inhibition of this type of enzymes with common hydrazines is simply due to blocking of the carbonyl group of its cofactor.
73 citations
TL;DR: Trichloroacetaldehyde tosylhydrazone acts as an excellent precursor of diazodithioacetate which is generated by treatment of the hydrazone with sulfide ion as mentioned in this paper.
Abstract: Trichloroacetaldehyde tosylhydrazone acts as an excellent precursor of diazodithioacetate which is generated by treatment of the hydrazone with sulfide ion. This spontaneously cyclizes it to 5-mercapto-1,2,3-thiadiazole. The precursor also gives a 5-amino-1,2,3-triazole on reaction with an amine. α,α-Dichloro ketone tosylhydrazones similarly cyclize to give 1,2,3-thiadiazoles and 1,2,3-triazoles.
62 citations
TL;DR: An efficient and highly anti-diastereo and enantioselective synthesis of 3,4-disubstituted 5-oxo-alkanoates 3 in good overall chemical yields is described.
57 citations
TL;DR: In this paper, the 13 C and 15 N-NMR spectra of compounds prepared by coupling benzenediazonium ions with 9-hydroxyanthracene, acetylcyclopentadiene, 8-hydroxy quino line, 3-cyano-1,4-dimethylpyridine-2,6-dione and 1-naphthol have been measured.
46 citations
TL;DR: A series of new 1-(2,4-dichlorobenzoyl) hydrazones and 2-aryl/aralkyl-5-2, 4-D-Dichlorophenyl-1, 3-4-oxadiazoles have been synthesized from different aldehydes as mentioned in this paper.
37 citations
35 citations
TL;DR: In this paper, the synthesis and chemical properties of some 2 and 3-substituted furo[2,3-b]pyridines were described, and a 2-methyl derivative was obtained by reduction, O-acetylation and subsequent pyrolysis.
30 citations
TL;DR: In this article, the metal-ligand complexes of phenyl-2-picolyl ketone hydrazone, PPKhy and PPKPhy with copper(II) nitrate in mole ratio 1:1 or 1:2, metal:ligand have been prepared.
29 citations
TL;DR: The lithium salts of trityl- and diphenyl-4-pyridylmethyl-hydrazones of both aldehydes and ketones react with electrophiles at low temperature to form C-trapped azo compounds ; these intermediates decompose homolytically with loss of nitrogen below room temperature and can be diverted in a synthetically useful way to alkanes, alkenes, alcohols or saturated esters as mentioned in this paper.
27 citations
TL;DR: The Thermal Ene reaction of aldehyde t -butyl- and phenyl- hydrazones with enophiles gave C -trapped azo-adducts which can be diverted into synthetically useful γ-keto-esters, γ -keto n-nitriles, β-alkyl-2-pyrrolidones, and β-amino-esters.
TL;DR: In this paper, the interaction of hydrated copper(II) chloride or bromide with phenyl-2-picolyl ketone hydrazone and phenyl 2-pinyl ketone phenyl hydrone, respectively, has been studied employing elemental analyses, spectral studies (IR and electronic spectra) and the variable temperature magnetic susceptibility together with the electron spin resonance spectra.
TL;DR: Novel 1-aryl-1H- and 1- Daryl-3-heteroaryl- 1H-pyrazolo[3,4-b]quinoxalines (flavazoles) 9a-c, 12, 13 were synthesized via a facile hydrazone synthesis using aryl diazonium salts and exhibited the antifungal activity in some extent.
TL;DR: Synthese des oxydes du titre par cyclisation oxydante des alkylhydrazones oximes du biacetyle, du pyruvaldehyde ou du glyoxal; desoxygenation douce en alkylin-2 v-triazoles
Abstract: Synthese des oxydes du titre par cyclisation oxydante des alkylhydrazones oximes du biacetyle, du pyruvaldehyde ou du glyoxal; desoxygenation douce en alkyl-2 v-triazoles
Patent•
27 Nov 1986TL;DR: In this article, the diazo compounds having the formula XYCNN and their parent hydrazones were provided, where X is an ortho-nitro aromatic group such as o-nitrophenyl and Y is a hydrocarbon groups such as methyl.
Abstract: of EP0233403The invention provides diazo compounds having the formula XYCNN and their parent hydrazones, where X is an ortho-nitro aromatic group such as o-nitrophenyl and Y is a hydrocarbon group such as methyl. The hydrazones may be prepared by reacting the corresponding ketone with hydrazine and the diazo compounds by hydrazone oxidation. The diazo compound may be reacted with an organic compound having a reactive hydrogen atom such as phosphate, thiophosphate, phosphonate, carboxyl and phenol, to form a caged compound from which the original organic compound can be released by photolysis, eg in situ in a biological system. Preferred organic compounds are ATP and other nucleotides.
Journal Article•
TL;DR: In this paper, 3-methyl-2-oxo-1,2-dihydroquinoxaline 3 with chlorophenyl diazonium salts, and 4b,c were found to exhibit the tautomeric equilibria between the hydrazone imine and diazenyl enamine forms in the dimethylsulfoxide solutions.
TL;DR: In this paper, trivalent lanthanides have been found to form complexes with o-hydroxyacetophenone isonicotinoyl hydrazone (o-HAINH) of the type M(o-HINH-2H)X(H2O)2 [M ≡ LaIII, PrIII, NdIII, SmIII, GdIII and DyIII; X ≡ OH or SCN].
Abstract: Trivalent lanthanides have been found to form complexes with o-hydroxyacetophenone isonicotinoyl hydrazone (o-HAINH) of the type M(o-HAINH-2H)X(H2O)2 [M ≡ LaIII, PrIII, NdIII, SmIII, GdIII, DyIII; X ≡ OH or SCN]. The complexes have been characterized by elemental analysis, molar conductance, magnetic susceptibility, IR and electronic spectral studies. The nephelauxetic ratio \ gb, covalency δ and bonding parameter b 1 2 of particularly neodymium complexes have been calculated. IR spectral studies reveal that o-HAINH acts as a tridentate ligand coordinating through azomethine nitrogen, phenolate oxygen and imidol oxygen and that thiocyanate is N bonded. A coordination number six around the metal ion has been proposed for all the complexes.
TL;DR: In this article, the 2-nitrophenyl hydrazone (2-NH(crystals) −νNH(CHCl3) was determined to be monoclinic, space group P21/a, Z= 4, with a= 12.074 and 0.068.
Abstract: Crystal structures have been determined of the two title compounds. The (2-nitrophenyl)hydrazone (2) is monoclinic, space group P21/a, Z= 4, with a= 12.074(5), b= 12.771(8), c= 11.998(8)A, β= 118.0°. The (4-nitrophenyl) hydrazone (3) is orthorhombic, space group Pcab, Z= 8, with a= 8.468(7), b= 13.98(1), c= 26.82(1)A. Respectively, 1 244 and 1 181 independent reflections above background were collected and the structures were refined to R 0.074 and 0.068. The two structures show remarkably different conformations. In (2), the hydrazone N(7)–H(7) group is involved in an intramolecular hydrogen bond to the ortho-nitro group, and there is also a possible H(7)⋯π intraction. In (3) there is a definite H(7)⋯π interaction with the C–C bond of a phenyl group, with H(7)⋯ C distances of 2.43 and 2.26 A. The difference between the two structures is probably due to the fact that in (2) the hydrogen bond requirements of the N(7)–H(7) group are satisfied by the ortho-nitro group, and that in consequence there is no need for much subsidiary overlap with the π-electrons. In (3) there is no ortho-group and therefore the hydrogen bond can only be formed with the C–C bond.Evidence for these N–H ⋯ C–C interactions is also obtained from the i.r. spectra of a series of compounds. Frequency difference values [νNH(crystals)–νNH(CHCl3)] of 14–15 cm–1 are observed for (3) and similar compounds, providing a clear indication of an intramolecular NH ⋯π bond in the crystals which does not survive in solution.
TL;DR: In this paper, the treatment of C-(triphenylphosphinimido)hydrazone with aryl and alkyl isocyanates results in 5-arylamino-1H-1,2,4-triazoles, often accompanied by a minor quantity of the triazol-5-one.
Abstract: Treatment of C-(triphenylphosphinimido)hydrazone (1) with aryl and alkyl isocyanates results in 5-arylamino- and 5-alkylamino-1H-1,2,4-triazoles (5), often accompanied by a minor quantity of the triazol-5-one (7). The related ortho-acyl-substituted substrates (8) react with phenyl isocyanate to give [1,2,4]triazolo[1,5-a]quinazolines (12) or (13) through the intermediacy of aminotriazoles (11).
TL;DR: In this paper, the C-alkylation products of t-butyldiphenylmethylhydrazones can be efficiently transformed into amines, hydrazines, and also alkanes under mild reaction conditions.
Abstract: α-Amino carbanion equivalents (NH2) and α-hydrazino anion equivalents (NHNH2) are readily accessible from the C-alkylation products of t-butyldiphenylmethylhydrazones; these azoalkanes can be efficiently transformed into amines, hydrazines, and also alkanes under mild reaction conditions.
TL;DR: The synthesis, spectroscopic characteristics and analytical applications of 1,2-cyclo-hexanedione bis-benzoylhydrazone are reported and has been satisfactorily applied to the determination of titanium in bauxite, Portland cement, amphibolites and granites.
TL;DR: In this paper, the characteristic tautomeric equilibria between the hydrazone imine form C and the diazenyl enamine form D with a long-range prototropy by means of the pmr and 13C-nmr spectroscopies were clarified.
TL;DR: In this paper, the authors composes du titre et de pyrazolo [3,4d] pyrimido [4,5-6] azepines par oxydation par Pb(Oac) 4 de tosylhydrazones d'allylamino-6- ou butene-3ylamino -6 uracile carbaldehydes-5 en nitrilimines suivie de cycloaddition dipolaire-1,3 intramoleculaire
Abstract: Synthese des composes du titre et de pyrazolo [3,4-d] pyrimido [4,5-6] azepines par oxydation par Pb(Oac) 4 de tosylhydrazones d'allylamino-6- ou butene-3ylamino-6 uracilecarbaldehydes-5 en nitrilimines suivie de cycloaddition dipolaire-1,3 intramoleculaire
TL;DR: In this article, the effect of pH variation on the rection products of rhodium-2-picolylketone-2pyridyl hydrazone (PPKPyH) is discussed.
Abstract: Mono, bis and tris complexes of rhodium(III) with phenyl-2-picolylketone-2-pyridyl hydrazone (PPKPyH) have been characterized. In every case, the imino-proton of PPKPyH shows marked acidity associated with the coordination to rhodium(III). Electronic spectra show that all complexes are octahedral. The B′-values suggest a strong covalency in the metal-ligand σ-bond and the Dq-values indicate a medium-strong ligand field. The magnetic susceptibility indicates that PPKPyH forms low-spin complexes with rhodium(III).1H n.m.r. spectra show that the tris(ligand) complexes arecis isomers. I.r. spectra show that the ligand is neutral or monobasic tridentate or bidentate. Far i.r. studies show that [Rh(PPKPyH)X3] · 2 H2O (X = Cl, Br or I) aremer isomers. The effect of pH variation on the rection products is also discussed.