Showing papers on "Hydrazone published in 1980"

New dyes based on 3‐aryl‐benzo‐ and ‐naphtho‐1,4‐thiazines

Abstract: 3-Aryl-2H-1,4-benzothiazines have been converted into cyanine dyes by condensing their hydroperchlorates with aldehydes, and into azo-compounds by coupling with reactive diazonium salts. The azo-compounds were also obtained by condensing arylglyoxal hydrazonyl bromides with o-aminothiophenol; they exist predominantly in their tautomeric hydrazone forms. 2-Amino-3-mercapto-1,4-naphthoquinone condenses with ω-bromoaceto-phenones to form 3-aryl-3,4-dihydro-3-hydroxy-2H-naphtho[2,3-b]-1,4-thiazine-5,10-quinones. Attempts to dehydrate these carbinolamines gave a variety of products. Oxidation of the phenyl analogue with iodosobenzene diacetate led to acetyoxylation at C-2 by an indirect Pummerer oxidation.

Spectrophotometric determination of microgram amounts of calcium in waters and foods using diphenylglyoxal bis(2-hydroxybenzoyl hydrazone)

Abstract: The synthesis, characteristics and analytical applications of diphenylglyoxal bis(2-hydroxybenzoyl hydrazone) are described. This compound reacts with calcium(II) at pH 12 to produce a yellow complex (λmax. = 432 nm, Iµ= 1.76 × 104 l mol–1 cm–1); another complex (1:1) can be detectd at pH 7.80. Dipyridylglyoxal bis(2-hydroxybenzoyl hydrozone). A sesnitive and selective spectrophotomeric method is proposed for the determination of clcium using diphenylglyoxal bis(2-hydroxybenzoyl hydrazone). Interferences have been investigated and when masking agents are added common cations do not interfere. The yellow calcium(II) complex has been used for the determination of clcium in waters and foods. The esults are compared with those obtained using glyoxal bis(2-hydroxyanil).

Coordination compounds of hydrazine derivatives with transition metals. Part 20. Nickel(II) chelates witho-hydroxy ando-methoxy-benzaldehyde aroylhydrazones. An example of coordination isomerism

Abstract: A series of monoligand nickel(II) chelates Ni(SalC6H4X) · 3 H2O containing salicylaldehyde aroylhydrazones H2SalC6H4X were isolated and characterized. The correspondingo-methoxyhenzaldcliyde aroylhydrazones (HMeOBhC6H4X) react with nickel(II) acetate to give isomeric red and green chelates of stoichiometry M(MeOBhC6H4X)2. The red isomers were assumed to possess a square planar arrangement with the hydrazone molecule acting, as a mononegative bidentate ligand, whereas an octahedral structure was assigned to the green isomer with the hydrazone molecule acting as mononegative tridentale ligand. The pyridine and 1,10-phenanthrolinc adducts of the complexes were characterizcd.

Komplexe von Hydrazinen mit Kronenethern und ihre Umsetzung mit Carbonylverbindungen

Abstract: Die erstmals dargestellten stabilen kristallinen, stochiometrischen Komplexe 3 – 8 mono- und di-substituierter Hydrazine mit Neutralliganden vom Kronenether-Typ (1, 2) lassen sich durch Umsetzung mit Carbonylverbindungen unter Phasentransfer in lipophilen Losungsmitteln zur Herstellung substituierter Hydrazone einsetzen. Complexes of Hydrazines with Crown Ethers and their Reaction with Carbonyl Compounds The stable crystalline stoichiometric complexes 3 – 8 of mono- and di-substituted hydrazines with crown ether-type neutral ligands (1, 2), described for the first time, are utilized for the synthesis of the corresponding substituted hydrazones in lipophilic solvents by the reaction with carbonyl compounds under phase transfer conditions.

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

Spectrophotometric determination of cobalt with biacetyl mono(2-pyridyl)hydrazone

Abstract: The absorbance versus pH graphs and stoicheiometry of the complexes formed by biacetyl mono(2-pyridyl)hydrazone (BPH) with cobalt(II), nickel(II), copper(II) and iron(II) have been studied. A method for the spectrophotometric determination of cobalt has been devised. The orange-red chelate is formed at acidities between 2 and 10–6M(pH 6), in aqueous ethanolic solution, and has λmax. at 505 nm with a molar absorptivity of 2.3 × 104 l mol–1 cm–1. The method has been applied to the determination of cobalt in nitrates and has been compared with other pyridylhydrazone procedures for the spectrophotometric determination of cobalt.

A Kinetic Fluorimetric Method for Determination of Microamounts of Pt(IV) with 2-2′ Dipyridylketone Hydrazone

Abstract: A kinetic method for determination of traces of Pt(IV) based on the aerobic oxidation of the hydrazone of 2-2′ dipyridylketone, in which the formation of a fluorescent product (λex = 359 nm, λem = 435 nm) takes place, is described. The reaction is followed by the measurement of the rate of appearance of the fluorescence. The proposed method suffers very few interferences.

Some metal-ion complexes with ligands formed by reactions of amines with aliphatic carbonyl compounds. IX. Nickel(II) compounds of some b-imino amines, a β-oximato amine and a β-hydrazino amine

Abstract: Singlet ground state compounds of nickel(II) with tetradentate β-imino amine ligands are formed by reaction of complexes of ethane-1,2- diamine, propane-1,2-diamine, 3-azapentane-1,5-diamine, 4-azaheptane- 1,7-diamine and (2-aminoethyl)piperazine with 4-amino-4-methylpentan-2- one, amp. With 3,6-diazaoctane-1,8-diamine, a compound with a pentadentate β-imino ligand is formed, water completing octahedral coordination, and with 2-aminoethanol a bis compound of a tridentate β-imino amine alcohol ligand is formed. More complex products are formed by the hydrazone and oxime of amp. The oxime compound shows appreciable antiferromagnetism, with the spin-coupling constant, J, about -70 cm-1, determined from magnetic susceptibility measurements over 100-300 K.

Monochromatic Light-induced Reactions of Benzophenone Hydrazones and the N-Acetyl Derivatives in Carbon Tetrachloride in the Presence of Oxygen

Abstract: Irradiation of hydrazones of benzophenone, 4-methylbenzophenone and 4-methoxybenzophenone in carbon tetrachloride with monochromatic light in the presence of oxygen afforded the corresponding azine, resulting from N–N bond cleavage, as the major product together with the hydrazone hydrochloride. In contrast to the hydrazones, benzophenone acetylhydrazone in carbon tetrachloride in the presence of oxygen afforded an unstable hydroperoxide as the only product, on photolysis with monochromatic light (288±8 nm); this product was transformed spontaneously into benzophenone on evaporation of the solvent at room temperature. 4-Methylbenzophenone acetylhyd razone and 4-methoxybenzophenone acetylhydrazone reacted in a manner similar to benzophenone acetylhydrazone. Irradiation of benzophenone diacetylhydrazone with 266±8 nm light under conditions analogous to the photo-reactions of hydrazones and acetylhydrazones resulted in loss of an acetyl group, resulting in N–CO bond cleavage to afford acetylhydrazone. The me...

Synthesis of vincaminic acid derivatives

Abstract: Vincaminic acid derivatives of formula (A) ##STR1## useful in treating cerebral insufficiency, are prepared by reacting 1-ethyl-2,3,4,6,7,12-hexahydroindolo[2,3-a]quinolizine with the 2,4-DNP hydrazone of ethyl or methyl bromopyruvate followed by (i) reduction of the C═N bond and (ii) simultaneous cyclization with removal of the ketone-protecting group in either order.

Novel hydrazone compounds and process for preparing the same

Abstract: Hydrazone compounds having the general formula ##STR1## wherein Ar is selected from the group consisting of a naphthalene ring radical, substituted naphthalene ring radicals, an anthracene ring radical, substituted anthracene ring radicals, styryl, substituted styryls, a pyridine radical, a furan ring radical and a thiophene ring radical. The hydrazone compounds can be prepared by allowing 1-methyl-1-phenylhydrazine having the formula ##STR2## to react with an aldehyde represented by the general formula Ar-CHO, wherein Ar is the same as mentioned above at a substantially equal molar ratio in an organic solvent selected from the group consisting of lower alcohols, cyclic ethers, cellosolves, N,N-dimethylforamide and acetic acid, in the presence of an acid catalyst, by heating and refluxing the reaction mixture. The hydrazone compounds are extremely useful as charge transport materials for use in electrophotographic photoconductors of the type comprising an electroconductive support material and a photosensitive layer containing a charge generation material and a charge transport material.

Identification of the Decomposition Products of Hydralazine Hydrazones with Three Endogenous Ketones and Kinetic Study of the Formation of 3-Methyl-s-triazolo [3, 4-a] phthalazine from Hydralazine and Pyruvic Acid

Abstract: The decomposition products of hydrazones of hydralazine with pyruvic acid, acetone and α-ketoglutaric acid were studied. The pyruvic acid hydrazone and acetone or α-ketoglutaric acid hydrazone were converted to 3-methyl-s-triazolo [3, 4-a] phthalazine (MTP) and phthalazinone, respectively, both of which are known hydralazine metabolites. New high pressure liquid chromatographic (HPLC) methods for determining hydralazine and MTP were developed. The formation of MTP and the disappearance of hydralazine at a physiological concentration ratio and pH at 37° were studied by the HPLC methods. The formation of MTP followed second-order kinetics, and its rate constant was determined.

Isomerism and lead(IV) acetate oxidation reactions of p-substituted phenylosazones of some substituted glyoxals and 1,2-diketones. Reactions of metallic acetates with nitrogen compounds. Part 5.

Abstract: The structures of the bis-(p-nitrophenyl)hydrazones and some bis-(p-bromophenyl)hydrazones of glyoxal, methylglyoxal, phenylglyoxal, butane-2,3-dione, benzil, and cyclohexane-1,2-dione were examined by i.r.,1H n.m.r., and 13C n.m.r. spectroscopy. Generally the E,E forms of the osazones were obtained from direct synthesis except for the bis-(p-nitrophenyl) hydrazoneofcyclohexane-1,2-dione and phenylglyoxaland the bis-(p-bromophenyl)hydrazones of phenylglyoxal, which were obtained as the E,Z-chelate forms. Unstable yellow crystalline forms of the bis-(pnitrophenyl)hydrazones of glyoxal, butane-2,3-dione, and benzil containing two molecules of hexamethylphosphoramide (HMPA) of crystallisation, which may contain the E,Z-isomers, were isolated from HMPA solutions. Lead tetra-acetate oxidation of a range of E,E-osazones gave dehydrogenations to 1,2-bisazoethylenes. Similar oxidations of E,Z-osazones gave mainly 2-aryl-1,2,3-triazole type products (osotriazoles) along with lower yields of azoethylenes. Oxidation of cyclohexane-1,2-dione bis-(p-nitrophenyl)hydrazone gave a mixture of osotriazoles containing an acetoxy- or p-nitroacetanilido-group at the 3-position of the cyclohexyl ring.

Crystal Structure of Dunnione p-Bromophenylhydrazone

Abstract: The crystal structure of dunnione p-bromophenylhydrazone has been determined by single-crystal X-ray diffraction methods at 295 K, the structure being refined to a residual of 0.054 for 1429 'observed' reflections. Crystals are triclinic, Pī, a 15.620(8), b 8.804(4), c 7.439(4) Ǻ, α 68.03(4), β 89.85(4), γ 77.44(4)°, Z 2. The conjugation throughout the molecule is extensive and the crystal packing is dominated by intermolecular charge-transfer interactions. Bonding in the hydrazone moiety lies intermediate between those expected for hydrazone and azo forms.

Reagent for detection of peroxidase

Abstract: PURPOSE:To provide a reagent for the detection of peroxidase, having high performance comparable to benzidine, and prepared by dissolving a specific hydrazone and a phenolic compound in a buffer solution. CONSTITUTION:The title reagent is obtained by dissolving (A) 0.5-5m-mol of 3-methyl-2-benzothiazolinone hydrazone hydrochloride and (B) 3-25m-mol of a phenolic compound of formula (A is NH2, NHCH3, N(CH3)2, OCH3, or halogen; B is CH3, H, or halogen; X is HCl, H2SO4, CH3COOH, or HCOOH; n is 0, 1, or 2), e.g. o-aminophenol, 2,3-dichlorophenol, etc. in (C) a buffer solution, e.g. a phosphate buffer solution, and adjusting the pH of the mixture to 5-7.

A new fluorescent hydrazide for sequencing ribonucleic acids

Abstract: This paper deals with the synthesis and properties of a fluorescent hydrazide and its hydrazones of nucleoside dialdehydes and of 5'-methylene nucleoside dialdehydes. Hydrazination of 1-dimethylaminonaphthalene-5-sulphonyl-glycyl ethyl ester (DNS-GlyOC 2 H 5 ) gives the fluorescent carbonyl reagent, 1-dimethylaminonaphthalene-5-sulphonyl-glycyl hydrazide (DNS-Gly-NHNH 2 ). The reaction of DNS-Gly-NHNH 2 with the nucleoside dialdehydes or the 5'-methylene nucleoside dialdehydes produced by the oxidation of the corresponding nucleosides or 5'-nucleotides with sodium periodate forms the respective fluorescent hydrazones. The coupling ratio of nucleoside dialdehydo to DNS-Gly-NHNH 2 is 1:1. The nucleoside hydrazones can be clearly resolved by polyamide plate chromatography with a sensitivity of 1 × 10 -10 mole. The ultraviolet absorption spectra, the molar extinction coefficients, the fluorescent spectra as well as the quantum yields of the hydrazide and its nucleoside hydrazones in water, ethanol and dioxane are measured. The fluorescent intensities of the hydrazone increase with the decrease of solvent polarity. Their quantum yields are about 0.4 in dioxane. A micromethod is described for sequencing oligoribonucleotides by stepwise β-elimination followed by fluorescent labeling of their 3'-terminal nucleosides. The sensitivity of this method indicates that tetraribonucleotide with A 260nm as little as 0.16 is sufficient for sequence determination.

Derivatives of 1,2,5,6,9,12-hexaazacyclotetradecatetraene and 1,2,5,6,9,14-hexaazacyclohexadecahexaene based on 2,3-dihydrazinoquinoxaline

Abstract: A bis(hydrazone) was synthesized by the reaction of 2,3-dihydrazinoquinoxaline with 3-methyl-1-phenyl-1H-pyrazole-4,5-dione. Treatment of the bis(hydrazone) with POC13 and Et3N gave a dichloro diazo compound, from which macrocyclic metal chelates, viz., derivatives of 1,2,5,6,9,12-hexaazacyclotetradecatetraene and 1,2,5,6,9,14-hexaazacyclohexadecahexaene, were obtained by reaction with diamines in dimethylformamide in the presence of Pd(II) and Ni(II)salts.

[Compounds with antitumor activity. V. Hydrazone derivatives of 5-formylimidazo(2,1-b)thiazoles and 6-substituted 2,3-dihydro-5-formylimidazo(2,1-b)thiazoles].

Abstract: The synthesis of 2,3-dihydro-5-formylimidazo[2,1-b]thiazoles with different substituents at position 6 (CH3, C6H5, Cl, Br) is reported; thiosemicarbazones and tosylhydrazones were prepared from these aldehydes and from the 2,3-unsaturated analogues: these derivatives, submitted to a preliminary test, did not show significant antileukemic activity.