Showing papers on "Hydrazone published in 1982"

Nickel transport in Methanobacterium bryantii.

Abstract: Methanobacterium bryantii, grown autotrophically on H2-CO2, transported nickel against a concentration gradient by a high-affinity system (Km = 3.1 microM). The system had a pH optimum of 4.9 and a temperature optimum of 49 degrees C with an energy of activation of 7.8 kcal/mol (ca. 32.6 kJ/mol). A headspace of H2-CO2 (4:1, vol/vol) was required for maximum rate of transport. The system was highly specific for nickel and was unaffected by high levels of all monovalent and divalent ions tested (including Mg2+) with the sole exception of Co2+. Kinetic experiments indicated that accumulated nickel became increasingly incorporated into cofactor F430 and protein. Nickel transport was inhibited by nigericin, monensin, and gramicidin but not by carbonyl cyanide-p-trifluoromethoxyphenyl hydrazone, carbonyl cyanide-m-chlorophenyl hydrazone, N,N'-dicyclohexylcarbodiimide, valinomycin plus potassium, or acetylene. The ineffectiveness of carbonyl cyanide-p-trifluoromethoxyphenyl hydrazone, carbonyl cyanide-m-chlorophenyl hydrazone, and N,N'-dicyclohexylcarbodiimide may be related to difficulties in the penetration of these compounds through the outer cell barriers. Nickel uptake was greatly stimulated by an artificially imposed pH gradient (inside alkaline). The data suggest that nickel transport is not dependent on the membrane potential or on intracellular ATP, but is coupled to proton movement.

Electrophotographic element with fluorenylidene hydrazone compounds

Abstract: Electrophotographic light-sensitive elements containing substituted or unsubstituted fluorenone hydrazones as charge generating or charge transport materials are described.

Electrochemical oxidation of hydrazones

Abstract: Anodic oxidation of keto-arylhydrazones produced the parent ketone while a cyclic hydrazone yielded a rearranged product.

Untersuchungen zum UV/Vis‐Spektralverhalten von Azofarbstoffen. VI. Zum Einfluß von Substituenten auf die Farbe von Derivaten des 1‐Phenylazo‐2‐naphthols

Abstract: Studies on UV/Vis Absorption Spectra of Azo Dyes. VI. The Effect of Substituents on the Color of Derivatives of 1-Phenylazo-2-naphthols The absorption spectrum of 1-(4′-diethylaminophenylazo)-2-naphthol has been examined, and it has been found that the absorption band at 510 nm corresponds to the azo form and the shoulder at 610 nm corresponds to the hydrazone tautomeric form. Substituents in 3-position of 2-naphthol which have a free proton (e.g. OH, COOH, CONHR) stabilize the hydrazone tautomeric form by an intramolecular hydrogen bonding between substituent and hydrazone oxygen. Substituents which have not a free proton (e.g. OCH3, COOCH3, CONR1R2) have little influence on the absorption spectrum. The relative intensities of the two bands of the tautomeric forms are dependent on: — the electron attracting or electron releasing effect of the substituent R in CONHR — the hydrogen bonding acidity of the substituents in 2′-position if R in CONHR is a phenylring — the hydrogen bonding acidity of the solvent. The effect of substituents in the phenylazo subsystem is also discussed.

Reactions with heterocyclic diazonium salts: novel synthesis of pyrazolo[4,3-c]pyridazines and of pyrazolo[4,3-c]pyrazoles

Abstract: Diazotised 4-amino-1,5-dimethyl-2-phenylpyrazol-3(2H)-one (1) coupled with active methylene nitriles to yield the corresponding cyanohydrazones (3a–c) and (11). Compounds (3a–c) afforded the 4-(3-aminopyrazol-4-ylidenehydrazino)-1,5-dimethyl-2-phenylpyrazol-3(2H)-ones (5a–c) on treatment with hydrazine hydrate, and cyclised to give the pyrazolo[4,3-c]pyridazines (7a–c) on treatment with ethanolic hydrochloric acid. The hydrazone (11) cyclised to give the pyridazin-6-one derivative (12) when boiled under reflux in ethanol. Diazotised pyrazolone (1) coupled with 3-chloropentane-2,4-dione and with ethyl 2-chloro-3-oxobutanoate to yield the pyrazolo[4,3-c]pyrazole derivatives (9a and b).

Kinetics and mechanism of the reaction of thionyl chloride with substituted acetophenone semicarbazones. The synthesis of 1,2,3-thiadiazoles

Abstract: The reaction of thionyl chloride with a series of para-substituted acetophenone semicarbazones, which gives 1,2,3-thiadiazoles, involved an electrophilic attack. The rates correlated with the substituent σ+ constants and gave a Hammett ρ value of –0.55. The reaction had a low activation energy and a high negative entropy in the solvents thionyl chloride and carbon tetrachloride (ΔE‡ 9.46 kcal mol–1; ΔH‡, 8.8 kcal mol–1; ΔS‡–43.3 cal K–1 mol–1 for p-methylacetophenone semicarbazone in SOCl2). The rates of reaction of the semicarbazones were the same as the rates of appearance of the cyclised products, and there were no long-lived intermediates. The stoicheiometry of the reaction involved equimolar proportions of SOCl2 and of semicarbazone and the reaction was first-order in both reagents. Along with 4-aryl-1,2,3-thiadiazoles the final products were carbon dioxide, ammonium chloride, and hydrogen chloride. The mechanism proposed involves an ordered transition state with an approach of the electrophile above the plane of the hydrazone E-isomer via complexation with the conjugated π–n electron system. Tautomeric non-hydrazone forms of the semicarbazone are not involved in the rate-determining step.

Characteristic Raman bands for Azo and hydrazone structures

Abstract: Raman spectra of two hydroxy azoic model compounds: 3,5-dimethoxy-4-hydroxyazobenzene and 2,6-dimethoxy-4-hydroxyazobenzene are compared. These compounds exist as the pure azo and pure hydrazone forms respectively, thus allowing the assignment of numerous Raman Bands characteristic of each tautomer. The usefulness of Raman spectroscopy for investigating azo-hydrazone tautomerism is illustrated by a study of 2-hydroxy-5-methyl-azobenzene which is clearly proved to exist entirely in the azo form.

Preparation of 1,2exo‐ and 1,2endo‐Diiodo‐bicyclo[2.2.1]heptane

Abstract: 1,2 exo-Diiodo-norbornane (4) was prepared from norcamphor hydrazone by oxidative iodination and subsequent rearrangement of the 2,2-diiodo-bicyclo [2.2.1]heptane (2). The stable α-iodohydrazone 11 was obtained from 1-iodo-bicyclo[2.2.1]heptan-2-one (10), which itself was prepared from 1-iodo-norbornene (5). Subsequent treatment of 11 with iodine lead to 1,2,2-triiodo-norbornane (12) and l,2-diiodo-norborn-2-ene (13). 1,2 endo-Diiodo-norbornane (14) was obtained by stereoselective reduction of 12 with tribtityltinhydride or by reaction of 13 with diimide.

Endogenous generation of hydralazine from labile hydralazine hydrazones.

Abstract: The hypothesis that the pharmacologically active hydralazine hydrazones (HH) are endogenously hydrolyzed to parent hydralazine (H) was tested in a series of in vitro and in vivo systems. The stable hydrazones H alpha-ketoglutaric acid hydrazone and H pyruvic acid hydrazone did not hydrolyze to H in vitro (buffer or plasma), were inactive in vivo and did not generate urinary metabolites of parent H. By contrast, the labile HH, H acetaldehyde hydrazone and acetone hydrazone (HAH) generated H in vitro. H acetaldehyde hydrazone produced in vitro effects that were equipotent to the H concentration measured in the dose solutions. When administered to conscious rats and rabbits, the labile hydrazones reduced blood pressure. This effect was more gradual in onset than that of H. The hypotensive effects of HH were significantly greater than predicted by the amount of H contained in the dose solutions. Metabolic studies were conducted with the labile HH, HAH. After administration of HAH to rabbits, the proportional excretion of the urinary H metabolite, H pyruric acid hydrazone, was equal to that observed after the administration of H. We conclude that HH are inactive, except when hydrolyzed to H. The hydrolysis of certain HH, including HAH and H acetaldehyde hydrazone, in vivo may be nearly complete. Differences in the pharmacodynamic properties between labile HH and H may be related to the time course of generation of H, sequestration of hydrolysis in physiologically inactive sites or other unrecognized mechanisms.

Thiadiazoles and thiadiazolines. Part 3. Synthesis of triazol-3-yl-Δ2-1,3,4-thiadiazolines and a new synthesis of unsymmetrical 2,5-di-substituted 1,3,4-thiadiazoles

Abstract: The reaction of 1-chloro-1,4-diphenyl-2,3-diazabutadiene (1) with 1-acetyl- and with 1-benzoyl-thiosemicarbazide yields initially the hydrochlorides of N2-acetyl- and N2-benzoyl-Δ2-1,3,4-thiadiazoline-4-carboxamide hydrazone (4a, b) which are converted by aqueous sodium hydroxide into the corresponding free bases (5a, b) and thence by cyclodehydration into 4-(4H-1,2,4-triazol-3-yl)-Δ2-1,3,4-thiadiazolines (6a, b). Treatment of (1) with thioacetamide, thionicotinamide, or the thiobenzamides 4-XC6H4CSNH2(where X = H, MeO, and Cl), leads at 20–95 °C to 2-phenyl-5-R-1,3,4-thiadiazoles (9a–e)(where R = Me, 3-pyridyl, or 4-XC6H4). The reaction of (1) with guanidine leads, via the hydrochloride, to 3-amino-5-phenyl-4H-1,2,4-triazole. The mechanism of these and related reactions of (1) with other S-nucleophiles are discussed.

Imidazole hydrazone and hydrazine derivatives

Abstract: Compounds of the general formulae: ##STR1## in which Ar and Ar 1 which may be the same or different represent aromatic radicals optionally substituted once or more than by substituents selected from halogen, lower alkyl and lower alkoxy and Alk represents an alkylene group containing from 1 to 4 carbon atoms which alkylene group may be interrupted with a heteroatom; and acid addition salts thereof. These compounds have anti-anaerobe and also anti-fungal activity and are non-mutagenic.

Reactions of mercury(II) acetate with nitrogen compounds. Part 9. Oxidations of the bis-(4-nitrophenylhydrazone)s of some 1,3-diketones with mercury(II) acetate and lead(IV) acetate

Abstract: Oxidation of bis-(4-nitrophenylhydrazone)s of 1,3-diketones containing an α-CH between the hydrazone chains resulted in cyclisation with fragmentation, giving pyrazoles. The reaction is considered to involve dehydrogenation of the conjugated tautomeric enamine form of the bis-hydrazone, giving a cis-azo-hydrazonoalkene intermediate. When the postulated azo-hydrazonoalkene intermediate had trans-stereochemistry, unfavourable for cyclisation, as in the oxidation of cyclohexa-1,3-dione bis-(4-nitrophenylhydrazone), the azo-alkene was stable and was the main product. When the conjugated enamine tautomeric form of the 1,3-bis-hydrazone could not exist, as with 3,3-dimethylpentane-2,4-dione bis-(4-nitrophenylhydrazone), pyrazoles were not formed and the hydrazone chains behaved as isolated monohydrazones.

Measurement of ceruloplasmin

Abstract: PURPOSE:To obtain stable and highly active substrates for measuring the titled substance, by using 4-aminoantipyrine and an N-substitued aniline compound, or 3- methyl-2-benzothizolinone hydrazone and the N-substituted aniline compound as substrates. CONSTITUTION:4-Aminoantipyrine and an N-substituted aniline compound shown by the formula (R1 and R2 are lower alkyl group or 1-5C hydroxyalkyl group, etc; R3 and R4 are H, lower alkyl group, acetyl group, etc.), or 3-methyl-2-benzothiazolinone hydrazone and the N-substituted aniline compound shown by the formula as substrates are added to serum for measuring. After this, increase in absorption is determined, and the concentration of ceruloplasmin is calculated from a calibration curve.

Synthesis of pyrrolo[3,2-b]indole derivatives

Abstract: The reaction of N-acetylindoxyl hydrazone with ketones in alcohol gave N-acetylindoxyl alkylindenehydrazones, which were converted to pyrrolo[3,2-b]indole derivatives by treatment with glacial acetic acid. Pyrrolo[3,2-b]indole derivatives were also obtained in the reaction of N-acetylindoxyl hydrazone with ketones in glacial acetic acid. The structures of the synthesized products were confirmed by data from the IR, UV, PMR, and mass spectra.

Cationic hydrazone derivatives, processes for their preparation and their use

Abstract: Hydrazone derivatives of the formula ##STR1## in which A 1 is an aromatic radical, B 1 is hydrogen, alkyl, cycloalkyl, aralkyl or aryl, R 1 , R 2 and R 3 independently of one another are alkyl, cycloalkyl, aralkyl or polyoxyalkylene, Z 1 is arylene, X.sup.⊖ is an anion and m is 0, 1, 2 or 3. The hydrazone derivatives are suitable as UV absorbers, especially in polymer coatings.

Novel hydrazone compound and electrophotographic receptor using it

Abstract: PURPOSE:To obtain a novel hydrazone compd. high in solubility in a binder polymer capable of forming a uniform and high-sensitivity charge transfer layer, and a high-sensitivity electrophotographic receptor having a layer contg. it. CONSTITUTION:A hydrazone compd. represented by general formula ( I ) is prepared by reacting aldehydes represented by genraal formula (II) with equimolar or a little excessive diphenylhydrazine or its minearl acid salt in a solvent at a temp. up to the reflux temp. of the solvent. In formulae ( I ), (II), R represents 5-10C straight or branched chain alkyl, alkenyl, alkadienyl, or 7-10C aralkyl. A photosensitive layer 5 consisting of a charge generating layer composed mainly of a charge generating substance 2 and a charge transfer layer 4 contg. a hydrazone compd. uniformly is formed on a conductive substrate 1 to obtain a photoreceptor. The hydrazone compd. constitutes the charge transfer layer 4 together with a binder.

Pyrroloindoles. 6. New synthesis of 1H, 5H-pyrrolo[2,3-f]indole and 3H,6H-pyrrolo[3,2-e]indole

Abstract: Ethyl pyruvate 1-acetyl-5-indolinylhydrazone was obtained by diazotization of 1-acetyl-5-aminoindoline with subsequent reduction of the diazonium salt and condensation of the hydrazine with ethyl pyruvate. A mixture of hydrogenated derivatives of linear and angular pyrroloindoles is formed as a result of cyclization of the hydrazone in polyphosphoric acid esters. Subsequent hydrolysis, decarboxylation, and dehydrogenation lead to 1H,5H-pyrrolo[2,3-f]indole and 3H,6H-pyrrolo-[3,2-e]indole.

2,4-Dinitrobenzaldehyde (1H-tetrazol-5-yl)hydrazone

Abstract: C s H 6 N 8 0 4 , M r = 278.2, monoclinic, P21/n, Z = 4, T = 293 K, a = 10.991 (2), b = 9.056 (2), c = 11.706(2)A, f l = 101.50(1) ° , V = 1141.8A3, D m = 1.60, D x 1.62 Mg m 3 , g 0.118 mm -~, C u K a radiation (2 -1.54051 A). Final R = 0.049 for 1228 independent reflections. The title compound, DBTYH, consists of a 2,4-dinitrobenzaldehyde moiety and a tetrazole moiety bridged by a hydrazone chain. Each molecule is hydrogen-bonded to three other molecules through four hydrogen-bond linkages (two acceptor and two donor) centered on the tetrazole ring. The entire molecule is approximately planar with the exception of one nitro group which is rotated 39 ° out of the plane of the benzene ring and has a short C H . . . O distance that could indicate a weak intramolecular hydrogen bond. The crystal was automatically recentered every 428 reflections, with four standard reflections checked after each 102 measurements. Of the resulting 1701 independent reflections, 1228 reflections with F > 3a(F) were used in the refinement. Lorentz-polarization corrections were applied; decay and absorption corrections were not necessary. The structure was solved with MULTAN (Declercq, Germain, Main & Woolfson, 1973) using 141 reflections (Emi n = 1.75) and three general phase relationships. All but one of the non-H atoms were located in Table 1. Fractional coordinates (x 104, for H x 103) and Beq or Bis o (A 2) with e.s.d.'s in parentheses, and deviations (A × 10 a A) of non-hydrogen atoms from the least-squares plane (see text) Introduetlon. DBTYH, which was prepared by reacting (1H-tetrazol-5-yl)hydrazine with 2,4-dinitrobenzaldehyde (Thiele, 1898), has been used in the preparation of explosives (Jaffery, 1976) as have other tetrazole x compounds (Duke, 1971; Bryden, 1958). Its thermal o ( 1 ) -1246(6) decomposition has been studied under dynamic and o(2) 34 (7) o(3) 850 (8) isothermal conditions using a differential scanning o(4) 1770(7) calorimeter (Om Reddy, Krishna Mohan, Mohan N ( 1 ) 2158(6) N(2) 2490 (7) Murali & Chatterjee, 1981). N(3) 1856 (6) Oscillation and Weissenberg photographs of a yellow N(4) 1128 (6) N(5) 807 (6) crystal of DBTYH (grown by slow evaporation from a N(6) 1127 (6) 2:1 methanol-dioxane mixture) showed the crystal N ( 7 ) -359(6) system to be monoclinic, with systematic absences 0k0, N(8) 1249 (7) C(1) 818 (7) k = 2n + 1 and hOl, h + l = 2n + 1, indicating space c(2) 325 (7) group P21/n, with general positions x,y,z and 1⁄2 x, 1⁄2 + c(3) 450 (7) y, 1⁄2 -z. The crystal density was measured by flotation c(4) 1113 (7) C(5) 1649 (8) using iodobenzene and kerosene, c(6) 1484 (8) Accurate unit-cell parameters were obtained by c(7) 614(7) least-squares refinement of 15 carefully centered c(8) 1341(7) H(N1) 247 (8) reflections and 1952 reflections (20ma x : 120 °) were H(N5) 36(9) measured using the 0-20 scan mode on a Syntex P21H(C3) 7 (6) F diffractometer (crystal size 0.06 x 0.09 x 0.11 mm). H(C5) 214 (7) H(C6) 186 (6) H(C7) 0 (5) * Permanent address: Depar tment of Physics, Central College, Bangalore University, Bangalore 560 001, India. 0567-7408/82/092487-04501.00 Beq or

Michael-type additions of oxime and hydrazone anions with methyl α-bromoacrylate. X-Ray structure determination of a bromocyclopropane derivative

Abstract: Oxime and hydrazone anions undergo a michael-type addition with methyl α-bromoacrylate leading to bromocyclopropane derivatives, the structure of which has been established by X-ray analysis.

Molecular and crystal structure of acetone N-methyl-N-(4-chloro-1-phthalazinyl) hydrazone and its bisulfate

Abstract: Acetone N-methyl-N-(4-chloro-1-phthalazinyl)hydrazone and its bisulfate salt were subjected to x-ray diffraction study. Rotation of the fragments about the C-N (23.5 °) and N-N (59.4 °) bonds occurs in the hydrazone. The amino nitrogen atom is pyramidal. Protonation of the hydrazone leads to the formation of a three-ring cation, viz., the 1,3,3-trimethyl-2,3-dihydro-1,2,4-triazolo[3,4-a]-phthalazinium cation.

Imidazole hydrazone and hydrazine derivatives, production thereof and use in medicine

Abstract: Compounds of the general formulae: in which Ar and Ar 1 which may be the same or different represent aromatic radicals optionally substituted once or more than by substituents selected from halogen. lower alkaly and lower alkoxy and Alk represents an alkylene group containing from 1 to 5 carbon atoms which alkylene group may be interrupted with a heteroatom: and acid addition salts thereof. These compounds have anti-anaerobe and also anti-fungal activity and are non-mutagenic.

Kinetics of Acid Hydrolysis of Resacetophenone Isoniazid Hydrazone in Presence & Absence of Molybdenum(VI) in Dimethylformamide

Abstract: Kineti£s of acid hydrolysis of re;acetopitenone isoniaDd hyd.ra%onealone and in presence of molybdenum(Vl) in 10% (vJv) N,N-4imethylformamlde have been studied at JOoC. The rate of hydrolysis lnaeases with increase in [nitric add], ionic strength and dielectric eoestant, The reaction is classified as AAC2 type involving two positive ions. The decrease in rate in the presence of molybdenum(Vl) is attributed to the formation of metal complex having a bichelate ring structure.

Process for the preparation of benzophenone hydrazone derivatives

Abstract: Title hydrazones I(R1,R5,R7=halogen, alkyl, haloalkyl, alkoxy; R1 or R5 makes naphthyl group with adjacent benzene; R2,R4=H, alkyl, acyl, ester, thioester group, optionally substituted carbamoyl or thiocarbamoyl; R2 and R4 make C5-7 cycle with adjacent N; R3=substituted alkyl, alkenyl, N,N-dialkylamino, substituted phenyl; when p is zero, R2 and R4 are not H; m,n,x= 0, 1; P= 0, 2, 3), useful insecticides, were prepd. by reacting compd. II with NH2NR2R4. Thus, 4-chloro-4'-methylsulfonylbenzophenone ethoxycarbonyl hydrazone (m.p. 132.5-140≰C) was prepd. from phenol, p-chlorobenzoyl chloride, and ethylcarbozate.