Showing papers on "Hydrazone published in 1975"

Enhydrazine, 10. Einige aliphatische Enhydrazone

Abstract: Die Enhydrazone 1a–g, 2a, c, d, f, g und 3a–d, f, g werden durch Addition aliphatischer Hydrazone an carbonylaktivierte Acetylenverbindungen dargestellt und ihre NMR- und UV-Spektren verglichen. Einige Thermolyse-Produkte werden beschrieben. Enehydrazines, 10. Some Aliphatic Enehydrazones The enehydrazones 1a–g, 2a, c, d, f, g and 3a–d, f, g are prepared by addition of aliphatic hydrazones to carbonyl activated acetylenic compounds and their n.m.r. and u.v. spectra are compared. Some products of thermolysis are described.

Amino-acids and peptides. Part II. A new method for preparing diazodiphenylmethane and related compounds

Abstract: Diazodiphenylmethane has been prepared from benzophenone hydrazone by oxidation with peracetic acid in the presence of a base and a trace of iodine. Two variants of the process are described: (a) benzophenone hydrazone in an organic solvent is oxidised with peracetic acid in the presence of 1,1,3,3-tetramethylguanidine and a trace of iodine; (b) a solution of benzophenone hydrazone, in a two-phase organic solvent–water mixture, is oxidised by adding peracetic acid and sodium hydroxide simultaneously and equivalently at pH ca. 10 in the presence of a phase-transfer catalyst and a trace of iodine. The preparation of a variety of aryldiazoalkanes is reported.

Further investigation on the structure of the arylhydrazones of α‐cyanoketones: Electroreduction of 3‐Phenyl‐2,3‐diketopropionitrile 2‐Phenylhydrazone

Abstract: The polarographic behaviour of the benzenediazonium coupling product with ω-cyanoacetophenone in aqueous ethanolic solutions of varying pH indicates that it exists in the hydrazone form (1). A mechanism for the reduction process is suggested.

Amino-acids and peptides. Part I. Esterification of the carboxy-group of penicillins and cephalosporins by hydrazone oxidation.

Abstract: A new and efficient process for esterifying N-blocked amino-acids and peptides with readily removed protecting groups is described. Illustrations are given with particular reference to S-oxides of penam acids. The new process comprises oxidation of a hydrazone in an organic or aqueous organic solvent in the presence of the N-blocked amino-acid or peptide, and with a trace of iodine as catalyst.

The hydrazinolysis of heterocyclic compounds. I. 1,4,6-Trimethylpyrimidine-2(1H)-thione and related compounds

Abstract: The reaction of hydrazine hydrate with 1,4,6-trimethylpyrimidine-2(1H)- thione is shown to follow two major pathways. The first gives 4-amino- 5-hydrazino-1,2,4-triazole-3-thiol and 3,5-dimethyl-pyrazole. The second leads rapidly to 1-amino-4,6-dimethylpyrimidin-2(1H)-one hydrazone, a bright red intermediate compound which is rapidly consumed yielding 3,5-dimethylpyrazole and triaminoguanidine. The N- aminopyrimidine structure assigned to the intermediate is discussed in terms of its spectroscopic and chemical properties. Hydrazinolysis of 1,4,6-trimethylpyrimidin-2(1H)-imine similarly gives the same N- aminopyrimidine as well as 2-methylamino-and 2-hydrazino-4,6- dimethylpyrimidine from the Dimroth rearrangement. 1,4,6- Trimethylpyrimidin-2(1H)-one gives only 3,5-dimethylpyrazole under the same conditions. Mechanisms of the reactions are discussed.

Hydrazidine, II. Die Synthese von Pyrrolo[1,2-b]-1,2,4,5-tetrazinen

Abstract: Durch Reaktion von Acethydrazidin-hydrochlorid (2) mit 1,4-bifunktionellen Verbindungen, wie Maleindialdehyd, Maleinsaurederivaten (4, 6a–c). Dichlor- (10a) oder Dibrommaleinaldehydsaure (10b), werden verschiedene Vertreter der bisher unbekannten Pyrrolo[1,2-b]-1,2,4,5-tetrazine (3, 5, 11) erhalten. Hydrazidines, II. Synthesis of Pyrrolo[1,2-b]-1,2,4,5-tetrazines The reaction of acetohydrazide hydrazone hydrochloride (2) with 1,4-bifunctional compounds, like malealdehyde, derivatives of maleic acid (4, 6a–c), dichloro- (10a) or dibromomalealdehydic acid (10b), affords derivatives of the unknown pyrrolo[1,2-b]-1,2,4,5-tetrazines (3, 5, 11).

Working up synthesis solutions obtained in production of hydrazine

Abstract: In the production of hydrazine wherein aqueous ammonia is oxidized in the presence of a ketone to form an aqueous solution containing at least one of a hydrazone and a ketazine along with ammonia, the hydrazone and ketazine are concentrated and the hydrazone and ketazine are subsequently hydrolyzed to hydrazine and ketone, the improvement which comprises effecting the concentration of the hydrazone and ketazine by extracting the aqueous solution with a substantially water-immiscible organic solvent whereby the hydrazone and ketazine preferentially enter the water-immiscible solvent, and separating the water-immiscible solvent extract from the aqueous solution. The organic solvent is preferably a higher alcohol, a chlorinated hydrocarbon, benzene or a substitution product thereof. The organic solvent extract, in one or more stages, and optionally with addition of ketone, can be re-extracted with water, hydrolyzed with aqueous acid or subjected to distillation to separate the hydrazine values from the organic solvent.

Storage stabilized methylchloroform formulations

Abstract: Methylchloroform formulations containing 1,3-dioxolanes and/or 1,4-dioxane are storage-stabilized by the addition of aliphatic aldehyde hydrazone.

Preparation of novel acylhydrazone derivatives and their salts

Abstract: PURPOSE: Title compounds of formula I[R 1 , R 3 are H, halogen, lower alkyl, lower alkoxy, acylamino N-alkylacylamino, etc.;R 3 is H, lower alkyl; R 4 is acyl;A is alkylene;Z is radical of formula II(R 5 is H, acylony, bydroxyl; R 6 is H, Ph, ELKYL), III, IV, and V, or their salts. For example, cyclopropyl carbonyl hydrazone of 1-[ϒ-(4-fluorobenzoyl) propyl]-4-p-chlorophenyl-4-hydroxy piperidine. COPYRIGHT: (C)1977,JPO&Japio

Structural criteria for hydrazone photochromism in solution

Abstract: In view of the unique photochromic property of salicylaldehyde 2-quinolylhydrazone (1) in solution, a systematic study of the effects of hydrazone substituents on photochromism has been made. We have synthesized nine derivatives of (1) which are photochromic, eleven non-photochromic derivatives, and three non-quinolylhydrazones for comparison. On this basis, the following structural criteria for a hydrazone R1R2N·N:CR3R4 to exhibit photochromism in solution are derived: R1 and R2 should be H and an unsaturated system containing an α-imino-group; R3 and R4 should be H and an α-enol, the latter being capable of internal chelation.

Reaction of lead tetra-acetate with aldehyde nitrophenylhydrazones

Abstract: Oxidation of aliphatic aldehyde 2-nitrophenyl- or 2,4-dinitrophenyl-hydrazones with lead tetra-acetate is exceptional, giving azo-acetates containing α-hydrogen atoms as major products. Lesser yields of the expected diacylhydrazine products are also formed in a competing reaction. The yields of these diacylhydrazines increase, at the expense of the azo-acetates, with increasing chain length of the aliphatic substituent at the methine carbon atom of the hydrazone. Aliphatic aldehyde 4-nitrophenylhydrazones and benzaldehyde 2-nitro- and 2,4-dinitrophenylhydrazones behave normally, giving diacylhydrazines.

Neue Derivate des Fluorenon-hydrazons

Abstract: Es wurden die Triaminoguanidine 3a und b sowie das N-[Bis(methylthio)methylen]-N′-fluorenylidenhydrazin (4) synthetisiert. Die Reaktion von 4 mit Aminen bzw. Hydrazinhydrat fuhrte in die Reihe der S-Methylisothioharnstoffe (5), Aminoguanidine (6) und Triaminoguanidine (7). New Fluorenone Hydrazone Derivatives The triaminoguanidines 3a and b and N-[bis(methylthio)methylene]-N′-fluorenylidenehydrazine (4) have been synthesized. Compound 4 reacted with amines and hydrazine hydrate to give S-methylisothioureas (5), aminoguanidines (6), and triaminoguanidines (7), respectively.

Characteristic Detection and Determination of Aliphatic Aldehydes

Abstract: Aliphatic aldehydes can be detected and determined by reaction with propionaldehyde (3-phenyl-2-quinoxalinyl) hydrazone in ethanolic solution. The red color is produced within 20 min at 40°, then faded gradually. Detectable responses are obtained with aliphatic aldehydes but not with aromatic aldehydes, glucose, and ketones. With acetaldehyde, propionaldehyde, butyraldehyde, and iso-butyraldehyde, absorbance of the reaction mixture measured at 465 nm is directly proportional to the concentration. Acetaldehyde can be determined in the concentration range of 5×10-5 to 1×10-3M and other aldehydes in the range of 1×10-4 to 1×10-3M.

Chapter 5 – Compounds containing five-membered rings with one hetero atom from group V: Nitrogen: Fused ring compounds

Abstract: Publisher Summary A number of new methods of synthesizing indoles and its new derivatives are described in this chapter. The overall [1,4] methyl migration in Fischer indole rearrangements, actually proceeds by a series of [1,2] shifts. The stereochemical effects on the direction of cyclization in the Fischer indole synthesis are discussed in the chapter. The migration of a methyl group, involving a double 1:2 shift is observed during the indolization of the hydrazone that yields the indole derivative. The radical copolymerization of 1-vinylindole with electron-accepting monomers is discussed. A convenient synthesis of 4-alkylindoles is achieved by utilizing the stannous chloride-effected reaction of the endoperoxide of 1-methoxycarbonylpyrrole with carbon nucleophiles. The endoperoxide is obtained by photooxidation of the pyrrole. A number of 3-arylazoindoles are prepared and their tuberculostatic activity is determined. The diazo coupling of indole with 2-aminophenyl methyl sulfide is also investigated. Carbon-13 nuclear magnetic resonance spectra (13C-NMR) of carbazole and some of its derivatives are presented. Comparative 13C-NMR studies have been made of carbazoles, deuteriated carbazoles, and related heterocycles.

Radiation-induced aldehydes in collagen.

Abstract: Aldehydes present in native and irradiated (30 krad) collagen were separated from its enzymic degradation products using molecular-sieve chromatography on Bio-Gel P-2 column. From the absorption spectra of N-methylbenzothiazolone hydrazone derivatives it was concluded that two out of five of the aldehydes separated from the irradiated collagen, were identical with those present in control collagen. The possible origin of three other aldehydes is discussed.

3-Formyl-4-hydroxycoumarin Derivatives Syntheses of Semicarbazone, Phenylsemicarbazone, Hydrazino(oxazolin-4-one-2-yl) Hydrazone, Urea Derivatives, and their Sulfur Analogues

Abstract: Considering certain kinds of pharmacologic activity previously found in semicarbazide derivatives of a number of compounds we decided to synthesize molecules containing a semicarbazide or thiosemicarbazide moiety for subsequent pharmacological testing. For a start we combined the semicarbazide grouping with another potentially active component, the 4-hydroxycoumarin ring system.

Neue derivate des fluorenon-hydrazons

Abstract: Es wurden die Triaminoguanidine 3a und b sowie das N-[Bis(methylthio)methylen]-N′-fluorenylidenhydrazin (4) synthetisiert. Die Reaktion von 4 mit Aminen bzw. Hydrazinhydrat fuhrte in die Reihe der S-Methylisothioharnstoffe (5), Aminoguanidine (6) und Triaminoguanidine (7). New Fluorenone Hydrazone Derivatives The triaminoguanidines 3a and b and N-[bis(methylthio)methylene]-N′-fluorenylidenehydrazine (4) have been synthesized. Compound 4 reacted with amines and hydrazine hydrate to give S-methylisothioureas (5), aminoguanidines (6), and triaminoguanidines (7), respectively.

Study of the Fischer cyclization of diarylhydrazones and related secondary hydrazones I. Relative orienting capacity of the p-methyl and p-methoxy groups of diarylhydrazines

Abstract: A mixture of isomeric N-arylindoles is formed in the Fischer cyclization of N,N-diphenyllydrazones variously substituted in the para position by CH3 or CH3O groups. The intramolecular competition method makes it possible to form a judgment regarding the relative orienting capacity of the substituents in the aromatic ring in the step involving rearrangement of the enamine form of the hydrazone; in this case the effect of the rate of protonation and tautomerization of the hydrazone is excluded. It was established that the rate of rearrangement increases for the para substituents in the order H< CH3< CH3O.