- Observation of CH AX, CN BX, and NH AX emissions in gas-phase collisions of fast O(3P) atoms with hydrazines
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Optical emissions in single-colision reactions of fast (20 eV laboratory translational energy) O(3P) atoms with hydrazine, methylhydrazine, and 1,1-dimethylhydrazine have been measured in a crossed-beams geometry.The emissions were observed in
- Orient, Otto J.,Chutjian, Ara,Murad, Edmond
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Read Online
- Electrochemical Reductive N-Methylation with CO2Enabled by a Molecular Catalyst
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The development of benign methylation reactions utilizing CO2 as a one-carbon building block would enable a more sustainable chemical industry. Electrochemical CO2 reduction has been extensively studied, but its application for reductive methylation reactions remains out of the scope of current electrocatalysis. Here, we report the first electrochemical reductive N-methylation reaction with CO2 and demonstrate its compatibility with amines, hydroxylamines, and hydrazine. Catalyzed by cobalt phthalocyanine molecules supported on carbon nanotubes, the N-methylation reaction proceeds in aqueous media via the chemical condensation of an electrophilic carbon intermediate, proposed to be adsorbed or near-electrode formaldehyde formed from the four-electron reduction of CO2, with nucleophilic nitrogenous reactants and subsequent reduction. By comparing various amines, we discover that the nucleophilicity of the amine reactant is a descriptor for the C-N coupling efficacy. We extend the scope of the reaction to be compatible with cheap and abundant nitro-compounds by developing a cascade reduction process in which CO2 and nitro-compounds are reduced concurrently to yield N-methylamines with high monomethylation selectivity via the overall transfer of 12 electrons and 12 protons.
- Rooney, Conor L.,Wu, Yueshen,Tao, Zixu,Wang, Hailiang
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supporting information
p. 19983 - 19991
(2021/12/01)
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- Improved technology of mono-methyl hydrazine production process
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The invention discloses an improved technology of a mono-methyl hydrazine production process. An improved process is invented on the basis of a hydrochloric acid methanol hydrazine hydrate method, andthe defects of many byproducts, low reaction yield, environmental pollution caused by formation of highly toxic polybasic hydrazine in a reaction solution, and the like, when mono-methyl hydrazine issynthesized by using a hydrochloric acid methanol hydrazine hydrate method at present are overcome. According to the method, further methyl diversification of the target product mono-methyl hydrazinegenerated firstly in the reaction process is avoided, single production of the target product is guaranteed, more importantly, the process is simplified and environmentally friendly, the yield is increased, and the cost is reduced.
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Sheet 0027-0036
(2020/07/13)
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- Preparation technology of methylhydrazine
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The invention discloses a preparation technology of methylhydrazine, and belongs to the technical field of organic synthesis. The preparation technology comprises the following steps: (1) adding hydrazine monohydrochloride and methanol into a reaction kettle, then adding water and a catalyst, and then rising the temperature for carrying out methylation, thus obtaining methylhydrazine hydrochloride; (2) directly cooling feed liquid after reaction, separating a solid catalyst from unreacted hydrazine hydrochloride, and carrying out dealcoholizing, dissociating, rectifying and the like on filtrate, thus obtaining the methylhydrazine. The preparation technology disclosed by the invention has the advantages that the reaction selectivity is good, the reaction pressure is low, the catalyst can becompletely and mechanically used, and safety, cleanliness, environment protection and the like are realized.
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Paragraph 0025-0032
(2019/04/04)
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- By using industrial waste 1, 2 - dimethyl jing into a method of monomethyl hydrazine
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The invention discloses a novel method for converting industrial waste 1,2-dimethylhydrazine into methylhydrazine. A by-product 1,2-dimethylhydrazine liquid waste in industrial production of methylhydrazine is directly oxidized by using an oxidant for the first time, and a high-purity methylhydrazine water solution is obtained in rectifying and concentrating manners, so that commercial use of the 1,2-dimethylhydrazine by-product is solved. The method is simple in reaction process, high in conversion rate, and low in cost, the fed oxidant can be recycled after being restored, above all, waste is changed into treasures, the environmental pollution caused by discharged highly toxic industrial waste is prevented, and the safety is improved.
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Paragraph 0020-0022
(2017/10/26)
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- Tris(2-carboxyethyl)phosphine promotes hydrolysis of iminoboronates
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Iminoboronates are stable and formed fast. Their B[sbnd]N bonds could be reverted by some endogenous biological molecules. The reversible characteristic attracts significant attention in biological and chemical fields. Although synthesis of iminoboronates is well-studied, less efforts have been devoted to disconnecting the units. Here, a series of selected compounds were screened to evaluate their hydrolytic capability of iminoboronates by 1H NMR or 11B NMR detection. Tris(2-carboxyethyl)phosphine (TCEP), was emerged as an excellent reagent, which decomposed most iminoboronates in short time with high yields. In addition, TCEP is also able to hydrolyze hydrazones and oximes with moderate yields.
- Liu, Xiaoyu,Li, Zhihong,Xu, Hongtao,Zhan, Yuexiong,Ma, Peixiang,Chen, Hongli,Jiang, Biao
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p. 3101 - 3106
(2017/07/18)
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- Preparation method of methylhydrazine
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The invention discloses a method for one-step preparation of methylhydrazine. The method comprises that under the protection of inert gas, hydrazine hydrate and methanol are subjected to alkylation reaction under an action of a catalyst for one-step synthesis of methylhydrazine, excess methanol is kept in the reaction process, and a mixed solution after the reaction is finished is rectified to obtain a high-purity methylhydrazine solution. The method has the following advantages of short process route, simple operation, high reaction yield, high selectivity of the catalyst, mild reaction conditions, and fewer by-products and side reactions; the catalyst and unreacted methanol and hydrazine can be recycled for use in the alkylation reaction, no solvents are used, no three wastes are generated, and the method is green and environmentally friendly.
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Paragraph 0017
(2017/08/04)
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- Provided is a new method of catalytic synthesis of methyl hydrazine
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The invention discloses a novel method of catalytic synthesis of methylhydrazine under normal pressure. The method is characterized in that hydrazine hydrate and methane chloride react under normal pressure and 70-74 DEG C by taking hydrochloric acid as a protective agent, silica gel as a catalyst and ethyl alcohol as a solvent, thus generating methylhydrazine hydrochloride. A hydrazine ionization method is adopted, after methylhydrazine is ionized by the hydrazine hydrate, and a methylhydrazine aqueous solution is obtained by a rectification process. The ionized side product hydrazine monohydrochloride can be repeatedly used. The method has the following advantages: equipment cost and raw material price are lower in cost, reaction yield is high, the selectivity is good, three wastes are not generated, environment friendliness is good, and the process realizes internal circulation, continuous production can be conveniently performed, moreover, reaction is performed under normal pressure, operation is simple and production is safe.
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Paragraph 0040-0049
(2017/08/25)
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- Electrochemical reduction of 3-methyl-1-phenyl-3-hydroxytriazene and its copper complex
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3-Methyl-1-phenyl-3-hydroxytriazene (MPHT) and its Cu complex were synthesized, purified and characterized by spectral techniques. The electrochemical reduction of MPHT was studied in aqueous methanolic solution containing BR buffer using DC-polarography and cyclic voltammetry. The DC-polarogram and cyclic voltammograms displayed only one reduction wave. The kinetic parameters have been evaluated. The cyclic voltammetric data reveals that the reduction is irreversible and follows an EC mechanism involving transfer of six electrons. Constant current electrolysis of MPHT was carried out using stainless steel electrode. The products of electro-reduction were isolated, purified and then characterized by spectroscopic methods. The proposed mechanism is given for electro-reduction of MPHT in acidic, aqueous and alkaline medium. The voltammetric studies of Cu complex of MPHT at Pt electrode in CH2CI2 shows one electron quasi-reversible electrode process.
- Gupta, Manu,Hemlata,Karnawat, Romila,Verma
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p. 1525 - 1530
(2013/02/23)
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- PROCESS FOR PREPARING MONOMETHYLHYDRAZINE
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The present invention relates to a process for preparing monomethylhydrazine by methylating hydrazine or hydrazinium hydrochloride or hydrazinium dihydrochloride with methyl chloride and/or a methano/HCl mixture, characterized in that the reaction mixture formed in the methylation is reacted with an organic base from the group of the alkylamines or alkanolamines and monomethylhydrazine is removed by distillation from the reaction mixture in a low boiler fraction and the low boiler fraction is optionally subjected to a further distillation.
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Page/Page column 4
(2009/07/25)
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- Novel route to N-alkyl- and N,N′-dialkylhydrazines by high-pressure alkylation of azines
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Reactions of alkyl halides with azines of p-nitrobenzaldehyde, benzaldehyde, and p-methoxybenzaldehyde at a high pressure (10 kbar) were studied. Hydrolysis of the reaction mixtures gives pure N-monoalkyl- or N,N′-dialkylhydrazines in high yields, depending on the structure of the starting azine and the solvent nature. It was found that non-symmetrical N,N′-dialkylhydrazines can be synthesized without isolating intermediate N-monoquaternary immonium salts. The effect of the phase transition of the solvent on the direction of the alkylation is discussed.
- Agafonov,Dudin,Preobrazhenskii
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p. 714 - 716
(2007/10/03)
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- METHOD FOR TREATING CHRONIC PAIN USING MEK INHIBITORS
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The invention features a method for treating chronic pain using a compound selected from formulae (I), (II)A, (I)B and (I)C.
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- Oxidation of aliphatic amides by N-chlorobenzenesulfonamide in acid medium catalyzed by ruthenium(III): A kinetic and mechanistic study
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The kinetics of the ruthenium(III)-catalyzed oxidation of urea and substituted ureas, namely, methylurea, ethylurea and propylurea by sodium N-chlorobenzenesulfonamide or chloramine-B (CAB) in HCI medium have been studied at 30°. The reaction rate shows a first order dependence each on [CAB], [amide] and [RuIII] and fractional order on [H+]. Additions of halide ions and the reaction product of CAB (benzenesulfonamide) and the variation of ionic strength and dielectric constant of the medium do not have any significant effect on the reaction rate. Activation parameters have been evaluated. The rate increases in D2O medium. Proton inventory studies were made in H2O-D2O mixtures for both the amides. A Taft linear free energy relationship is observed for the reaction with ρ* = -0.88 and -3.20 and δ = -0.33, indicating that electron-donating groups enhance the rate. An isokinetic relation is observed with β = 372 K confirmed by the Exner criterion. The protonation constant of monochloramine-B has been evaluated to be 8.6. A mechanism consistent with the observed kinetic data has been proposed. The rate of oxidation increases in the order: propylurea > ethylurea > methylurea > urea.
- Puttaswamy,Jagadeesha,Ramalingaiah, Hulivana
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p. 426 - 432
(2007/10/03)
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- Benzenesulfonamide derivatives and their use as MEK inhibitors
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Benzenesulfonamides of formula (I), in which W is OR1, NR2OR1, NRARB, NR2NRARB, or NR2(CH2)2-4NRARBand the other variables as defined in the claims, are inhibitors of MEK and are effective in the treatment of proliferative diseases, cancer, stroke, heart failure, xenograft rejection, arthritis, cystic fibrosis, hepatomegaly, cardiomegaly, Alzheimer's disease, complications of diabetes, septic shock, and viral infection.
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- Nodulisporic acid derivatives
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The present invention relates to novel nodulosporic acid derivatives, which are acaricidal, antiparasitic, insecticidal and anthelmintic agents.
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- Triazinyl reactive dyestuffs in which triazinyl group is further substituted with a beta-chloroethylsulfonyl- or vinylsulfonylbutyrylamino moiety
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Reactive dyes of the formula STR1 in which D is the radical of an organic dye of the monoazo, polyazo, metal complex azo, anthraquinone, phthalocyanine, formazan, azomethine, dioxazine, phenazine, stilbene, triphenylmethane, xanthene, thioxanthrone, nitroaryl, naphthoquinone, pyrenequinone or perylenetetracarbimide series, R is hydrogen or substituted or unsubstituted C1-4 -alkyl, X is a substituent which is detachable as an anion, B is a radical of the formula STR2 R1 and R2, independently of each other, are hydrogen or substituted or unsubstituted C1-4 -alkyl or phenyl, A is a substituted or unsubstituted aliphatic or aromatic bridge member, Y is a --CO--Z or --SO2 --Z radical, Z is an aliphatic, aromatic or heterocyclic reactive radical, and n is 1 or 2, are suitable for dyeing or printing cellulose-containing and nitrogen-containing materials and in high dyeing yield produce dyeings and prints having good fastness properties.
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- REACTION OF 3,3-DIMETHYL-2,4-PENTANEDIONE WITH ALKYL- AND ARYLHYDRAZINES
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Depending on the conditions and on the substituent, the reaction of 3,3-dimethyl-1,4-pentanedione with alkyl- and arylhydrazines can be used for the synthesis of the corresponding mono- and bishydrazones and also substituted 5-hydroxy-, 5-hydrazino-, or 5-methylene-2-pyrazolines.The addition of trifluoroacetic acid, water, hydrazines, and amines to the latter was studied.For the "unsymmetrical" products from addition of the hydrazines to the substituted 5-methylene-2-pyrazolines an equilibrium or mutual transition between the two 5-hydrazino-2-pyrazoline forms is observed.
- Zelenin, K. N.,Malov, M. Yu.,Yakimovich, S. I.,Terent'ev, P. B.,Kaladarishvili, A. G.
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p. 377 - 385
(2007/10/02)
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- Reduction of Nitrosamines with Aqueous Titanium Trichloride: Convenient Preparation of Aliphatic Hydrazines
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The reduction of selected nitrosamines by aqueous TiCl3 has been investigated.In general, aliphatic nitrosamines were converted in good yield to the corresponding hydrazines, with little overreduction to the amines.Reaction proceeded rapidly at room temperature in both alkaline and acidic media.A variety of N,N-dialkylhydrazines have been isolated by using the TiCl3 method, which compares favorably with previously reported procedures for preparatively converting nitrosamines to hydrazines.In the reduction of N-nitroso-N-methylaniline, the proportion of amine in the product increased significantly as the pH of the reaction mixture was lowered, presumably reflecting the known instability of arylalkylnitrosamines in strong acid, coupled with a ready reducibility of the corresponding Fischer-Hepp intermediates; some tendency toward reductive cleavage of the N-aryl-N-alkylhydrazine's N-N-bond was also noted.Reduction of an α-nitrosamino ether gave the monoalkylhydrazine as the major product, while all other reducing agents studied converted this starting material chiefly to a mixture of primary and secondary amines.
- Lunn, George,Sansone, Eric B.,Keefer, Larry K.
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p. 3470 - 3473
(2007/10/02)
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- Synthese et reactivite de quelques α-amino azocomposes: mecanisme de la cyclisation thermique en triazoles-1,2,4
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The reaction of O-mesitylenesulfonylhydroxylamine (MSH) with hydrazones leads to carbon amination with the formation of α-amino azo compounds.Thermolysis of these compounds affords 1,2,4-triazoles.The mechanism of this cyclization is discussed.
- Metra, Pierre,Hamelin, Jack
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p. 285 - 290
(2007/10/02)
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- CINETIQUE DE LA REACTION DE FORMATION DE LA MONOMETHYLHYDRAZINE PAR ACTION DE LA MONOCHLORAMINE SUR LA METHYLAMINE
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The kinetics of monomethylhydrazine formation has been investigated in terms of concentrations, pH from 11.5 to 15 and temperature in teh range 20-35 degC.The overall reaction, first order in both reagents, is the result of two competitive reactions: -the first being pH independent, -the second accelerated by increasing pH.The energy of activation for each reaction has been derived from our results.
- Ferriol, Michel,Abraham, Robert,Delalu, Henri,Saugier-Cohen-Adad, Marie-Therese
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p. 725 - 728
(2007/10/02)
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- Organic compounds substituted heptadeca-5,9- and 5,10-dienoic acid
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The present invention provides novel substituted heptadeca-5,9- and 5,10-dienoic acid and similar fatty acid compounds which are derivatives of certain prostaglandins and are potent thromboxane A2 inhibitors. By virtue of this pharmacological property, they represent useful pharmacological agents for a wide variety of purposes.
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- Transformations in the Dibenzocyclopentene Series
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The synthesis of 5-aminomethyl-5-hydroxy-5H-dibenzocycloheptene derivatives 3 was accomplished by two separate routes.The first route involves the reaction of 4 with Corey's Reagent followed by reaction with either amines or hydrazines.The reaction products with hydrazines (e.g. 6) were hydrogenolyzed, either with hydrogen in the presence of platinum, or with hydrazine in the presence of Raney nickel to yield 3.The second route to these compounds (3) proceeds by a Reformatsky reaction on 4 followed by acid-hydrazide formation and Curtius degradationn of 8 to afford spirooxazolidones 9.Compound 9 can be alkylated on nitrogen (10), and either 9 or 10 hydrolyzed to give target compounds 3.
- Coppola, Gary M.,Hardtmann, Goetz .,Koletar, Gabor,Kroin, Stanley
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- Ureas as Amine Substrate for Hydrazine and Alkylhydrazine Synthesis---Reaction of Chloramine with Monomethylurea and Formation of 1-Methyltriazane
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Reaction of chloramine with monomethylurea has been shown to yield monomethylhydrazine and several side products, e. g., formaldehyde monomethylhydrazone, 1,1-dimethylhydrazine, methyliminotarazane, and methanol, originating from the further oxidation of monomethylhydrazine with chloramine.Evidence for the existance of 1-methyltriazane, CH3NHNHNH2, is presented for the first time.
- Prakash, Hari,Sisler, Harry H.
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p. 825 - 828
(2007/10/02)
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- Pyrazol-4-acetic acid compounds
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Pyrazol-4-acetic acid compounds, such as substituted pyrazol-4-acetic acid, its esters, amides, nitriles and their pharamaceutically acceptable salts and method for the preparation of these compounds are disclosed. The novel compounds are useful analgesics, anti-inflammatory, and antipyretics.
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