- Synthesis of hydroxyethylhydrazine by the Raschig process and comparison with synthesis by the alkylation process
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The Raschig synthesis of hydroxyethylhydrazine (HEH) is studied, that is, the reaction of monochloramine on ethanolamine. The formation of HEH is monitored by UV spectrometry, and the influence of temperature and pH is studied. The primary reaction is an SN2-type mechanism, whereas the main secondary reaction is the oxidation of HEH by monochloramine. This reaction is also monitored by UV spectrometry, and the oxidation product is identified by GC-MS analysis, showing the formation of hydroxyethylhydrazone. The reaction mechanisms and the rate constants were determined, and the results permit establishing the main reactions occurring during HEH synthesis. These reactions were validated in a concentrated medium, with the systematic study of the influence of the molar ratio p ([HEH]0/[NH2Cl] 0) and the final sodium hydroxide concentration and temperature. A comparison is made with the other synthesis process already published, that is, the alkylation of hydrazine by either chloroethanol or epoxide.
- Goutelle,Pasquet,Hajj, A. El,Bougrine,Delalu
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- Kinetic studies of hydrazine and 2-hydroxyethylhydrazine alkylation by 2-chloroethanol: influence of a strong base in the medium
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To optimize yields, the study of reaction kinetics related to the synthesis of 2-hydroxyethylhydrazine (HEH) obtained from the alkylation of N 2H4 by 2-chloroethanol (CletOH) was carried out with and without sodium hydroxide. In both cases, the main reaction of HEH formation was followed by a consecutive, parallel reaction of HEH alkylation (or dialkylation of N2H4), leading to the formation of two isomers: 1,1-di(hydroxyethyl)hydrazine and 1,2-di(hydroxyethyl)hydrazine. In this study, hydrazine and hydroxyalkylhydrazine alkylations followed SN2 reactions triggered directly by CletOH or indirectly in the presence of a strong base by ethylene oxide, an intermediate compound. The kinetics was studied in diluted mediums by quantifying HEH and CletOH by gas chromatography and gas chromatography coupled with mass spectrometry (GC-MS). The activation parameters of each reaction and the influence of a strong base present in the medium on the reaction mechanisms were established. A global mathematical treatment was applied for each alternative. It allowed modeling the reactions as a function of reagent concentrations and temperature. In the case of direct alkylation by CletOH, simulation was established for semi-batch and batch syntheses and was confirmed in experiments for concentrated mediums (1.0 M≤[CletOH]0 ≤3.2 M and 15.7 M≤[N2H4]0 ≤18.8 M). Simulation therefore permits the prediction of the instantaneous concentration of reagents and products, in particular ethylene oxide concentration in the case of indirect alkylation, which must be as weak as possible.
- Goutelle,Pasquet,Stephan,Bougrine,Delalu
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- Comparative Study on the Multielectron Reduction of HOC2H4N3 catalyzed by n4>42- and n4>2-modified Glassy Carbon Electrodes
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Both N4>42- and n4>2-modified glassy carbon electrodes (/GC and /GC, respectively) can catalyse the multielectron reduction of HOC2H4N3 to afford not only HOC2H4NH2 and N2 but
- Tanaka, Koji,Uezumi, Satoshi,Tanaka, Toshio
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- Synthetic method of furazolidone metabolite AOZ
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The invention discloses a preparation method of 3-amino-2-oxazolidinone (AOZ). The method comprises the following steps: 1) carrying out a reaction on ethylene glycol and PBr3 to obtain 2-bromoethanol; 2) carrying out a substitution reaction on 2-bromoethanol and an alkali, then adding hydrazine hydrate into the system, continuously carrying out a ring-opening reaction, and removing excessive 2-bromoethanol and water after the reaction is completed to obtain an intermediate 2-hydrazinoethanol; and 3) in the presence of an alkali, carrying out a reaction on 2-hydrazinoethanol and diethyl carbonate to obtain 3-amino-2-oxazolidinone (AOZ). According to the method, a nitrofuran metabolite AOZ is synthesized by adopting a one-pot method at the rear half part, so that the loss of a separated andpurified sample in the synthesis process is greatly reduced.
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Paragraph 0022; 0025
(2020/07/13)
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- Production of 2-hydroxy [...] of the micro-reactor apparatus and process for preparing
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The invention discloses a microreactor device for producing 2-hydroxyethylhydrazine and preparation process. The device comprises a feeding system, a mixing system, a reaction system, a backpressure valve, a cooling receiving system, a washing system and an external circulating bathing system, wherein the feeding system comprises a hydrazine hydrate storing tank, an oxirane storing tank and a feeding pump; the mixing system comprises a CPMM or SIMM or Starlam serial micro mixer; the reaction system comprises a rimule reactor section; the pressure of the backpressure valve ranges from 0 to 15MPa; the cooling receiving system comprises a CRMH serial micro heat exchanger and a receiving storing tank; the washing system comprises a washing storing tank and a washing pump which are connected in series; the hydrazine hydrate storing tank or oxirane storing tank, the feeding pump, the micro mixer, the rimule reactor, the backpressure valve, the micro heat exchanger and the receiving storing tank are connected in series; the mixing system, the reaction system and the cooling receiving system are respectively arranged at the circulating bathing system.
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Paragraph 0037; 0038
(2017/04/07)
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- NOVEL BACTERIAL COLONY SENSING REGULATOR AND MEDICAL USE
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The invention relates to a compound of formula I, and a preparation method and use thereof. The compound has a bacterial quorum-sensing regulatory effect, and can be used for prevention and/or treatment of a disease caused by a bacterial infection.
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Paragraph 0041; 0042
(2015/12/19)
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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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