- Synthesis method of o-Dibromo compound
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The present invention discloses a synthesis method of o-dibromo compounds, said synthesis method comprising the following steps: preparation of olefins, brominated salts and a mixed solution of bromate; to the mixed solution of dropwise addition of hydrochloric acid solution for reaction; to the end of the reaction, the extraction of o-dibromo compounds in the reaction product; the synthesis method to inexpensive brominated salts (industrial or recycled brominated salts) and bromate as a bromine source, enhance the full use of applicable resources; after the end of the reaction after a simple filtration treatment to obtain a sufficient purity of the product, It can reduce production costs; at the same time, facilitate the transportation and storage of raw materials, and improve the working environment. The synthesis method of the present invention is simple and easy to operate, high safety, small pollution, simple post-treatment, low production cost, product yield and purity can meet the production needs, is both cost advantages and safety and environmental advantages of the industrializable process.
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Paragraph 0060-0067
(2022/01/04)
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- Method of treating DBA mother liquor
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The present invention relates to a method of treating a DBA mother liquor, wherein a small amount of a reagent is used, high DBA yield is provided, and waste is less.
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Paragraph 0048-0058
(2020/04/02)
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- Preparation method of butynedioic acid
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The invention discloses a preparation method of butynedioic acid. The method comprises the following steps of: (1) firstly, carrying out water-free and oxygen-free treatment on a closed reaction kettle; (2) putting calcium carbide, a solvent, a catalyst and an auxiliary agent into the reaction kettle, introducing carbon dioxide into the reaction kettle, and heating and pressurizing for reaction; (3) separating the reacted mixture obtained in the step (2) to obtain a liquid mixture, and adding a KOH solution into the liquid mixture; stirring to separate out a white precipitate; and dissolving the white precipitate in hot water, acidifying with concentrated sulfuric acid, cooling, separating out the white precipitate, and filtering to obtain the product. The synthesis method disclosed by theinvention is relatively environment-friendly and low in production cost.
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Paragraph 0050-0051
(2020/07/21)
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- Preparation method of 1,3-dibenzyl-2-oxoimidazolidine-4,5-dicarboxylic acid
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The invention relates to a preparation method of 1,3-dibenzyl-2-oxoimidazolidine-4,5-dicarboxylic acid, comprising the steps of subjecting fumaric acid, bromine and hydrobromic acid to additive reaction to generate meso-2,3-dDibromosuccinic acid, subjecting the meso-2,3-dDibromosuccinic acid, benzylamine and a strong base to aminating reaction to generate dibenzylamino salt, subjecting the dibenzylamino salt and triphosgene to cyclization to generate the 1,3-dibenzyl-2-oxoimidazolidine-4,5-dicarboxylic acid. The fumaric acid is subjected to addition, and then substitution and cyclization are performed to obtain the 1,3-dibenzyl-2-oxoimidazolidine-4,5-dicarboxylic acid, and detection shows that HPLC (high-performance liquid chromatography) content of the 1,3-dibenzyl-2-oxoimidazolidine-4,5-dicarboxylic acid may reach 98-99%. The preparation method has the advantages that hydrobromic acid is added for bromination additive reaction, the concentration and reaction temperature of the hydrobromic acid are optimized, and bromine loss is more reduced; amination mother liquid is used in amination, the cost is saved, and product yield is increased; in ring-closure reaction, pH and reaction product concentration are decreased, the yield of the 1,3-dibenzyl-2-oxoimidazolidine-4,5-dicarboxylic acid is increased greatly, and the quality of the 1,3-dibenzyl-2-oxoimidazolidine-4,5-dicarboxylic acid is improved; experiments verify that through process innovation, production cost is reduced greatly, production efficiency is improved, and the process is energy efficient and environmentally friendly.
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Paragraph 0046; 0047; 0054; 0055; 0058-0063
(2017/08/30)
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- Towards the cis-bromination of double bonds
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The bromination of olefins yielding a trans-1,2-dibromo-product was studied. Reagents were proposed to brominate the double bonds of cis-olefins mildly and stereospecifically. Reagents delivering two bromine atoms to the same side of olefins through a cyclic six-membered transition state were studied.
- Carman,Derbyshire,Hansford,Kadirvelraj,Robinson
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p. 117 - 126
(2007/10/03)
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- Kinetic study of the Ce(III)-, Mn(II)-, or ferroin-catalyzed Belousov-Zhabotinsky reaction with pyruvic acid
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Ce(III)-, Mn(II)-, or ferroin (Fe(phen)32+)-catalyzed reaction of bromate ion and pyruvic acid (PA) or its dimer exhibits oscillatory behavior. Both the open-chain dimer (parapyruvic acid, γ-methyl-γ-hydroxyl-α-keto-glutaric acid, DP
- Lin, Hsing-Lien,Yu, Yueh-O,Jwo, Jing-Jer
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p. 408 - 418
(2007/10/03)
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- Synthesis of Pyrazinamide
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The key intermediate, pyrazinoic acid (III) in the synthesis of pyrazinamide has been prepared starting from 2,3-dibromsuccinic acid.
- Rao, A. V. Rama,Yadav, J. S.,Ravichandran, K.,Sahasrabudhe, A. B.,Chaurassia, S. S.
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