526-78-3Relevant articles and documents
Synthesis method of o-Dibromo compound
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Paragraph 0060-0067, (2022/01/04)
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.
Preparation method of 1,3-dibenzyl-2-oxoimidazolidine-4,5-dicarboxylic acid
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Paragraph 0046; 0047; 0054; 0055; 0058-0063, (2017/08/30)
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.
Synthesis of Pyrazinamide
Rao, A. V. Rama,Yadav, J. S.,Ravichandran, K.,Sahasrabudhe, A. B.,Chaurassia, S. S.
, p. 850 (2007/10/02)
The key intermediate, pyrazinoic acid (III) in the synthesis of pyrazinamide has been prepared starting from 2,3-dibromsuccinic acid.
