99-52-5Relevant articles and documents
Antioxidant and method for preparing antioxidant
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Paragraph 0014; 0046; 0049; 0054; 0057; 0062; 0065, (2021/08/06)
The invention discloses an antioxidant and a method for preparing the antioxidant. An intermediate 2 reacts with an intermediate 5 to obtain an intermediate 14, the intermediate 14 isoxidized with potassium permanganate, an esterification reaction is then carried out with an intermediate 13 to obtain an intermediate 15, the intermediate 15 is reduced with tin powder to obtain an intermediate 16, the intermediate 16 and the intermediate 8 are subjected to dehydration condensation, the antioxidant is prepared, the antioxidant contains a large number of sulfur atoms, the sulfur atoms can be oxidized to form sulfoxide and sulfone compounds, the antioxidant has good oxidation resistance, free radicals generated by macromolecules can be captured, then the free radical branching reaction is inhibited, and the antioxidant activity is improved. The oxidation resistance of the high-molecular material is improved, and the self relative molecular mass is large and is not easy to separate out from the high-molecular material.
A green and recyclable ligand-free copper (I) catalysis system for amination of halonitrobenzenes in aqueous ammonia solution
Li, Yan,Shi, Ruhui,Lin, Weiwei,Cheng, Haiyang,Zhang, Chao,Arai, Masahiko,Zhao, Fengyu
, (2019/06/18)
The amination of halonitrobenzenes is an important reaction to produce the corresponding nitroanilines. Direct amination of p-chloronitrobenzene (p-CNB) to p-nitroaniline (p-NAN) with aqueous NH3 solution was investigated over various transition metal salts in the absence of ligand, inorganic base and organic solvent. It was found that CuI is the most effective catalyst with respect to p-CNB conversion, p-NAN selectivity (≈ 100%) and the post-reaction separation and recycling. A high p-NAN yield of 97% could be obtained at 200 °C in 6.5 h with molar ratios of NH3/p-CNB and CuI/p-CNB of 21 and 0.1, respectively. A possible reaction mechanism was proposed, in which NH3 was not only a substrate but also a ligand to coordinate with CuI and formed a water-soluble Cu complex, and then it started the catalytic cycle. The influence of reaction variables such as NH3 concentration, CuI concentration, temperature and time on the p-CNB conversion and the p-NAN selectivity was examined. At room temperature the desired product of p-NAN is insoluble in water but the Cu complex catalyst is water-soluble and so the aqueous phase including the catalyst and NH3 can be easily separated and reused for the subsequent reaction runs. The green and sustainable system is effective for the conversion of diverse halonitrobenzenes to nitroanilines.
Synthesis method of 2-methyl-4-nitrobenzoic acid
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Paragraph 0010, (2017/01/02)
The invention discloses a synthesis method of 2-methyl-4-nitrobenzoic acid, and belongs to the technical field of chemosynthesis. According to the method, methylbenzene is used as raw materials; reaction liquid formed by mixing concentrated nitric acid and concentrated sulfuric acid is added for mixing; after being washed by a sodium hydroxide solution, the materials take an reaction with stannous chloride, iron powder and glacial acetic acid; then, hydrochloric acid is dropwise added for mixing to obtain 2-amino-5-nitrotoluene; then, the 2-amino-5-nitrotoluene is mixed with acetic acid and the concentrated sulfuric acid for taking a reaction; after the oxidization by an oxidizing agent of sodium perborate, temperature lowering by ice water and washing by deionized water are carried out; then, under the oxidization effect of an oxidizing agent of potassium permanganate, the materials are mixed with hydrochloric acid for reaction; then, still standing, suction filtering and drying are carried out, and the 2-methyl-4-nitrobenzoic acid is obtained. The synthesis method has the beneficial effects that the synthesis process is simple; the cost is low; byproducts are few; the yield of obtained products is as high as more than 95 percent; the purity is as high as more than 99 percent.
