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.
Synthetic method of p-nitro o-toluidine
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Paragraph 0008, (2020/01/12)
The invention discloses a synthesis method of p-nitro-o-toluidine. O-toluidine is used as a starting raw material, and three steps of reactions comprising amino protection, nitric acid nitrification and acidic hydrolysis are carried out in an acetic anhydride-glacial acetic acid mixed solution to obtain p-nitro-o-toluidine. The method has the advantages of simple equipment requirements, high process safety and small sewage treatment capacity and saves cost of enterprises.
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.
STABILIZATION OF ACTIVE METAL CATALYSTS AT METAL-ORGANIC FRAMEWORK NODES FOR HIGHLY EFFICIENT ORGANIC TRANSFORMATIONS
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Paragraph 0354-0356; 0359, (2019/01/07)
Metal-organic framework (MOFs) compositions based on post?synthetic metalation of secondary building unit (SBU) terminal or bridging OH or OH2 groups with metal precursors or other post-synthetic manipulations are described. The MOFs provide a versatile family of recyclable and reusable single-site solid catalysts for catalyzing a variety of asymmetric organic transformations, including the regioselective boryiation and siiylation of benzyiic C—H bonds, the hydrogenation of aikenes, imines, carbonyls, nitroarenes, and heterocycles, hydroboration, hydrophosphination, and cyclization reactions. The solid catalysts can also be integrated into a flow reactor or a supercritical fluid reactor.
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.
Unique Chemoselective Hydrogenation using a Palladium Catalyst Immobilized on Ceramic
Monguchi, Yasunari,Marumoto, Takahisa,Ichikawa, Tomohiro,Miyake, Yutaka,Nagae, Yoshiyuki,Yoshida, Michiyuki,Oumi, Yasunori,Sawama, Yoshinari,Sajiki, Hironao
, p. 2155 - 2160 (2015/11/24)
A heterogeneous palladium catalyst supported on a ceramic (5 % Pd/ceramic) was developed. The catalyst exhibited a specific chemoselectivity for hydrogenation that has never been achieved by other palladium-catalyzed methods. Either aliphatic or aromatic N-Cbz groups could be deprotected to the corresponding free-amines, while the hydrogenolysis of benzyl esters and ethers did not proceed. Furthermore, aryl chlorides and epoxides were tolerant under the Pd/ceramic-catalyzed hydrogenation conditions. 5 % Pd/ceramic could be reused without any loss of catalyst activity, as no palladium leaching was detected in the reaction media.
A Nucleophilic Strategy for Enantioselective Intermolecular α-Amination: Access to Enantioenriched α-Arylamino Ketones
Miles, Dillon H.,Guasch, Joan,Toste, F. Dean
, p. 7632 - 7635 (2015/07/02)
The enantioselective addition of anilines to azoalkenes was accomplished through the use of a chiral phosphoric acid catalyst. The resulting α-arylamino hydrazones were obtained in good yields and excellent enantioselectivities and provide access to enantioenriched α-arylamino ketones. A serendipitous kinetic resolution of racemic α-arylamino hydrazones is also described.
Steric-Hindrance-Induced Regio- and Chemoselective Oxidation of Aromatic Amines
Patil, Vilas Venunath,Shankarling, Ganapati Subray
, p. 7876 - 7883 (2015/09/01)
Unusual regio- and chemoselective oxidation of aromatic amines hindered with ortho substituents (except -NH2, -NHCH3, and -OH) to the corresponding nitro compounds is described by use of nonanebis(peroxoic acid). The mechanistic investigation for selective oxidation of amines ortho-substituted with -NH2 or -OH showed the involvement of H-bonding between the ortho hydrogen of the adjacent -XH group (where X = NH, NR, or O) and an oxygen atom from the diperoxy acid. Various mono- and diamines are oxidized into corresponding mononitro derivatives in high yield and purity without employing any protection strategies. The protocol was also found to successful on the gram scale.
Chemoselective hydrogenation catalyzed by Pd on spherical carbon
Esaki, Hiroyoshi,Hattori, Tomohiro,Tsubone, Aya,Mibayashi, Satoko,Sakata, Takao,Sawama, Yoshinari,Monguchi, Yasunari,Yasuda, Hidehiro,Nosaka, Kazuto,Sajiki, Hironao
, p. 3629 - 3635 (2014/01/06)
We have developed a highly chemoselective hydrogenation method using a novel palladium catalyst supported on spherical carbon (0.5 % Pd/SC). The 0.5 % Pd/SC exhibited a novel catalytic activity and could achieve the chemoselective hydrogenation of alkynes, alkenes, azides, nitro groups, and aliphatic O-tert-butyldimethylsilyl (TBS) ethers without hydrogenolysis of benzyl esters, benzyl ethers, nitriles, aromatic ketones, N-carbobenzyloxy (N-Cbz) protective groups, and aromatic O-TBS ethers. Highly selective spheres: The chemoselective hydrogenation of C-C multiple bonds, azides, nitro groups, and aliphatic O-tert-butyldimethylsilyl (TBS) ethers is achieved in the presence of benzyl esters, benzyl ethers, nitriles, aromatic ketones, N-carbobenzyloxy (Cbz) protective groups, and aromatic O-TBS ethers by a novel heterogeneous palladium catalyst supported on spherical carbon (0.5 % Pd/SC). Copyright
Easily-controlled chemoselective hydrogenation by using palladium on boron nitride
Yabe, Yuki,Sawama, Yoshinari,Yamada, Tsuyoshi,Nagata, Saori,Monguchi, Yasunari,Sajiki, Hironao
, p. 2360 - 2366 (2013/08/23)
The hydrogenation catalyzed heterogeneously by palladium on boron nitride (Pd/BN) in methanol realized the chemoselective hydrogenation of only azides, alkenes, and alkynes in the presence of other reducible functionalities such as benzyl ethers, aryl halides, aryl ketones, and nitro groups. Furthermore, the totally chemoselective semihydrogenation of alkynes could also be achieved without the reduction of other coexisting reducible functionalities, which include azides and alkenes, by using Pd/BN in pyridine as a solvent. Be unique, be selective: The chemoselective hydrogenation of azides, alkenes, and alkynes was achieved without the reduction of other reducible functionalities by the use of a heterogeneous palladium on boron nitride (Pd/BN) catalyst. Furthermore, Pd/BN was applicable to the unique and chemoselective semihydrogenation of alkynes without the reduction of azido functionalities in the presence of pyridine or diethylenetriamine.