- Antioxidant and method for preparing antioxidant
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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.
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Paragraph 0014; 0046; 0049; 0054; 0057; 0062; 0065
(2021/08/06)
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- Synthetic method of p-nitro o-toluidine
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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.
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Paragraph 0008
(2020/01/12)
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- A green and recyclable ligand-free copper (I) catalysis system for amination of halonitrobenzenes in aqueous ammonia solution
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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.
- Li, Yan,Shi, Ruhui,Lin, Weiwei,Cheng, Haiyang,Zhang, Chao,Arai, Masahiko,Zhao, Fengyu
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- STABILIZATION OF ACTIVE METAL CATALYSTS AT METAL-ORGANIC FRAMEWORK NODES FOR HIGHLY EFFICIENT ORGANIC TRANSFORMATIONS
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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.
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Paragraph 0354-0356; 0359
(2019/01/07)
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- Synthesis method of 2-methyl-4-nitrobenzoic acid
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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.
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Paragraph 0010
(2017/01/02)
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- A Nucleophilic Strategy for Enantioselective Intermolecular α-Amination: Access to Enantioenriched α-Arylamino Ketones
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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.
- Miles, Dillon H.,Guasch, Joan,Toste, F. Dean
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p. 7632 - 7635
(2015/07/02)
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- Steric-Hindrance-Induced Regio- and Chemoselective Oxidation of Aromatic Amines
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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.
- Patil, Vilas Venunath,Shankarling, Ganapati Subray
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p. 7876 - 7883
(2015/09/01)
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- Unique Chemoselective Hydrogenation using a Palladium Catalyst Immobilized on Ceramic
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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.
- Monguchi, Yasunari,Marumoto, Takahisa,Ichikawa, Tomohiro,Miyake, Yutaka,Nagae, Yoshiyuki,Yoshida, Michiyuki,Oumi, Yasunori,Sawama, Yoshinari,Sajiki, Hironao
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p. 2155 - 2160
(2015/11/24)
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- Chemoselective hydrogenation catalyzed by Pd on spherical carbon
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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
- Esaki, Hiroyoshi,Hattori, Tomohiro,Tsubone, Aya,Mibayashi, Satoko,Sakata, Takao,Sawama, Yoshinari,Monguchi, Yasunari,Yasuda, Hidehiro,Nosaka, Kazuto,Sajiki, Hironao
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p. 3629 - 3635
(2014/01/06)
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- Easily-controlled chemoselective hydrogenation by using palladium on boron nitride
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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.
- Yabe, Yuki,Sawama, Yoshinari,Yamada, Tsuyoshi,Nagata, Saori,Monguchi, Yasunari,Sajiki, Hironao
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p. 2360 - 2366
(2013/08/23)
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- Chemoselective hydrogenation using molecular sieves-supported Pd catalysts: Pd/MS3A and Pd/MS5A
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Palladium catalysts embedded on molecular sieves (MS3A and MS5A) were prepared by the adsorption of Pd(OAc)2 onto molecular sieves with its in situ reduction to Pd0 by MeOH as a reducing agent and solvent. 0.5% Pd/MS3A and 0.5% Pd/MS5A catalyzed the hydrogenation of alkynes, alkenes, and azides with a variety of coexisting reducible functionalities, such as nitro group, intact. It is noteworthy that terminal alkenes of styrene derivatives possessing electron-donating functionalities on the benzene nucleus were never hydrogenated under 0.5% Pd/MS5A-catalyzed conditions, while internal alkenes of 1-propenylbenzene derivatives were readily reduced to the corresponding alkanes.
- Takahashi, Tohru,Yoshimura, Masatoshi,Suzuka, Hiroyasu,Maegawa, Tomohiro,Sawama, Yoshinari,Monguchi, Yasunari,Sajiki, Hironao
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experimental part
p. 8293 - 8299
(2012/09/21)
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- Development of molecular sieves-supported palladium catalyst and chemoselective hydrogenation of unsaturated bonds in the presence of nitro groups
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The chemoselective hydrogenation of unsaturated bonds and azide functionalities is achieved in the presence of nitro groups by a heterogeneous palladium catalyst supported on molecular sieves (MS3A). The present method shows a widerange of applicability with regard to substrates and the catalyst can be easily prepared and reused at least three times without any loss of activity.
- Maegawa, Tomohiro,Takahashi, Tohru,Yoshimura, Masatoshi,Suzuka, Hiroyasu,Monguchi, Yasunari,Sajiki, Hironao
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supporting information; experimental part
p. 2091 - 2095
(2009/12/26)
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- Highly chemoselective nitration of aromatic amines using the Ph3P/Br2/AgNO3 system
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The use of PPh3/Br2/AgNO3 provides a new reagent system for the novel and highly chemoselective nitration of aromatic amines under mild reaction conditions.
- Iranpoor, Nasser,Firouzabadi, Habib,Nowrouzi, Najmeh,Firouzabadi, Dena
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p. 6879 - 6881
(2007/10/03)
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- Syntheses and resolutions of new chiral biphenyl backbones: 2-Amino-2′-hydroxy-6,6′-dimethyl-1,1′-biphenyl and 2-amino-2′-hydroxy-4,4′,6,6′-tetramethyl-1,1′- biphenyl
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The new chiral backbones (R)-(+)- and S-(-)-2-amino-2′-hydroxy-6,6′-dimethyl-1,1′-biphenyl and (R)-(+)- and (S)-(-)-2-amino-2′-hydroxy-4,4′,6,6′- tetramethyl-1,1′-biphenyl were synthesized from o-methylaniline and 2,4-dimethyl-aniline respectively in seven steps. A new resolution method was developed to provide homochiral enantiomers (from diastereomeric salts) in reasonably high yields. The absolute configuration of the new biphenyls was confirmed by X-ray structural analysis.
- Liang, Yuxue,Gao, Shuang,Wan, Huihui,Wang, Junwei,Chen, Huilin,Zheng, Zhuo,Hu, Xinquan
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p. 1267 - 1273
(2007/10/03)
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- Chemoselective conversion of azides to t-butyl carbamates and amines
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Azides were converted to the corresponding carbamates using a system of 20 mol% of decaborane (B10H14) and 20 weight% of 10% Pd/C in methanol in the presence of di-tert-butyl dicarbonate at rt in high yields and to the corresponding amines using a system of 10 mol% of decaborane and 20 weight% of 10% Pd/C in methanol in the absence of di-tert-butyl dicarbonate at rt in high yields.
- Jung, Yeon Joo,Chang, Yu Mi,Lee, Ji Hee,Yoon, Cheol Min
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p. 8735 - 8739
(2007/10/03)
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- Nitroarylamines via the Vicarious Nucleophilic Substitution of Hydrogen: Amination, Alkylamination, and Arylamination of Nitroarenes with Sulfenamides
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A new reaction of sulfenamides with electrophilic arenes under basic conditions is described. The σ adducts formed from nitroarenes and the anions of sulfenamides undergo elimination of thiol to produce the corresponding o- and/or p-nitroanilines. This reaction is analogous to the known alkylation and hydroxylation of nitroarenes via the vicarious nucleophilic substitution of hydrogen (VNS). The reaction gives access to a wide range of substituted nitroanilines, nitronaphthylamines, and aminoheterocycles. By means of the reaction with N-alkyl- and N-arylsulfenamides, it is possible to obtain N-alkylnitroanilines and nitrodiarylamines. By varying the structure of sulfenamide and the reaction conditions, particularly the nature and concentration of the base, it is possible to control the orientation of animation.
- Makosza, Mieczyslaw,Bialecki, Maciej
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p. 4878 - 4888
(2007/10/03)
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- Chromogenic compounds, processes for the preparation thereof and use thereof as enzyme substrates
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The present invention provides compounds of the general formula: STR1 wherein R1 is an amino acid residue or a residue of an oligopeptide in which the amino groups are optionally substituted by protective groups, R2 and R3, which are the same or different, are hydrogen atoms, a lower alkyl, lower alkoxy, carboxyl or lower alkoxycarbonyl radicals or carboxamido groups optionally substituted by lower alkyl or, if R2 and R3 are adjacent, can represent a --CH=CH--CH=CH-- radical, Z is a conjugated-through positively charged, bicyclic heterocyclic system and X is an anion of an organic or inorganic acid. The present invention also provides processes for the preparation of these compounds and diagnostic agents containing them for the determination of peptide bond-cleaving enzymes.
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- Direct Nitration of Anilines Using Nitrocyclohexadienones
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Nitrocyclohexadienones (in particular, 2,3,5,6-tetrabromo-4-methyl-4-nitro-2,5-cyclohexadienone) are used as reagents for the direct nitration of anilines.Depending on the conditions, good yields of C-nitroanilines are obtained.Under the same conditions, N,N-dimethylaniline is converted into N-methyl-N-nitroaniline.
- Lemaire, M.,Guy, A.,Boutin, P.,Guette, J. P.
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p. 761 - 763
(2007/10/02)
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- The Willgerodt-Kindler Reactions. 6. Isomerization of the Carbonyl Group in Alkanones and Cycloalkanones
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The most unusual feature of the Willgerodt-Kindler Reactions is the facile isomerization of the carbonyl function along a chain of unbranched methylene groups, or around a cycloaliphatic ring containing several connected methylene groups.We have demonstrated that the first step in the Kindler process is the formation of enamines by reaction of the carbonyl function with secondary aliphatic amines, followed by reaction of the enamine with certain sulfur-amine catalysts to form reactive heterocyclic sulfur intermediates that facilitate the elimination-readdition of the amines reversibly along the chain.It was shown that compounds of the type R2N-S-S-NR2 are effective catalysts but not compounds of the type R2N-S-NR2.Some cyclohexanone derivatives undergo aromatization, with anomalous results in certain cases.
- Carmack, Marvin,Behforouz, Mohammad,Berchtold, Glenn A.,Berkowitz, Samuel M.,Wiesler, Donald,Barone, Ralph
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p. 1305 - 1318
(2007/10/02)
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- Direct Amination of Nitrobenzenes by Vicarious Nucleophilic Substitution
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4-Amino-1,2,4-triazole reacts at 25 deg C with nitrobenzene and some substituted nitrobenzenes in the presence of potassium tert-butoxide in Me2SO to give 4-nitroanilines in good yields.The reaction represents an extension of Makosza's vicarious substitution to a convenient nitrogen nucleophile.
- Katritzky, Alan R.,Laurenzo, Kathleen S.
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p. 5039 - 5040
(2007/10/02)
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- Process for preparing 2-amino-5-nitrotoluene
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2-Amino-5-nitrotoluene is obtained in high yield by reacting 2-chloro-5-nitrotoluene with excess aqueous ammonia which has a concentration of at least 30% by weight. The product is used as a diazo component for preparing azo compounds.
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- Imidazolylacetic acid amides
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Imidazolylacetic acid amides of the formula: SPC1 Or pharmaceutically acceptable nontoxic salts thereof wherein Either R1 is phenyl or cycloalkyl, unsubstituted or substituted by one or more substituents; and R2 is hydrogen; Or R1 and R2, together with the nitrogen atom to which they are attached, form a saturated 5 to 7-membered heterocyclic ring which ring may contain an --SO2 -- or --NY-- moiety wherein Y is alkoxycarbonyl, dialkylaminocarbonyl, or phenyl or diphenylmethyl, unsubstituted or substituted by one or more substituents and wherein said 5 to 7-membered heterocyclic ring itself is otherwise unsubstituted or substituted by one or more substituents; and X1, x2, x3 and X4 are the same or different and are each hydrogen or halogen, Are produced by A. reacting a halodiphenylacetic acid amide of the formula: SPC2 Wherein R1, r2, x1, x2, x3 and X4 are as above defined, and Hal is halogen, With imidazole; or B. reacting a halodiphenylacetic acid halide of the formula: SPC3 Wherein X1, x2, x3 and X4 are as above defined and Hal is halogen With imidazole to produce an imidazolide of the formula: SPC4 Wherein X1, x2, x3 and X4 are as above defined which in turn is transaminated by reaction with an amine of the formula: wherein R1 and R2 are as above defined.
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- Azo pigments derived from 2-hydroxy-3-carboxynaphthalene containing a substituted or unsubstituted phthalimide
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Azo pigments derived from 2-hydroxy-3-carboxy-naphthalene and containing a substituted or unsubstituted phthalimide radical. The majority give red colorations and due to their excellent fastness properties are particularly valuable for use in surface coatings and resins.
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