- Preparation method of 3-methyl-2-aminobenzoic acid
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The invention discloses a preparation method of 3-methyl-2-aminobenzoic acid. The preparation method comprises the steps that 2-chloro-m-xylene is added into an acetic acid solvent for stirring, sodium acetate is added as a catalyst, the temperature is raised to 80-100 DEG C by heating, hydrogen peroxide is dropped for a reaction, after the reaction, 3-methyl-2-chlorobenzoic acid is obtained through rectification under vacuum; the 3-methyl-2-chlorobenzoic acid is added into a DMSO solvent, and catalysts of copper chloride and sodium carbonate are added and heated to 120-140 DEG C, and then ammonia is introduced and heated to 150-160 DEG C for a heat preservation of 3-6 hours, and the 3-methyl-2-aminobenzoic acid is obtained. According to the preparation method, a new design idea is provided for the synthesis of the 3-methyl-2-aminobenzoic acid, the preparation method is simple, operation is easy, the cost is low, and the preparation method is environmentally friendly.
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Paragraph 0015-0017
(2019/11/12)
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- 2 - Chloro -3 - methyl benzoic acid and intermediate preparation method (by machine translation)
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The invention discloses a 2 - chloro - 3 - methyl benzoic acid and intermediate preparation method. A 2 - chloro - 3 - methyl benzoic acid and intermediate preparation method, comprising the following steps, in the oxygen pressure is 0.1 mpa - 0.8 mpa under the condition of, under the action of the catalyst and promoter, the 2, 6 - dimethyl chlorobenzene to carry out oxidation reaction, can be; wherein said 2, 6 - dimethyl chlorobenzene and the oxygen molar amount ratio of 1: 1.8 - 1: 2.2. The 2 - chloro - 3 - methyl benzoic acid, in order to industrially easily available raw materials for the reaction, after treatment is simple, high yield, purity is good, small pollution to the environment, is more suitable for industrial. (by machine translation)
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Paragraph 0101; 0102
(2018/10/11)
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- A highly efficient heterogeneous copper-catalyzed chlorodeboronation of arylboronic acids leading to chlorinated arenes
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A highly efficient heterogeneous copper-catalyzed chlorodeboronation of arylboronic acids with inexpensive N-chlorosuccinimide (NCS) was achieved in MeCN in the presence of 10 mol% of l-proline-functionalized MCM-41-immobilized copper(i) complex [MCM-41-l-proline-CuCl] under mild conditions, yielding a variety of aryl chlorides in excellent yields. This method proved to be tolerant of a broad range of functional groups and particularly useful for the conversion of electron-deficient arylboronic acids to aryl chlorides, a transformation that is inefficient without copper catalysis. This heterogeneous copper catalyst can be recovered by a simple filtration of the reaction solution and recycled for at least 10 times without any decreases in activity.
- He, Wen,Zhang, Rongli,Cai, Mingzhong
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p. 764 - 770
(2017/01/13)
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- Ring expansion and vinylic nucleophilic substitution competing for (tert-alkyl)2CC(Li)-Cl in carbenoid chain processes
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Vinylic nucleophilic substitution (SNV) reactions of unactivated, cyclic α,α-dichloroalkenes [(tert-alkyl) 2CCCl2] with aryllithiums (RLi) to give (tert-alkyl) 2CC(Cl)-R are presented to be carbenoid chain react
- Knorr, Rudolf,Menke, Thomas,Hennig, Karsten-Olaf,Freudenreich, Johannes,B?hrer, Petra,Schubert, Bernhard
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p. 2703 - 2710
(2014/04/17)
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- Copper-catalyzed chlorination of functionalized arylboronic acids
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"Chemical Equation Presented" A mild, efficient, Cu(I)-catalyzed method for the conversion of arylboronic acids to aryl chlorides Is reported. This method is particularly useful for the conversion of electron-deficient arylboronic acids to aryl chlorides, a transformation that is inefficient In the absence of Cu catalysis.
- Wu, Hong,Hynes Jr., John
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supporting information; experimental part
p. 1192 - 1195
(2010/04/27)
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- PROCESS FOR HALOGENATION OF BENZENE AND BENZENE DERIVATIVES
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In a process of halogenation of benzene or benzene derivatives, di-substituted halobenzene derivatives having para-aromatic compounds or tri-substituted halobenzene derivatives having 1,2,4-substituted aromatic compounds are selectively produced. In halogenation of benzene or benzene derivatives, a fluorine-containing zeolite catalyst such as L-type zeolite, or a zeolite catalyst having the crystal size of at most 100 nm is used. The reaction is preferably effected in the presence of a solvent, and the solvent is preferably a halogenated compound.
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Page/Page column 23-24
(2008/06/13)
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- Efficient one-pot transformation of aminoarenes to haloarenes using halodimethylisulfonium halides generated in situ
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Halodimethylsulfonium halide 1, which is readily formed in situ from hydrohaloic acid and DMSO, is a good nucleophilic halide. This activated nucleophilic halide rapidly converts aryldiazonium salt prepared in situ by the same hydrohaloic acid and nitrite ion to aryl chlorides, bromides, or iodides in good yield. The combined action of nitrite ion and hydrohaloic acid in DMSO is required for the direct transformation of aromatic amines, which results in the production of aryl halides within 1 h. Substituted compounds with electron-donating or -withdrawing groups or sterically hindered aromatic amines are also smoothly transformed to the corresponding aromatic halides. The only observed by-product is the deaminated arene (usually 7%). The isolated aryldiazonium salts can also be converted to the corresponding aryl halides using 1. The present method offers a facile, one-step procedure for transforming aminoarenes to haloarenes and lacks the environmental pollutants that usually accompany the Sandmeyer reaction using copper halides.
- Baik, Woonphil,Luan, Wanqiang,Lee, Hyun Joo,Yoon, Cheol Hun,Koo, Sangho,Kim, Byeong Hyo
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p. 213 - 219
(2007/10/03)
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- Fast and easy halide exchange in aryl halides
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We report here the rapid halide exchange in aryl halides facilitated by microwave and conventional heating using nickel(II) halides as reagents. The methodology can be used for conversion of aryl chlorides to bromides, aryl iodides to bromides and chlorides and aryl bromides to chlorides. Reactions are fast (5 minutes reaction time for microwave heating and 4 hours for conventional heating) and can be performed without the need for exclusion of air and water.
- Arvela, Riina K.,Leadbeater, Nicholas E.
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p. 1145 - 1148
(2007/10/03)
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- A radical and an electron transfer process are compared in their regioselectivities towards a molecule with two different C-I bonds: Effect of steric congestion
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Steric compression in 1,4-diiodo-2,6-dimethylbenzene (2a) makes the C-I bond flanked by methyls substantially weaker (a buttressing effect) than the unhindered C-I bond. Calculations also confirm the weaker bonding interaction of the hindered C-I bond of 2a. This causes a remarkable regioselectivity toward the weaker bond in dehalogenation by stannyl radicals. Conversely, a much lower regioselectivity is found for a process -a photostimulated S(RN)1 reaction with the enolate ion of a ketone - which requires the conversion of 2a into a radical anion. A calculation of the BDE of the C-I bond for aa ArI·- system is offered. Finally, the hindered awl radical intermediate resulting from cleavage of the weaker C-I bond of 2a·- shows a modest but detectable discrimination between reduction or substitution, this once again being due to the steric congestion.
- Branchi, Barbara,Galli, Carlo,Gentili, Patrizia,Marinelli, Manuela,Mencarelli, Paolo
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p. 2663 - 2668
(2007/10/03)
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- Process for the preparation of chlorinated aromatics
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Chlorinated aromatics are obtained in a simple manner and in particularly good yield if the corresponding chloroformic esters are heated in the liquid phase to 90° to 240° C. in the presence of an inert organic solvent and a catalytic amount of one or more Lewis acids selected from the group consisting of the aluminium halides, iron halides and antimony halides.
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- Chlorination of aromatic compounds with chlorous acid under non-aqueous conditions
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The non-aqueous solution of chlorous acid is a versatile chlorinating agent for aromatic compounds, e.g. alkylbenzenes, anisoles, and acetanililides. It is also an effective chlorine-substitute for the conversion of aryl bromides into aryl chlorides under mild conditions. The stoichiometry of the chlorination reaction is ArH+3HOClO→ArCl+2ClO2+2H2O, and the mode of dissociation of chlorous acid in dichloromethanc is 3HOClO→HOCl+2ClO2+H2O.
- Muathen, Hussni A.
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p. 1493 - 1497
(2007/10/03)
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- Liquid-Phase Decarboxylation of Aromatic Haloformates: A New Access to Chloro- and Fluoroaromatics
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The treatment of phenyl chloroformates 1 with a Lewis acid in the liquid phase resulted in decarboxylation to the corresponding chloroaromatics 2. Fluoroaromatic compounds were synthesized from phenylchloroformates 1 through a sequential fluorination/decarboxylation in the liquid phase by treatment with excess anhydrous hydrogen fluoride under mild conditions. In all cases, yields were increased by performing the reaction in 1,2,4-trichlorobenzene, which is inert to Friedel-Crafts reactions.
- Lui, Norbert,Marhold, Albrecht,Rock, Michael H.
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p. 2493 - 2496
(2007/10/03)
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- Process for the preparation of halogenated aromatic compounds
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Halogenated aromatic compounds are prepared by passing esters of halogenoformic acid at temperatures in the range 150° to 600° C. and pressures from 0.1 to 3 bar over a catalyst containing chromium, magnesium, iron, silicon and/or aluminium, wherein if Al2 O3 catalysts are used these have been activated with hydrogen halide.
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- Process for the preparation of halogenated aromatics
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Halogenated aromatics are prepared by heating halogenoformic acid esters to 80° to 280° C. in the presence of hydrogen fluoride or a catalytic amount of one or more Lewis acids from the group comprising aluminium halides, iron halides and antimony halides, and in the liquid phase.
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- Versatility of Zeolites as Catalysts for Ring or Side-Chain Aromatic Chlorinations by Sulfuryl Chloride
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Zeolites catalyze chlorination of aromatics by sulfuryl chloride SO2Cl2.It is possible by an appropriate choice of the catalyst to effect at will, with very high selectivity, either the ring or the side-chain chlorination.Zeolite ZF520 is the choice catalyst for the former, because of its high Broensted acidity.Zeolite NaX (13X) is a fine catalyst for the latter, free-radical chlorination; the reaction is best effected in the presence of a light source; the catalyst can be reused many times with no loss in activity.Both reaction modes, the ionic (ring chlorination)and the radical (side-chain substitution), are likely to occur outside of the channel network in the microporous solid.The effects of various experimental factors - such as the nature of the solvent, the reaction time and temperature, the Broensted acidity of the solid support, the presence of radical inhibitors, and the quantity of catalysts - were investigated.The procedures resulting from this study are very easy to implement in practice and are quite effective.
- Delaude, Lionel,Laszlo, Pierre
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p. 5260 - 5269
(2007/10/02)
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- Halogenation Using Quaternary Ammonium Polyhalides. XIX. Aromatic Chlorination of Arenes with Benzyltrimethylammonium Tetrachloroiodate
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The reaction of arenes with a calculated amount of benzyltrimethylammonium tetrachloroiodate in acetic acid at room temperature or at 70 deg C gave nuclear chloro-substituted arenes in fairly good yields.
- Kajigaeshi, Shoji,Ueda, Yasuhiro,Fujisaki, Shizuo,Kakinami, Takaaki
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p. 2096 - 2098
(2007/10/02)
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