- Oxidative chlorination, desulphonation, or decarboxylation to synthesize pharmaceutical intermediates: 2,6-Dichlorotoluene, 2,6-dichloroaniline, and 2,6-dichlorophenol
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An alternative manufacturing process scheme was developed for 2,6-dichlorotoluene, 2,6-dichloroaniline, and 2,6-dichlorophenol, involving oxidative chlorination after protection of the starting material in the para position followed by deprotection involving desulphonation or decarboxylation. Oxidative chlorination of 4-methylbenzenesulphonic acid, 4-methylbenzoic acid, 4-aminobenzoic acid, and 4-hydroxybenzoic acid by using HCl-H2O2, and their subsequent desulphonation or decarboxylation, gave a 60-75% yield of the desired product.
- Mukhopadhyay,Chandalia
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- Method for preparing 2, 6-dichlorotoluene by chlorination of chlorine-containing organic solvent in subcritical state
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The invention relates to the field of organic synthesis, and provides a method for preparing 2, 6-dichlorotoluene by chlorination of a chlorine-containing organic solvent in a subcritical state, The preparation method is as follows: the chlorine-containing organic solvent is used as a raw material, and 2-chloro-6-nitrotoluene is converted into 2, 6-dichlorotoluene in the subcritical state. The method is characterized in that the chlorine-containing organic solvent reaches a subcritical state at selected temperature and pressure, C-Cl bonds in the solvent are cracked to generate chlorine free radicals and side chains of chlorinated aromatic hydrocarbon, 2-chloro-6-nitrotoluene is chlorinated into 2, 6-dichlorotoluene, and finally the product is separated and purified to obtain the target product. According to the method, the product can be obtained only through one-step reaction, the process is simple, and the yield is stable.
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Paragraph 0018-0026
(2021/09/21)
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- A process for preparing 2, 6 - dichloro toluene method (by machine translation)
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The invention discloses a method for preparing 2, 6 - dichloro toluene, in this method, 2, 3 - dichloro toluene react with chlorine to obtain 2, 3 - benzene ring chlorinated product of abnormal growth; the hydrogen gas as a reducing agent, supported palladium catalyst catalytic reduction of 2, 3 - benzene ring of abnormal growth of chlorinated product so as to obtain 2, 6 - dichloro toluene, the reaction by-product is repeated chlorinated, catalytic reduction reaction, so that the 2, 3 - dichloro toluene is transformed 2, 6 - dichloro toluene yields up to 30% or more; 2, 6 - dichloro toluene as an important chemical industry intermediate, to generate new economic value. (by machine translation)
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Paragraph 0017-0028
(2019/01/23)
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- Sodiation of Arenes and Heteroarenes in Continuous Flow
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The first sodiations of (hetero)arenes in continuous flow using NaDA (sodium diisopropylamide) in Me2EtN are reported. This flow procedure enables sodiation of functionalized arenes and heteroarenes that decompose under batch-sodiation conditions. The resulting sodiated (hetero)arenes react instantly with various electrophiles, such as ketones, aldehydes, isocyanates, alkyl bromides, and disulfides, affording polyfunctionalized (hetero)arenes in high yields. Scale-up is possible without further optimization.
- Weidmann, Niels,Ketels, Marthe,Knochel, Paul
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supporting information
p. 10748 - 10751
(2018/07/30)
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- H β molecular sieve catalytic O-chlorotoluene preparation 2, 6 - dichloro toluene method (by machine translation)
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The invention relates to 2, 6 - dichloro toluene preparation technology field, in particular to a molecular sieve catalyst H β of O-toluene selective chlorination of preparation 2, 6 - dichloro toluene. The invention relates to a low cost of O-toluene as the raw materials, chlorine is the chlorinating agent, H β molecular sieve as the catalyst, adopt the one-step chlorination process, catalytic O-toluene selective chlorination of preparation 2, 6 - dichloro toluene, the process is easy to operate, simple steps, low production cost, easy industrialization. (by machine translation)
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Paragraph 0026; 0028-0031
(2017/08/26)
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- Synthesis method of intermediate 2,6-dichlorotoluene for dicloxacillin sodium monohydrate drug
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The invention discloses a synthesis method of an intermediate 2,6-dichlorotoluene for a dicloxacillin sodium monohydrate drug. The synthesis method comprises the following steps: (i) adding 500 mL of potassium chloride solution with the mass percentage of 40 to 50 and a certain amount of aqueous solution into a reaction container, retaining the temperature of the solution between 85 to 90 DEG C, adding 1.2 mol of 2-methyl-3-chloroaniline in batches, titrating 1.2 to 1.6 moL of potassium nitrite into 200 mL of aqueous solution after reactants are completely dissolved to prepare a solution, measuring a reaction end point with potassium iodide test paper, and generating diazonium salt; (ii) dissolving 0.3 to 0.5 mol of nitrate and a certain amount of nitrite into 600 to 700 mL of aqueous solution, adding 500 mL of potassium chloride solution with the mass percentage of 60 to 80, slowly adding the diazonium salt solution in the step (i) into a chloride salt solution, finally adding a sodium hydrogen carbonate solution to retain the pH of the solution at 7 to 8 after the solution is layered, separating out the water layer, dewatering with calcium oxide, distilling the solution, collecting fractions with the temperature of 180 to 192 DEG C, and obtaining 2,6-dichlorotoluene.
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Paragraph 0008; 0018; 0019; 0020
(2016/10/20)
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- A chloro-toluene-ionic liquid catalyst preparation 2,6 the method of [...] dichloro-toluene
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The invention discloses a method for preparing 2,6-dichlorotoluene by catalyzing o-chlorotoluene with an ionic liquid. According to the method for preparing 2,6-dichlorotoluene, Cl2 is taken as a chlorinating agent, under the action of a catalyst, namely, an aluminium chlorate ionic liquid, a raw material, namely, o-chlorotoluene, is directionally chlorinated, and the 2,6-dichlorotoluene is prepared; an intermediate of the aluminium chlorate ionic liquid is [BMIM]Cl, the molar ratio of AlCl3 to [BMIM]Cl is 1:3, and the usage amount of the aluminium chlorate ionic liquid accounts for 0.1%-1% of the mass of o-chlorotoluene; the method for preparing 2,6-dichlorotoluene by selectively chlorinating the o-chlorotoluene is simple in technology and mild in reaction condition, the used aluminium chlorate ionic liquid is good in catalytic activity and good in stability, can be separated from a product easily and can significantly improve the selectivity of 2,6-dichlorotoluene, and the method has the very high industrial application value.
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Paragraph 0024; 0027; 0032
(2017/02/24)
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- Electroreduction of Organic Compounds, 34 [1]. Cathodic Dehalogenation of Chloroarenes with Electron-Donating Substituents
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The electrochemical reduction of chlorinated arenes with electron-donating substituents, i.e. chlorotoluenes, -anisoles and -phenols, is studied. Preparative electrolyses are run in various solvent-supporting electrolytes under potentiostatic and galvanostatic conditions at lead or carbon cathodes. A partial and mostly regioselective hydrodechlorination of compounds with two or more chloro substituents is possible under suitable conditions. The replacement of one single chloro substituent, in particular in a para-position, is difficult. Highly toxic and persistent oligochloro derivatives are thus transformed into less problematic compounds with a low degree of chlorination. The chlorine content of real-life materials such as extracts of soil contaminated with chlorinated phenols and Nitrofen can also be significantly decreased by electroreduction.
- Kranz, Olaf,Voss, Jürgen
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p. 1187 - 1200
(2007/10/03)
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- Copper(I)-catalyzed intramolecular cyclization reaction of 2-(2'- chlorophenyl)ethanol to give 2,3-dihydrobenzofuran
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Functionalized 2,3-dihydrobenzofuran can be synthesized in good yield via an intramolecular cyclization of an aryl chloride and a primary alcohol under the catalysis of copper(I) chloride salt. (C) 2000 Elsevier Science Ltd.
- Zhu, Jingyang,Price, Benjamin A.,Zhao, Shannon X.,Skonezny, Paul M.
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p. 4011 - 4014
(2007/10/03)
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- Process for synthesizing benzoic acids
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A nucleophilic substitution reaction on optionally substituted dihalobenzenes is carried out in the presence of an optional catalyst followed by formation of and subsequent carboxylation of a Grignard reaction intermediate. In particular the present invention provides a process leading to optionally substituted hydroxybenzoic, alkanoyloxybenzoic, formyloxybenzoic and alkoxybenzoic acids from 1-substituted 2,6-dihalobenzenes. The invention also provides a process for the direct formation of an acyl chloride from a Grignard reagent by quenching with phosgene.
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- Process for synthesizing benzoic acids
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Nucleophilic substitution reactions on halobenzenes or triflyl substituted benzenes are carried out in the presence of catalysts. In particular the present invention provides a process leading to optionally substituted hydroxybenzoic, alkanoyloxybenzoic, formyloxybenzoic and alkoxybenzoic acids and optionally substituted hydroxybenzonitriles and alkoxybenzonitriles from substituted 2,6-dihalobenzenes, 2-halo-6-triflylbenzene and 2,6-ditriflylbenzenes.
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- The method for parallel-producing 2,5-dichlorotoluene and 2,6-dichlorotoluene
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The method for parallel-producing 2,5-dichlorotoluene and 2,6-dichlorotoluene comprising chlorinating the mixture of 4--tert-butyl (or isopropyl) toluene and 3,5-tert-butyl (or isopropyl) toluene in the presence of Lewis acid and simple substance sulphur, using the same chlorination apparatus, producing 4-tert-butyl (or isopropyl)-2,5-dichlorotoluene and 3,5-di-tert-butyl (or isopropyl)-2,6-dichlorotoluene, and transalkylating individually the same.
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- Process for preparing 2,6-dichlorotoluene
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Liquid para-toluenesulfonyl chloride is reacted with chlorine gas at elevated temperatures in the presence of a catalytic amount of a Lewis acid catalyst, preferably antimony trichloride. Sulfuric acid is added then the reaction mixture is heated and subsequently cooled to about room temperature. Ammonium hydroxide is added then the reaction mixture is distilled to yield a substantially pure 2,6-dichlorotoluene.
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- Synthesis, Stability, and Reactions of 2,6-Dichlorophenyllithium
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A convenient, general, and regioselective synthesis of 2,6-dichloroaromatic compounds from m-dichlorobenzene is described.The stability of 2,6-dichlorophenyllithium is examined.
- Kress, Thomas H.,Leanna, M. Robert
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p. 803 - 805
(2007/10/02)
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- Monoorganylation of dihaloaromatics
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Process for the monoalkylation/monoarylation of dihaloaromatic compounds by treating the latter with selected magnesium or zinc organometallic reagents in the presence of a nickel/bidentate or tridentate phosphorus ligand. The products are intermediates to agricultural and pharmaceutical compounds.
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- PHOTOCHEMISTRY OF 1-(2,6-DICHLOROBENZYL)-1,4-DIHYDRONICOTINAMIDE
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The cleavage of the N-benzyl bond characterizes the photochemical behaviour of I in methanol.Beside the coupling or the hydrogen abstraction products, the interconvertible 1,4,6,6-tetrahydropyridines VIa and VIb were obtained.
- Adembri, Giorgio,Donati, Donato,Fusi, Stefania,Ponticelli,Fabio
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p. 5089 - 5092
(2007/10/02)
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