- Simple and convenient preparation method of 2,6-dichlorophenylacetic acid
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The invention provides a simple and convenient preparation method of 2,6-dichlorophenylacetic acid. By using the method, cyclohexanone is used as initial raw materials; chlorination reaction is performed with chlorination reagents to prepare 2,2,6,6-tetrachlorocyclohexanone; then, ethyl malonate condensation and hydrogen chloride removal are performed under the basic conditions, hydrolysis and rearrangement; the 2,6-dichlorophenylacetic acid is prepared through acidification decarboxylation. The used raw materials are cheap and can be easily obtained; the operation is safe, simple and convenient; the waste water quantity is small; the process achieves green and environmental-friendly effects; the product yield and the purity are high; the cost is low.
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Paragraph 0042-0047
(2019/06/08)
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- Reaction of α,β-Unsaturated Carboxylic Acids with Manganese(III) Acetate in the Presence of Chloride Ion
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The reaction of 3-phenylpropenoic acids with manganese(III) acetate - Cl- complex yielded 1,2,2-trichloro-1-phenylethanes, 1-acetoxy-2,2-dichloro-1-phenylethanes, and 2,2-dichloro-1-phenylethanols. (E)-2,3-Diphenylpropenoic acids gave 2,2-dichloro-1,2-diphenylethanones and 2-acetoxy-1,2-diphenylethanones. 3,3-Diphenylpropenoic acids yielded 2,2-dichloro-1,1-diphenylethenes, 1-acetoxy-2,2-dichloro-1,1-diphenylethanes, 2,2-dichloro-1,1-diphenyl-1-ethanols, and 2-hydroxy-2,2-diphenylethanal.Fluorenylideneacetic acid gave 9-chloro-9-(dichloromethyl)fluorene, 9-acetoxy-9-(dichloromethyl)fluorene, and 9-fluorenone. 1-Cyclohexenecarboxylic acid yielded 1,2-dichlorocyclohexanecarboxylic acid and 1-acetoxy-2-chlorocyclohexanecarboxylic acid.The reaction can be explained in terms of a free-radical mechanism involving manganese(III) acetate - Cl- complexation, addition of Cl. radical, decarboxylation, and the oxidation of chloroethenes which are the reaction intermediates.
- Yonemura, Hiroshi,Nishino, Hiroshi,Kurosawa, Kazu
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p. 3153 - 3160
(2007/10/02)
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- PRACTICAL SYNTHESIS OF 2,2,5,5-TETRACHLORO-1,6-HEXANEDIOIC ACID, FROM TRANS-1,2-CYCLOHEXANEDIOL OR CYCLOHEXANONE, INVOLVING OXIDATION OF 3,3,6,6-TETRACHLORO-1,2-CYCLOHEXANEDIONE
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Trans-1,2-cyclohexanediol was quantitatively converted into 3,3,6,6-tetrachloro-1,2-cyclohexanedione (2) by treatment with chlorine in dimethylformamide.The hydrate of the dione was oxidized by aqueous potassium permanganate to afford the title acid 1 in 91percent overall yield.An alternative low cost preparation was elaborated, providing 2 in 61-74percent yield starting from cyclohexanone in a three step procedure without isolation of intermediates.The reaction seqence involves substitution of α-dichloro- and trichlorocyclohexanones by sodium acetate in acetic acid and chlorination of the resulting 2-hydroxy- and 2-acetoxy-2-cyclohexenones in dimethylformamide.
- Buyck, Laurent de,Vanslembrouck, Jan,Kimpe, Norbert de,Verhe, Roland,Schamp, Niceas
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p. 913 - 918
(2007/10/02)
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