- Regioselectivity of the methanolysis of polychlorinated biphenyls
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Regioselectivity of the methanolysis of lower polychlorinated biphenyls with sodium methoxide in a mixture of methanol and DMSO at 100–130°С was studied. It was found that 2,4,4'-tricholobiphenyl is much more reactive than 2,4-dichlorobiphenyl. This results in different mechanisms of substitution. 2,4-Dichlorobiphenyl reacts with sodium methoxide by the elimination–addition mechanism to form four monosubstitution products in comparable quantities. 2,4,4'-Trichlorobiphenyl reacts with the methodixe ion by the classical SNAr mechanism, with preferential substitution of the 2-chlorine atom.
- Khaibulova, T. Sh.,Boyarskaya,Polukeev,Boyarskii
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- Synthesis method and application of novel p-aryl azophenol derivative
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The invention provides a synthesis method of a p-aryl azophenol derivative. The synthesis method comprises the following step of: subjecting two aryl diazonium salts serving as raw materials to reacting in a mixed solvent of water under the action of an additive to generate the p-aryl azophenol derivative with a structure as shown in a formula (I) that is described in the specification. The chemical structure of the diazonium salt is as described in the specification, and in the chemical structure, R and R1 groups are selected from straight-chain or branched-chain alkyl groups, straight-chain alkoxy groups, halogen, nitryl groups, ester groups, trifluoromethyl groups and cyano groups. The additive is one or more selected from a group consisting of lithium acetate, sodium acetate, potassium acetate, cesium acetate, sodium carbonate, triethylamine, N,N-diisopropylethylamine, diazabicyclo and potassium tert-butoxide. The solvent is one or more selected from the group consisting of benzyl alcohol, acetonitrile, methanol, ethanol, acetone and water. According to the invention, a one-pot cascade reaction of aryl diazonium salt and water is realized under mild and transition metal-free conditions, and the multifunctional p-substituted azophenol derivative is conveniently and efficiently synthesized.
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Paragraph 0121-0125
(2021/07/14)
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