| 摘要 |
Phenols and carbonyl compounds are obtained by decomposing an alkyl aromatic hydroperoxide by treatment with a mineral acid and washing the fission product with an aqueous solution of a normally solid carboxylic acid which is weaker than oxalic acid. Normally, solid carboxylic acids are defined as acids which are solid at normal room temperature, i.e. 65 DEG F. Specified acids are citric, tartaric, lactic, salicyclic and phthalic acids. The acids are preferably employed in low concentration such as 1 to 2 per cent. The hydroperoxide starting material is prepared by incomplete oxidation of the corresponding hydrocarbon and any hydrocarbon remaining after the oxidation is preferably removed before the hydroperoxide is treated with the mineral acid. The solution of carboxylic acid extracts the mineral acid from the fission mixture, giving a better phase separation than a water washing, and also, in the fission of cumene hydroperoxide, accelerates the dehydration of any dimethylphenylcarbinol present to a -methylstyrene without promoting polymerization of a -methylstyrene or condensation of a -methylstyrene with phenol. Specified hydrocarbons, the hydroperoxides of which may be used in the process, are cumene, p-cymene, diisopropylbenzenes and ethylbenzene. In an example, cumene hydroperoxide is decomposed with sulphuric acid and the fission product, containing 2.5 per cent dimethylphenylcarbinol, washed with a 2 per cent citric acid solution to remove the sulphuric acid, the washed product being distilled to remove acetone. Less than 20 per cent of the dimethylphenyl carbinol is converted into polymethylstyrene and no cumylphenol is formed. A similar washing of the fission product with water does not remove all the sulphuric acid, the phase separation is more difficult, and after distillation 60 per cent of the dimethylphenylcarbinol has been converted into a -methylstyrene, 39 per cent into polymer and 1 per cent into cumylphenol.
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