- Preparation method of P-benzoquinone dioxime
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The preparation method of p-benzoquinone dioxime generates intermediate p-benzoquinone monooxime and byproduct alcohol under the action of an acid reaction promoter, and the intermediate is directly reacted with hydroxylamine hydrochloride to generate p-benzoquinone dioxime. The discharge of production waste water is reduced, and the requirement of green color production is met. The by-product ethanol obtained by nitrosation reaction can be finally recovered by distillation together with an organic solvent, so that the utilization rate of raw materials is improved. The whole synthesis process adopts an inert gas to isolate air, avoids the disproportionation and decomposition and intermediate of ethyl nitrite, reduces the generation of side reactions, improves the conversion rate of the reaction, and further improves the yield and purity of the benzoquinone dioxime, the yield is 85.0% - 95.0%, the purity ≥ 99.0 wt % and the melting point are 250 °C - 255 °C.
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Paragraph 0061; 0071-0078; 0088-0095; 0105-0111
(2021/12/07)
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- NEW TELESCOPING SYNTHESES OF 2-METHOXYMETHYL-P-PHENYLENEDIAMINE
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The invention relates to processes for preparing 2 -methoxymethyl-p-phenylenediamine (I), cosmetically acceptable salts thereof, or mixtures thereof.
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Page/Page column 30-31
(2021/02/19)
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- Hydrohalogenation of 1,4-Benzoquinone Mono- and Bis(O-acyloximes)
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Hydrohalogenation of 1,4-benzoquinone O-acyloximes involves intermediate formation of corresponding 1,4-benzoquinone monooximes and hydroxyamino derivatives. The final hydrochlorination products are 2,6-dichloro-4-alkoxyanilines, hydrobromination yields 3,5-dibromo-4-aminophenol as the final product. O-Acyl- and O,O′-diacyl-1,4-benzoquinone dioximes do not undergo hydrohalogenation.
- Avdeenko,Glinyanaya
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p. 1154 - 1159
(2007/10/03)
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