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US 4,270,010 AGranted
Hydroquinone by hydrolysis of p-aminophenol or salts
OwnerEfim Billerinventor
Life of this patent
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Abstract
Hydroquinone is made by heating an aqueous solution of p-aminophenol, or of a salt of p-aminophenol with an acid made by catalytic or electrolytic reduction of nitrobenzene, with an organic sulfonic acid, and extracting from the reaction mixture the hydroquinone by contact with a water-insoluble solvent. Residual organic sulfonic acid can be recovered from the hydroquinone-free reaction mixture and reused.
Claims6
Process of making hydroquinone from p-aminophenol or from salts of p-aminophenol with acids made by catalytic or electrolytic reduction of nitrobenzene, which process comprises
- heating at a temperature of 190.degree.-300.degree. C. an aqueous solution containing 0.5 to 30% by weight of said p-aminophenol or p-aminophenol salt and containing 0.3-3 moles of organic sulfonic acid per mole of said p-aminophenol or p-aminophenol salt to form a reaction mixture containing hydroquinone, and
- extracting said hydroquinone from said reaction mixture by contacting said mixture with a water-insoluble solvent for said hydroquinone to leave a hydroquinone-free aqueous mixture.
Dependencies are inferred from the claim text.