The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 15, 1983
Filed:
Jan. 29, 1982
Douglas C Caskey, O'Fallon, MO (US);
Douglas W Chapman, St. Louis, MO (US);
Mallinckrodt, Inc., St. Louis, MO (US);
Abstract
A process for the production of unsubstituted and lower alkyl substituted p-aminophenols. A charge mixture is prepared comprising an unsubstituted or lower alkyl substituted nitrobenzene substrate, a platinum catalyst and a sulfur compound. The sulfur compound may be a divalent sulfur compound in which sulfur is bonded to two other moieties or a compound reducible to such sulfur compound under catalytic hydrogenation conditions. Hydrogen is introduced into the mixture while it is agitated at a temperature of 0.degree.-40.degree. C., thereby reducing the substrate to an unsubstituted or alkyl substituted phenylhydroxylamine. The hydroxylamine is thereafter heated to a temperature of at least 70.degree. C. and agitated at at least 70.degree. C. in the presence of a highly dissociated acid, thereby effecting rearrangement of the hydroxylamine to the corresponding p-aminophenol.