Process for monohydroxylation of phenolic compounds
AssigneeRhone-Poulenc Chimie
InventorsMichel Costantini, Dominique Laucher
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Abstract
The present invention relates to a process for monohydroxylation of phenolic compounds which allows an increase in the amount of para isomer. The invention relates to a process for monohydroxylation of a phenolic compound having a hydrogen atom in the para position to the hydroxyl group, for the purpose of obtaining a dihydroxylated aromatic compound by reacting the initial phenolic compound with hydrogen peroxide in the presence of an effective amount of a strong acid and of a ketonic compound, said process being characterized by the fact that the reaction is carried out in the presence of an effective amount of a polar aprotic organic solvent with a basicity such that it has a "donor number" below 25.
Claims38
A process for the hydroxylation of an aromatic compound having both an --OR group and a hydrogen atom attached to the aromatic ring with the hydrogen atom being in the para position to the --OR group, where R is a hydrogen atom or a hydrocarbon radical having 1 to 24 carbon atoms which can be saturated or unsaturated, linear or branched aliphatic radicals or a saturated or unsaturated, or aromatic, monocyclic, bicyclic, or polycyclic cycloaliphatic radical, comprising
- reacting the aromatic compound with hydrogen peroxide in the presence of effective amounts of a strong acid, a ketonic compound, and a polar aprotic organic solvent having a basicity donor number less than 25.
Dependencies are inferred from the claim text.