Process for the recovery of 4-hydroxybenzaldehyde from reaction mixtures containing same

US5773664A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Albert Schnatterer · Leverkusen, DE
• Helmut Fiege · Leverkusen, DE
• Frank Jelitto · Bensberg, DE
• Peter Skornia · Bonn, DE
• Karl-Heinz Theisen · Neunburg vorm Wald, DE

Key dates

• Filing date: Jan 26, 1996
• Grant date: Jun 30, 1998
• Expiry date: Jan 26, 2016

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C45/78
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for separating off poorly soluble by-products from reaction mixtures which are produced in the oxidation of p-cresol with oxygen or an oxygen-containing gas in methanol as solvent in the presence of alkali metal hydroxide and in the presence of metal compounds as catalyst, is characterized in that, after the oxidation, excess alkali is neutralized to the extent that a salt precipitate forms and this salt precipitate is separated off together with the poorly soluble by-products.