Process for preparing acyl aminophenols

US5648535A · kind A · utility

Assignee

• Hoechst Celanese Corporation · US

Inventors

• James A. Foster · Richmond, US
• Werner H. Mueller · Port Aransas, US
• Debra A. Ryan · Port Aransas, US
• Hartmut Wiezer · Gersthofen, DE

Key dates

• Filing date: May 26, 1995
• Grant date: Jul 15, 1997
• Expiry date: May 26, 2015

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C231/02
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for the production of N-acylaminophenols by the concurrent hydrogenation of a nitrophenol to an aminophenol and the acylation of the aminophenol with acyl anhydride takes place on a continuous basis in a stirred tank reactor in which liquid product is continuously withdrawn from the reactor. Of particular interest is the manufacture of acetaminophen, N-acetyl-p-aminophenol by continuous reaction of p-ntirophenol, hydrogen and acetic anhydride.