Process for preparing 1,3-dialkyl-5-hydroxyoxindoles and the ether derivatives thereof

US5614637A · kind A · utility

Assignee

• Boehringer Ingelheim GmbH · DE

Inventors

• Rainer Sobotta · Ingelheim am Rhein, DE
• Rainer Schwarz · Immenstadt im Allgäu, DE
• Manfred Psiorz · Ingelheim am Rhein, DE

Key dates

• Filing date: May 23, 1995
• Grant date: Mar 25, 1997
• Expiry date: May 23, 2015

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D209/34
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The invention is directed to a process for preparing a 1,3-dialkyl-5-hydroxyoxindole of formula 1: ##STR1## comprising heating an N-alkyl-p-alkoxy-(.alpha.-haloacyl)anilide of formula 2: ##STR2## wherein the substituents are as defined herein, in the presence of an anhydrous zinc halide to a temperature in the range from about 120.degree. C. to about 160.degree. C., and isolating the 1,3-dialkyl-5-hydroxyoxindole prepared.