Process for the preparation 4-chloro-2,5-dimethoxy-aniline

US5041671A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Klaus Warning · Eppstein, DE
• Kurt Habig · Mörfelden, DE

Key dates

• Filing date: Jun 21, 1989
• Grant date: Aug 20, 1991
• Expiry date: Jun 21, 2009

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C213/02
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Process for the preparation of 4-chloro-2,5-dimethoxyaniline by catalytic reduction of 4-chloro-2,5-dimethoxynitrobenzene with hydrogen in the liquid phase at an elevated temperature and elevated pressure, which comprises carrying out the reduction at temperatures from about 80.degree. to about 110.degree. C. and under a pressure of about 5 to 50 atmospheres gauge in an aromatic solvent in the presence of a modified platinum-on-carbon catalyst in the presence of about 0.01 to about 0.2 mole of a compound which gives a pH of 8 to 10 in aqueous solution, and in the presence of about 0.1 to about 1.0% by weight of an aliphatic, open-chain, primary, secondary or tertiary amine or a cyclic amine, in each case relative to the amount in moles and weight, respectively, of 4-chloro-2,5-dimethoxynitrobenzene employed.