Process for preparing 4,6-diamino-resorcinol dihydrochloride

US6093852A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Horst Behre · Odenthal, DE
• Helmut Fiege · Leverkusen, DE
• Heinz U. Blank · Odenthal, DE
• Wolfgang Eymann · Neunburg vorm Wald, DE

Key dates

• Filing date: Nov 17, 1998
• Grant date: Jul 25, 2000
• Expiry date: Nov 17, 2018

Classification

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

Abstract

The invention concerns 4,6-diamino-resorcinol which is prepared in the form of its dihydrochloride by catalytic hydrogenation of 1,3-benzyloxy-4,6-dinitrobenzene on a noble metal contact in a two-phase mixture of dilute aqueous hydrochloric acid and an organic solvent which is not miscible with dilute aqueous hydrochloric acid. This process is carried out at a pressure of between 1 and 200 bar and a temperature of between 0 and 200.degree. C.