Diaminophenyl ureas

US4246196A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Otto Arndt · Hofheim, DE
• Theodor Papenfuhs · Frankfurt, DE
• Peter Bohme · Kelkheim, DE
• Wolfgang Tronich
• Bernhard Mees · Charlotte, US

Key dates

• Filing date: Dec 20, 1979
• Grant date: Jan 20, 1981
• Expiry date: Dec 20, 1999

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D235/26
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Diaminophenyl ureas of the formula ##STR1## in which R is an inert substituent, are obtained from the corresponding dinitrophenyl urea by way of reduction, especially catalytic hydrogenation. Through a cyclization process, while splitting off ammonia, these ureas yield the corresponding aminobenzimidazolones, advantageously without an intermediate isolation of the diaminophenyl ureas.