Method for removing nitrosation agent(s) from a nitrated aromatic compound

US4338473A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Kurt Habig · Mörfelden, DE
• Konrad Baessler · Frankfurt am Main, DE
• Lothar Schulz · Eppstein, DE
• Heinz Schutte · Hofheim, DE

Key dates

• Filing date: May 19, 1980
• Grant date: Jul 6, 1982
• Expiry date: May 19, 2000

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07B43/02
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Nitrosation agent(s), contained as by-products in nitrated aromatic compounds after nitration with nitric acid or nitration acid, are removed by a water treatment, wherein the water is distilled off at least partially in vapor form, advantageously under reduced pressure. In the further reaction of the nitrocompounds treated in this manner undesired nitrosamines are practically not formed. The process is especially suitable for the manufacture of 4-di-n-propylamino-3,5-dinitrobenzotrifluoride (Trifluralin), a valuable herbicide, substantially free from nitrosamine(s).