Process for making phosphonic anhydrides

US4473509A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Jurgen Grosse · Hürth, DE
• Werner Pieper · Kerpen, DE

Key dates

• Filing date: Nov 16, 1982
• Grant date: Sep 25, 1984
• Expiry date: Nov 16, 2002

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07F9/3895
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The disclosure relates to a process for making phosphonic anhydrides of general formula (I) EQU (RPO.sub.2).sub.n.H.sub.2 O (I) in which R stands for an alkyl or aryl radical having from 1 to 6 carbon atoms and n stands for a value between 2 and 20. To this end, the disclosure provides for a compound of general formula (II) ##STR1## in which R has the meaning given above to be oxidized with concentrated sulfuric acid under inert gas and in the presence of a diluent at a temperature between 0.degree. and 100.degree. C., the compound of general formula (II) and sulfuric acid being used in a molar ratio of about 1:1.