Production of dialkylphosphine oxides

US4092363A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Horst Staendeke · Lohmar, DE
• Hubert Neumaier

Key dates

• Filing date: Sep 30, 1976
• Grant date: May 30, 1978
• Expiry date: Sep 30, 1996

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07F9/5304
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Production of dialkylphosphine oxides of the general formula: ##STR1## in which R.sup.1 and R.sup.2 each stand for an alkyl group having from 1 to 4 carbon atoms by subjecting a dialkylchlorophosphine of the general formula: ##STR2## in which R.sup.1 and R.sup.2 have the meanings given above, or an addition product thereof with hydrogen chloride, to alcoholysis with an aliphatic C.sub.1 - C.sub.4 alcohol in the presence of a protective gas at temperatures between -30.degree. and +30.degree. C, and subjecting the resulting alcoholysate to thermolysis. The compounds are more specifically produced by continuously adding the dialkylchlorophosphine component to the alcohol; subjecting the resulting alcoholysate to thermolysis in a heated separation zone; introducing into the separation zone, countercurrently to the alcoholysate, 10 to 150 l/h of a protective gas, per liter of alcoholysate; removing simultaneously from the separation zone the gaseous thermolysis products and, separately from said products, an alcoholic solutions containing desirable final product; neutralizing the alcoholic solution and recovering the final product from said solution in known manner.