Production of carboxylic acid fluorides

US6489510B1 · kind B1 · utility

Assignee

• SOLVAY FLUOR und DERIVATE GmbH · DE

Inventors

• Max Braun · Großburgwedel, DE
• Kerstin Eichholz · Langenhagen, DE
• Werner Rudolph · Hannover, DE

Key dates

• Filing date: Jul 29, 1999
• Grant date: Dec 3, 2002
• Expiry date: Jul 29, 2019

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B01J2219/0875
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A method for producing carboxylic acid fluorides of the formula RCFXC(O)F, where X represents fluorine or chlorine, in good yields and with good selectivity for the carboxylic acid fluorides by reacting compounds of the formula RCFXCHFCl with oxygen by photochemical oxidation in the gaseous phase, preferably under sensitization with chlorine and using light having a wavelength &lgr;≧280 nm, which conditions make it possible to work without the use of pressure. Glass apparatus may be covered with a protective coating so as to protect it against traces of hydrogen fluoride. To this end, for example, heat-shrinkable sleeves made of light-permeable hydrogen fluoride-resistant material may be used. Polytetrafluoroethylene, polyfluoropropylene or a mixture thereof are especially suitable for this purpose. This type of protection is also suitable for other reactions such as photo-induced fluoro-dediazonation in hydrogen fluoride/pyridine for the production of aromatic compounds fluorinated in the nucleus or the oxidation of CHCl2 groups for the production of carboxylic acid chlorides.