Process for making 4,4'-dihydroxydiphenyl sulfone

US4996367A · kind A · utility

Assignee

• Amoco Corporation · US

Inventors

• Andreas Ernst · Worms, DE
• Gunter Caspari · Wheaton, US

Key dates

• Filing date: Dec 20, 1989
• Grant date: Feb 26, 1991
• Expiry date: Dec 20, 2009

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C315/00
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process is described to make a dihydroxydiphenol sulfone product with a 4,4'-dihydroxydiphenol sulfone purity in excess of 90 wt. % by reaction of phenol and concentrated sulfuric acid in a solvent mixture containing a lower-boiling and a higher-boiling hydrocarbon, removal by azeotropic distillation of water, hydrocarbon, and phenol, phase separation of the distillate, and return of at least the phenol to the reaction at a rate which maintains a phenol to sulfuric acid mol ratio in the reaction of at least 2 to 1.