The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 30, 1979
Filed:
Aug. 15, 1977
Wong F Ark, Bridgewater, NJ (US);
James H Kawakami, Piscataway, NJ (US);
Ulrich A Steiner, North Plainfield, NJ (US);
Union Carbide Corporation, New York, NY (US);
Abstract
A process is provided for producing a mixture of aromatic sulfonyl chlorides and aromatic sulfones substantially free of the corresponding aromatic sulfonic acids and their anhydrides, which comprises the steps of (a) reacting a monosubstituted benzene such as monochlorobenzene with sulfur trioxide in the presence of at least about 15 mole percent to about 50 mole percent of thionyl chloride, based on the sulfur trioxide, at a temperature from about the freezing point of the reactants to about 40.degree. C.; (b) adding to the reaction mixture of step (a) at least about 60 mole percent thionyl chloride, based on the sulfur trioxide, and preferably a small catalytic amount of dimethylformamide, wherein the total thionyl chloride in the reaction mixture is at least about 110 mole percent, based on the sulfur trioxide, while maintaining the reaction mixture at a temperature between about 25.degree. C. and 70.degree. C.; and then (c) continuing the reaction up to a temperature of about 160.degree. C. The mixture produced can be used without further purification to form diaryl sulfones in high yield, for example, by reacting with monochlorobenzene in the presence of ferric chloride.