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:
Aug. 01, 1988
Filed:
Mar. 06, 1985
Applicant:
Inventors:
George Levitt, Wilmington, DE (US);
Richard V Pater, Wilmington, DE (US);
Assignee:
E. I. Du Pont de Nemours, Wilmington, DE (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07D / ; C07D / ;
U.S. Cl.
CPC ...
549 64 ;
Abstract
A process for preparation of chlorosulfonyl thiophene compounds comprising contacting a thiophenamine with sodium or potassium nitrite to produce a diazonium salt, then contacting said salt with sulfur dioxide and cuprous or cupric chloride, or bromide. Addition of gaseous HCl, concentrated H.sub.2 SO.sub.4, or oleum to the diazotization mixture enhances yield.