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:
Jan. 21, 1992
Filed:
Oct. 31, 1990
Applicant:
Inventors:
Rolf Losch, Ketsch, DE;
Winfried Orth, Hassloch/Pflaz, DE;
Wolfgang Weiss, Neckarhausen, DE;
Hans W Kleffner, Battenberg, DE;
Assignee:
Rutgerswerke AG, , DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07D / ; C07D / ;
U.S. Cl.
CPC ...
546294 ; 546345 ;
Abstract
A method for the production of heavy metal-free pyridine -3-sulfonic acid by oxidation of 3-chloro-pyridine to 3-chloro-pyridine-N-oxide, substitution of the chlorine through a sulfonic acid group, and subsequent reduction to pyridine-3-sulfonic acid. The method can be carried out using raw 3-chloropyridine-N-oxide and direct further reaction of the pyridine-3-sulfonic acid-N-oxide in the presence of Raney nickel in an alkaline solution.