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. 25, 1994
Filed:
Nov. 24, 1993
Applicant:
Inventors:
Assignee:
Bayer Aktiengesellschaft, Leverkusen, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
562125 ;
Abstract
Sodium salts of aromatic sulphinic acids containing nitro groups are obtained in particularly pure form and good yield by introducing the corresponding sulphonyl chlorides into an aqueous alkali metal sulphite solution which is at a temperature of -10.degree. to 45.degree. C. and has a pH of 6 to 10, then cooling the suspension to -10.degree. to 0.degree. C., then metering in sodium hydroxide solution in such a way that the temperature does not exceed 0.degree. C. throughout the reaction, and then raising the temperature, maintaining stirring and simultaneously keeping the pH at 8 to 9 by the addition of sodium hydroxide solution.