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:
Feb. 23, 1982
Filed:
Apr. 21, 1980
Wolfgang Schenk, Leverkusen, DE;
Heinz U Blank, Odenthal, DE;
Ferdinand Hagedorn, Leverkusen, DE;
Werner Evertz, Monheim, DE;
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
An improved process for the preparation of a sulphonic acid chloride of the formula ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 are identical or different and denote hydrogen, a lower alkyl radical or a cycloalkyl radical, halogen, aryl, aralkyl, aryl ether or a radical --SO.sub.2 Cl, --SO.sub.2 aryl, ##STR2## or wherein adjacent radicals R.sup.1 and R.sup.2 are linked to form a cycloaliphatic, aromatic or hetero-aromatic ring which is optionally substituted by a sulphonic acid chloride group by contacting an aromatic compound of the formula ##STR3## wherein R.sup.1, R.sup.2 and R.sup.3 of the above-mentioned meaning, with chlorosulphonic acid and thionyl chloride, the improvement residing in employing initially approximately stoichiometric amounts of aromatic compound and chlorosulphonic acid, effecting reaction of the aromatic compound and chlorosulphonic acid and thereafter contacting the reaction product with excess thionyl chloride.