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:
Dec. 19, 1989
Filed:
Oct. 15, 1987
Applicant:
Inventor:
Rainer Hamprecht, Odenthal, DE;
Assignee:
Bayer Aktiengesellschaft, Leverkusen, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ; C07C / ; C07D / ; C07D / ;
U.S. Cl.
CPC ...
549 57 ; 534573 ; 534768 ; 534787 ; 549 55 ; 558388 ; 558408 ;
Abstract
2-Aminothiophenes of the formula ##STR1## wherein R=substituent and n=0-4, are prepared by dehydrogenating ring closure of thioamides of the formula ##STR2## The 2-aminothiophenes are useful for preparing useful azo dyestuffs. A process for preparing a compound of the formula ##STR3## comprising reacting a compound of the formula ##STR4## in which R and n have the abovementioned meanings with a compound of the formula ##STR5## in which T denotes NH.sub.2, aryl or alkyl, in the presence of an acid. An azo dyestuff of the formula ##STR6## in which V denotes Cl, Br or CF.sub.3,