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:
Jul. 15, 1997
Filed:
Feb. 29, 1996
Applicant:
Inventors:
Heinz Landscheidt, Duisburg, DE;
Alexander Klausener, Koln, DE;
Eberhard Zirngiebl, Koln, DE;
Jorg-Dietrich Jentsch, Ruhr, DE;
Assignee:
Bayer Aktiengesellschaft, Leverkusen, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
548440 ; 548441 ;
Abstract
Substituted 1,2,3,4-tetrahydrocarbazoles of the formula ##STR1## having the meaning for R.sup.1 to R.sup.8 indicated in the description, can be prepared by catalytically hydrogenating a substituted phenol of the formula ##STR2## reacting the hydrogenation solution with a phenylhydrazine of the formula ##STR3## to give the hydrazone and cyclizing the hydrazone under acidic conditions.