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:
Aug. 03, 1999
Filed:
Jul. 30, 1998
Applicant:
Inventors:
Assignee:
Bayer AG, Leverkusen, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
564416 ; 564415 ; 564433 ; 564434 ;
Abstract
4-aminodiphenylamines are prepared by hydrogenating nitrosobenzene or mixtures of nitrosobenzene and nitrobenzene with hydrogen in the presence of bases containing hydroxide, oxide and/or alkoxide groups and heterogeneous catalysts in inert aprotic solvents at temperatures of from 0 to 200.degree. C. and at pressures of from 0.1 to 150 bar.