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:
Sep. 10, 1991
Filed:
Sep. 06, 1988
Applicant:
Inventor:
Werner Stegmann, Liestal, CH;
Assignee:
Ciba-Geigy Corporation, Ardsley, NY (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
564331 ; 564330 ; 564332 ; 564334 ; 564335 ;
Abstract
Bis-(amino-nitrophenyl)-methane can be produced in one stage with an approximately quantitative yield by condensing o-nitraniline and formaldehyde in water at a temperature of between 20.degree. and 40.degree. C. in the presence of sulfuric acid, and subsequently rearranging the formed methylene-bis-(o-nitraniline) by treatment of the reaction mixture at a temperature of between 90.degree. and 100.degree. C.