Granted Patent
Utility
US 4,892,957 · App. 07/232,043
Process for the preparation of a n-alkylated bipyrazoleanthrone
Inventor:
Rainer Hildebrand
Patented Case
View Patent ↗
Granted: Jan 9, 1990
Filed: Aug 15, 1988
Inventor
Rainer Hildebrand
Assignee (at issue)
Ciba-Geigy
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.