Granted Patent
Utility
US 5,144,033 · App. 07/654,487
Process for obtaining almost fluorescence-free xanthines
Inventors:
Rudolf Knieps, Ottnar Jaenicke, Walter Schonfeld
Patented Case
View Patent ↗
Granted: Sep 1, 1992
Filed: Feb 13, 1991
Inventors
Rudolf Knieps
Ottnar Jaenicke
Walter Schonfeld
Assignee (at issue)
Hoechst GmbH
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.