Granted Patent
Utility
US 4,243,668 · App. 06/054,447
Octahydro-1H-benzo[4,5]furo[3,2-e]-isoquinoline analgesic and narcotic antagonistic compounds
Inventor:
Engelbert Ciganek
Patented Case
View Patent ↗
Granted: Jan 6, 1981
Filed: Jul 9, 1979
Inventor
Engelbert Ciganek
Assignee (at issue)
E.I. DU PONT DE NEMOURS AND COMPANY
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.