Granted Patent
Utility
US 4,751,306 · App. 06/774,025
Imide intermediates for the preparation of analgesic and/or antagonist octahydrobenzofuroisoquinolines
Inventors:
Engelbert Ciganek, Bet-key Wong
Patented Case
View Patent ↗
Granted: Jun 14, 1988
Filed: Sep 9, 1985
Inventors
Engelbert Ciganek
Bet-key Wong
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.