Granted Patent
Utility
US 4,639,520 · App. 06/593,752
Preparation of 14-hydroxy-N-ethoxy-carbonyl-norcodeinone
Inventor:
Frank Kavka
Patented Case
View Patent ↗
Granted: Jan 27, 1987
Filed: Mar 27, 1984
Inventor
Frank Kavka
Assignee (at issue)
MALLINCKRODT LLC
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.