Granted Patent
Utility
US 5,631,385 · App. 08/671,535
Method for the preparation of N-substituted 4-ketoproline derivatives
Inventors:
Karlheinz Drauz, Matthias Kottenhahn, Klaus Stingl
Patented Case
View Patent ↗
Granted: May 20, 1997
Filed: Jun 27, 1996
Inventors
Karlheinz Drauz
Matthias Kottenhahn
Klaus Stingl
Assignee (at issue)
Degussa AG
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.