Granted Patent
Utility
US 5,091,554 · App. 07/622,786
Method of preparing 1,3,3-trimethyl-5-oxo-cyclohexane carbonitrile
Inventors:
Klaus Huthmacher, Hermann Schmitt
Patented Case
View Patent ↗
Granted: Feb 25, 1992
Filed: Dec 5, 1990
Inventors
Klaus Huthmacher
Hermann Schmitt
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.