Granted Patent
Utility
US 5,157,150 · App. 07/641,242
Preparation of 2-(chloro, bromo or nitro)-4-(alkylsulfonyl)benzoic acids and intermediates
Inventor:
Richard W. Brown
Patented Case
View Patent ↗
Granted: Oct 20, 1992
Filed: Jan 15, 1991
Inventor
Richard W. Brown
Assignee (at issue)
IMPERIAL CHEMICAL INDUSTRIES LIMITED
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.