Process for the preparation of a mixture of 1-amino-2-chloro-4-hydroxyanthraquinone and 1-amino-2-bromo-4-hydroxyanthraquinone

Granted: Aug 30, 1988 Filed: Jun 10, 1987

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.