[2-(1H-indol-1-yl)ethyl]-2-piperazine and pyrido[1,2-a]indol-9-one as intermediates for pyrazino(2,3-3,4)pyrido(1,2-a) indoles which are useful for treating hypertension in mammals

Granted: May 7, 1985 Filed: Feb 27, 1984

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.