Pyridoquinoxaline N-oxides. 1. A new class of antitrichomonal agents.

: An aspect of our work with quinoxaline 1,4-dioxides involved the synthesis and reactivity of (quinoxalin-2-yl)acrylonitrile 1,4-dioxide. We have found that treatment of a methanolic solution of this unsaturated nitrile (cis or trans) with primary alkylamines affords a novel series of pyrido[2,3-b]quinoxaline 5-oxides. These tricyclic pyridoquinoxalines represent a unique class of agents with oral activity against trichomoniasis.