Synthesis and properties of fluorine‐containing heterocyclic compounds. V. Trifluoromethyl‐1,8‐ and 1,10‐phenanthrolines

The condensation of ethyl trifluoroacetoacetate with various heterocyclic amines yielded 2‐(trifluoromethyl)phenanthrolin‐4‐ones. The structures of these compounds were established from a study of their infrared and ultraviolet spectra. Substituted phenanthrolines were prepared by nucleophilic attack on a chlorophenanthroline. The oxidation of 5‐methoxy‐2‐trifluoromethyl‐1,10‐phenanthroline yielded an o‐quinone which was treated with typical quinone reagents. A molecular orbital calculation was carried out in an attempt to explain the ease of reduction of the 1,10‐phenanthroline system and the colors of the reduced compounds.