Efficient synthesis of 1,4,5,12-tetraazatriphenylene and derivatives

Condensation of 5,6-diamino-4,7-phenanthroline with glyoxal provides 1,4,5,12-tetraazatriphenylene in quantitative yield. This procedure avoids the 50% loss of product inherent in previous methods. Derivatives were also prepared by using alpha-dicarbonyl compounds other than glyoxal. Additional derivatives were prepared from 1,4,5,12-tetraazatriphenylene-2,3-dicarbonitrile, produced by condensation of diaminomaleonitrile with 4,7-phenanthroline-5,6-dione.