3-Substituted Blatter Radicals: Cyclization of N -Arylguanidines and N -Arylamidines to Benzo[ e ][1,2,4]triazines and PhLi Addition.

A series of 3-amino- and 3-alkyl-substituted 1-phenyl-1,4-dihydrobenzo[ e ][1,2,4]triazin-4-yls was prepared in four steps involving N-arylation, cyclization of N -arylguanidines and N -arylamidines, reduction of the resulting N -oxides to benzo[ e ][1,2,4]triazines, and subsequent addition of PhLi followed by aerial oxidation. The resulting seven C(3)-substituted benzo[ e ][1,2,4]triazin-4-yls were analyzed by spectroscopic and electrochemical methods augmented with density functional theory (DFT) methods. Electrochemical data were compared to DFT results and correlated with substituent parameters.