Synthesis of pyrido[3,4-c][1,9]phenanthroline - A five-step procedure to a novel N-containing ring skeleton

摘要

The condensation of paraformaldehyde with two equivalents of 4-methylpyridine-3-carbonitrile under basic conditions afforded 6-amino-11,12-dihydropyrido[3,4-c][1,9]phenanthroline, which was converted via the corresponding 6-oxo- and 6-chloro derivatives- and a dehalogenation into 11,12-dihydropyrido[3,4-c][1,9]phenanthroline. The fully aromatized derivative pyrido[3,4-c][1,9]phenanthroline was obtained in an ultimate dehydrogenation procedure.