The photochemical reactions of 9,10-anthracenedicarbonitrile and 1,4-naphthalenedicarbonitrile in acetonitrile in the presence of bases

Irradiation of 9,10-anthracenedicarbonitrile(DCA) in MeCN-MeOH or MeCN-H2O containing hydroxides or methoxides leads to 9-methylimino-10-anthracenecarbonitrile (isolated, but easily hydrolyzed to the corresponding amine). Minor products are polycyanated amines and 9-hydroxy-10-anthracenecarbonitrile. Irradiation in neat MeOH causes decyanation. In both cases the first step is reduction to DCA−., which persists for hours under these conditions. Evidence for the mechanism leading from the radical anion to the observed products is supplied. The key steps are protonation to yield the radical DCAH. and addition of the latter to acetonitrile, or to better nucleophiles when these are present. 1,4-Naphthalenedicarbonitrile is similarly transformed to the 4-amino-1-carbonitrile.