On the regioselectivity of the nucleophilic aromatic photosubstitution. The photoreaction of 4-nitroveratrole with n-hexylamine.

4-Nitroveratrole is photosubstituted with n-hexylamine giving rise to two isomeric anilines, N-hexyl-2-methoxy-5-nitroaniline and N-hexyl-2-methoxy-4-nitroaniline. Mechanistic evidence indicates that the first is produced in an SN2Ar reaction through singlet and triplet excited states, whereas the second arises from a radical ion pair via electron transfer from the amine to a triplet excited state. © 1987.