Synthesis of N‐ and p‐(Diphenylmethyl)anilines. ESR Study of their Photofragmentation

The reaction of N‐substituted anilines 2 with diphenylmethyl halides 1 at room temperature in the presence of AlCl3 affords p‐substituted derivatives 3 in good yields according to an electrophilic aromatic substitution. In contrast, aniline itself is only converted to the N‐substituted compounds 4. A novel rearrangement from Ph3C‐NHPh (4c) to p‐(triphenylmethyl)‐aniline (5) is described. Unexpected photofragmentations of 4a, b are studied by using ESR and ENDOR spectroscopy; e.g., irradiation of 4b with quartz‐ or pyrex‐filtered light leads to the formation of the radicals Ph2C‐SiMe3 (7b) and Ph2C – NHPh (6) respectively, following selective cleavage of the C – N and C – Si bond.