Photoreactions of 2-(N-alkylarylamino)succinimides and related compounds

On irradiation (254 nm), 2-(N-methylanilino)-N-phenylsuccinimide (6a) underwent homolysis of the C(2)-N bond to yield fission products N-methylaniline and N-phenylsuccinimide (12), along with the products of ortho- and para-rearrangement 2-[2-(N-methylamino)phenyl]-N-phenylsuccinimide (13) and 2-[4- (N-methylamino)phenyl]-N-phenylsuccinimide (14a) respectively. Similarly, irradiation of 2-(N-methyl- anilino)succinimide (6b) and N-benzyl-2-(N-methylanilino)succinimide (6c) gave N-methylaniline and the corresponding products of para-rearrangement. In contrast, both fission and type II cyclisation photo-products 12 and 17 respectively were formed from N-phenyl-2-(1,2,3,4-tetrahydroquinolin-1-yl)succinimide (16) and only the type II cyclisation product 1-hydroxy-2,7-diphenyl-2,7-diazabicyclo-[3.3.0]octan-3-one (21) was obtained from 2-(N-methylanilinomethyl)-N-phenylsuccinimide (20).