The Photochemical Formation of Dihydrocarbazoles from Diphenylamines and Their Thermal Rearrangement and Disproportionation Reactions

Article abstract of DOI:10.1021/ja00413a019

N-Methyldiphenylamine, A, is in oxygen-free solution converted by light into N-methylcarbazole, C, and N-methyltetrahydrocarbazole, THC, via a disproportionation reaction.The precursor of C and THC is an unstable 4a,4b-dihydrocarbazole, DHC.Its decay was studied by means of flash and steady state illumination experiments at different temperatures.The primary photoproduct of the A derivative N-methyl-2,4,6-trimethyldiphenylamine, TMA, is a 4a-methyl-4b-hydrocarbazole, MDHC.Like DHC it is unstable but rearranges into stable methylhydrocarbazoles, MDHC'.It does not disproportionate like DHC.The photoproducts formed from A, deuterated A, and TMA were analyzed by means of NMR and mass spectrometry.