99740-54-2Relevant academic research and scientific papers
Intramolecular Nitrene Insertion into Aromatic and Heteroaromatic Rings. Part 9. Synthesis of 2-Azidodiphenylmethanes and the Kinetics of their Thermal Decomposition in Solution
Jones, Gurnos,Long, Brian D.,Thorne, Melanie P.
, p. 903 - 913 (2007/10/02)
The synthesis of some new o-azidodiphenylmethanes 3b, 10, 15, 18, 21 and 22 is described.The first-order kinetics of the thermal decomposition in trichlorobenzene of these and some previously studied azides (3a, 3c and 3d) has been studied in the range 140-180 K.The initial step is evolution of nitrogen and formation of a nitrene intermediate, which reacts to give a 10H-azepinoindole together with some amine.Rate constants for the first step were compared with those for product formation and show it to be the rate-determining factor.Electron-donating substituentspara to the azide group stabilise the incipient nitrene by resonance interactions (rate constants correlate with ?R+) yielding higher proportions of amine products, which result from the spin forbidden singlet-triplet nitrene transition.Substituents at the 4'-position influence the nature of the products but not decomposition rates.A new compound, 1a-methoxy-1a,9b-dihydro-1H-cyclopropapyridolindole (28), is obtained from 2-azido-4'-methoxydiphenylmethane (3d) in addition to the expected azepinoindole and amine.Kinetic measurements show that it is an intermediate in one, but not the sole, route to formation of 8-methoxyazepinoindole 27 from 3d.
