The Synthesis of 3H-Azepines: Thermal Reorganization of 2,4- and 3,5-Di-t-butyl-3a,5a-dihydro-3H-cyclobuta[b]pyrroles to 2,5- and 3,6-Di-t-butyl-3H-azepines

Thermal reaction of cyclobuta[b]pyrroles, which derived by photochemical cyclization of methyl 2,5- and 3,6-di-t-butyl-1H-azepine-1-carboxylate gave di-t-butyl substituted 3H-azepines. The kinetics of the reaction were measured and the activation energy of the reorganization to 3H-azepines was estimated.