Thermolysis of 7-isopropylidene-2,3-diazabicyclo [2.2.1] hept-2-ene in the presence of spin trap

Article abstract of DOI:10.1016/S0040-4039(00)79775-9

Thermolysis of 7-isopropylidene-2,3-diazabicyclo-[2.2.1] hept-2-ene (1) in the presence of trapping agent, α-phenyl tert-butyl nitrone (2) in acetonitrile solution at 70-90°C produced a six-line EPR spectrum with the following hyperfine coupling constants: A(N) = 14.9 G and A(H) = 2.0 G. The structure was assigned to an isopropylidenecyclopentanyl radical diadduct (5) whose hyperfine coupling constants were found to be consistent with those in cyclohexadienyl adducts (4) observed by Mao and Kevan. The formation of the biradical (3) is ruled out.