Reactions of the potassium salt of 1,7,7-trimethyl-N-nitrobicyclo[2.2.1] heptan-2-imine with bromine and nitrous acid: Synthesis of 3-exo-bromo-1,7,7-trimethyl-N-nitrobicyclo[2.2.1]heptan-2-imine, 3-endo-bromo-1,7,7-trimethyl-N-nitrobicyclo[2.2.1]heptan-2-imine, 1,7,7-trimethyl-N-nitro-3-nitrosobicyclo[2.2.1]hept-2-en-2-amine and their reactions with nitrogen nucleophiles.