Synthesis of 1-iodo-1,2,3,4,4a,9a-hexahydrocarbazole, 2a,3,4,5,5a,10a-hexahydrooxazolocarbazolium iodide and 4-bromo-1,2,3,4,4a,11b-hexahydrodibenzoxazepine from N-benzoyl-2-(cyclohex-2-en-1-yl)aniline

The reaction of N-benzoyl-2-(cyclohex-2-en-1-yl)aniline 1 with molecular oxygen in the presence of NaHCO₃ results in N-benzoyl-1-iodo-1,2,3,4,4a,9a-hexahydrocarbazole, which was isomerised to 1-phenyl-2a,3,4,5,5a,10a-hexahydro[1,3]oxazolo-[5,4,3-j,k]carbazol-10-ium iodide, whereas the reaction of amide 1 with molecular bromine results in dibromide, but the interaction with NBS leads to 4-bromo-6-phenyl-1,2,3,4,4a,11b-hexahydrodibenzo[d,f][1,3] oxazepine.