(Figure Presented.) Dimethyl 3-(2-bromophenyl)dibenzo[b,f]pyrrolo[1,2-d][1, 4]oxazepine-1,2-dicarboxylate and its 3,13b-dihydro and 1,2,3,13b-tetrahydro analogs undergo intramolecular cyclization under free radical conditions with the formation of dimethyl 7-oxa-2a1-azabenzo[b]-cyclopenta[pq]pleiadene-1,2-dicarboxylate, the unique representative of pyrrole-fused dibenzo[b,f][1, 4]oxazepines, consisting of six fused rings. This nonplanar oxazapolyheterocycle shows a strong blue emission in dichloromethane.