A concise synthesis of monoazaporphyrin from 1,19-dideoxybiladiene-ac

1,19-Dideoxybiladiene-ac was found to be cyclized into monoazaporphyrin in 18–33% yield in the presence of iodine/potassium iodide mixture and ammonium hydroxide or sodium azide as the nitrogen source. The synthesis circumvents the tedious preparation of 1,19-dibromobiladiene-ac for monoazaporphyrin.