A mixture of iso-amyl nitrite/HBr is shown to be a mild and efficient reagent for electrophilic aromatic bromination. The reaction succeeds with slightly activated arenes and heterocyclic compounds. By using HCl instead of HBr, chlorination can also be performed in few cases. The i-amONO2/HBr mixture can also be utilized for bromination in the α-position of electron withdrawing groups. A possible mechanism
The synthesis of potential precursors of ketones, which could be used to obtain camptothecin analogs, is described. Noteworthy is the difference of reactivity between indolizinone and pyrrolidinoquinazolinone heterocycle.