Efficient reduction of aromatic nitro/azido groups on solid support employing indium: synthesis of pyrrolo[2,1-c][1,4]benzodiazepine-5,11-diones

An efficient method for the reduction of aromatic nitro and azido compounds on solid support using indium/NH4Cl is described. This solid-phase reduction technique has been applied to the synthesis of pyrrolo[2,1-c][1,4]benzodiazepine-5,11-diones.