AlCl3/PCC-SiO2-PROMOTED OXIDATION OF AZAINDOLES AND INDOLES

A simple and efficient method is described for the oxidation of 7-azaindoles and indoles to 7-azaisatins and isatins using pyridinium chlorochromate-silica gel (PCC-SiO2) with the aid of Lewis acid catalyst aluminium chloride (AlCl3) in dichloroethane. Simplicity of the reaction conditions, easy workup procedure, and good yields are the key features of this protocol.