Nenitzescu Synthesis of 5-Hydroxyindoles with Zinc, Iron and Magnesium Salts in Cyclopentyl Methyl Ether

In this work, mild Lewis acids and low environmental impact solvents were investigated for Nenitzescu synthesis. Cyclopentyl methyl ether can be used at room temperature in substitution of halogenated solvents with zinc, iron and magnesium salts as homogeneous catalysts to give 5-hydroxyindoles in fair to good yields. The reaction features a straightforward workup and excellent solvent recycle.