Synthesis of a Series of Diaminoindoles

James S. Martin, Claire J. Mackenzie, and Ian H. Gilbert

J. Org. Chem. 2021, 86, 17, 11333–11340 ,


A selection of 3,4-diaminoindoles were required for a recent drug discovery project. To this end, a 10-step synthesis was developed from 4-nitroindole. This synthesis was subsequently adapted and used to synthesize 3,5-; 3,6-; and 3,7-diaminoindoles from the corresponding 5-, 6-, or 7-nitroindole. These novel intermediates feature orthogonal protecting groups that allow them to be further diversified. This is the first reported synthesis of these types of compounds.