Hydrazine hydrate (1:1) → 4-Fluoro-2-methyl-1H-indol-5-amine

Participants

Reaction Steps

4-Fluoro-2-methyl-5-phthalimidoindole (1.2, 4 mmol) was dissolved in methanol (30 ml). Hydrazine monohydrate (260 μl, 5.3 mmol) was added and the reaction mixture was stirred at ambient temperature for 2 hours. The solvent was evaporated off and the residue taken up in methylene chloride. The phthalhydrazide by-product was removed by filtration and the filtrate purified by flash chromatography 0.5% methanol in methylene chloride. Evaporation of the solvent gave a white solid which contained traces of phthalhydrazide. Further purification was done by dissolving it in ethyl acetate, washing the organic phase with NaOH 2N and brine, drying over MgSO4. Rotary evaporation of the solvent gave 5-amino-4-fluoro-2-methylindole (500 mg, 76%).

Provenance & Evidence