Sulfuric Acid → 1-methansulfonyl-1H-indol-6-ol

Participants

Reaction Steps

N-methansulfonyl-6-amino indole (2.10 g, 10.0 mmol), prepared as described in Forbes, et al., J. Med. Chem. (1996) 39:4968, was suspended in 40 ml of water, then cooled in an ice bath. Concentrated sulfuric acid (3 ml) was added slowly dropwise. The mixture was warmed to room temperature for 5 min then cooled back down to 0° C. A solution of NaNO2 (Mallinckrodt, 0.76 g, 11.0 mmol) in 10 ml of water was added slowly and the resultant foam was treated with 10 ml of ethanol. The mixture was added in portions to a boiling solution of CuSO4 (J. T. Baker, 16.0 g, 0.1 mol) in 75 ml of water. After 15 min, the mixture was cooled. The brown solid which had formed was broken up with a glass stirring rod. NaHCO3 was added to neutralize the reaction and the product was extracted with ethyl acetate (2×100 ml). The extracts were dried (anhydrous MgSO4) and concentrated to give 1-methansulfonyl-1H-indol-6-ol (1.62 g), a brown oil which was used with out purification.

Provenance & Evidence