Sulfuric Acid → 1-[4-(2.2.2-Trifluoro-ethanesulfonylamino)-benzyl]-5-(2-oxo-propyl)-1H-indole-2-carboxylic Acid Ethyl Ester

Participants

Reaction Steps

To a solution of crude 1-[4-(2,2,2-trifluoro-ethanesulfonylamino)-benzyl]-5-(2-methyl-[1,3]dioxolan-2-ylmethyl)-1H-indole-2-carboxylic acid ethyl ester (2.85 g, ≈5 mmol) in acetone (60 ml) was added concentrated sulfuric acid (0.6 ml). The solution was stirred at room temperature for about 45 minutes, and most of the solvent was removed under reduced pressure. The residue was taken up in ethyl acetate, washed with water and brine, dried over sodium sulfate, and concentrated in vacuo. The residue was purified by flash chromatography (silica, 130 g) eluting with a gradient from 30% -ethyl acetate/hexane to 40% ethyl acetate/hexane, to give the title compound (1.48 g).

Provenance & Evidence