Trifluoroacetic acid → 2-ethyl-4-methoxy-1H-indole

Participants

Reaction Steps

To a solution of [5-methoxy-2-(2-oxo-butyl)-phenyl]-carbamic acid t-butyl ester 73b (1.36 g, 4.65 mmole) in 10 ml THF was added 4 ml TFA. The reaction mixture was stirred at room temperature for 5 h, quenched with 50 ml H2O and extracted with EtOAc. The organic layer was dried over MgSO4 and concentrated. The residue was purified by flash column chromatography (10–15% EtOAc in hexane) to give pale yellow solid (1.36 g, 73%). 1H NMR (CDCl3) δ 7.75 (1H, bs), 7.49 (1H, d, J=8.6 Hz), 6.81 (1H, s), 6.73 (1H, d, J=8.6 Hz), 3.83 (3H, s), 2.75 (2H, q, J=7.5 Hz), 1.32 (3H, t, J=7.5 Hz). ESIMS (MH+): 272.10.

Provenance & Evidence