2-Oxobutanoic Acid → Ethyl 5-methoxy-3-methyl-1H-indole-2-carboxylate

Participants

Reaction Steps

Concentrated sulphuric acid (1 ml) was added to a solution of 4-methoxyphenyl hydrazine hydrochloride (11.2 g) and 2-oxobutyric acid (8.72 g) in ethanol (250 ml), and the solution heated at reflux for 16 hours. The reaction was cooled, concentrated in vacuo, and the residue triturated with ethanol to give the title compound as a white solid (8.8 g, 59%). NMR δ 1.36 (t, 3H), 3.76 (s, 3H), 4.30 (q, 2H), 6.88 (dd, 1H), 7.03 (d, 1H), 7.28 (d, 1H), 11.28 (bs, 1H); m/z 232 (M−H+).

Provenance & Evidence