2-Methyl-2-butene → Indole-3-Carboxylic Acid

Participants

Reaction Steps

To a solution of 6-chloro-5-[4-(3-hydroxy-2,2-dimethylpropoxy)phenyl]-1H-indole-3-carbaldehyde (60 mg, 0.17 mmol) in acetonitrile (3 mL) was added tert-butanol (3 mL), water (3 mL) and 2-methyl-2-butene (1.38 mL). The reaction mixture was stirred for 2 min then treated with sodium chlorite (338 mg, 3.76 mmol) and sodium phosphate monobasic (787 mg, 5.04 mmol). The mixture was stirred at room temperature overnight. The reaction was quenched with sodium sulfite and concentrated in vacuo to give a residue, which was dissolved with ethyl acetate (50 mL), washed with brine (3×15 mL), dried over sodium sulfate and concentrated in vacuo. The residue was purified by prep-HPLC to give 2,2-dimethylpropoxy)phenyl]-1H-indole-3-carboxylic acid (20 mg, 32%) as an off-white solid. MS (ES−) 372.1 (M−H)−. 1H NMR (400 MHz, CD3OD) δ 8.01 (s, 1H), 7.99 (s, 1H) 7.56 (s, 1H), 7.35 (d, 2H), 6.98 (d, 2H), 3.80 (s, 2H), 3.49 (s, 2H), 1.04 (s, 6H).

Provenance & Evidence