2-Methyl-2-butene → 6-Chloro-5-phenyl-1H-indole-3-carboxylic acid

Participants

Reaction Steps

To a solution of 6-chloro-5-phenyl-1H-indole-3-carbaldehyde (90 mg, 0.35 mmol) in MeCN (4 mL), tert-butanol (4 mL) and 2-methyl-2-butene (4 mL, 27.5 mmol) at 0° C. was added a solution of sodium chlorite (327 mg, 4.88 mmol) and sodium phosphate monobasic hydrate (761 mg, 4.88 mmol) in water (4 mL) dropwise. The ice bath was removed and the solution was stirred at room temperature. After 6 hours, additional sodium chlorite (327 mg, 4.88 mmol) and sodium phosphate monobasic hydrate (761 mg, 4.88 mmol) were added as solids and the resulting solution was stirred at room temperature for an additional 14 hours. The reaction mixture was concentrated in vacuo and the aqueous residue was extracted with EtOAc (30 mL). The organic layer was washed with brine, dried over Na2SO4 and concentrated in vacuo. The crude material was purified by reverse phase HPLC to afford the title compound (30.0 mg, 31%) as a white solid. MS (ES+) 271.9 (M+H)+. 1H NMR (400 MHz, DMSO-d6) δ 12.13 (br. s., 1H), 11.96 (s, 1H), 8.09 (s, 1H), 7.93 (s, 1H), 7.62 (s, 1H), 7.48-7.38 (m, 5H).

Provenance & Evidence