2-Methyl-2-butene → 6-chloro-5-[4-(1-methylpyrrolidin-2-yl)phenyl]-1H-indole-3-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

To a mixture of 6-chloro-5-[4-(1-methylpyrrolidin-2-yl)phenyl]-1H-indole-3-carbaldehyde (150 mg, 0.443 mmol) in acetonitrile/t-butanol (9 mL/9 mL) was added 2-methyl-2-butene (7.50 mL, 28.2 mmol). The reaction mixture was cooled to 0° C. followed by the addition of an aqueous solution of sodium chlorite (598 mg, 8.86 mmol) and sodium phosphate (monobasic and monohydrate, 1220 mg, 8.860 mmol) in water (9 mL) dropwise via syringe. The ice bath was removed and the reaction was stirred at room temperature overnight. The reaction was quenched with sodium sulfite (1.12 g, 8.86 mmol) in water (3 mL). The reaction mixture was concentrated under reduced pressure to remove the volatile organics. The aqueous layer was extracted three times with ethyl acetate. The combined organic layers were dried over sodium sulfate, filtered, and concentrated under reduced pressure. The resulting residue was purified by reverse phase HPLC to give the title compound (10 mg, 5.0% yield). MS (ES+) 355.0 (M+H)+. 1H NMR (400 MHz, CD3OD) δ 8.11 (s, 1H), 7.97 (s, 1H), 7.59-7.58 (m, 5H), 4.19 (m, 1H), 3.74-3.71 (m, 1H), 3.17-3.14 (m, 1H), 2.70 (s, 3H), 2.55-2.52 (m, 1H), 2.33-2.21 (m, 1H), 2.28-2.21 (m, 3H).

Provenance & Evidence