2-Methyl-2-butene → 6-Chloro-5-(4-(3-hydroxyoxetan-3-yl)phenyl)-1H-indole-3-carboxylic acid

Participants

Reaction Steps

To the mixture of 6-chloro-5-[4-(3-hydroxy-oxetan-3-yl)-phenyl]-1H-indole-3-carbaldehyde (50.0 mg, 0.15 mmol) in MeCN (2 mL) was added 2-methyl-2-butene (2.0 mL, 13.7 mmol), followed by sodium chlorite (138 mg, 1.53 mmol) and sodium phosphate monobasic hydrate (211.0 mg, 1.53 mmol) in water (1 mL). The reaction mixture was stirred at room temperature for 20 hours, and concentrated in vacuo. The residue was acidified with 1 N aqueous citric acid (1 mL) and extracted with EtOAc. The organic layer was dried over MgSO4 and concentrated in vacuo. The crude material was purified by flash chromatography (34-80% EtOAc/heptanes, with 0.2% formic acid modifier) to afford the title compound (18 mg, 34%) as a brown solid. MS (ES−) 342.3 (M−H)−. 1H NMR (400 MHz, CD3OD) δ 8.02 (s, 1 H), 7.98 (s, 1 H), 7.66 (d, J=8.20 Hz, 2 H), 7.56 (s, 1 H), 7.47 (d, J=8.20 Hz, 2 H), 4.87-4.80 (m, 4 H).

Provenance & Evidence