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

Participants

Reaction Conditions

Reaction Steps

To a mixture of 1-[4-(6-chloro-3-formyl-1H-indol-5-yl)phenyl]cyclobutane carboxylic acid (120 mg, 0.30 mmol) in acetonitrile (3 mL) and tert-butanol (3 mL) was added 2-methyl-2-butene (3 mL). The reaction mixture was cooled to 0° C. and treated with a solution of sodium chlorite (550 mg, 6.00 mmol) and sodium phosphate monobasic (800 mg, 6.00 mmol) in water (3 mL) dropwise via additional funnel. The ice water bath was removed, and the reaction mixture was stirred at room temperature for 18 hours. The reaction mixture was concentrated in vacuo to give a residue, which was purified by prep-HPLC (Column: Boston Symmetrix ODS-H 150*30 mm*5 μm Mobile phase: from 39% MeCN in water (0.1% TFA) to 39% MeCN in water (0.1% TFA); Wavelength: 220 nm Flow rate: 30 mL/min;) to give the title compound (35 mg, 27% yield) as a white solid. MS (ES+) 392.0 (M+Na)+. 1H NMR (400 MHz, CD3OD) δ 8.03 (s, 1H), 7.99 (s, 1H), 7.58 (s, 1H), 7.44-7.38 (m, 4H), 2.90-2.84 (m, 2H), 2.62-2.54 (m, 2H), 2.11-1.97 (m, 1H), 1.95-1.91 (m, 1H).

Provenance & Evidence