Potassium Carbonate → 1-[4-(6-chloro-3-formyl-1H-indol-5-yl)phenyl]cyclobutanecarboxylic acid

Participants

Reaction Steps

To a solution of 6-chloro-5-(5,5-dimethyl-1,3,2-dioxaborinan-2-yl)-1H-indole (200 mg, 0.80 mmol) in 1,4-dioxane (5 mL) and DMF (1 mL) was added N,N-dimethylformiminium chloride (250 mg, 2.00 mmol). The reaction mixture was sealed and stirred at room temperature for 10 minutes. To the resulting slurry was added 2M aqueous potassium carbonate (2 mL, 4 mmol), 1-(4-bromophenyl)cyclobutanecarboxylic acid (255 mg, 1.00 mmol) and [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (50 mg). The reaction mixture was degassed with nitrogen, sealed, and heated to 90° C. for 30 minutes. The reaction was quenched with H2O (20 mL), then washed with ethyl acetate (3×20 mL). The combined organic phases were dried and concentrated in vacuo to give the title compound (180 mg, 63% yield) in crude form, which was used in the next step without further purification. 1H NMR (400 MHz, CD3OD) δ 9.90 (s, 1H), 8.17 (s, 1H), 8.13 (s, 1H), 7.62-7.61 (m, 1H), 7.48-7.45 (m, 2H), 7.41-7.37 (m, 2H), 2.86-2.79 (m, 2H), 2.62-2.45 (m, 2H), 2.05-2.01 (m, 2H).

Provenance & Evidence