Potassium Carbonate → 6-Chloro-5-(4-hydroxymethyl-phenyl)-1H-indole-3-carbaldehyde

Participants

Reaction Conditions

Reaction Steps

A mixture of 5-bromo-6-chloro-1H-indole-3-carbaldehyde (783 mg, 3.03 mmol), 4-(hydroxymethyl)benzene boronic acid (460 mg, 3.03 mmol), 2 N aqueous potassium carbonate (6.4 mL, 13 mmol) in toluene (9 mL) and EtOH (13 mL) was degassed with N2 for 5 minutes, then treated with [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (247 mg, 0.30 mmol). The mixture was heated in a sealed tube to 120° C. and stirred for 2.5 hours. The reaction mixture was cooled to room temperature, diluted with EtOAc (200 mL), then washed with water (50 mL) and brine (50 mL). The organic layer was dried over MgSO4 and concentrated in vacuo. The resulting brown foam was purified by flash chromatography (20-100% EtOAc/heptane) to afford a pale yellow solid. The solid was dissolved in 5:1 EtOAc/heptane (30 mL), and a colorless precipitate formed. The precipitate was collected by filtration, washed with heptane and dried under vacuum to afford the title compound (173 mg, 20% yield) as a colorless solid. MS (ES+) 286.0 (M+H)+. 1H NMR (500 MHz, CD3OD) δ 9.92 (s, 1 H) 8.07 (s, 1 H) 8.25 (s, 1 H) 7.64 (s, 1 H) 7.44 (m, 4 H) 4.70 (s, 2 H).

Provenance & Evidence