Potassium Carbonate → 6-chloro-5-(4-(3-hydroxyoxetan-3-yl)phenyl)-1H-indole-3-carbaldehyde

Participants

Reaction Conditions

Reaction Steps

A mixture of 5,5,5′,5′-tetramethyl-[2,2′]bi[[1,3,2]dioxaborinanyl] (149.0 mg, 0.44 mmol), oven dried potassium acetate (173.0 mg, 1.75 mmol) and 3-(4-bromo-phenyl)-oxetan-3-ol (100.0 mg, 0.44 mmol) in 1,4-dioxane (2 mL) was degassed with N2 for 5 minutes, treated with [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (33.0 mg, 0.044 mmol) and subjected to microwave irradiation at 110° C. for 1 hour. The cooled reaction mixture was filtered through celite and concentrated in vacuo to give a black oil. To the dark oil was added 5-bromo-6-chloro-1H-indole-3-carbaldehyde (112.0 mg, 0.43 mmol), 2N aqueous potassium carbonate (0.4 mL, 0.80 mmol), toluene (1.5 mL) and EtOH (0.5 mL). The reaction mixture was degassed with N2 for 10 minutes, treated with [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (25.0 mg, 0.034 mmol), and heated in a pressure tube to 110° C. for 2 hours. The cooled reaction mixture was purified by flash chromatography (33-100% EtOAc/heptanes) to give a solid. The solid was triturated in MeOH and filtered to afford the title compound (50 mg, 35%) as a yellow solid. MS (ES+) 328.0 (M+H)+. 1H NMR (400 MHz, DMSO-d6) δ 12.23 (s, 1H), 9.92 (s, 1H), 8.35 (s, 1H), 8.02 (s, 1H), 7.66 (d, J=9.4 Hz, 2H), 7.44 (d, J=8.2 Hz, 2H), 6.36 (s, 1H), 4.80-4.76 (m, 2H), 4.75-4.71 (m, 2H).

Provenance & Evidence