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

Participants

Reaction Conditions

Reaction Steps

A mixture of 5-bromo-6-chloro-1H-indole-3-carbaldehyde (6.15 g, 23.8 mmol), 1-[4-(5,5-dimethyl-[1,3,2]dioxaborinan-2-yl)-phenyl]-cyclobutanol (8.35 g, 32.1 mmol), 2 M aqueous potassium carbonate (47.5 mL, 95.0 mmol) in EtOH (33 mL) and toluene (86 mL) was degassed with N2 for 25 minutes, then treated with [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (1.93 g, 2.64 mmol). The reaction mixture was heated to 110° C. and stirred for 2 hours. The reaction mixture was cooled to room temperature, poured into a 3:1 mixture of saturated aqueous NH4Cl solution/water (450 mL) and extracted with EtOAc (10×150 mL), followed by 9:1 CH2Cl2/i-PrOH (4×100 mL). The combined organic layers were dried over Na2SO4 and concentrated in vacuo. The crude material was purified by flash chromatography (0-100% EtOAc/heptane, with 0.03% formic acid modifier) to afford the title compound (4.98 g, 64%) as a red solid. MS (ES+) 326.5 (M+H)+. 1H NMR (400 MHz, DMSO-d6) δ 12.21 (br. s., 1 H), 9.91 (s, 1 H), 8.35 (s, 1 H), 8.02 (s, 1 H), 7.67 (s, 1 H), 7.54 (d, J=8.00 Hz, 2 H), 7.38 (d, J=8.20 Hz, 2 H), 5.50 (s, 1 H), 2.36-2.45 (m, 2 H), 2.22-2.33 (m, 2 H), 1.92 (m, 1 H), 1.61-1.71 (m, 1 H).

Provenance & Evidence