Toluene → methyl 6-chloro-5-[3-fluoro-4-(1-hydroxycyclobutyl)phenyl]-1H-indole-3-carboxylate

Participants

Reaction Steps

A mixture of methyl 6-chloro-5-(5,5-dimethyl-1,3,2-dioxaborinan-2-yl)-1H-indole-3-carboxylate (75 mg, 0.23 mmol), 1-(4-bromo-2-fluorophenyl)cyclobutanol (57 mg, 0.23 mmol), 4 M aqueous potassium carbonate (0.47 mL, 0.9 mmol), toluene (3 mL), and ethanol (1 mL) was sparged with nitrogen for 10 minutes, then treated with [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) dichloromethane adduct (9 mg, 0.011 mmol). The reaction mixture was placed in a pre-heated oil bath at 105° C. and stirred for 2 hours. The reaction was cooled to room temperature, diluted with ethyl acetate, washed with water and saturated brine (lx each), dried over magnesium sulfate, filtered and concentrated in vacuo to afford a brown semi-solid, which was purified by flash chromatography (12 g silica, 10-50% ethyl acetate/heptane, 21 column volumes). The product fractions were combined and concentrated in vacuo to afford the title compound as a colorless solid (49 mg, 56% yield). MS (ES−) 372.2 (M−H)−. 1H NMR (400 MHz, CDCl3) δ 8.59 (s, 1 H), 8.10 (s, 1 H), 7.94 (d, J=2.93 Hz, 1 H), 7.54 (s, 1 H), 7.38-7.44 (m, 1 H), 7.18-7.28 (m, 2 H), 3.89 (s, 3 H), 2.66-2.77 (m, 2 H), 2.42 (m, 2 H), 2.11-2.22 (m, 1 H), 1.74-1.86 (m, 1 H).

Provenance & Evidence