Potassium Carbonate → 6-chloro-5-[4-(1-methylpyrrolidin-2-yl)phenyl]-1H-indole-3-carbaldehyde

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Reaction Steps

To a suspension of 6-chloro-5-(5,5-dimethyl-1,3,2-dioxaborinan-2-yl)-1H-indole (290 mg, 1.10 mmol) in mixture of 1,4-dioxane/N,N-dimethylformamide=5:1 (3 mL) was added Vilsmer-salt (330 mg, 3.30 mmol) under nitrogen and stirred at room temperature for 30 minutes. Potassium carbonate (2.0 M in water, 2.9 mL) was added to the above suspension followed by the addition of 2-(4-bromophenyl)-1-methylpyrrolidine (200 mg, 0.84 mmol) in a mixture of 1,4-dioxane/N,N-dimethylformamide=5:1 (3 mL). The mixture was degassed with nitrogen for 10 minutes. The mixture was then treated with Pd(dppf)Cl2 (125 mg, 0.165 mmol). The mixture was stirred at 90° C. under nitrogen for 30 minutes. The mixture was filtered through a celite pad and the filtrate was partitioned between ethyl acetate (10 mL) and water (20 mL), the aqueous phase was extracted three additional times with ethyl acetate (10 mL) and the combined organic phases were washed with brine (15 mL), dried over sodium sulfate, filtered and concentrated to afford crude product which was purified by silica-gel chromatography to afford the title compound (150 mg, 53.2% yield).

Provenance & Evidence