Sodium Carbonate → HCID 68565294, compound

Participants

Reaction Steps

To a solution of 0.20 g (0.50 mmol) 6-bromo-5-methoxy-indole-1,2-dicarboxylic acid 1-tert-butyl ester 2-ethyl ester in 8 mL 1,2-dimethoxyethane were added 58 μg (0.050 mmol) tetrakis(triphenylphosphine)palladium(0). After stirring 30 min at room temperature, 76 μg (0.60 mmol) trimethylboroxine and 0.16 g (1.50 mmol) sodium carbonate dissolved in 4 mL water were added and the reaction mixture was heated 3 h at reflux. The solution was poured into 10% aqueous sodium bicarbonate solution and ethyl acetate, the layers were separated and the aqueous layer was extracted three times with ethyl acetate. The combined organic layers were washed with brine, dried over magnesium sulfate, filtered and evaporated. The residue was purified twice by flash chromatography on silica gel using a gradient of dichloromethane:methanol (100:0 to 50:50 v/v) as eluant, to afford 95 mg (57%) of the title compound as colourless oil.

Provenance & Evidence