1-Methyl-1H-indole-5-boronic acid → ethyl 2-methyl-4-(1-methyl-1H-indol-5-yl)pyrimidine-5-carboxylate

Participants

Reaction Conditions

Reaction Steps

In a mixture of saturated NaHCO3:toluene:ethanol (1:2:1) (12 mL) was dissolved ethyl 4-chloro-2-methylpyrimidine-5-carboxylate (500 mg, 2.49 mmol), N-methylindole-5-boronic acid (872 mg, 4.98 mmol) and to this was added tetrakis(triphenylphosphine)-palladium(0) (58 mg). The reaction stirred at 75° C., under Ar, overnight. The reaction was allowed to cooled to RT, diluted with ethyl acetate (25 mL) and water (25 mL) and filtered free of insolubles. The organic phase was washed with 5% citric acid (25 mL), saturated sodium bicarbonate (25 mL) and brine (25 mL), evaporated at reduced pressure to give a reddish thick foam, and purified by chromatography (Biotage Si-25 column, 15-40% ethyl acetate/hexane) to give ethyl 2-methyl-4-(1-methyl-1 H-indol-5-yl)pyrimidine-5-carboxylate as a thick clear oil. The oil solidified overnight (391 mg, 53% yield). MS (ESI) m/z: 296.0 (M+H+).

Provenance & Evidence