Cesium carbonate → 3-Bromo-5-phenylpyrazin-2-amine

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 3,5-dibromo-2-aminopyrazine (200 mg; 0.79 mmol) and phenyl boronic acid (106 mg; 0.87 mmol) in dioxane (4 mL) and ethanol (2 mL) was added cesium carbonate (571 mg; 1.75 mmol in 2 mL of water) followed by Pd(PPh3)4 (46 mg; 0.04 mmol). The reaction was heated to 75° C. and stirred for 12 hours. The reaction was cooled to room temperature, diluted with 50 mL of ethyl acetate and washed with aqueous 10% sodium carbonate (1×50 mL), brine (50 mL), then dried (MgSO4) and filtered. The material was purified using a biotage 12L cartridge eluting with hexanes and ethyl acetate (3:1) to yield an off white solid (88% yield).

Provenance & Evidence