Triphenylphosphine → HCID 14042135, compound

Participants

Reaction Steps

(Step 8-iv) Methyl 3-amino-6-bromopyrazine-2-carboxylate (700 mg, 3 mmol) was dissolved in dioxane (4 mL) with 3-furan boronic acid (0.36 g, 3.2 mmol), potassium acetate (980 mg 10 mmol) and tetrakispalladium triphenylphosphine (200 mg, 0.17 mmol) in a microwave vessel. Nitrogen was bubbled through for 5 minutes, followed by sealing the vessel and microirradiating the mixture for 20 minutes at 170° C. The reaction mixture was diluted with ethyl acetate/saturated sodium bicarbonate, dried over sodium sulfate, and concentrated to give a solid, which was purified by silica gel column chromatography (0 to 70% EtOAc/hexanes) to give methyl 3-amino-6-(furan-3-yl)pyrazine-2-carboxylate as a solid. This methyl ester was dissolved in THF/MeOH and an aqueous solution of LiOH hydrate (150 mg, 3.6 mmol) was added. The reaction mixture was stirred for 1 hour at room temperature, concentrated to half the volume, and diluted with ethyl acetate/10% aqueous citric acid solution. The organic layer was washed with brine, dried, and concentrated in vacuo to yield 3-amino-6-(furan-3-yl)pyrazine-2-carboxylic acid as a solid (0.46 g, 2.3 mmol, 77% overall yield).

Provenance & Evidence