Potassium Carbonate → Ethyl 6-isobutyl-3-methylpyrazine-2-carboxylate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A suspension of ethyl 6-chloro-3-methylpyrazine-2-carboxylate (1.94 g, 9.67 mmol), isobutylboronic acid (1.97 g, 19.3 mmol), [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II)(212 mg, 0.290 mmol), and potassium carbonate (2.67 g, 19.3 mmol) in 1,4-dioxane (30 mL) was heated at 100° C. for 4.5 h. After being cooled to ambient temperature, the reaction mixture was diluted with ethyl acetate and filtrated through celite with ethyl acetate. The filtrate was combined and concentrated in vacuo. The residue was diluted ethyl acetate, and washed with saturated aqueous sodium bicarbonate and saturated brine, dried over sodium bicarbonate, filtrated and concentrated in vacuo. The residue was dissolved to dichloromethane, and the insoluble materials were filtered off. The filtrate was concentrated in vacuo. The residue was purified by silica gel column chromatography (hexane:ethyl acetate=9:1 to 3:1) to give ethyl 6-isobutyl-3-methylpyrazine-2-carboxylate. MS (APCI): m/z 223 (M+H).

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