Potassium Carbonate → methyl 5-chloro-4-(1-methyl-1H-pyrazol-5-yl)-2-furancarboxylate

関与物質

反応手順

A solution of methyl 4-bromo-5-chloro-2-furancarboxylate (1.1 g, 4.59 mmol), 1-methyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (1.05 g, 5.05 mmol) [prepared according to Preparation 7], potassium carbonate (3.17 g, 22.97 mmol) and bis(tri-t-butylphosphine)palladium(0) (0.117 g, 0.23 mmol) in 1,4-dioxane (19.14 ml) and water (3.83 ml) was stirred at 80° C. in a sealed tube for 1 h. The reaction mixture was partitioned between H2O-DCM and the aqueous phase was washed several times with DCM. The combined organic fractions were dried over Na2SO4, concentrated and purified via column chromatography (silica, 4-25% EtOAc in hexanes) yielding methyl 5-chloro-4-(1-methyl-1H-pyrazol-5-yl)-2-furancarboxylate (800 mg, 2.53 mmol, 55% yield) as a yellow oil: LCMS m/e ES 240, 242 (M, M+2)+.

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