反应详情

A solution of methyl 4-bromo-5-methyl-2-furancarboxylate (2.1 g, 9.59 mmol), potassium carbonate (6.63 g, 47.9 mmol), 1-methyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (2.19 g, 10.55 mmol) [prepared according to Preparation 7] and bis(tri-t-butylphosphine)palladium(0) (0.24 g, 0.48 mmol) in 1,4-dioxane (40 ml) and water (8 ml) was stirred at 80° C. in a sealed tube for 1 h. 1-methyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (2.19 g, 10.55 mmol) and bis(tri-t-butylphosphine)palladium(0) (0.245 g, 0.48 mmol) were added and the reaction stirred an additional 1 h and was partitioned between H2O-DCM. The aqueous phase was washed several times with DCM and the combined organic fractions were dried over Na2SO4, concentrated and purified via column chromatography (10-40% EtOAc in hexanes) affording methyl 5-methyl-4-(1-methyl-1H-pyrazol-5-yl)-2-furancarboxylate (1.7 g, 7.72 mmol, 81% yield) as a yellow oil: LCMS (ES) m/e 221 (M+H)+.

1. customwas partitioned between H2O-DCM
2. washThe aqueous phase was washed several times with DCM
3. dry with materialthe combined organic fractions were dried over Na2SO4
4. concentrationconcentrated
5. custompurified via column chromatography (10-40% EtOAc in hexanes)