Potassium Carbonate → methyl 4-bromo-3-hydroxy-5-(1-methyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate

Participants

Reaction Steps

Methyl 4,5-dibromo-3-hydroxy-2-thiophenecarboxylate (500 mg, 1.59 mmol), 5-(5,5-dimethyl-1,3,2-dioxaborinane-2-yl)-1-methyl-1H-pyrazole (339 mg, 1.75 mmol), Pd(PPh3)4 (92 mg, 79.4 μmol) and K2CO3 (876 mg, 6.35 mmol) in dioxane (6.6 mL) and H2O (1.3 mL) were combined in a sealed tube. After 12 h at 80° C., the reaction contents were 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 (silica, 0.5% MeOH in DCM) affording the title compound (75 mg, 15%) as a brown residue: LCMS (ES) m/z=318 (M+H)+.

Provenance & Evidence