Potassium Carbonate → methyl 1-methyl-5-(1-methyl-1H-pyrazol-5-yl)-1H-pyrrole-3-carboxylate

Participants

Reaction Steps

A solution of methyl 5-bromo-1-methyl-1H-pyrrole-3-carboxylate (950 mg, 4.36 mmol), 1-methyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (1088 mg, 5.23 mmol)[prepared according to Preparation 3], potassium carbonate (3011 mg, 21.78 mmol) and bis(tri-t-butylphosphine)palladium(0) (111 mg, 0.218 mmol) in 1,4-Dioxane (18.200 ml) and Water (3.64 ml) was stirred at 80° C. in a sealed tube for 1 h. Additional 1-methyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (1088 mg, 5.23 mmol) and bis(tri-t-butylphosphine)palladium(0) (111 mg, 0.218 mmol) were added and the solution stirred for 1 h. The reaction mixture was then 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 1-methyl-5-(1-methyl-1H-pyrazol-5-yl)-1H-pyrrole-3-carboxylate (300 mg, 1.341 mmol, 30.8% yield) as a clear oil: LCMS m/e ES 220 (M+H)+.

Provenance & Evidence