Potassium Carbonate → Methyl 5-chloro-4-(1-ethyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate

Participants

Reaction Conditions

Reaction Steps

To a 100 mL sealed flask was added 1-ethyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (2.61 g, 11.74 mmol), potassium carbonate (3.25 g, 23.48 mmol), methyl 4-bromo-5-chloro-2-thiophenecarboxylate (2 g, 7.83 mmol) and bis(tri-t-butylphosphine)palladium(0) (0.4 g, 0.78 mmol) in 1,2-dimethoxyethane (DME) (50 mL) and H2O (10 ml). After stirring for 3 h at 70° C., the reaction solution was diluted with DCM (100 mL) and washed with H2O. The organic layer was dried Na2SO4, filtered and concentrated. The residue was purified on silica gel [EtOAc/hexanes, 10-30%] to give the product [1.8 g, 85%] as an off white solid: LC-MS (ES) m/z 271 (M+H)+.

Provenance & Evidence