Cesium carbonate → methyl 4-(4-cyclopropyl-1-methyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate

Participants

Reaction Conditions

Reaction Steps

To a 20 mL sealed tube reactor was added methyl 4-(4-bromo-1-methyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate (505 mg, 1.68 mmol), cyclopropylboronic acid (447 mg, 5.20 mmol), Cesium Carbonate (1.90 g, 5.84 mmol) and PdCl2(dppf)-CH2Cl2Adduct (43.6 mg, 0.05 mmol) in Tetrahydrofuran (THF) (8.5 mL). The reaction was heated to 70° C. for 1.5 hours, cooled and partitioned between CHCl3 and H2O. The organic layer was dried with Na2SO4, adsorbed onto silica and purified via column chromatography (20-40% EtOAc/Hexane) affording the title compound (0.42 g, 1.60 mmol, 95%): LC-MS (ES) m/z=251 (M+H)+.

Provenance & Evidence