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

Participants

Reaction Conditions

Reaction Steps

To a 5 mL sealed tube reactor was added methyl 4-(4-bromo-1-methyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate (473 mg, 1.57 mmol) [prepared according to the procedure of Example 156], pyridine-triethenylboroxine (1:1) (666 mg, 2.77 mmol), Pd(PtBu3)2 (16.8 mg, 0.03 mmol) and Cs2CO3 (1.72 g, 5.28 mmol) in 1,4-Dioxane (6.3 mL) and water (1.6 mL). The reaction was heated at 70° C. for 2 hours and partitioned between CHCl3 (75 mL)/H2O (75 mL). The organic layer was dried with Na2SO4, adsorbed onto silica and purified via column chromatography (25-70% EtOAc/Hexane) affording the desired product: LC-MS (ES) m/z=249 (M+H)+.

Provenance & Evidence