Potassium Carbonate → methyl 5-chloro-4-(1,4-dimethyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate

Participants

Reaction Conditions

Reaction Steps

To a 350 mL sealed flask reactor was added methyl 4-bromo-5-chloro-2-thiophenecarboxylate (409 mg, 1.60 mmol) [prepared according to the procedure of Example 95], 1,4-dimethyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (388 mg, 1.75 mmol) [prepared according to the procedure of Preparation 17], K2CO3 (676 mg, 4.89 mmol) and Pd(PtBu3)2 (32 mg, 0.06 mmol) in 1,4-Dioxane (6 mL) and water (1.5 mL). The reaction was heated at 85° C. for 3 hours. The reaction was partitioned between CHCl3/H2O and the pH of the aqueous layer was adjusted to ˜3 with 6N HCl. The separated organic layer was dried with Na2SO4, adsorbed onto silica and purified via column chromatography (10-65% EtOAc/Hexanes) affording the title compound (106 mg, 0.39 mmol, %); LC-MS (ES) m/z=271 (M+H)+.

Provenance & Evidence