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

Participants

Reaction Conditions

Reaction Steps

A solution of methyl 4-bromo-5-ethyl-2-thiophenecarboxylate (300 mg, 1.204 mmol), potassium carbonate (832 mg, 6.02 mmol), 1-methyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (326 mg, 1.565 mmol) [prepared according to Preparation 7] and bis(tri-t-butylphosphine)palladium(0) (30.8 mg, 0.060 mmol) were combined in a sealed tube and stirred at 80° C. for 1 h. The reaction contents were then partitioned between H2O-DCM and the aqueous phase was washed several times with DCM. The combined organic fractions were dried over Na2SO4 and concentrated affording methyl 5-ethyl-4-(1-methyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate (301 mg, 1.204 mmol, 100° A yield) as a brown oil: LCMS (ES) m/e 251 (M+H)+.

Provenance & Evidence