Potassium Carbonate → 2-(3-Ethoxycarbonyl-propyl)-5-phenyl-2H-pyrazole-3-carboxylic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

5-Phenyl-2H-pyrazole-3-carboxylic acid methyl ester (9.10 g, 45.0 mmol) is taken up in 100 mL acetonitrile and heated to 60° C. Ethyl 4-bromobutanoate (8.78 g, 45.0 mmol) and potassium carbonate (8.09 g, 58.5 mmol) are added and the reaction mixture is heated to 85° C. and stirred under reflux for 5 h. The reaction mixture is filtered and the filtrate is concentrated under reduced pressure. The residue is taken up in water and extracted with ethyl acetate. The combined organic phases are dried over Na2SO4 and concentrated under reduced pressure. The residue is purified by flash column chromatography (silica gel, 8-40% ethyl acetate in heptane). Yield: 10.3 g. Rf (silica gel, 2% methanol in DCM)=0.41.

Provenance & Evidence