Potassium Hydroxide → 4-(1-ethyl-4-methyl-1H-pyrazol-5-yl)-2-thiophenecarboxylic Acid

Participants

Reaction Conditions

Reaction Steps

To a solution of methyl 4-(1-ethyl-4-methyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate (270 mg, 1.08 mmol) in THF/H2O (2 mL/0.4 mL) was added KOH (303 mg, 1.79 mmol). The reaction mixture was heated to 50° C. for 4 h. After the mixture was concentrated and diluted with H2O, the pH was adjusted to 3. The mixture was extracted with DCM (5 mL×3). The collected organic layers were concentrated under vacuum to give the crude acid (240 mg), which was used directly in the next step without further purification: LC-MS m/z=237 (M+H)+.

Provenance & Evidence