Potassium Hydroxide → 5-chloro-4-(1,4-dimethyl-1H-pyrazol-5-yl)-2-thiophenecarboxylic Acid

Participants

Reaction Conditions

Reaction Steps

To a solution of methyl 5-chloro-4-(1,4-dimethyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate (7.6 g, 28.1 mmol) in THF/H2O (30 mL/5 mL) was added KOH (4.72 g, 84 mmol). The reaction mixture was heated to 50° C. for 1 h. After the mixture was concentrated and diluted with H2O, the pH was adjusted to 3. The mixture was extracted with DCM (50 mL×3). The collected organic layers were concentrated under vacuum to give the crude acid (6.8 g, 94%), which was used directly in the next step without further purification: LCMS (ES) m/z 257 (M+H)+.

Provenance & Evidence