Potassium Hydroxide → 4-(4-chloro-1-ethyl-1H-pyrazol-5-yl)-2-thiophenecarboxylic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of methyl 4-(4-chloro-1-ethyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate (0.3 g, 1.1 mmol) in THF/H2O (5 mL/0.5 mL) was added KOH (0.2 g, 3.4 mmol). The reaction mixture was heated to 50° C. for 4 h and then concentrated and diluted with H2O (2 mL). The pH was adjusted to 3 with aqueous HCl. The mixture was extracted with DCM (3×5 mL) and the collected organic fractions were concentrated under vacuum to give crude 4-(4-chloro-1-ethyl-1H-pyrazol-5-yl)-2-thiophenecarboxylic acid (260 mg) which was used directly without further purification. LC-MS (ES) m/z=256 (M+H)+.

Provenance & Evidence