Hydrochloric Acid → 5-Cyclopropyl-3-(3,5-dichloro-4-pyridyl)isoxazole-4-carboxylic Acid

Participants

Reaction Conditions

Reaction Steps

To a solution of ethyl 5-cyclopropyl-3-(3,5-dichloro-4-pyridinyl)-4-isoxazolecarboxylate (210 mg, 0.642 mmol) in 2:1 tetrahydrofuran:methanol (3 mL) was added 1 N sodium hydroxide (0.963 mL, 0.963 mmol). The solution was heated in a microwave reactor to 120° C. for 500 seconds. Then 1 N hydrochloric acid (0.963 mL, 0.963 mmol) was added and the solution was concentrated. The residue was taken up with water and extracted twice with ethyl acetate. The combined organic layers were washed with brine, dried over magnesium sulfate and concentrated to afford 5-cyclopropyl-3-(3,5-dichloro-4-pyridinyl)-4-isoxazolecarboxylic acid (158 mg, 82%). 1H-NMR (400 MHz, DMSO-d6) δ 13.35 (s, 1H), 8.81 (s, 2H), 2.91-2.84 (m, 1H), 1.34-1.24 (m, 4H).

Provenance & Evidence