Hydrochloric Acid → 5-Cyclobutyl-3-(3,5-dichloro-4-pyridinyl)-4-isoxazolecarboxylic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of ethyl 5-cyclobutyl-3-(3,5-dichloro-4-pyridinyl)-4-isoxazolecarboxylate (1.00 g, 2.93 mmol), in 2:1 tetrahydrofuran:methanol (15 mL) was added 1 N aqueous sodium hydroxide (4.40 mL, 4.40 mmol). The solution was heated in a microwave reactor to 120° C. for 500 seconds. Then 1 N aqueous hydrochloric acid (4.40 mL, 4.40 mmol) was added and the solution was concentrated. Water was added and the mixture was extracted twice with ethyl acetate. The combined organic layers were washed with brine, dried over magnesium sulfate, concentrated and dried under a nitrogen stream at 45° C. overnight to afford 5-cyclobutyl-3-(3,5-dichloro-4-pyridinyl) -4-isoxazolecarboxylic acid (808 mg, 88%). 1H-NMR (400 MHz, DMSO-d6) δ 13.34 (br s, 1H), 8.81 (s, 2H), 4.33-4.25 (m, 1H), 2.42-2.32 (m, 4H), 2.15-2.05 (m, 1H), 1.96-1.88 (m, 1H).

Provenance & Evidence