Isopropyl chloroformate → [5-Cyclobutyl-3-(3,5-dichloro-4-pyridinyl)-4-isoxazolyl]methanol

Participants

Reaction Conditions

Reaction Steps

To a solution of 5-cyclobutyl-3-(3,5-dichloro-4-pyridinyl)-4-isoxazolecarboxylic acid (808 mg, 2.59 mmol) in THF (13 mL) at 0° C. was added triethylamine (0.361 mL, 2.59 mmol) followed by isopropyl chloroformate (1 M in toluene, 2.59 mL, 2.59 mmol). The solution was stirred at 0° C. for approximately 1 hour and then was filtered into a solution of sodium borohydride (127 mg, 3.37 mmol) in water (1 mL) at 0° C. The solution was allowed to warm to ambient temperature and was then concentrated. Water was added and the mixture was extracted three times with ethyl acetate. The combined organic layers were washed with brine, dried over magnesium sulfate, concentrated and purified by chromatography (silica gel, 0-40% ethyl acetate in hexanes gradient elution) to afford [5-cyclobutyl-3-(3,5-dichloro-4-pyridinyl)-4-isoxazolyl]methanol (478 mg, 62%). 1H-NMR (400 MHz, DMSO-d6) δ 8.79 (s, 2H), 4.97-4.94 (m, 1H), 4.16-4.15 (m, 2H), 3.92-3.83 (m, 1H), 2.40-2.30 (m, 4H), 2.10-2.01 (m, 1H), 1.99-1.89 (m, 1H).

Provenance & Evidence