Potassium Carbonate → Phenyl 5-tert-butylisoxazol-3-ylcarbamate

Participants

Reaction Steps

To a solution of 5-tert-butylisoxazol-3-amine (35.00 g, 250 mmol) in THF (300 mL), potassium carbonate (45.61 g, 330 mmol) and phenyl chloroformate (43.84 g, 280 mmol) were added and the solution stirred at rt overnight. The reaction mixture was filtered through Celite and the pad washed thoroughly with THF. The filtrate was concentrated to a solid and portioned between brine and DCM, then extracted with 2 additional portions of DCM. The combined extracts were dried over magnesium sulfate, filtered and concentrated to a solid. The resulting solid was recrystallized from 10% DCM/ether and hexane. The solid collected by filtration to afford phenyl 5-tert-butylisoxazol-3-ylcarbamate (50.72 g, 78% yield). 1H NMR (300 MHz, DMSO d6) δ 1.35 (s, 9H), 6.43 (s, 1H), 7.20 (m, 3H), 7.44 (m, 2H).

Provenance & Evidence