51677-09-9

1313396-20-1

51677-09-9

GENERAL METHODS: Alkyne oxime ether 1 (0.15 mmol) was dissolved in THF (5 mL) and phenol (28 mg, 0.3 mmol) and AgBF4 (5.8 mg, 0.03 mmol) were added sequentially. The reaction system was equipped with a drying tube (filled with silica gel) and heated to reflux at 50 °C in an oil bath. The reaction process was monitored by TLC with continuous stirring for 1-12 hours. After completion of the reaction, the reaction mixture was concentrated under reduced pressure. The residue was purified by preparative thin layer chromatography (unfolding reagent: hexane/ethyl acetate = 3-10:1) to afford the target product methyl 5-phenylisoxazole-3-carboxylate (3a and 3j). The physical properties and spectral data of the obtained compounds were in agreement with those reported in the literature.