反应详情

A solution of methyl 5-phenylisoxazole-3-carboxylate (100 mg, 0.492 mmol) and N-bromosuccinimide (119 mg, 0.669 mmol) in 5% fuming nitric acid in acetic acid (2 mL) was heated to 150° C. for 10 minutes via microwave. The reaction mixture was concentrated and purified by silica gel chromatography with hexanes/ethyl acetate (10/1) to afford methyl 4-bromo-5-phenylisoxazole-3-carboxylate (108 mg). The compound had an HPLC ret. time=3.21 min.−Column: YMC S5 COMBISCREEN® 4.6×50 mm; Gradient time: 4 min; Flow rate=4 ml/min; Solvent A=10% MeOH−90% Water−0.2% H3PO4; Solvent B=90% MeOH−10% water−0.2% H3PO4; Start % B=0; Final % B=100. LC-MS: M+1=284+.

1. concentrationThe reaction mixture was concentrated
2. custompurified by silica gel chromatography with hexanes/ethyl acetate (10/1)