反应详情

温度

60 °C

A solution of (4-bromo-2-nitro-phenyl)-acetic acid methyl ester (0.99 g, 3.61 mmol) in ethanol (8 mL) at room temperature is treated with isoamyl nitrite (0.60 mL, 4.47 mmol). A solution of NaOEt in ethanol (1.9 M, 2.0 ml) is added, and the mixture is stirred at 60° C. for 2 hours and at room temperature for 16 hours. The mixture is neutralized with HCl (1.0 M, 4.0 mL) and concentrated. The residue is extracted with ethyl acetate (20 mL×2) and the combined organic layers are dried over sodium sulfate and concentrated. The residue is purified via silica gel chromatography eluting with 25% ethyl acetate in hexanes to give 6-bromo-benzo[d]isoxazole-3-carboxylic acid ethyl ester (0.36 g, 37%). ES/MS m/e 269.8; 271.8 (M+1).

1. concentrationconcentrated
2. extractionThe residue is extracted with ethyl acetate (20 mL×2)
3. dry with materialthe combined organic layers are dried over sodium sulfate
4. concentrationconcentrated
5. customThe residue is purified via silica gel chromatography
6. washeluting with 25% ethyl acetate in hexanes