反应详情

温度

145 °C

Phosphorous pentoxide (4.14 g, 29.41 mmol) was added portion-wise to a solution of N-(2,2-dimethoxyethyl)-3-fluoro-4-nitro-benzamide (2.0 g, 7.35 mmol) in methane sulphonic acid (3 mL) at 0° C. over a period of 30 min. The mixture was heated to 145° C. for 5 h. The reaction mixture was allowed to cool to ambient temperature and quenched with crushed ice and then extracted with ethyl acetate. The combined organic layers were washed with water, brine, dried over anhydrous sodium sulfate and concentrated to afford the crude residue. Purification by flash chromatography with silica (60-120 mesh) using 15% ethyl acetate-petroleum ether as eluent to afforded 2-(3-fluoro-4-nitrophenyl)oxazole (500 mg, 33%) as a white solid.

1. temperatureto cool to ambient temperature
2. customquenched with crushed ice
3. extractionextracted with ethyl acetate
4. washThe combined organic layers were washed with water, brine
5. dry with materialdried over anhydrous sodium sulfate
6. concentrationconcentrated
7. customto afford the crude residue
8. customPurification by flash chromatography with silica (60-120 mesh)