反应详情

温度

10 °C

3-Amino-N-(4-fluoro-2-hydroxyphenyl)pyrazine-2-carboxamide (1.6 g) and triphenylphosphine (5.1 g) were dissolved into pyridine (20 ml). The mixture was cooled to 10° C. in a salt-ice bath. 2,2,2-Trichloroacetonitrile (2.79 g) was added slowly to the mixture. The mixture was warmed up to room temperature, and then heated to 130° C. for 13 hours. The resulting mixture was diluted with ethyl acetate/methanol (4/1, 100 ml). The mixture was filtered through Celite (diatomaceous earth), and the mixture was washed to pH 6 with 1 M hydrochloric acid. The organic layer was concentrated, and the residue was purified by chromatography on silica gel to give 3-(6-fluoro-1,3-benzoxazol-2-yl)pyrazin-2-amine (0.3 g). NMR Spectrum: (DMSOd6, 400 MHz) 7.30 (m, 1H), 7.80 (m, 4H), 7.85 (m, 1H), 8.00 (s, 1H), 8.23 (s, 1H); Mass spectrum: M+H+ 231

1. temperatureThe mixture was warmed up to room temperature
2. temperatureheated to 130° C. for 13 hours
3. filtrationThe mixture was filtered through Celite (diatomaceous earth)
4. washthe mixture was washed to pH 6 with 1 M hydrochloric acid
5. concentrationThe organic layer was concentrated
6. customthe residue was purified by chromatography on silica gel