反应详情

温度

25 °C

1-bromopyrrolidine-2,5-dione (233 mg) was added to a stirred solution of methyl 2-(2-amino-3-pyridyl)-1,3-benzoxazole-7-carboxylate (335 mg) dissolved in tetrahydrofuran (10 ml) over a period of 5 minutes. The resulting solution was stirred at 25° C. for 2 hours. The solvent was evaporated and the mixture was washed with water and dried over phosphorus pentoxide under reduce pressure to afford a brown solid. The mixture was adsorbed on silica gel with chloroform and methanolic ammonia (7N). The crude product was purified by flash chromatography on silica gel eluting with 0 to 2% methanol in dichloromethane. The solvent was evaporated to dryness to afford methyl 2-(2-amino-5-bromo-3-pyridyl)-1,3-benzoxazole-7-carboxylate (405 mg) as a pale brown solid. NMR Spectrum: (DMSOd6) 3.99 (s, 3H), 7.56 (dd, 1H), 7.85 (bs, 2H), 7.97 (d, 1H), 8.12 (d, 1H), 8.29 (s, 1H), 8.35 (s, 1H); Mass spectrum: M+H+ 348-350.

1. customThe solvent was evaporated
2. washthe mixture was washed with water
3. dry with materialdried over phosphorus pentoxide
4. customto afford a brown solid
5. customThe crude product was purified by flash chromatography on silica gel eluting with 0 to 2% methanol in dichloromethane
6. customThe solvent was evaporated to dryness