反应详情

温度

120 °C

Phosphorus pentachloride (2.27 g) was added to methanesulfonic acid (8 ml), and the mixture was stirred at 120° C. for 1 hour. To the solution were added 2-amino-5-bromophenol (1.50 g) and 4-chlorophenylacetic acid (1.36 g) and the mixture was stirred at 100° C. for 1 hour. The mixture was poured onto ice, neutralized with 8 N sodium hydroxide and extracted with ethyl acetate-tetrahydrofuran (3:1, v/v). The organic layer was washed with water and dried over MgSO4. The solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography and the fraction eluted with ethyl acetate-hexane (1:4, v/v) was concentrated under reduced pressure. The resulting crystals were collected by filtration to obtain 6-bromo-2-(4-chlorobenzyl)benzoxazole (1.83 g, 71%).

1. stirringthe mixture was stirred at 100° C. for 1 hour
2. additionThe mixture was poured onto ice
3. extractionextracted with ethyl acetate-tetrahydrofuran (3:1
4. washThe organic layer was washed with water
5. dry with materialdried over MgSO4
6. distillationThe solvent was distilled off under reduced pressure
7. washthe fraction eluted with ethyl acetate-hexane (1:4, v/v)
8. concentrationwas concentrated under reduced pressure
9. filtrationThe resulting crystals were collected by filtration