反应详情

In xylene (4 ml), 2-chlorobenzoxazole (278 μl, 2.43 mmol) and ethyl (4-amino-5-chloro-2-fluorophenyl)acetate (512 mg, 2.21 mmol) were heated under reflux for 2 hours. After the reaction mixture was cooled to room temperature, the solvent was distilled off under reduced pressure. The residue was dissolved in ethyl acetate. The resulting solution was washed with a saturated aqueous solution of sodium bicarbonate, dried over anhydrous sodium sulfate, and distilled under reduced pressure to remove the solvent. The residue was purified by chromatography on a silica gel column, whereby from n-hexane/ethyl acetate (7:1, v/v) eluate fractions, ethyl (4-(2-benzoxazolyl)amino-5-chloro-2-fluorophenyl)acetate (570 mg, 74%) was obtained as a pale yellow solid.

1. temperatureunder reflux for 2 hours
2. distillationthe solvent was distilled off under reduced pressure
3. dissolutionThe residue was dissolved in ethyl acetate
4. washThe resulting solution was washed with a saturated aqueous solution of sodium bicarbonate
5. dry with materialdried over anhydrous sodium sulfate
6. distillationdistilled under reduced pressure
7. customto remove the solvent
8. customThe residue was purified by chromatography on a silica gel column, whereby from n-hexane/ethyl acetate (7:1