反应详情

Methyl 2-hydroxy-3-(3-(pyridin-2-yl)benzamido)benzoate (1.4 g, 4 mmol) and 4-methylbenzenesulfonic acid (1.9 g, 10 mmol) were added to toluene (30 mL) and the mixture was stirred under reflux for 2 days. The resulting mixture was extracted with ethyl acetate (100 mL×4) and concentrated. The crude product was purified by column chromatography (silica gel, petroleum ether/ethyl acetate=20:1 to 10:1). 264 mg of methyl 2-(3-(pyridin-2-yl)phenyl)benzo[d]oxazole-7-carboxylate as a solid was obtained, yield: 20%. LC-MS (ESI) m/z: 331 (M+1)+.

1. temperatureunder reflux for 2 days
2. extractionThe resulting mixture was extracted with ethyl acetate (100 mL×4)
3. concentrationconcentrated
4. customThe crude product was purified by column chromatography (silica gel, petroleum ether/ethyl acetate=20:1 to 10:1)