反应详情

Methyl 2-hydroxy-3-(4-(pyridin-2-yl)benzamido)benzoate (1.04 g, 3 mmol) and 4-methylbenzenesulfonic acid monohydrate (1.2 g, 6 mmol) were added to toluene (20 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). 170 mg of solid of methyl 2-(4-(pyridin-2-yl)phenyl)benzo[d]oxazole-7-carboxylate was obtained. Yield: 17%. 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)