反应详情

Methyl 2-hydroxy-3-(1H-indole-2-carboxamido)benzoate (170 mg, 0.5 mmol) and 4-methylbenzenesulfonic acid monohydrate (400 mg, 4.0 mmol) were added to xylene (10 mL) and the mixture was stirred at reflux for 10 hr. The resulting mixture was extracted with dichloromethane (100 mL×4) and concentrated. Then the crude product was purified by column chromatography (silica gel, petroleum ether:ethyl acetate 20:1) to obtain methyl 2-(1H-indol-2-yl)benzo[d]oxazole-7-carboxylate as a solid (70 mg, yield 43%). LC-MS (ESI) m/z 293 [M+1]+.

1. temperatureat reflux for 10 hr
2. extractionThe resulting mixture was extracted with dichloromethane (100 mL×4)
3. concentrationconcentrated
4. customThen the crude product was purified by column chromatography (silica gel, petroleum ether:ethyl acetate 20:1)