反应详情

Thionyl chloride (30 mL) was added to 1 (4.5 g, 33 mmol) and the mixture was stirred at reflux overnight. Thionyl chloride was evaporated under reduced pressure and the residue was dried in vacuum to obtain 3-methylbenzoyl chloride (3.59 g). Methyl-3-amino-2-hydroxybenzoate (3.34 g, 20.0 mmol) and pyridine (2 mL) were added to toluene (10 mL) and the mixture was stirred at room temperature for 30 min. Then 3-methylbenzoyl chloride (1.54 g, 10 mmol) was added. The mixture was stirred at room temperature for 30 min and then at 80° C. for 2 hr. 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 5:1) to obtain methyl 2-hydroxy-3-(3-methylbenzamido)benzoate as a solid (1.8 g, yield 63%). LC-MS (ESI) m/z 287 [M+1]+.

1. stirringThe mixture was stirred at room temperature for 30 min
2. waitat 80° C. for 2 hr
3. extractionThe resulting mixture was extracted with ethyl acetate (100 mL×4)
4. concentrationconcentrated
5. customThe crude product was purified by column chromatography (silica gel, petroleum ether:ethyl acetate 20:1 to 5:1)