反应详情

2-Amino-3-methoxy-6,7-dimethylquinoxaline (2.34 g, 11.5 mmol) and ethyl chloroformate (2.50 g, 23.0 mmol) were dissolved in dichloromethane (50 ml) at room temperature and thereto pyridine (1.82 g, 23.0 mmol) was added. The mixture was stirred at room temperature for 12 hours and concentrated under the reduced pressure to remove the solvent, and purified by SiO2 column chromatography. Extraction of the residue with a n-hexane:ethyl acetate (3:1) mixture and concentration gave 2.65 g of the titled compound (yield, 84%).

1. concentrationconcentrated under the reduced pressure
2. customto remove the solvent
3. custompurified by SiO2 column chromatography
4. extractionExtraction of the residue
5. concentrationwith a n-hexane:ethyl acetate (3:1) mixture and concentration