反应详情

Oxalyl chloride (0.8 ml, 10.3 mmol) was added to a solution of 5-Methyl-isoxazole-4-carboxylic acid (1 g, 6.9 mmol) in dichloromethane (30 ml) followed by 1 drop of dimethylformamide. The mixture was stirred at room temperature for 5 hours before concentrating in vacuo and azeotroping with dichloromethane. The residue was taken up in pyridine (3 ml) and added to a solution of 3-chloro-pyrazine-2,6-diamine (Preparation 1) (0.65 g, 4.6 mmol) in anhydrous pyridine (30 ml) and the mixture heated at 50° C. for 3 hours before cooling to room temperature and concentrating in vacuo. The residue was purified by silica gel column chromatography, eluting with ethyl acetate:heptane 1:1, to afford the product as a white solid (360 mg).

1. concentrationbefore concentrating in vacuo
2. customazeotroping with dichloromethane
3. temperaturethe mixture heated at 50° C. for 3 hours
4. temperaturebefore cooling to room temperature
5. concentrationconcentrating in vacuo
6. customThe residue was purified by silica gel column chromatography
7. washeluting with ethyl acetate:heptane 1:1