反应详情

A three necked round bottom flask containing 5-(2-chloropyridin-4-yloxy)-4,6-dimethylnicotinic acid (11.7 g, 42.0 mmol) was charged with ethanol (250 mL), benzene (300 mL) and sulphuric acid (10 mL). The flask was fitted with Dean Stark apparatus and the reaction stirred at reflux overnight. The solution was cooled and carefully neutralized with saturated NaHCO3 solution. The material was extracted with EtOAc, dried, and concentrated to afford ethyl 5-(2-chloropyridin-4-yloxy)-4,6-dimethylnicotinate (8.6 g, 67%) as an oil which solidified to a white solid upon standing in a refrigerator (4° C.) overnight.

1. customThe flask was fitted with Dean Stark apparatus
2. temperatureat reflux overnight
3. temperatureThe solution was cooled
4. extractionThe material was extracted with EtOAc
5. customdried
6. concentrationconcentrated