反应详情

2-Amino-3-ethylpyridine (Wonda Science, CAS[42753-67-3]; 12.2 g, 0.1 mol) is dissolved by stirring in 500 ml of ethyl acetate with 10 ml DMF. A thermometer is placed in the solution to monitor temperature. N-Chlorosuccinimide (13.3 g, 0.1 mol) is added in several portions to keep the solution at room temperature. The solution becomes dark in color and is stirred at room temperature overnight. The supernatant is decanted from the dark solids that formed and transferred to a separatory funnel. The organic solution is washed with 500 ml saturated aqueous sodium bisulfite and then 500 ml brine. The organic layer is dried with MgSO4 and concentrated on a rotovap. The dark brown crude product is chromatographed on 500 g of flash silica-gel eluting with 35% EtOAc/Hexanes. Concentration of the appropriate fractions on a rotovap gives a light-tan oil. The oil is dissolved in hexanes and decolorized with activated carbon. The solvent is cooled to −20° C. and the solid which forms is isolated by filtration to give the product as a flaky off-white solid. (MP 67-68° C.).

1. customat room temperature
2. customThe supernatant is decanted from the dark solids
3. customthat formed
4. customtransferred to a separatory funnel
5. washThe organic solution is washed with 500 ml saturated aqueous sodium bisulfite
6. dry with materialThe organic layer is dried with MgSO4
7. concentrationconcentrated on a rotovap
8. customThe dark brown crude product is chromatographed on 500 g of flash silica-gel
9. washeluting with 35% EtOAc/Hexanes
10. customConcentration of the appropriate fractions on a rotovap gives a light-tan oil
11. temperatureThe solvent is cooled to −20° C.
12. customthe solid which forms is isolated by filtration