反应详情

温度

70 °C

To a solution of 5-bromo-2,3-dichloropyridine (10.0 g, 0.044 mol) in N-methyl-2-pyrrolidone (70 mL) at 0° C. was added potassium hydroxide (5.4 g, 0.097 mol), and the resulting mixture was heated to 70° C. Ethyl cyanoacetate (5.65 mL, 0.53 mol) was added via syringe over 15 min, and then heating at 70° C. was continued for 3 h more. The pH of the reaction mixture was adjusted to 2 by careful addition of concentrated aqueous hydrochloric acid, and the resulting mixture was heated at 130° C. for 2 h. The reaction mixture was cooled to 20° C., treated with 1 N aqueous sodium hydroxide (15-16 mL) and extracted with three portions of methyl tert-butyl ether (3×100 mL). The combined organic extracts were washed with water, dried (Na2SO4) and concentrated under reduced pressure to afford the title compound (6.0 g) as a brown colored solid, which was used without further purification.

1. temperatureheating at 70° C.
2. temperaturethe resulting mixture was heated at 130° C. for 2 h
3. temperatureThe reaction mixture was cooled to 20° C.
4. extractionextracted with three portions of methyl tert-butyl ether (3×100 mL)
5. washThe combined organic extracts were washed with water
6. dry with materialdried (Na2SO4)
7. concentrationconcentrated under reduced pressure