反应详情

To a solution of potassium ethoxide (2.44 g, 27.7 mmol) in diethyl ether (90 mL) and ethanol (8 mL) was added diethyl oxalate (3.79 mL, 27.7 mmol) resulting in a yellow suspension. The reaction mixture was stirred for 5 min prior to the addition of 2-methyl-3-nitropyridine (Preparation 29, 3.40 g, 24.6 mmol) in one portion. The resulting red suspension was stirred at rt, under argon, for 20 h. The mixture was filtered, washed thoroughly with diethyl ether and dried. The red solid was dissolved in water and the mixture adjusted to pH 4 by addition of glacial acetic acid. The resulting precipitate was collected by filtration, dissolved in dichloromethane, washed with brine, dried (MgSO4), and then filtered and concentrated in vacuo to give the title compound as an orange solid. δH (CDCl3): 1.40 (3H, t), 4.39 (2H, q), 7.34 (1H, s), 7.36 (1H, dd), 8.43 (1H, dd), 8.66 (1H, dd).

1. customresulting in a yellow suspension
2. stirringThe resulting red suspension was stirred at rt, under argon, for 20 h
3. filtrationThe mixture was filtered
4. washwashed thoroughly with diethyl ether
5. customdried
6. dissolutionThe red solid was dissolved in water
7. additionthe mixture adjusted to pH 4 by addition of glacial acetic acid
8. filtrationThe resulting precipitate was collected by filtration
9. dissolutiondissolved in dichloromethane
10. washwashed with brine
11. dry with materialdried (MgSO4)
12. filtrationfiltered
13. concentrationconcentrated in vacuo