反应详情

Diethyl 1-amino-1,2-ethylenedicarboxylate (1.7 g) and α-ethylacrolein (0.84 g) are dissolved in n-butanol (10 ml), and thereto is added p-toluenesulfonic acid (35 mg). The mixture is refluxed for 15 hours (the degree of reaction of aminodiester is 97%). After distilling off the solvent, the residue is subjected to silica gel column chromatography, eluting with chloroform/methanol (1:0-1:0.01), to give diethyl 5-ethylpyridine-2,3-dicarboxylate (1.93 g., 84.6%). The product has a purity of 92.2% by liquid chromatographic analysis.

1. temperatureThe mixture is refluxed for 15 hours (
2. distillationAfter distilling off the solvent
3. washeluting with chloroform/methanol (1:0-1:0.01)