反应详情

Sodium (156 mg) is added to methanol (5ml) and thereto is added a solution of ethyl 2-(1,3-dithiol-2-ylidene)-2-[N-(3-pyridylmethyl)-N-(methoxycarbonylethyl)carbamoyl]acetate (2.21 g) in benzene (35 ml). The mixture is refluxed for 3 hours, and distilled to remove the solvent. The residue is dissolved in ethyl acetate, and the solution is washed with water, dried and then distilled to remove the solvent. The residue is recrystallized from a mixture of ethyl acetate and n-hexane to give methyl 1-(3-pyridylmethyl)-5-(1,3-dithiol-2-ylidene)-4,6-dioxopiperidine-3-carboxylate (1.0 g, 51%) as pale yellow needles, m.p. 111°-114° C.

1. temperatureThe mixture is refluxed for 3 hours
2. distillationdistilled
3. customto remove the solvent
4. dissolutionThe residue is dissolved in ethyl acetate
5. washthe solution is washed with water
6. customdried
7. distillationdistilled
8. customto remove the solvent
9. customThe residue is recrystallized from a mixture of ethyl acetate and n-hexane