反应详情

Triethylamine (19.6 ml, 144 mmol) was added cautiously to a solution of ethyl (ethoxymethylene)cyanoacetate (10.1 g, 60 mmol) and ethyl hydrazine oxalate (9.9 g, 66 mmol) in ethanol (200 ml). The mixture was heated at reflux for 24 h then concentrated in vacuo. The residue was redissolved in EtOAc, washed with 5% KHCO3 solution then brine, dried and concentrated in vacuo. The residue was purified by flash chromatography on silica gel (eluant; 25% pet. ether:75% EtOAc) to yield the title compound (8.8 g, 80%).

1. temperatureThe mixture was heated
2. temperatureat reflux for 24 h
3. concentrationthen concentrated in vacuo
4. dissolutionThe residue was redissolved in EtOAc
5. washwashed with 5% KHCO3 solution
6. dry with materialbrine, dried
7. concentrationconcentrated in vacuo
8. customThe residue was purified by flash chromatography on silica gel (eluant; 25% pet. ether:75% EtOAc)