反应详情

A solution of 3-aminopyridine (20.0 g, 0.21 m) in excess triethyl orthoformate (100 ml) and ethanolic hydrogen chloride (0.3 ml) was heated under reflux for 72 hours. Ethanol and excess triethyl orthoformate were then removed by distillation over a period of 5 hours. Solid potassium carbonate (100 mg) was added to the residue, and the last traces of triethyl orthoformate were removed in vacuo. The residue was then distilled under reduced pressure to yield the desired imido ester, ethyl N-(3-pyridyl)-formimidate, as a colourless liquid, (b.p. 62°/0.5 mm) (24 g, 75%), n.m.r. (CDCl3): δ=1.4 (t, --CH2CH3), 4.32 (q, --CH2CH3), 7.73 (s, --N=CH--O).

1. temperatureunder reflux for 72 hours
2. customEthanol and excess triethyl orthoformate were then removed by distillation over a period of 5 hours
3. additionSolid potassium carbonate (100 mg) was added to the residue
4. customthe last traces of triethyl orthoformate were removed in vacuo
5. distillationThe residue was then distilled under reduced pressure