反应详情

A solution of diethyl ketomalonate 1 (51.0 g, 0.293 mmol), o-methylhydroxylamine hydrochloride (24.46 g, 0.293 mmol) and pyridine (23.2 g, 0.293 mmol) in ethanol (250 ml) is heated to reflux for 3 hr. The solvent is removed under reduced pressure. The residue is dissolved in ethyl acetate and washed with water, dilute hydrogen chloride, aqueous sodium hydrogencarbonate solution, and water successively. After drying over sodium sulfate, the solvent is removed under reduced pressure. The resultant residue is distilled under reduced pressure at 80°-85° C./0.5 mmHg to obtain Compound 2 (55.5 g, 93.2%). NNMR (CDCl3)δ: 1.35 (3H, t, J=7.1 Hz), 1.35 (3H, t, J=7.1 Hz), 4.11 (3H, s), 4.36 (2H, q, J=7.1 Hz), 4.37 (2H, q, J=7.1 Hz).

1. temperatureto reflux for 3 hr
2. customThe solvent is removed under reduced pressure
3. dissolutionThe residue is dissolved in ethyl acetate
4. washwashed with water, dilute hydrogen chloride, aqueous sodium hydrogencarbonate solution, and water successively
5. dry with materialAfter drying over sodium sulfate
6. customthe solvent is removed under reduced pressure
7. distillationThe resultant residue is distilled under reduced pressure at 80°-85° C./0.5 mmHg