Sulfuric Acid → Ethyl 3-ethoxy-4-oxo-1-piperidinecarboxylate

Reaktionsgleichung

[CH2:1]([O:3][CH:4]1[C:9](OC)([O:10]C)[CH2:8][CH2:7][N:6]([C:14]([O:16][CH2:17][CH3:18])=[O:15])[CH2:5]1)[CH3:2].S(=O)(=O)(O)O.C(=O)([O-])[O-].[Na+].[Na+]>O>[CH2:1]([O:3][CH:4]1[C:9](=[O:10])[CH2:8][CH2:7][N:6]([C:14]([O:16][CH2:17][CH3:18])=[O:15])[CH2:5]1)[CH3:2]

Komponenten

Versuchsvorschrift

A mixture of 34.1 parts of ethyl 3-ethoxy-4,4-dimethoxy-1-piperidinecarboxylate and 1110 parts of a sulfuric acid solution 1% in water was stirred and refluxed for 3 hours. The reaction mixture was cooled and saturated with sodium carbonate. The product was extracted with dichloromethane. The extract was washed with a small amount of water, dried, filtered and evaporated. The residue was stirred in petroleumether. The product was separated and distilled, yielding 21.1 parts of ethyl 3-ethoxy-4-oxo-1-piperidinecarboxylate bp. ±95° C. at 0.05 mm. pressure (intermediate 68).