Dimethyl Sulfate → Ethyl (2Z)-2-methoxyimino-3-oxo-butanoate

Pulverized potassium carbonate (160 g.) was added to a solution of ethyl 2-hydroxyiminoacetoacetate (a mixture of syn and anti isomers) (152 g.) in acetone (500 ml.). Dimethyl sulfate (130 g.) was dropwise added thereto with stirring over 1 hour at 45° to 50° C. and the mixture was stirred for 2 hours. An insoluble material was filtered off and the filtrate was concentrated under reduced pressure. The filtered insoluble material was dissolved in water (500 ml.) and this solution was added to the residue. The mixture was extracted twice with ethyl acetate (300 ml.). The extract was washed twice with water (200 ml.) and with a saturated sodium chloride aqueous solution (200 ml.) and dried over magnesium sulfate. The solvent was distilled off under reduced pressure and the residue was distilled under reduced pressure to give colorless oil of ethyl 2-methoxyiminoacetoacetate (a mixture of syn and anti isomers) (145.3 g.), bp 55° to 64° C./0.5 mm Hg.

1. stirringthe mixture was stirred for 2 hours
2. filtrationAn insoluble material was filtered off
3. concentrationthe filtrate was concentrated under reduced pressure
4. dissolutionThe filtered insoluble material was dissolved in water (500 ml.)
5. additionthis solution was added to the residue
6. extractionThe mixture was extracted twice with ethyl acetate (300 ml.)
7. washThe extract was washed twice with water (200 ml.) and with a saturated sodium chloride aqueous solution (200 ml.)
8. dry with materialdried over magnesium sulfate
9. distillationThe solvent was distilled off under reduced pressure
10. distillationthe residue was distilled under reduced pressure

ORD record

ord-2b3498ca228f449f85e3cc26b3895c9f

Source dataset

uspto-grants-1979_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04166115