Water → HCID 54071723, compound

To 200 ml of water were added 38 g of sodium nitrite together with 53 g of methyl acetoacetate. Under ice-cooling and stirring, 200 ml of 4 N-sulfuric acid were added dropwise over a period of about 1 hour. During this period, the temperature of the reaction mixture was maintained at 5°-8° C. The mixture was further stirred within this temperature range for 2.5 hours. Then, it was extracted twice with 300 ml portions of ethyl acetate and the extracts are combined and washed twice with a standard aqueous solution of sodium chloride. Then, a solution of 96.9 g of sodium carbonate in 1 l of water was divided into three portions and the methyl 3-oxo-2-hydroxyiminobutyrate was extracted from the ethyl acetate layer previously obtained (3 times). To the water layer (1 l) were added 200 ml of methanol and, under ice-cooling and stirring, 150 g of dimethyl sulfate were added dropwise over a period of 10 minutes. After the dropwise addition was completed, the mixture was stirred at room temperature for 1.5 hours. It was then extracted twice with 300 ml of ethyl acetate, washed with water and dried. The ethyl acetate layer was distilled off and the residue is cooled with ice, whereupon it solidified. This solid was collected by filtration and rinsed with a small amount of water. By this procedure was obtained methyl 3-oxo-2-methoxyiminobutyrate as white crystals. 52.3 g; m.p. 64.4° C.

1. temperatureUnder ice-cooling
2. waitDuring this period
3. temperaturethe temperature of the reaction mixture was maintained at 5°-8° C
4. stirringThe mixture was further stirred within this temperature range for 2.5 hours
5. extractionThen, it was extracted twice with 300 ml portions of ethyl acetate
6. washwashed twice with a standard aqueous solution of sodium chloride
7. extractionthe methyl 3-oxo-2-hydroxyiminobutyrate was extracted from the ethyl acetate layer
8. custompreviously obtained (3 times)
9. temperatureunder ice-cooling
10. stirringstirring
11. additionAfter the dropwise addition
12. stirringthe mixture was stirred at room temperature for 1.5 hours
13. extractionIt was then extracted twice with 300 ml of ethyl acetate
14. washwashed with water
15. customdried
16. distillationThe ethyl acetate layer was distilled off
17. temperaturethe residue is cooled with ice, whereupon it
18. filtrationThis solid was collected by filtration
19. washrinsed with a small amount of water

ORD record

ord-057f627115db4066b99b6cf0b709ef8c

Source dataset

uspto-grants-1983_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04380541