Water → HCID 54071723, compound

HRID 2049276Notes

Reaction equation

HRID 2049276 reaction equation
O.[N:2]([O-:4])=O.[Na+].[C:6]([O:12][CH3:13])(=[O:11])[CH2:7][C:8]([CH3:10])=[O:9].S(OC)(O[CH3:18])(=O)=O>CO>[O:9]=[C:8]([CH3:10])[C:7](=[N:2][O:4][CH3:18])[C:6]([O:12][CH3:13])=[O:11]

Participants

6

Reactant 4

HCID 962Water2×HCID 6497Dimethyl SulfateHCID 7757Methyl acetoacetateHCID 23668193Sodium Nitrite

Product 1

HCID 54071723HCID 54071723, compoundYield 72%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To 200 ml of water is added 38 g of sodium nitrite together with 53 g of methyl acetoacetate, followed by dropwise addition of 200 ml of 4 N-sulfuric acid under ice-cooling and stirring over a period of about an hour. During this period, the temperature of the reaction mixture is maintained at 5° to 8° C. The mixture is further stirred within this temperature range for 2.5 hours, at the end of which time it is extracted twice with each 300 ml of ethyl acetate. The extracts are washed twice with a saturated aqueous solution of sodium chloride. Then, a solution of 96.7 g of sodium carbonate in 1 l of water is divided in three parts, which are used to extract methyl 3-oxo-2-hydroxyiminobutyrate from the ethyl acetate layer previously obtained as above (3 times). To the water layer (1 l) was added 200 ml of methanol and, under ice-cooling and stirring, 150 g of dimethyl sulfate is added dropwise over a period of 10 minutes. After the dropwise addition has been completed, the mixture is stirred at room temperature for 1.5 hours. It is then extracted twice with each 300 ml of ethyl acetate, dried and distilled to remove the ethyl acetate. The residue is cooled with ice, whereupon it solidifies. This solid is collected by filtration and rinsed with a small quantity of water. By the above procedure is obtained 52.3 g of methyl 3-oxo-2-methoxyiminobutyrate as white crystals melting at 64.4° C.

Workup

  1. temperaturecooling
  2. waitDuring this period
  3. temperaturethe temperature of the reaction mixture is maintained at 5° to 8° C
  4. stirringThe mixture is further stirred within this temperature range for 2.5 hours, at the end of which time it
  5. extractionis extracted twice with each 300 ml of ethyl acetate
  6. washThe extracts are washed twice with a saturated aqueous solution of sodium chloride
  7. extractionto extract methyl 3-oxo-2-hydroxyiminobutyrate from the ethyl acetate layer
  8. custompreviously obtained as above (3 times)
  9. temperatureunder ice-cooling
  10. stirringstirring
  11. additionAfter the dropwise addition
  12. stirringthe mixture is stirred at room temperature for 1.5 hours
  13. extractionIt is then extracted twice with each 300 ml of ethyl acetate
  14. customdried
  15. distillationdistilled
  16. customto remove the ethyl acetate
  17. temperatureThe residue is cooled with ice, whereupon it
  18. filtrationThis solid is collected by filtration
  19. washrinsed with a small quantity of water

Sources & evidence

ORD record
ord-c7df33357ff747a9ac288561e4e82636
Source dataset
uspto-grants-1980_04
Patent number
US04197298

Reaction notes

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