Dimethyl Sulfate → Tert-butyl 2-methoxyimino-3-oxobutyrate

HRID 2371780Notes

Reaction equation

HRID 2371780 reaction equation
[C:1](OC(C)(C)C)(=O)CC(C)=O.N([O-])=O.[Na+].[OH:16][N:17]=[C:18]([C:26](=[O:28])[CH3:27])[C:19]([O:21][C:22]([CH3:25])([CH3:24])[CH3:23])=[O:20].C(=O)([O-])[O-].[K+].[K+].S(OC)(OC)(=O)=O>C(O)(=O)C.O.ClCCl>[CH3:1][O:16][N:17]=[C:18]([C:26](=[O:28])[CH3:27])[C:19]([O:21][C:22]([CH3:24])([CH3:23])[CH3:25])=[O:20]

Participants

9

Reactant 5

HCID 6497Dimethyl SulfateHCID 11430Potassium CarbonateHCID 15538Tert-butyl acetoacetateHCID 23668193Sodium NitriteHCID 178468384tert-butyl 2-hydroxyimino-3-oxobutanoate

Product 1

HCID 54110352Tert-butyl 2-methoxyimino-3-oxobutyrateYield 95%

Reagents, catalysts & solvents 3

HCID 176Acetic AcidSolventHCID 962WaterSolvent2×HCID 6344DichloromethaneSolvent2×

Procedure

In 31.6 g of glacial acetic acid was dissolved 31.6 g (0.2 mole) of tert-butyl acetoacetate, and a solution of 15.2 g (0.22 mole) of sodium nitrite in 30 ml of water was added dropwise at 0° to 5° C. over a period of 2 hours and stirred at room temperature for 1 hour. After completion of the reaction, 100 ml of water and 100 ml of dichloromethane were added and then stirred, and the resulting mixture was allowed to stand to be separated and the aqueous layer was removed. To the thus obtained solution of tert-butyl 2-hydroxyimino-3-oxobutyrate in dichloromethane was added 41.5 g (0.3 mole) of potassium carbonate with cooling, after which 27.8 g (0.22 mole) of dimethyl sulfate was added dropwise at 20° C. over a period of 2 hours and stirred at 20° C. for another 1 hour. After completion of the reaction, the reaction solution was washed with 150 ml of water and dried over anhydrous magnesium sulfate, and then the solvent was distilled off under reduced pressure to obtain 38.0 g (yield 95%) of tert-butyl 2-methoxyimino-3-oxobutyrate as a light-yellow, oily substance.

Workup

  1. additionwere added
  2. stirringstirred
  3. customto be separated
  4. customthe aqueous layer was removed
  5. temperaturewith cooling
  6. stirringstirred at 20° C. for another 1 hour
  7. customAfter completion of the reaction
  8. washthe reaction solution was washed with 150 ml of water
  9. dry with materialdried over anhydrous magnesium sulfate
  10. distillationthe solvent was distilled off under reduced pressure

Sources & evidence

ORD record
ord-f6ac0a7fb34444ef97b1d4b2106088e4
Source dataset
uspto-grants-1992_03
Patent number
US05095149

Reaction notes

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