Hydrogen Bromide → HCID 9920915, compound

HRID 1981590Notes

Reaction equation

HRID 1981590 reaction equation
[CH3:1][O:2]/[N:3]=[C:4](/[C:8](=[O:10])[CH3:9])\[C:5]([OH:7])=[O:6].[BrH:11].BrBr>C(O)(=O)C.ClCCl>[Br:11][CH2:9][C:8](=[O:10])/[C:4](=[N:3]/[O:2][CH3:1])/[C:5]([OH:7])=[O:6]

Participants

6

Reactant 3

HCID 260Hydrogen BromideHCID 24408BromineHCID 12961156HCID 12961156, compound

Product 1

HCID 9920915HCID 9920915, compound

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 6344DichloromethaneSolvent

Procedure

145 g of (Z)-2-methoxyimino-3-oxo-butyric acid are dissolved in 1000 ml of alcohol-free anhydrous dichloromethane. 10 ml of 30% hydrobromic acid in glacial acetic acid are added to this solution. Then, a solution of 37.5 ml of bromine in 112.5 ml of dichloromethane are added dropwise during about 2 hours, the temperature of the mixture being held at 20°-25° C. by means of slight cooling. Now, in order to remove hydrogen bromide from the mixture, nitrogen is vigorously blown through. Subsequently, 250 g of ice, 250 ml of water and 2 l of ether are successively added. The aqueous phase is separated and discarded. The organic phase is washed with 250 ml of water and 250 ml of saturated sodium chloride solution, dried with sodium sulphate and evaporated in vacuo. There remains a brown oil which is crystallized from carbon tetrachloride. There is obtained almost colourless (Z)-4-bromo-2-methoxyimino-3-oxo-butyric acid.

Workup

  1. custombeing held at 20°-25° C. by means of slight cooling
  2. customNow, in order to remove hydrogen bromide from the mixture, nitrogen
  3. additionSubsequently, 250 g of ice, 250 ml of water and 2 l of ether are successively added
  4. customThe aqueous phase is separated
  5. washThe organic phase is washed with 250 ml of water and 250 ml of saturated sodium chloride solution
  6. dry with materialdried with sodium sulphate
  7. customevaporated in vacuo
  8. customis crystallized from carbon tetrachloride

Sources & evidence

ORD record
ord-d5624ebe1e634ce9ae20e39c755f9e17
Source dataset
uspto-grants-1986_06
Patent number
US04593093

Reaction notes

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