Hydrochloric Acid → Ethyl 2-bromo-3-oxobutanoate

HRID 1380643Notes

Reaction equation

HRID 1380643 reaction equation
[Na].[O-]CC.[Br:5][C:6]1[C:7](=[O:15])[O:8][C:9](C)([CH3:13])[O:10][C:11]=1[CH3:12].Cl>C(O)C.CCOCC>[CH2:9]([O:8][C:7](=[O:15])[CH:6]([Br:5])[C:11]([CH3:12])=[O:10])[CH3:13]

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 1194401-Hydroxyethyl radical2×HCID 5360545SodiumHCID 103534354H-1,3-Dioxin-4-one, 5-bromo-2,2,6-trimethyl-

Product 1

HCID 11206579Ethyl 2-bromo-3-oxobutanoateYield 65.7%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 3283Diethyl EtherSolvent

Conditions

Temperature
0 °C

Procedure

Sodium metal (13.7 g, 0.59 mol) was dissolved in 500 ml of absolute ethanol, and the resulting ethoxide solution was cooled to 0° C. Crude 5-bromo-2,2,6-trimethyl-4H-1,3-dioxin-4-one (115.5 g, 0.5 mole at 95% purity) was then added, dropwise, to the chilled ethoxide solution over 30 minutes and the dark orange reaction mixture was stirred an additional 30 minutes at 0° C. The reaction was poured into 500 ml of ether and 550 ml of 1N HCl, and the organic layer was washed repeatedly with water (4×250 ml) and then dried over Na2SO4. Removal of solvent in vacuo (30° C., 2 Torr), followed by distillation on a 2-inch wiped-film molecular still (120° C. jacket, 0.2 Torr) afforded 68.7 g (71%) of a pale yellow oil (98% pure by gc).

Workup

  1. washthe organic layer was washed repeatedly with water (4×250 ml)
  2. dry with materialdried over Na2SO4
  3. customRemoval of solvent in vacuo (30° C., 2 Torr)
  4. distillationfollowed by distillation on a 2-inch
  5. customstill (120° C. jacket, 0.2 Torr)

Sources & evidence

ORD record
ord-6207dcc131b74f48a3c4aecd640d3da3
Source dataset
uspto-grants-1986_04
Patent number
US04582913

Reaction notes

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