Ethyl bromoacetate → Ethyl 3-acetyl-4-oxopentanoate

HRID 220456

Reaction equation

HRID 220456 reaction equation
[CH3:1][C:2](=[O:7])[CH2:3][C:4](=[O:6])[CH3:5].[H-].[Na+].[CH2:10]([O:12][C:13](=[O:16])[CH2:14]Br)[CH3:11]>O1CCCC1>[CH2:10]([O:12][C:13](=[O:16])[CH2:14][CH:3]([C:2](=[O:7])[CH3:1])[C:4](=[O:6])[CH3:5])[CH3:11]

Participants

5

Reactant 3

HCID 7748Ethyl bromoacetateHCID 24758Sodium hydrideHCID 31261Acetylacetone

Product 1

HCID 87820Ethyl 3-acetyl-4-oxopentanoateYield 94%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent3×

Procedure

Add pentane-2,4-dione (2.0 g, 20.6 mmol) in tetrahydrofuran (30 mL) to a chilled (0° C.) suspension of 60% sodium hydride (0.99 g, 24.7 mmol) in tetrahydrofuran (40 mL). Stir for 1 hr. Then add bromoacetic acid ethyl ester (2.73 mL, 24.7 mmol) in tetrahydrofuran (30 mL) dropwise. Stir at 0° C. to room temperature for 16 hr. Partition between diethyl ether (100 mL) and saturated aqueous ammonium chloride solution (50 mL). Separate organic layer, dry (sodium sulfate), filter, concentrate and purify (silica gel chromatography, eluting with 9:1 hexanes:ethyl acetate), to give 3-acetyl-4-oxopentanoic acid ethyl ester (3.34 g, 94%). 1H NMR (CDCl3) δ 5.15 (q, 2H), 5.1 (t, 1H), 2.84 (d, 2H), 2.23 (s, 6H), 1.22 (t, 3H).

Workup

  1. temperaturea chilled
  2. stirringStir at 0° C. to room temperature for 16 hr
  3. customPartition between diethyl ether (100 mL) and saturated aqueous ammonium chloride solution (50 mL)
  4. dry with materialSeparate organic layer, dry (sodium sulfate)
  5. filtrationfilter
  6. concentrationconcentrate
  7. custompurify
  8. wash(silica gel chromatography, eluting with 9:1 hexanes:ethyl acetate)

Sources & evidence

ORD record
ord-470d29832e0b4449b6e113eba46b2f63
Source dataset
uspto-grants-2012_06
Patent number
US08202873B2

Linked notes

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