4-Methyl-2-oxovaleric acid → Benzyl 4-methyl-2-oxopentanoate

HRID 234086

Reaction equation

HRID 234086 reaction equation
[Na].[CH3:2][CH:3]([CH3:10])[CH2:4][C:5](=[O:9])[C:6]([OH:8])=[O:7].[CH2:11](Br)[C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1>CN(C)C=O>[CH3:2][CH:3]([CH3:10])[CH2:4][C:5](=[O:9])[C:6]([O:8][CH2:11][C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)=[O:7]

Participants

5

Reactant 3

HCID 704-Methyl-2-oxovaleric acidHCID 7498Benzyl BromideHCID 5360545Sodium2×

Product 1

HCID 4072499Benzyl 4-methyl-2-oxopentanoateYield 92%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

With reference to reaction Scheme 2, a slurry of 25 g (0.164 mol) of the sodium salt of 4-methyl-2-oxopentanoic acid, sodium salt in anhydrous N,N-dimethylformamide (50 ml) containing 19.6 ml (0.164 mol) of benzyl bromide was agitated at room temperature for 4 days. The solvent was removed in vacuo. The residue was dissolved in 250 ml of hexane and washed with water (3×50 ml) and brine (50 ml). After drying over anhydrous magnesium sulfate, the solution was filtered and concentrated in vacuo to give 33.2 g (92% yield) of benzyl 4-methyl-2-oxopentanoate (1a) as a viscous, colorless oil. TLC: Rf 0.70 (ethyl acetate-hexane 1:4); 1H NMR(CDCl3) δ 0.94(d, 6H), 2.18(m, 1H), 2.71(d, 2H), 5.26(s, 2H), 7.37(m, 5H); 13C NMR (CDCl3) δ 22.5, 24.2, 48.1, 67.9, 128.7, 128.8, 128.9, 134.7, 161.3, 194.0.

Workup

  1. customWith reference to reaction Scheme 2
  2. customThe solvent was removed in vacuo
  3. dissolutionThe residue was dissolved in 250 ml of hexane
  4. washwashed with water (3×50 ml) and brine (50 ml)
  5. dry with materialAfter drying over anhydrous magnesium sulfate
  6. filtrationthe solution was filtered
  7. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-b7b3da173c1f4ffa94eeb2125bd8fbac
Source dataset
uspto-grants-1997_01
Patent number
US05594106

Linked notes

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