Ethyl 2-methylacetoacetate → HCID 539291, compound

HRID 1172393Notes

Reaction equation

HRID 1172393 reaction equation
[CH2:1]([O:3][C:4](=[O:10])[CH:5]([CH3:9])[C:6](=[O:8])[CH3:7])[CH3:2].[H-].[Na+].BrC[CH:15]=[C:16]([CH3:18])[CH3:17].[Cl-].[NH4+].[CH3:21]N(C)C=O>>[CH2:1]([O:3][C:4](=[O:10])[C:5]([C:6](=[O:8])[CH3:7])([CH3:21])[CH2:9][CH:15]=[C:16]([CH3:18])[CH3:17])[CH3:2]

Participants

6

Reactant 5

HCID 701Ethyl 2-methylacetoacetateHCID 6228DimethylformamideHCID 24758Sodium hydrideHCID 25517Ammonium ChlorideHCID 700922-Butene, 1-bromo-3-methyl-

Product 1

HCID 539291HCID 539291, compoundYield 78%

Procedure

A solution of 2-methyl-3-oxo-butyric acid ethyl ester (3.0 g, 0.0208 mol) in anhydrous N,N-dimethylformamide (80 mL) was cooled to 0° C. and treated with a 60% oil dispersion of sodium hydride (1.0 g, 0.0416 mol). The cooling bath was removed and the reaction mixture was stirred for 10 min. 4-Bromo-2-methyl-2-butene (3.73 g, 0.025 mol) was added and the reaction mixture was stirred for 16 h. The reaction mixture was poured into a mixture of ice and 4.0 M aqueous ammonium chloride solution. The mixture was extracted with ethyl acetate, dried over magnesium sulfate, filtered and concentrated in vacuo. The crude yellow oil was purified by flash column chromatography (ISCO RediSep column, 0 to 15% ethyl acetate in hexanes) to afford the desired product, 2-Acetyl-2,5-dimethyl-hex-4-enoic acid ethyl ester (3.45 g, 78%) as an oil. 1H NMR (400 MHz, CDCl3) δ: 1.26 (3H, t, J=7.3 Hz), 1.31 (3H, s), 1.61 (3H, s), 1.69 (3H, s), 2.14 (3H, s), 2.49 (1H, dd, J1=14.8 Hz, J2=7.7 Hz), 2.58 (1H, dd, J1=14.9 Hz, J2=7.5 Hz), 4.18 (2H, q, J=7.3 Hz), 4.92-4.96 (1H, m).

Workup

  1. customThe cooling bath was removed
  2. stirringthe reaction mixture was stirred for 16 h
  3. extractionThe mixture was extracted with ethyl acetate
  4. dry with materialdried over magnesium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo
  7. customThe crude yellow oil was purified by flash column chromatography (ISCO RediSep column, 0 to 15% ethyl acetate in hexanes)

Sources & evidence

ORD record
ord-0635a67c42b94566a19020b797126686
Source dataset
uspto-grants-2010_11
Patent number
US07834009B2

Reaction notes

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