Toluene → Diethyl 2-acetyl-2-methyloctanedioate

HRID 1667353Notes

Reaction equation

HRID 1667353 reaction equation
[H-].[Na+].[CH2:3]([O:5][C:6](=[O:12])[CH2:7][C:8]([CH2:10]C)=[O:9])[CH3:4].Br[CH2:14][CH2:15][CH2:16][CH2:17][CH2:18][C:19]([O:21][CH2:22][CH3:23])=[O:20].[C:24]1(C)C=CC=CC=1>>[C:8]([C:7]([CH3:24])([CH2:14][CH2:15][CH2:16][CH2:17][CH2:18][C:19]([O:21][CH2:22][CH3:23])=[O:20])[C:6]([O:5][CH2:3][CH3:4])=[O:12])(=[O:9])[CH3:10]

Participants

5

Reactant 4

HCID 1140TolueneHCID 24758Sodium hydrideHCID 78656Ethyl 3-oxovalerateHCID 117544Ethyl 6-bromohexanoate

Product 1

HCID 22266834Diethyl 2-acetyl-2-methyloctanedioateYield 46%

Procedure

In a 1 L three necked flask equipped with a mechanical stirrer and reflux condenser was placed dry toluene (300 ml). The system was flushed with argon and sodium hydride (Aldrich, 60% dispersion in mineral oil) (7.2 g, 0.18 mmol) was added. Ethyl-γ-methylacetoacetate (Aldrich, 21 g, 0.15 mole) was added with stirring over a 30 minutes. The resulting solution was heated under reflux for 2 hrs and cooled slightly. (Note: Reaction mixture becomes a thick paste and mechanical stirrer is essential). Ethyl 6-bromohexanoate (Aldrich, 33.5 g, 0.15 mol) was added (all at once) and the suspension was heated under reflux for 12 hrs, cooled, filtered and the solvent evaporated under pressure. The residue was distilled under vacuum to yield 20 g (46%) of colorless liquid, b.p. 110-115° C. (0.1 mm). IR (neat): σcm−1=1735 (s) and 1713 (s). 1H NMR in CDCl3 δ, 4.1-4.2 (m, 4H, (O—CH2)2); 2.1 (t, J=8.4 Hz, 2H, CH2COO—); 2.15 (s, 3H, CH3CO); 1.5-2.0 (m, 4H, (CH2)2); 1.2-1.4 (m, 13H, 2 CH2 and three —CH3).

Workup

  1. temperaturereflux condenser
  2. additionwas added
  3. temperatureThe resulting solution was heated
  4. temperatureunder reflux for 2 hrs
  5. temperaturecooled slightly
  6. custom(Note: Reaction mixture
  7. temperaturewas heated
  8. temperatureunder reflux for 12 hrs
  9. temperaturecooled
  10. filtrationfiltered
  11. customthe solvent evaporated under pressure
  12. distillationThe residue was distilled under vacuum

Sources & evidence

ORD record
ord-625c1508bfd0442fab53aac95f1105f4
Source dataset
uspto-grants-2011_10
Patent number
US08044203B2

Reaction notes

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