Ethyl 2-methylacetoacetate → HCID 57937746, compound

HRID 1667356Notes

Reaction equation

HRID 1667356 reaction equation
[H-].[Na+].[CH2:3]([O:5][C:6](=[O:12])[CH:7]([CH3:11])[C:8]([CH3:10])=[O:9])[CH3:4].Br[CH2:14][CH2:15][CH2:16][CH2:17][CH2:18][O:19][C:20](=[O:22])[CH3:21]>C1(C)C=CC=CC=1>[C:8]([C:7]([CH3:11])([CH2:14][CH2:15][CH2:16][CH2:17][CH2:18][O:19][C:20](=[O:22])[CH3:21])[C:6]([O:5][CH2:3][CH3:4])=[O:12])(=[O:9])[CH3:10]

Participants

5

Reactant 3

HCID 701Ethyl 2-methylacetoacetateHCID 24758Sodium hydrideHCID 851405-Bromopentyl acetate

Product 1

HCID 57937746HCID 57937746, compoundYield 49%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

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, 1.2 eq.) was added. Ethyl-α-methylacetoacetate (Aldrich, 21 g, 0.15 mole) was added with stirring over a 30 minutes. The resulting solution was heated under reflux for 2 hours and cooled slightly. (Note: Reaction mixture becomes a thick paste and a mechanical stirrer is essential). 5-Bromopentylacetate (Aldrich, 31.5 g, 15 mol) was added (all at once) and the suspension was heated under reflux for 12 hr, cooled, filtered and the solvent evaporated under reduced pressure. The residue was distilled under vacuum to yield 20 g (45%) of colorless liquid, b.p 90-92 (0.5 mm). 1H NMR in CDCl3 δ, 4.1-4.2 (m, 2H, O—CH2CH3): 3.5 (t, J=7 Hz, 2H, CH2OCO—); 2.2 (s, 3H, CH3CO); 2.1 (s, 3H, —COCH3); 1.5-2.0 (m, 10H, 4-(CH2)2, C—CH3, OCH2CH3).

Workup

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

Sources & evidence

ORD record
ord-490654611b544660b33cd141531e8b61
Source dataset
uspto-grants-2011_10
Patent number
US08044203B2

Reaction notes

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