Phenethyl bromide → Tert-butyl 3-oxo-2-phenethylbutanoate

HRID 1995105Notes

Reaction equation

HRID 1995105 reaction equation
[Na].[C:2]([O:8][C:9]([CH3:12])([CH3:11])[CH3:10])(=[O:7])[CH2:3][C:4]([CH3:6])=[O:5].Br[CH2:14][CH2:15][C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1>C(O)C>[C:16]1([CH2:15][CH2:14][CH:3]([C:4](=[O:5])[CH3:6])[C:2]([O:8][C:9]([CH3:12])([CH3:11])[CH3:10])=[O:7])[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1

Participants

5

Reactant 3

HCID 7666Phenethyl bromideHCID 15538Tert-butyl acetoacetateHCID 5360545Sodium

Product 1

HCID 13195717Tert-butyl 3-oxo-2-phenethylbutanoate

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Sodium (2.3 g; 0.10 mol) was allowed to react with dry ethanol (50 ml) under nitrogen. The resulting clear solution was cooled (ice bath) and t-butyl acetoacetate (15.8 g; 0.10 mol) was added during 10 minutes with stirring. After 10 minutes, 2-(bromoethyl)benzene (18.5 g; 0.10 mol) was added during 30 minutes. The resulting solution was heated at reflux for 4 hours, then cooled and filtered. After concentration, the residue was partitioned between water and ether, and the ether layer was dried (MgSO4) and concentrated. Distillation of the residue gave 21.0 g (0.080 mol; 80%) of the title product; bp 110°-120° (0.3 mm). NMR (CDCL3); 1.45 (9H,s), 2.17 (3H,s), 1.8-2.4 (2H,m), 2.5-2.7 (2H,m); 3.28 (1H,J=7); 7.2-7.4 (5H, broad s). MS (m/e); 262 (M+).

Workup

  1. additionwas added during 10 minutes
  2. temperatureThe resulting solution was heated
  3. temperatureat reflux for 4 hours
  4. temperaturecooled
  5. filtrationfiltered
  6. concentrationAfter concentration
  7. customthe residue was partitioned between water and ether
  8. dry with materialthe ether layer was dried (MgSO4)
  9. concentrationconcentrated
  10. distillationDistillation of the residue

Sources & evidence

ORD record
ord-b621a161861b44cebe0a0054a1713501
Source dataset
uspto-grants-1983_09
Patent number
US04402969

Reaction notes

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