Acetone → Ethyl 2-[2-(4-bromophenyl)-2-oxoethyl]pentanoate

HRID 9527Notes

Reaction equation

HRID 9527 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([C:8](=[O:20])[CH2:9][C:10]([CH2:17][CH2:18][CH3:19])([C:14]([O-:16])=[O:15])C([O-])=O)=[CH:4][CH:3]=1.[CH3:21][C:22](C)=O.[OH-].[Na+]>C(O)C>[Br:1][C:2]1[CH:3]=[CH:4][C:5]([C:8](=[O:20])[CH2:9][CH:10]([CH2:17][CH2:18][CH3:19])[C:14]([O:16][CH2:21][CH3:22])=[O:15])=[CH:6][CH:7]=1

Participants

5

Reactant 3

HCID 180AcetoneHCID 14798Sodium HydroxideHCID 219858152-[2-(4-Bromophenyl)-2-oxoethyl]-2-propylmalonate

Product 1

HCID 21985789Ethyl 2-[2-(4-bromophenyl)-2-oxoethyl]pentanoateYield 20%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Conditions

Temperature
55 °C

Procedure

To a 200 mL flask was added crude 2-[2-(4-bromophenyl)-2-oxoethyl]-2-propylmalonate (7.62 g, 19.2 mmol), acetone (21 mL), and ethanol (19 mL), followed by addition of 1 N aqueous sodium hydroxide solution (19.1 mL). The reaction mixture was heated to 55° C. for 3 h. The clear, orange-red reaction mixture was then concentrated under reduced pressure and the residue was redissolved in dimethoxyethane (30 mL). The mixture was heated to 80° C. for 3 h. The reaction mixture was cooled to rt, diluted with ethyl acetate (100 mL) and water (100 mL), and stirred for 15 minutes until almost all color was extracted into the organic layer. The layers were separated and the aqueous layer extracted with additional ethyl acetate (75 mL). The combined organic layers were washed with saturated aqueous sodium chloride solution (75 mL), dried over anhydrous sodium sulfate, and concentrated under reduced pressure to afford an orange oil. The crude product was purified by flash chromatography (10:1 hexane:ethyl acetate) to afford ethyl 2-[2-(4-bromophenyl)-2-oxoethyl]pentanoate (1.33 g, 20%). LC-MS ret. time 3.60 min, m/z 326.05 (MH+); 1H NMR (300 MHz, CDCl3) δ 0.87 (t, 3H), 1.25 (t, 3H), 1.29–1.43 (m, 2H), 1.57–1.73 (m, 2H), 2.90–3.08 (m, 2H), 3.34–3.47 (m, 2H), 4.15 (q, 2H), 7.59 (d, 4H), 7.82 (d, 2H).

Workup

  1. concentrationThe clear, orange-red reaction mixture was then concentrated under reduced pressure
  2. dissolutionthe residue was redissolved in dimethoxyethane (30 mL)
  3. temperatureThe mixture was heated to 80° C. for 3 h
  4. temperatureThe reaction mixture was cooled to rt
  5. additiondiluted with ethyl acetate (100 mL) and water (100 mL)
  6. extractionwas extracted into the organic layer
  7. customThe layers were separated
  8. extractionthe aqueous layer extracted with additional ethyl acetate (75 mL)
  9. washThe combined organic layers were washed with saturated aqueous sodium chloride solution (75 mL)
  10. dry with materialdried over anhydrous sodium sulfate
  11. concentrationconcentrated under reduced pressure
  12. customto afford an orange oil
  13. customThe crude product was purified by flash chromatography (10:1 hexane:ethyl acetate)

Sources & evidence

ORD record
ord-ee9c0b103ab042eea52701b076134912
Source dataset
uspto-grants-2006_08
Patent number
US07091228B2

Reaction notes

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