Hydrochloric Acid → Bis(4-bromobenzyl) ketone

HRID 1869062Notes

Reaction equation

HRID 1869062 reaction equation
[H-].[Na+].[Br:3][C:4]1[CH:9]=[CH:8][C:7]([CH2:10][C:11]([O:13]CC)=O)=[CH:6][CH:5]=1.[H][H].Cl>C1(C)C=CC=CC=1.O>[Br:3][C:4]1[CH:9]=[CH:8][C:7]([CH2:10][C:11](=[O:13])[CH2:10][C:7]2[CH:6]=[CH:5][C:4]([Br:3])=[CH:9][CH:8]=2)=[CH:6][CH:5]=1

Participants

7

Reactant 4

HCID 313Hydrochloric Acid2×HCID 24758Sodium hydrideHCID 7020609Ethyl 2-(4-bromophenyl)acetateHCID 178418361HCID 178418361, compound

Product 1

HCID 12420215Bis(4-bromobenzyl) ketoneYield 82%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 1140TolueneSolvent2×

Conditions

Temperature
50 °C

Procedure

To a slurry of sodium hydride (9.17 grams, 0.23 mole) in 50 milliliters of toluene was added dropwise, a solution of ethyl 4-bromophenylacetate (50 grams, 0.21 mole) in toluene (50 milliliters) at 30-32° C. After addition was completed, the reaction mixture was slowly warmed to 50° C. where the reaction began to rapidly exotherm with evolution of hydrogen gas. The reaction mixture was further heated to 78° C. for 2 hours, cooled to room temperature and then HCl (45 grams) in water (22.5 grams) was slowly added dropwise to neutralize the solution. The layers were separated and the aqueous phase was extracted with diethylether. The combined organic extracts were dried and the solvent was removed to leave a yellow oil. This oil was refluxed for 24 hours in a mixture of glacial acid (60 milliliters) and concentrated HCl (30 milliliters). After cooling, the layers were separated, and the organic layer solidified to provide a yellow solid. This crude product was recrystallized from n-heptane to give a pure product as a white solid (31.2 grams, 82% isolated yield).

Workup

  1. customat 30-32° C
  2. additionAfter addition
  3. temperatureThe reaction mixture was further heated to 78° C. for 2 hours
  4. temperaturecooled to room temperature
  5. customThe layers were separated
  6. extractionthe aqueous phase was extracted with diethylether
  7. customThe combined organic extracts were dried
  8. customthe solvent was removed
  9. customto leave a yellow oil
  10. temperatureAfter cooling
  11. customthe layers were separated
  12. customto provide a yellow solid
  13. customThis crude product was recrystallized from n-heptane

Sources & evidence

ORD record
ord-e886f5c5d56a459692b7709997bfb689
Source dataset
uspto-grants-2009_12
Patent number
US07635741B2

Reaction notes

Loading…