Hydrogen Bromide → 3-(3-Bromopropyl)-2,4-pentanedione

HRID 1905414Notes

Reaction equation

HRID 1905414 reaction equation
[C:1]([C:4]1[CH2:5][CH2:6][CH2:7][O:8][C:9]=1[CH3:10])(=[O:3])[CH3:2].[BrH:11]>C(O)(=O)C>[Br:11][CH2:7][CH2:6][CH2:5][CH:4]([C:9](=[O:8])[CH3:10])[C:1](=[O:3])[CH3:2]

Participants

4

Reactant 2

HCID 260Hydrogen BromideHCID 130501371-(6-methyl-3,4-dihydro-2H-pyran-5-yl)ethan-1-one

Product 1

HCID 143062233-(3-Bromopropyl)-2,4-pentanedione

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

35.0 g. (0.25 mole) of 5-acetyl-6-methyl -3,4-dihydro-2H-pyrane prepared according to Example 21 are added dropwise into 250 ml. of a 33% solution of of hydrogen bromide in acetic acid, at room temperature, under stirring. The mixture is refluxed for 4 hours, with stirring. After cooling it is poured into 1 kg. of ice water and is then extracted with three 100-ml. portions of chloroform. The combined chloroform solution is washed subsequently with three 50-ml. portions of water, three 50-ml. portions of a 5% aqueous sodium bicarbonate solution and two 50-ml. portions of water, dried over solid anhydrous magnesium sulfate, decoloured with activated carbon and evaporated. The product obtained is purified by fractionated distillation on a short Wigreux column, in vacuum.

Workup

  1. additionare added dropwise into 250 ml
  2. temperatureThe mixture is refluxed for 4 hours
  3. temperatureAfter cooling it
  4. additionis poured into 1 kg
  5. extractionof ice water and is then extracted with three 100-ml
  6. washThe combined chloroform solution is washed subsequently with three 50-ml
  7. dry with materialportions of water, dried over solid anhydrous magnesium sulfate
  8. customevaporated
  9. customThe product obtained
  10. distillationis purified by fractionated distillation on a short Wigreux column, in vacuum

Sources & evidence

ORD record
ord-2eadbe6b7a4e4eaab944f56f4375dabd
Source dataset
uspto-grants-1989_06
Patent number
US04843080

Reaction notes

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