3-Hydroxy-3-methyl-2-butanone → 1,1-Dibromo-3-hydroxy-3-methylbutan-2-one

HRID 891841Notes

Reaction equation

HRID 891841 reaction equation
[CH3:1][C:2]([OH:7])([CH3:6])[C:3](=[O:5])[CH3:4].[Br-:8].[Br-:9].[Br-].[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1>ClCCl>[Br:8][CH:4]([Br:9])[C:3](=[O:5])[C:2]([OH:7])([CH3:6])[CH3:1]

Participants

4

Reactant 2

HCID 82613-Hydroxy-3-methyl-2-butanoneHCID 21124087Pyridiniumtribromide

Product 1

HCID 114368661,1-Dibromo-3-hydroxy-3-methylbutan-2-oneYield 31%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a stirred solution of 3-methyl-3-hydroxy-2-butanone (40 g, 0.392 mol) in anhydrous dichloromethane (2.2 l) under nitrogen was added solid pyridinium tribromide (250.4 g, 0.784 mol) in portions and the mixture was stirred at room temperature for 14 h. The mixture was then washed with dilute aqueous sodium hydrogensulphite (500 ml), then saturated aqueous NaCl (500 ml), dried (Na2SO4), and evaporated in vacuo. The residue was purified by flash chromatography (silica gel, CH2Cl2) to afford 31.4 g (31%) of the title compound as a colourless oil: 1H NMR (360 MHz, CDCl3) δ 1.54 (6H, s), 2.45 (1H, br s), 6.62 (1H, s).

Workup

  1. washThe mixture was then washed with dilute aqueous sodium hydrogensulphite (500 ml)
  2. dry with materialsaturated aqueous NaCl (500 ml), dried (Na2SO4)
  3. customevaporated in vacuo
  4. customThe residue was purified by flash chromatography (silica gel, CH2Cl2)

Sources & evidence

ORD record
ord-e4925a836c104878bf8e14a24d908998
Source dataset
uspto-grants-2006_02
Patent number
US07005431B2

Reaction notes

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