1,2-Dibromoethane → 3-(3,4-Dimethylbenzoyl)-2-methylpropionaldehyde ethylene acetal

HRID 1415827Notes

Reaction equation

HRID 1415827 reaction equation
BrCCBr.[Mg].[CH2:6]1[O:14][CH:9]([CH:10]([CH3:13])[CH2:11]Br)[O:8][CH2:7]1.CON(C)[C:18](=[O:27])[C:19]1[CH:24]=[CH:23][C:22]([CH3:25])=[C:21]([CH3:26])[CH:20]=1.[Cl-].[NH4+]>O1CCCC1>[CH2:6]1[O:14][CH:9]([CH:10]([CH3:13])[CH2:11][C:18](=[O:27])[C:19]2[CH:24]=[CH:23][C:22]([CH3:25])=[C:21]([CH3:26])[CH:20]=2)[O:8][CH2:7]1

Participants

7

Reactant 5

HCID 78391,2-DibromoethaneHCID 25517Ammonium ChlorideHCID 5462224MagnesiumHCID 14383752HCID 14383752, compoundHCID 14973055N-Methoxy-N,3,4-trimethylbenzamide

Product 1

HCID 218628313-(3,4-Dimethylbenzoyl)-2-methylpropionaldehyde ethylene acetalYield 39%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

0.29 ml (3.4 mmol) of 1,2-dibromoethane was added to a suspension of 1.66 g (68.1 mmol) of magnesium in 5 ml of anhydrous tetrahydrofuran under a stream of nitrogen. 9.96 g (51.1 mmol) of 3-bromo-2-methylpropionaldehyde ethylene acetal [prepared as described in step (i) above] were then added dropwise to the resulting mixture, whilst ice-cooling, after which the mixture was stirred for 1 hour. A solution of 6.58 g (34.1 mmol) of N-methoxy-N-methyl-3,4-dimethylbenzamide in 30 ml of tetrahydrofuran was then added dropwise to the mixture, and the resulting mixture was stirred, whilst ice-cooling for 1 hour. A saturated aqueous solution of ammonium chloride was then added to the mixture, and the resulting mixture was extracted twice with ethyl acetate. The organic extracts were combined and washed with a saturated aqueous solution of sodium chloride, after which they were dried over anhydrous magnesium sulfate and concentrated by evaporation under reduced pressure. The residue thus obtained was applied to a silica gel chromatography column and eluted with a 6:1 by volume mixture of hexane and ethyl acetate, to give 3.26 g (yield 39%) of the title compound as a colorless oily substance.

Workup

  1. temperaturecooling
  2. stirringthe resulting mixture was stirred, whilst ice-
  3. temperaturecooling for 1 hour
  4. extractionthe resulting mixture was extracted twice with ethyl acetate
  5. washwashed with a saturated aqueous solution of sodium chloride
  6. dry with materialafter which they were dried over anhydrous magnesium sulfate
  7. concentrationconcentrated by evaporation under reduced pressure
  8. customThe residue thus obtained
  9. washeluted with a 6:1 by volume mixture of hexane and ethyl acetate

Sources & evidence

ORD record
ord-0f88ab90ee4946f490b129062cec3d03
Source dataset
uspto-grants-1999_06
Patent number
US05908858

Reaction notes

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