Diethyl Ether → 11-Bromo-1,1-diethoxyundecane

HRID 2102255Notes

Reaction equation

HRID 2102255 reaction equation
[Cr](Cl)([O-])(=O)=O.[NH+]1C=CC=[CH:8][CH:7]=1.[CH2:12]([O:14]CC)[CH3:13].[Br:17][CH2:18][CH2:19][CH2:20][CH2:21][CH2:22][CH2:23][CH2:24][CH2:25][CH2:26][CH2:27][CH2:28][OH:29]>ClCCl>[CH2:7]([O:29][CH:28]([O:14][CH2:12][CH3:13])[CH2:27][CH2:26][CH2:25][CH2:24][CH2:23][CH2:22][CH2:21][CH2:20][CH2:19][CH2:18][Br:17])[CH3:8]

Participants

5

Reactant 3

HCID 3283Diethyl EtherHCID 7416311-Bromo-1-undecanolHCID 178418287HCID 178418287, compound

Product 1

HCID 5780204811-Bromo-1,1-diethoxyundecane

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

In a 250 ml round bottomed flask, 12.5 g of 11-bromoundecanol was dissolved in 50 ml of dichloromethane. A slurry of 16.2 g pyridiniumchlorochromate (PCC) in 100 ml of dichloromethane was added. The mixture was stirred at room temperature for 2 hours and then poured into 300 ml of diethylether. A brown solid was filtered off and the liquid phase was passed through a short column of silica gel using diethylether as eluent. The organic solvent was evaporated under reduced pressure and the residue was dissolved in absolute ethanol (EtOH) and anhydrous calcium chloride was added together with a small amount of p-toluene sulphonic acid (not shown in Scheme IV). This reaction mixture was left at room temperature over night. The solvent was removed under vacuum and the residue was taken up in diethyl ether and washed with saturated sodium bicarbonate solution. The organic layer was dried over magnesium sulphate, filtered, and evaporated until no more solvent came off. The residue was dissolved in 15 ml of ethyl acetate/petroleum ether 1:4 mixture (v/v) and purified using column chromatography with said solvent mixture as eluent. 9.5 g of 11-bromoundecanal diethyl acetal was isolated. The 1H-NMP spectrum of the compound was found to be in accordance with the structure in Scheme IV.

Workup

  1. filtrationA brown solid was filtered off
  2. customThe organic solvent was evaporated under reduced pressure
  3. dissolutionthe residue was dissolved in absolute ethanol (EtOH)
  4. additionanhydrous calcium chloride was added together with a small amount of p-toluene sulphonic acid (not
  5. waitThis reaction mixture was left at room temperature over night
  6. customThe solvent was removed under vacuum
  7. washwashed with saturated sodium bicarbonate solution
  8. dry with materialThe organic layer was dried over magnesium sulphate
  9. filtrationfiltered
  10. customevaporated until no more solvent
  11. dissolutionThe residue was dissolved in 15 ml of ethyl acetate/petroleum ether 1:4 mixture (v/v)
  12. custompurified

Sources & evidence

ORD record
ord-70aa7a6a62e9406f9042fabbc5a3a45c
Source dataset
uspto-grants-2009_08
Patent number
US07575788B2

Reaction notes

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