Triphenylphosphine → (R)-1-bromo-3,7-dimethyloctane

HRID 1390186Notes

Reaction equation

HRID 1390186 reaction equation
[Br:1]N1C(=O)CCC1=O.[CH3:9][C@H:10]([CH2:14][CH2:15][CH2:16][CH:17]([CH3:19])[CH3:18])[CH2:11][CH2:12]O.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>C(Cl)Cl>[Br:1][CH2:12][CH2:11][C@H:10]([CH3:9])[CH2:14][CH2:15][CH2:16][CH:17]([CH3:19])[CH3:18]

Participants

5

Reactant 3

HCID 11776TriphenylphosphineHCID 67184N-bromobutanimideHCID 6999991(3R)-3,7-Dimethyl-1-octanol

Product 1

HCID 12801557(R)-1-bromo-3,7-dimethyloctaneYield 87.3%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

5.65 g (31.8 mmol) of N-bromosuccinimide are added portionwise while stirring to a solution of 5 g (31.6 mmol) of (R)-3,7-dimethyl-1-octanol and 9.05 g (34.5 mmol) of triphenylphosphine in 20 ml of methylene chloride. The temperature is held below 25° by occasional cooling of the reaction vessel. After 30-minutes stirring at room temperature, the solvent is removed on the rotary evaporator. The residue is washed out several times with n-hexane, then filtered and again rinsed with n-hexane. The combined n-hexane phases are concentrated on the rotary evaporator and the crude product is chromatographed on 200 g of silicagel with n-hexane. Distillation in the bulb-tube at 105°/15 Torr gives 6.1 g (87%) of (R)-1-bromo-3,7-dimethyloctane; [α]D20 = -5.0 (c = 0.82, CHCl3).

Workup

  1. customis held below 25°
  2. temperatureby occasional cooling of the reaction vessel
  3. customthe solvent is removed on the rotary evaporator
  4. washThe residue is washed out several times with n-hexane
  5. filtrationfiltered
  6. washagain rinsed with n-hexane
  7. concentrationThe combined n-hexane phases are concentrated on the rotary evaporator
  8. customthe crude product is chromatographed on 200 g of silicagel with n-hexane
  9. distillationDistillation in the bulb-tube at 105°/15 Torr

Sources & evidence

ORD record
ord-a55925e117bf4c048dd1192b50f3c37e
Source dataset
uspto-grants-1979_02
Patent number
US04138289

Reaction notes

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