Hydrogen Bromide → DL-alpha-Tocopherol

HRID 376506

Reaction equation

HRID 376506 reaction equation
[CH3:1][C:2]1[C:8]([CH3:9])=[C:7]([OH:10])[C:6]([CH3:11])=[CH:5][C:3]=1O.C(=O)(OCC)OCC.Br.[CH3:21][CH:22]([CH2:24][CH2:25][CH2:26][CH:27]([CH2:29][CH2:30][CH2:31][CH:32]([CH2:34][CH2:35][CH2:36][C:37]([OH:41])([CH:39]=[CH2:40])[CH3:38])[CH3:33])[CH3:28])[CH3:23]>[Br-].[Zn+2].[Br-]>[CH3:9][C:8]1[C:2]([CH3:1])=[C:3]2[C:5]([CH2:40][CH2:39][C:37]([CH2:36][CH2:35][CH2:34][CH:32]([CH2:31][CH2:30][CH2:29][CH:27]([CH2:26][CH2:25][CH2:24][CH:22]([CH3:21])[CH3:23])[CH3:28])[CH3:33])([CH3:38])[O:41]2)=[C:6]([CH3:11])[C:7]=1[OH:10]

Participants

6

Reactant 4

HCID 260Hydrogen BromideHCID 7766Diethyl CarbonateHCID 10453IsophytolHCID 12785Trimethylhydroquinone

Product 1

HCID 2116DL-alpha-TocopherolYield 101.2%

Reagents, catalysts & solvents 1

HCID 10421208Zinc bromideCatalyst

Conditions

Temperature
50 °C

Procedure

To a mixture consisting of 23.3 g (0.153 mol) of 2,3,5-trimethylhydroquinone, 23.2 g (0.153 mol) of zinc bromide, 52.9 ml of diethyl carbonate and 4.3 g of 47% hydrobromic acid, was added dropwise, under stirring at 50±5° C. over one hour, 46.2 g (0.153 ml) of isophytol (purity: 98.1%). Further, the resulting mixture was stirred for one hour at the same temperature. The reaction liquid was washed several times with 50 ml of water, followed by concentrating under a reduced pressure, whereby 66.7 g of the title compound was obtained as a brown oil (yield: 99.1 %, GLC purity: 98.0%).

Workup

  1. additionwas added dropwise
  2. stirringFurther, the resulting mixture was stirred for one hour at the same temperature
  3. customThe reaction liquid
  4. washwas washed several times with 50 ml of water
  5. concentrationby concentrating under a reduced pressure

Sources & evidence

ORD record
ord-6e997ba4f955466e8f03b9847f05127f
Source dataset
uspto-grants-2000_02
Patent number
US06020505

Linked notes

Loading…