Reaktion #463684

Reaktionsgleichung

2,3,5-trimethylhydroquinone

hydrochloric acid

isophytol

→

title compound

Ausbeute 101.7%

α-tocopherol

Ausbeute 101.7%

Lösungsmittel

diethyl carbonate

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added dropwise
2. 2
   workup.STIRRINGAt the same temperature, the reaction mixture was stirred for an additional 2 hours
3. 3
   WaschenAfter the reaction mixture was washed with 10 ml of water
4. 4
   workup.DISTILLATIONthe solvent was distilled off
5. 5
   workup.ADDITIONToluene (100 ml) was added to the residue
6. 6
   workup.DISSOLUTIONto dissolve the same
7. 7
   WaschenThe resulting solution was washed successively with water
8. 8
   Trocknenalkaline water and a saturated aqueous solution of NaCl, dried over magnesium sulfate
9. 9
   Einengenconcentrated under reduced pressure

Vorschrift

To a mixture consisting of 23.3 g (0.153 mol) of 2,3,5-trimethylhydroquinone, 17.5 g (128 mol) of zinc chloride, 50 ml of diethyl carbonate and 2.5 g of concentrated hydrochloric acid, 46.1 g (0.153 mol) of isophytol (purity: 98.3%) was added dropwise under stirring at 30-40° C. over 3 hours. At the same temperature, the reaction mixture was stirred for an additional 2 hours. After the reaction mixture was washed with 10 ml of water, the solvent was distilled off. Toluene (100 ml) was added to the residue to dissolve the same. The resulting solution was washed successively with water, alkaline water and a saturated aqueous solution of NaCl, dried over magnesium sulfate and then concentrated under reduced pressure, whereby 67.0 g of the title compound was obtained as a brown oil (yield: 98.9%, GLC purity: 97.3%).

Quelle