Reaktion #463685

Reaktionsgleichung

isophytol

2,3,5-trimethylhydroquinone

hydrochloric acid

→

title compound

Ausbeute 101.8%

α-tocopherol

Ausbeute 101.8%

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 30 ml of water
4. 4
   workup.DISTILLATIONthe solvent was distilled off
5. 5
   workup.ADDITIONToluene (300 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 saturate aqueous solution of NaCl, dried over magnesium sulfate
9. 9
   Einengenconcentrated under reduced pressure

Vorschrift

To a mixture consisting of 69.9 g (0.460 mol) of 2,3,5-trimethylhydroquinone, 52.5 g (0.386 mol) of zinc chloride, 150 ml of diethyl carbonate and 7.5 g of concentrated hydrochloric acid, 138.3 g (0.459 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 30 ml of water, the solvent was distilled off. Toluene (300 ml) was added to the residue to dissolve the same. The resulting solution was washed successively with water, alkaline water and a saturate aqueous solution of NaCl, dried over magnesium sulfate and then concentrated under reduced pressure, whereby 201.2 g of the title compound was obtained as a brown oil (yield: 99.2%), GLC purity: 97.5%).

Quelle