Hydrochloric Acid → alpha-Tocopherol

Participants

Reaction Steps

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%) were added dropwise under stirring at 30°-40° C. over 3 hours. At the same temperature, the reaction mixture was stirred for 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 saturated aqueous solution of NaCl dried over magnesium sulfate and then concentrated under reduced pressure, whereby 201.2 g of the title compound were obtained as a brown oil (yield: 99.2%, GLC purity: 97.5%).

Provenance & Evidence