1-Butanol → L-Ascorbic Acid

Participants

Reaction Conditions

Reaction Steps

594 g (3 mol) of anhydrous 2-keto-L-gulonic acid were suspended in a solvent mixture consisting of 72 ml (0.7 mol) of perchloroethylene and 1 l (11 mol) of n-butanol. After addition of 7 g (69 mmol) of conc. sulfuric acid, the mixture was evacuated to 300 mbar and heated to an internal temperature of 85° C. The distillate was removed. After 2 hours, 24 ml of water were removed. After addition of 725 ml (7 mol) of fresh perchloroethylene, the viscous reaction mixture was rapidly treated with 79 g (0.8 mol) of conc. hydrochloric acid and stirred at 75° C. for 17 hours. The precipitated L-ascorbic acid was filtered off with suction, washed with n-butanol and dried in vacuo. Yield: 460 g (86%) of a gray crystallizate having a vitamin C purity of 99%. Vitamin C of high purity can be obtained by processes known from the literature, e.g. recrystallization.

Provenance & Evidence