Sulfuric Acid → L-Aspartyl-L-phenylalanine

Participants

Reaction Conditions

Reaction Steps

A medium composed of 25.5 g of concentrated sulfuric acid and 72.5 g of water was heated to 50° C., followed by a gradual addition of 30.8 g (0.1 mole) of N-formyl-α-L-aspartyl-L-phenylalanine over about 1 hour. The reaction was conducted for further 3 hours at 50°-60° C. to remove the formyl group, so that α-L-aspartyl-L-phenylalanine was formed. The reaction mixture was then cooled to 20° C., and 9.6 g of methanol and 18.7 g of anhydrous magnesium chloride were added. The reaction mixture was heated to 30° C., followed by a reaction at 30°-35° C. for 4 days. As the reaction proceeded, crystals of α-APM hydrochloride precipitated little by little. After the reaction, the reaction mixture was cooled to 20° C., and the precipitated crystals were collected by filtration and washed with chilled water to obtain a wet α-APM.HCl cake containing 23.9 g of α-APM (as converted into its free form). Yield: 81.4% (based on N-formyl-α-L-aspartyl-L-phenylalanine).

Provenance & Evidence