Hydrochloric Acid → 5-Benzyl-3,6-dioxo-2-piperazine acetic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

To a solution having 9.6 g of hydrogen chloride dissolved in 400 ml of methanol was fed 61.6 g of N-formyl-α-L-aspartyl-L-phenylalanine and the resulting mixture was reacted at 50°-60° C. for 6 hours. The reaction solution was cooled to 10° C., added dropwise with 105.6 g of a 10% aqueous sodium hydroxide solution and then subjected to reaction at 30°-40° C. for 20 hours. Thereafter, the reaction mixture was cooled to 5° C. and the crystal thereby deposited was filtered, washed with methanol and water and dried to obtain 37.6 g of 5-benzyl-3,6-dioxo-2-piperazine acetic acid methyl ester having a melting point of 216°-217.5° C.

Provenance & Evidence