| 摘要 |
PURPOSE: To obtain the subject compound useful as a sweetener in high yield by using a strong acid addition salt of L-aspartic acid anhydride as an aspartic acid component to be condensed with a D-amino acid-N-(S)-a-alkylbenzylamide. CONSTITUTION: Thisα-L-aspartyl-D-amino acid-N-(S)-α-alkylbenzylamide expressed by formula (R1 is a 1-4C alkyl; R2 is a 1-3C alkyl) and useful as a sweetener, etc., can be produced in high reaction selectivity and yield by condensing a strong acid addition salt of L-aspartic acid anhydride (e.g. L- aspartic acid anhydride hydrochloride) to a D-amino acid-N-(S)-α- alkylbenzylamide [e.g. D-valine-N-(S)-a-ethylbenzylamide] in ethyl acetate at -30 deg.C under agitation for 30min, adding water to the reaction system, adjusting the pH of the mixture to 10 with 1N-NaOH, adjusting the pH of the obtained alkaline water layer to 4.5-6.5 to effect the crystallization and separating the produced crystal from the system. |
