Method for preparing .alpha.-L-aspartyl-L-phenylalanine methyl ester
AssigneeMitsui Toatsu Chemicals, Inc.
InventorsMasanobu Ajioka, Takeshi Oura, Chojiro Higuchi, Toshio Katoh, Akihiro Yamaguchi
Life of this patent
Estimating the term…
Abstract
A method for preparing .alpha.-L-aspartyl-L-phenylalanine methyl ester (.alpha.-APM), substantially free from acid ion contamination, is disclosed which comprises the steps of contacting a solution of a mineral acid salt or an organic sulfonic acid salt of .alpha.-APM in an aqueous solvent with an anion exchange resin in free base form, separating the resin from the thus-produced solution of .alpha.-APM; and isolating the .alpha.-APM therefrom, preferably with regeneration and recycling the resin.
Claims9
A method for converting substantially pure .alpha.-L-aspartyl-L-phenylalanine methyl ester (.alpha.-APM) in acid addition salt form to its free base form, substantially free from acid ion contamination, which comprises the steps of contacting a solution of a substantially pure acid addition salt of .alpha.-L-aspartyl-L-phenylalanine methyl ester in an aqueous solvent with an anion exchange resin in free base form, thereby producing an aqueous solution of substantially pure .alpha.-APM in free base form;
- separating the ion exchange resin therefrom;
- and then isolating therefrom .alpha.-APM substantially free from the acid anions of the acid addition salt.
Dependencies are inferred from the claim text.