Processes for preparation, isolation and purification of dipeptide sweeteners
AssigneePfizer Inc.
InventorConstantine Sklavounos
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Abstract
Aromatic sulfonic acid salts of certain dipeptide sweeteners which are L-aspartyl-D-alaninamides or L-aspartyl-D-serinamides, each substituted on amide nitrogen with an organic radical having a highly branched carbon skeleton; the process for preparing said salts by crystallization; and utilization of this crystallization process in processes for the preparation, isolation and purification of said amides.
Claims24
A process for the purification of an L-aspartyl-D-amino acid dipeptide amide of the formula ##STR12## wherein A is hydrogen or hydroxy and X is S, SO or SO.sub.2 ;
- which comprises selectively crystallizing said L-aspartyl-D-amino acid dipeptide amide in the form of a salt with an aromatic sulfonic acid of the formula ##STR13## wherein R.sup.1 is hydrogen, chloro or methyl and R.sup.2 is hydrogen or methyl, from an aqueous solvent.
A substantially pure, anhydrous or hydrated salt comprising an L-aspartyl-D-amino acid dipeptide amide of the formula ##STR14## wherein A is hydrogen or hydroxy and X is S, SO, or SO.sub.2 ;
- and an aromatic sulfonic acid of the formula ##STR15## wherein R.sup.1 is hydrogen, chloro or methyl and R.sup.2 is hydrogen or methyl.
Dependencies are inferred from the claim text.