Patent ID: 9302980
Filing Date: 2016-04-05
CPC Classification: C07C,C07D

Claim Text:
1. A process for producing an unprotected amino acid comprising 2 to 7 carbon atoms, the process comprising precipitating a solid of the unprotected amino acid wherein the precipitating is carried out by adding an amine to a sulfonic acid salt of an unprotected amino acid in an aprotic polar solvent, adding an amine to a sulfonic acid salt of an amino acid produced by reacting a N-(tert-butoxycarbonyl) amino acid with a sulfonic acid in an aprotic polar solvent, adding an amine to a sulfonic acid salt of an amino acid produced by reacting an amino acid tert-butyl ester with a sulfonic acid in an aprotic polar solvent or by adding a sulfonic acid to an amine salt of an unprotected amino acid in an aprotic polar solvent, wherein optionally the addition of the amine or the sulfonic acid continues until pH of a solution comprising the sulfonic acid salt or the amine salt reaches a range of isoelectric point of the amino acid pI value ±3.