摘要 |
<p>An amino-protected L-aspartic acid, such as t-butyloxycarbonyl-beta-benzyl-L-aspartic acid, is prepared by first forming the amino-protected compound in the presence of a tertiary amine base having a pKa value of about 9 to about 12, water, and a water-immiscible polar organic solvent so as to produce a non-aqueous solution containing a salt form of amino-blocked-beta-benzyl-L-aspartic acid. The thus produced non-aqueous solution is then isolated, or next acidified and treated further to ultimately recover therefrom the amino-protected L-aspartic acid in crystalline form.</p> |