| 摘要 |
<p>The present invention provides a process for preparing a compound of formula (I); wherein R is a C1-C6 alkyl; or a salt thereof; comprising:(c) hydrolyzing (D,L)-N-acetyl-2-amino-5-phenylpentanoic acid with a suitable base in the presence of D-aminoacylase to provide (D)-2-amino-5-phenylpentanoic acid; and (d) esterifying (D)-2-amino-5-phenylpentanoic acid with an alkanol. In a further embodiment, the present invention provides a process for selectively preparing (D)-2-amino-5-phenylpentanoic acid comprising hydrolyzing (D,L)-N-acetyl-2-amino-5-phenyl pentanoic acid with a suitable base in the presence of D-aminoacylase. In a still further embodiment, the present invention provides an improved process for preparing a growth hormone secretagogue compound of formula (II) disclosed herein.</p> |
