| 摘要 |
<p>Disclosed is a process for industrial synthesis of the compound formula (I) and its pharmaceutically acceptable salts, characterised in that a compound of formula (II) wherein R1 represents a benzyl or linear or branched (C1-C6)alkyl group, is reacted with a compound of formula (III) having the S configuration wherein X represents a halogen atom and R2 represents a protecting group for the amino function, in the presence of a base to yield after deprotection of the amino function, a compound of formula (IV) wherein R1 is as defined hereinbefore, which is reacted with ethyl 2-oxopentanoate under hydrogen pressure, in the presence of platinum-on-carbon to yield a compound of formula (V) wherein R-1 is as defined hereinbefore, which is deprotected to yield the compound of formula (I).</p> |
