| 摘要 |
<p>In the present invention there is disclosed a process for preparing a substantially pure enantiomer piperazine derivative of the general formula IX, in which X represents oxygen, sulfur, the group NH, N-alkyl containing 1 to 4 carbon atoms or CHi2, Yi1, Yi2 and Yi3 each represents hydrogen, a halogen alkyl containing 1 to 4 carbon atoms , alkoxyl containing 1 to 4 carbon atoms, haloalkyl containing 1 to 4 carbon atoms a nitro group or a cyano group, A represents alkylene containing 2 to 4 carbon atoms, B represents an optionally substituted phenyl or heterocyclic group and C*-atom is in R-configuration. The invented process is characterized in that (a) a racemic alcohol of the general formula I is acylated with an acylating agent in the presence of an enzyme exhibiting stereoselective esterification activity, the non-esterified compound is separated from the formed ester that is subsequently subjected to hydrolysis and a waste undesired alcohol enantiomer is then converted under basic conditions to the starting racemic alcohol that is brought again back into reaction, (b) a free hydroxy group of so obtained alcohol enantiomer is protected, (c) a nitro group of the product is reduced to an amino group, (d) the amino compound is then converted to a piperazine compound, (e) said piperazine compound is subsequently subjected to derivatization and (f) from the obtained compound the protecting group is cleaved.</p> |
