Process for making chiral 1,4-disubstituted piperazines

Abstract

A process for a stereoselective preparation of novel chiral nitrogen mustard derivatives useful in synthesizing optically active 1,4-disubstituted piperazines of formula: wherein R, Ar, and Q are defined as set forth herein, and intermediate compounds therefor. The 1,4-disubstituted piperazines act as 5HT1A receptor binding agents useful in the treatment of Central Nervous System (CNS) disorders.

1 . A compound of formula II  
       
         
           
           
               
               
           
         
       
       wherein R and R′ each independently represents a lower alkyl of C 1 -C 3 , and optical isomers and salts thereof.  
     
     
         2 . A compound according to  claim 1  wherein said salt is:  
       
         
           
           
               
               
           
         
       
     
     
         3 . A compound selected from the group consisting of 
 N,N-bis(2-chloroethyl)-(R)-alanine methyl ester, trifluoromethanesulfonate; and    N,N-bis(2-chloroethyl)-(R)-alanine ethyl ester, trifluoromethanesulfonate;    and the optical isomers thereof.