Synthetic Methods and Intermediates for Stereoisomeric Compounds Useful for the Treatment of Gastrointestinal and Central Nervous System Disorders

Abstract

The subject invention provides methods and/or processes for making stereoisomeric compounds of formula (X): wherein the variables are as defined herein, and compositions for the safe and effective treatment of various gastrointestinal disorders including, but not limited to, gastroparesis, gastroesophageal reflux and related conditions. The compounds of the subject invention are also useful in treating a variety of conditions involving the central nervous system.

1 .- 18 . (canceled)  
     
     
         19 . A compound of formula II′ 
       
         
           
           
               
               
           
         
         or a salt thereof, wherein X 1  is a nitrogen protecting group and X 2  is selected from the group consisting of hydrogen and a nitrogen protecting group, and R is (C 1 -C 8 )alkyl.  
       
     
     
         20 . (canceled)  
     
     
         21 . A compound of formula III′ 
       
         
           
           
               
               
           
         
         or a salt thereof, wherein X 1  is a nitrogen protecting group and X 2  is selected from the group consisting of hydrogen and a nitrogen protecting group.  
       
     
     
         22 .- 24 . (canceled)  
     
     
         25 . A compound of formula III″ 
       
         
           
           
               
               
           
         
         or a salt thereof, wherein X 1  is a nitrogen protecting group and X 2  is selected from the group consisting of hydrogen and a nitrogen protecting group.  
       
     
     
         26 . (canceled)  
     
     
         27 . A compound of formula IV′ 
       
         
           
           
               
               
           
         
         or a salt thereof, wherein R′ is (C 1 -C 8 )alkyl (preferably ethyl), and X 1  is a nitrogen protecting group and X 2  is selected from the group consisting of hydrogen and a nitrogen protecting group.  
       
     
     
         28 .- 30 . (canceled)  
     
     
         31 . A compound of formula V′ 
       
         
           
           
               
               
           
         
         or a salt thereof, wherein X 1  is a nitrogen protecting group and X 2  is selected from the group consisting of hydrogen and a nitrogen protecting group.  
       
     
     
         32 .- 36 . (canceled)