Synthetic route to anti-viral agents

Abstract

The invention provides methods of synthesizing a viral protease inhibitor in high yield, without using expensive catalysts or challenging reaction conditions.

1 - 18 . (canceled) 
     
     
         19 . A method, comprising the reaction shown in Scheme B: 
       
         
           
           
               
               
           
         
       
       wherein the reaction takes place in a solvent, thereby forming a product mixture comprising 
       
         
           
           
               
               
           
         
       
     
     
         20 . The method of  claim 19 , wherein the solvent comprises toluene, dichloromethane, THF, acetone, heptane, hexane, methyl tert-butyl ether, ethyl acetate, dioxane, DMF, DMA, acetonitrile, or DMSO, or a mixture thereof. 
     
     
         21 . The method of  claim 20 , wherein the solvent comprises toluene, acetonitrile, or dichloromethane or a mixture thereof. 
     
     
         22 . The method of  claim 19 , wherein the reaction of scheme B takes place at a temperature from about −20° C. to about 10° C. 
     
     
         23 . The method of  claim 22 , wherein the temperature is about −20° C., about −15° C., about −10° C., about −5° C., about 0° C., about 5° C., or about 10° C. 
     
     
         24 . The method of  claim 22 , wherein the temperature is about −10° C. to about 10° C. 
     
     
         25 . The method of  claim 22 , wherein the temperature is about 0° C. 
     
     
         26 . The method of  claim 19 , further comprising:
 isolating   
       
         
           
           
               
               
           
         
       
       from the product mixture, thereby obtaining substantially pure 
       
         
           
           
               
               
           
         
       
     
     
         27 . The method of  claim 19 , further comprising the reaction shown in Scheme A: 
       
         
           
           
               
               
           
         
       
       wherein the reaction takes place in a second solvent, thereby forming a second product mixture comprising 
       
         
           
           
               
               
           
         
       
     
     
         28 . The method of  claim 26 , further comprising the reaction shown in Scheme A: 
       
         
           
           
               
               
           
         
       
       wherein the reaction takes place in a third solvent, thereby forming a third product mixture comprising