Processes of producing glutamic acid compounds and production intermediates therefore and novel intermediate for the processes

Abstract

The present invention relates to processes of producing glutamic acid compounds, for example, monatin, which are useful as, for example, production intermediates for sweetener or pharmaceutical products.

1 - 32 . (canceled) 
   
   
       33 . A process of making monatin represented by formula (7′) or a salt thereof: 
     
       
         
         
             
             
         
       
     
     said process comprising:
 (1) reacting indole-3-pyruvic acid represented by formula (1′) or a salt thereof: 
 
     
       
         
         
             
             
         
       
     
     with either oxalacetic acid represented by formula (2) or a salt thereof or pyruvic acid represented by formula (2′) or a salt thereof: 
     
       
         
         
             
             
         
       
     
     to obtain 4-hydroxy-4-(3-indolylmethyl)-2-ketoglutaric acid represented by formula (4′): 
     
       
         
         
             
             
         
       
     
     or a salt thereof; and
 (2) converting said 4-hydroxy-4-(3-indolylmethyl)-2-ketoglutaric acid or a salt thereof to monatin. 
 
   
   
       34 . A process according to  claim 33  which comprises:
 reacting indole-3-pyruvic acid represented by formula (1′) or a salt thereof:   
     
       
         
         
             
             
         
       
     
     with oxalacetic acid represented by formula (2) or a salt thereof: 
     
       
         
         
             
             
         
       
     
     to obtain said 4-hydroxy-4-(3-indolylmethyl)-2-ketoglutaric acid represented by formula (4′) or a salt thereof. 
   
   
       35 . A process according to  claim 33 , comprising:
 reacting indole-3-pyruvic acid represented by formula (1′) or a salt thereof:   
     
       
         
         
             
             
         
       
     
     with pyruvic acid represented by the formula (2′) or a salt thereof: 
     
       
         
         
             
             
         
       
     
     to obtain said 4-hydroxy-4-(3-indolylmethyl)-2-ketoglutaric acid represented by formula (4′) or a salt thereof. 
   
   
       36 . A process according to  claim 33 , which comprises:
 adding oxalacetic acid to a mixture consisting of potassium hydroxide, water, indole-3-pyruvic acid, to obtain a reaction mixture having a pH of about 13; and maintaining said reaction mixture at ambient temperature for 72 hours, to obtain said 4-hydroxy-4-(3-indolylmethyl)-2-ketoglutaric acid represented by formula (4′) or a salt thereof.   
   
   
       37 . A process according to  claim 33 , which comprises:
 adding oxalacetic acid to a mixture consisting of potassium hydroxide, water, indole-3-pyruvic acid, to obtain a reaction mixture having a pH of about 13; and maintaining said reaction mixture at a temperature of 35° C. for 24 hours, to obtain said 4-hydroxy-4-(3-indolylmethyl)-2-ketoglutaric acid represented by formula (4′) or a salt thereof.   
   
   
       38 . A process according to  claim 33 , which comprises:
 adding an aqueous sodium hydroxide solution and a mixture of pyruvic acid and water to a mixture consisting of sodium hydroxide, water, indole-3-pyruvic acid, to obtain a reaction mixture having a pH of about 11; and   maintaining said reaction mixture at a temperature of 35° C. for 14 hours, to obtain said 4-hydroxy-4-(3-indolylmethyl)-2-ketoglutaric acid represented by formula (4′) or a salt thereof.