Process for the preparation of sulfomate-carboxylate derivatives

Abstract

Disclosed is a process for the preparation of Compound (III), salt or solvate thereof by reacting Compound (I), salt or solvate thereof with Compound (II) in a toluene solvent in the presence of an additive such as water or an alcohol. Also disclosed is a process for the preparation of Compound (IV) comprising hydrolyzing the obtained Compound (III) if necessary, and then oxidizing. In the formula, R 1 is hydrogen, optionally substituted lower alkyl, optionally substituted aryl or optionally substituted aryl lower alkyl, and R 2 is optionally substituted lower alkyl, optionally substituted cycloalkyl or optionally substituted aryl lower alkyl.

1 . A process for the preparation of a compound of the formula (IVb): 
       
         
           
           
               
               
           
         
         wherein R 2  is lower alkyl, 
         or a salt thereof, 
         comprising hydrolyzing a compound of the formula (IIIa) under alkaline condition: 
       
       
         
           
           
               
               
           
         
         wherein R 1a  is optionally substituted lower alkyl, and R 2  is lower alkyl, 
         or a salt thereof, to obtain a compound of the formula (IIIb): 
       
       
         
           
           
               
               
           
         
         wherein R 2  is lower alkyl, 
         or a salt thereof; and oxidizing the obtained compound or salt thereof. 
       
     
     
         2 . A compound of the formula (IIIb-1): 
       
         
           
           
               
               
           
         
       
       or a salt thereof.