Procedure for producing formylimidazoles

Abstract

A new process for the catalytic conversion of hydroxymethyl imidazoles to formylimidazoles is described. The reaction takes place in the presence of a peroxide. Formylimidazoles are important intermediate products for pharmaceutical substances.

1 . A process for producing formylimidazoles of the formula (I):  
                   
       in which R 1  is C 1-6 alkyl, which comprises catalytic oxidation of hydroxymethyl imidazoles of the general formula (II):  
                 
 
       in which R 1  is as defined above, in the presence of a noble metal catalyst, wherein the catalytic oxidation takes place in the of a peroxide.  
     
     
         2 . The process according to    claim 1    wherein R 1  is butyl.  
     
     
         3 . The process according to claims  1  or  2  wherein the noble metal catalyst is a platinum/bismuth catalyst or a platinum/lead catalyst.  
     
     
         4 . The process according to    claims 1    to    3    wherein the peroxide is hydrogen peroxide.  
     
     
         5 . The process according to    claims 1    to    4    wherein the catalytic oxidation is performed in the presence of water, a water-miscible solvent or mixtures thereof, in an alkaline medium.  
     
     
         6 . The process according to    claim 5    wherein the alkaline medium is obtained by adding an alkali hydroxide, an alkali carbonate or an alkali acetate to the reaction mixture.  
     
     
         7 . The process according to    claims 1    to    6    wherein the reaction is performed at a temperature of 20°-120° C.