New Process For The Preparation Of Nitroorotic Acid

Abstract

Subject of the present invention is a new improved process for the preparation of nitroorotic acid via nitration of orotic acid.

1 . A process for making dipyridamol using nitroorotic acid as an intermediate, wherein the nitroorotic acid is prepared by nitrating orotic acid at a temperature of about 40-80° C., using a mixture of concentrated sulphuric acid and concentrated, but not fuming nitric acid. 
     
     
         2 . The process according to  claim 1  wherein the concentration of the nitric acid is about 65%. 
     
     
         3 . The process according to  claim 1  wherein the nitration is carried out at a temperature of about 40-60 ° C. 
     
     
         4 . The process according to  claim 3  wherein the nitration is carried out at a temperature of about 50-60 ° C. 
     
     
         5 . The process according to  claim 1  wherein the molar ratio between sulphuric acid and nitric acid is between 1:1 and 6:1. 
     
     
         6 . The process according to  claim 5  wherein the molar ratio between sulfuric acid and nitric acid is about 3:1. 
     
     
         7 . The process according to  claim 1  wherein orotic acid is added portionwise to the mixture of sulphuric acid and nitric acid. 
     
     
         8 . The process according to  claim 1  wherein the reaction mixture does not contain any ethanol. 
     
     
         9 . The process according to  claim 1  for large scale industrial production.