On the oxidation of N‐methylpyrimidinium salts

Abstract

Oxidation of 1,2‐dihydro‐1,3‐dimethyl‐2‐oxopyrimidinium bisulfate (1+·HSO −4) with hydrogen peroxide in acetic acid in the presence of potassium iodide gave 1,3‐dimethyl‐5‐iodouracil (65‐70%), 1,3‐dimethyluracil (10‐15%) and 3‐methyl‐2,4‐oxazolidinedione (10‐15%). Similar results were obtained on oxidation of the iodide (1+·I−). Oxidation of 1‐methyl‐4‐phenylpyrimidinium iodide or oxidation of 1‐methyl‐4‐phenylpyrimidinium methylsulfate in the presence of potassium iodide gave 1,6‐dihydro‐5‐iodo‐1‐methyl‐6‐oxo‐4‐phenylpyrimidine.