Products from the sensitised photo-oxidation of 2-dimethylamino-5,6-dimethylpyrimidin-4-ol

The products from the methylene blue sensitised photo-oxidation of 2-dimethylamino-5,6-dimethylpyrimidin-4-ol (I) in deuterochloroform/deuteroacetone have been investigated. A zwitterion and a hydroperoxide are formed initially, with the zwitterion predominating. The zwitterion compound degrades or reacts in the solid state on silica gel to give further products.