150728-13-5

150728-12-4

150728-13-5

General procedure for the synthesis of 4,6-dichloro-5-(2-methoxyphenoxy)-[2,2'-dipyrimidin]-4,6(1H,5H)-dione from 5-(2-methoxyphenoxy)-[2,2'-dipyrimidin]: Example of implementation: 1. 343.70 g of phosphoryl chloride was added to a reactor followed by 175.0 g of 5-(2-methoxyphenoxy)-[2,2'-dipyrimidin]-4,6(1H,5H)-dione (Compound 1). 2. The reaction mixture was heated to reflux temperature and stirred under reflux conditions for 4.0 hours. The reaction process was monitored by HPLC. 3. Upon completion of the reaction, the reaction mixture was slowly cooled to 40-50 °C. The reaction mixture was then cooled at 5-10 °C. The reaction mixture was then cooled at 5-10 °C. 4. The reaction mixture was quenched by slowly pouring into 2.625 liters of water at 5-10 °C. 5. the reaction mixture was continued to be stirred at 5-10 °C for 2.0 hours. 6. the reaction mixture was filtered and the wet filter cake was washed three times with 175.0 mL of water. 7. The wet filter cake was collected to give 4,6-dichloro-5-(2-methoxyphenoxy)-2,2'-dipyrimidine (Compound 2) with a wet weight of 255 g. The reaction was carried out at 55° C. The wet filter cake was washed three times with 175.0 mL of water. 8. The wet filter cake was dried under vacuum at 55-60°C for 8.0 hours. 9. After drying, 182 g of Compound 2 was obtained in 93% yield and >98% HPLC purity.