5-Iodocytosine

71-30-7

1122-44-7

A mixture of N-iodosuccinimide (18.562 g, 82.5 mmol) and 6-aminopyrimidin-2(1H)-one (8.333 g, 75 mmol) was dissolved in DMF (50 mL) under argon protection. The reaction vessel was covered with aluminum foil and sonicated for 30 min to fully dissolve the solids at the bottom. Subsequently, the reaction mixture was stirred at room temperature for 12 hours. Upon completion of the reaction, the mixture was poured into water (150 mL) to quench the reaction. The resulting precipitate was collected by filtration, washed with water and dried in the presence of phosphorus pentoxide (P2O5) to afford 4-amino-5-iodopyrimidin-2(1H)-one as a light tan solid (17.703 g, 99% yield). The product could be used in the subsequent reaction without further purification.