Synthesis
General procedure for the synthesis of 5-iodo-6-methylpyrimidin-4(1H)-one using 6-methylpyrimidin-4(3H)-one as starting material: 127 g (0.56 mol) of N-iodosuccinimide (NIS) was added in batches to an acetic acid solution containing 70 g (0.64 mol) of 6-methylpyrimidin-4(3H)-one at room temperature, and the addition process lasted 15 minutes. The reaction mixture was stirred at room temperature until thin layer chromatography (TLC) monitoring showed complete consumption of the feedstock (about 30 hours). Upon completion of the reaction, the mixture was diluted with water and the precipitated solid product was collected by filtration. Subsequently, the solid was washed with aqueous sodium thiosulfate to remove residual iodine. Finally, the product was dried under vacuum to give 90 g of the target compound in 60% yield.
References
[1] Bioorganic and Medicinal Chemistry Letters, 2011, vol. 21, # 6, p. 1601 - 1606
[2] Synthesis, 1984, # 3, p. 252 - 254
[3] Patent: WO2012/101184, 2012, A1. Location in patent: Page/Page column 50
[4] Patent: WO2012/101186, 2012, A1. Location in patent: Page/Page column 47
[5] Patent: EP2546249, 2013, A1. Location in patent: Paragraph 0177; 0178
