A solution of pyrimidin-4-amine (0.944 g, 9.93 mmol) in 10 mL DMF was treated with SEM-Cl (1.761 ml, 9.93 mmol) and was allowed to stir at room temperature 30 minutes. Perfluorophenyl 5-bromonaphthalene-2-sulfonate (INTERMEDIATE M; 4.50 g, 9.93 mmol) was added and the reaction mixture was treated with lithium tert-butoxide 1N in THF (19.86 ml, 19.86 mmol) drop wise. After stirring for one hour, the reaction mixture was concentrated. The crude residue was diluted with DCM, washed with water, the organics dried over MgSO4 and concentrated. The material (INTERMEDIATE CCC) was carried forward crude without further purification.
