Ag-Assisted Fluorination of Unprotected 4,6-Disubstituted 2-Aminopyrimidines with Selectfluor

A direct fluorination of 4,6-disubstituted 2-aminopyrimidines with Selectfluor in the presence of Ag(I) is presented, affording the corresponding 4,6-disubstituted 5-fluoro-2-aminopyrimidines with acceptable to high yield. Ag(I) is crucial for this chemoselective fluorination process. The transformation of 4,6-diphenyl 5-fluoro-2-aminopyrimidine into N-(5-fluoro-4,6-diphenylpyrimidin-2-yl)-4-methylbenzenesulfonamide is discussed, and the reaction mechanism is investigated, as well.