Organolithium addition to 5,6-disubstituted pyrimidines

The addition of organolithium reagents to the azomethine bond of 5,6-disubstituted pyrimidines provided, in every case, a single adduct. When reacted with either ethyl chloro-formate or hydrogen chloride, these adducts gave a single dihydro pyrimidine. The resulting N-H dihydro pyrimidines were oxidized with potassium permanganate to the corresponding pyrimidines.