Interaction of dimethyl-N-pyrimidine-formamidine derivatives 2a,b with the reagents 3 and 7 afforded the corresponding adducts 6a,b and 8. The addition products 10 and 12 produced upon interaction of 2a,b with dimedone and barbutric acids respectively. Treatment of 2a with excess CS2 yielded adduct 13. Interaction of 2b with acrylonitrile and methyl acrylate formed compounds 14 and 16. Heterocycles 21a-c and 22-24 produced via the reaction of 19 with different aromatic amines and amino reagents.