Abstract The reaction of 2-amino-1, 1-dicyanobut-1-ene and 2-amino-1, 1-dicyano-2- phenylethene, respectively, with N, N-dimethylformamide dimethylacetal provided the corresponding (N, N-dimethylaminomethylene) amino derivatives. 2-[(N, N- Dimethylaminomethylene) amino]-1, 1-dicyano-2-phenylethene was converted into 4-amino- 5-cyano-6-phenylpyrimidines by treatment with primary aliphatic and aromatic amines. ...