Two Step Synthesis of Pyridopyrimidines from Acyclic Precursors. Cyclization of 2-Cyanamino-4,6-diphenylpyridine-3-carbonitrile by Hydrogen Halides

Article abstract of DOI:10.1016/0040-4020(95)00585-V

The cyclization of 2-cyanamino-4,6-diphenylpyridine-3-carbonitrile promoted by hydrogen halides takes place regiospecifically leading in all the cases to the 4-amino-2-halogen substituted pyrido<2,3-d>pyrimidine.This procedure completes a flexible and straightforward approach to aromatic pyrido<2,3-d>pyrimidines from acyclic precursors.