Ra. Mekheimer et al., A convenient one pot synthesis of pyrido[2,3-d]-pyrimidines and pyrimido[2,3-c]pyrimidines (N-5-deazapetrins), HETEROCYC C, 6(4), 2000, pp. 301-307
A convenient one pot synthesis of pyrido[2,3-d]pyrimidines and pyrimido[2,3
-c]pyrimidines via reaction of 6-amino-2-oxo-4-thioxotetrahydropyrimidine
1 with cinnamonitrile derivatives 2 has been reported.