Ring Transformations in Reactions of Heterocyclic Compounds with Nucleophiles. 1,3- and 1,4-Cycloadducts as Intermediates in the Pyrimidine to Pyridine Ring Transformation of 5-Nitropyrimidines by α-Phenylacetamidines

Article abstract of DOI:10.1021/jo00164a007

5-Nitropyrimidine reacts with α-phenylacetamidines at -40 deg C to form ? adducts at the C-2 position of the ring but gives 2-aminopyridine derivatives at temperatures above 0 deg C.Experiments with ¹⁵N-labeled α-phenylacetamidine have shown th