The ring transformation of nitropyrimidinone 1 with acetophenone derivatives 2 affords two kinds of azaheterocyclic compounds, 4-phenylpyrimidines 3 and 3-nitro-6-phenyl-2-pyridones 4. On the basis of the relationship between electronic properties of the substituent and ratios of products, a plausible reaction mechanism is provided. Furthermore, the present reaction could be applied to heterocyclic ketones giving bihetaryl compounds.
Mechanistic aspect of ring transformations in the reaction of 5-nitro-4-pyrimidinone with acetophenone derivatives and cycloalkanones depending on the electron density/ring size of the ketone
idinone undergoes two kinds of nucleophilic type ring transformations upon treatment with cycloalkanones in the presence of ammonium acetate, which affords 4,5-disubstituted pyrimidines and 5,6-disubstituted 3-nitro-2-pyridones. In order to improve the synthetic utility of this reaction, it is necessary to control the regioselectivity of these ring transformations. In the present work, we performed