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
3-Methyl-5-nitropyrimidin-4(3H)-one reacts with
ketones in the presence of ammonium salts to afford disubstituted
pyrimidines and disubstituted 3-nitro-2-pyridones in a novel ring
transformation reaction; nitropyrimidinone behaves as an activated
diformylamine in the former case, and as a synthetic equivalent of
α-nitroformylacetic acid in the latter case.