Nitropyrimidinone 1 revealed new reactivity upon treatment with active methylene compounds 2 under basic conditions. The N1-C2-C3-C4 moiety of 1 combined with two carbon units of 2 affording polyfunctionalized pyridones 4, which was hitherto unknown ring transformation. On the other hand, the N1-C2 moiety of 1 was transferred to the methylene group of 2 giving functionalized enamines 3. It was also
3-Methyl-5-nitropyrimidin-4(3H)-one reacted with enaminones to cause the ring transformation leading to functionalized 4-aminopyridines. Various kinds of amino groups can be introduced at the 4-position by modifying the enaminones. The modification of its vicinal positions was also possible. In addition, a bicyclic pyridine could be synthesized by making use of the vicinal functionality of a 4-aminopyridine-3-carboxylic acid.
The title compounds are readily available by ring transformation of nitropyrimidinone with active methylene compounds in the presence of ammonium acetate.
在乙酸铵存在下,通过硝基嘧啶酮与活性亚甲基化合物的环状转化,很容易得到标题化合物。
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.