1-Methyl-3,5-dinitropyridone serves as an excellent substrate for the nucleophilic-type three-component ring transformation (TCRT). The reaction of dinitropyridone with aromatic ketones in the presence of ammonium acetate afforded 2-arylated 5-nitropyridines. In the TCRTs using cycloalkanones and α,β-unsaturated ketones, nitrated cycloalka[
b]pyridines and alkenyl/alkynylpyridines were obtained, respectively. This protocol was also applicable to reactive aldehydes, which affords 3-substituted 5-nitropyridines. On the other hand, aliphatic ketones having two kinds of α-protons underwent a different type ring transformation leading to 2,6-disubstituted 4-nitroanilines. It was possible to use a combination of amine and acetic acid, by which
N,
N,2,6-tetrasubstituted nitroanilines were synthesized. This TCRT will be an efficient method for the synthesis of compounds possessing both an electron-donating and electron-withdrawing groups, which are useful for developing new functional materials.
View full abstract