Synthesis of 2-Methyl-3-nitropyridines, 2-Styryl-3-nitropyridines and Their Reactions with S-Nucleophiles

Abstract

One of the most important and flexible tools for nitroarenes functionalization is nucleophilic aromatic substitution (SNAr). This reaction generally requires number of conjugated electron-withdrawing groups and SNAr of non-activated nitro groups is rather uncommon. Most of these examples were obtained on polynitrobenzenes, but little is known about reactions of nonactivated 3-nitropyridines. Here we report synthesis of several 2-methyl-3-nitropyridines and their reactions with various aromatic aldehydes, leading to corresponding 2-styrylpyridines under mild conditions. Both 2-methyl-and 2-styryl-3-nitropyridines readily react with thiolate-anions and give substitution products in good yields. Chemo-and regioselectivity is discussed, some of 2styrylpyridines also showed remarkable fluorescent properties.