Cyclocondensation of sodium nitromalone dialdehyde with different enamines gave 3-acetyl (benzoyl, cyano, cyclopropanoyl, carbethoxy)-2-methyl(phenyl)-5-nitropyridines. With the aim of increasing the yield of pyridines we have activated the nitromalonic dialdehyde through acylation of its enol form.Aliphatic nitro compounds are widely used in the synthesis of nitropyridines unavailable by direct nitration of pyridines and by other known methods [2][3][4][5]. Nitromalone dialdehyde is one of the most available of the nitro ketones used but examples of nitropyridines obtained in this way are few [6][7][8][9][10].The aim of this work was to synthesize 5-nitropyridines by cyclocondensation of nitromalone dialdehyde with different enamines.Analysis of the experimental work has shown that an activated form of the nitromalone dialdehyde is most efficiently used in the cyclocondensation. With this in view, tosylation and acetylation of its enol form have been carried out [9,10]. We have checked both variants of the acylation of nitromalone dialdehyde in the synthesis of nitropyridines experimentally and found that use of acetic anhydride for elimination of a molecule of water from the sodium malone dialdehyde monohydrate salt with simultaneous acetylation is more H O CHO O 2 N Ac 2 O, Py H OAc CHO O 2 N X R N H 2 N X R O 2 N O _ 1a, 2a-d, 3a,b,e,f4a, 5a-d, 6a,b,e,f 1, 4 R = H, 2, 5 R = Me, 3, 6 R = Ph a X = COPh, b X = CN, c X = COMe, d X = , e X = NO 2 , f X = CO 2 Et Na +
