Multicomponent synthesis of unsymmetrical derivatives of 4-methyl-substituted 5-nitropyridines D. M. Turgunalieva, A. L. Stalinskaya, I. I. Kulakov [et al.]
Material type: ArticleContent type: Текст Media type: электронный Subject(s): 2-нитроацетофенон | нитроацетон | ацетальдегид диэтилацеталь | 5(3)-нитро-1,4-дигидропиридины | 5(3)-нитропиридины | зеленая химия | многокомпонентные реакции | β-дикарбонильные соединенияGenre/Form: статьи в журналах Online resources: Click here to access online In: Processes Vol. 11, № 2. P. 576 (1-12)Abstract: The multicomponent reaction of 2-nitroacetophenone (or nitroacetone), acetaldehyde diethyl acetal, β-dicarbonyl compound, and ammonium acetate in an acetic acid solution allowed the acquisition of previously undescribed 4-methyl-substituted derivatives of 5-nitro-1,4-dihydropyridine in satisfactory yields. The oxidation of the obtained 5-nitro-1,4-dihydropyridine derivatives resulted in the corresponding 2,4-dimethyl-5-nitropyridines. In addition, for the first time in the synthesis of unsymmetrical 1,4-dihydropyridines by the Hantzsch reaction acetaldehyde, diethyl acetal was used as a source of acetaldehyde. The use of more volatile and sufficiently reactive acetaldehyde in this reaction did not lead to a controlled synthesis of unsymmetrical 5-nitro-1,4-dihydropyridines. The proposed multicomponent approach to the synthesis of 4-methyl-substituted 5-nitro-1,4-dihydropyridines and their subsequent aromatization into pyridines made it possible to obtain previously undescribed and hardly accessible substituted 5(3)-nitropyridines.Библиогр.: 76 назв.
The multicomponent reaction of 2-nitroacetophenone (or nitroacetone), acetaldehyde diethyl acetal, β-dicarbonyl compound, and ammonium acetate in an acetic acid solution allowed the acquisition of previously undescribed 4-methyl-substituted derivatives of 5-nitro-1,4-dihydropyridine in satisfactory yields. The oxidation of the obtained 5-nitro-1,4-dihydropyridine derivatives resulted in the corresponding 2,4-dimethyl-5-nitropyridines. In addition, for the first time in the synthesis of unsymmetrical 1,4-dihydropyridines by the Hantzsch reaction acetaldehyde, diethyl acetal was used as a source of acetaldehyde. The use of more volatile and sufficiently reactive acetaldehyde in this reaction did not lead to a controlled synthesis of unsymmetrical 5-nitro-1,4-dihydropyridines. The proposed multicomponent approach to the synthesis of 4-methyl-substituted 5-nitro-1,4-dihydropyridines and their subsequent aromatization into pyridines made it possible to obtain previously undescribed and hardly accessible substituted 5(3)-nitropyridines.
There are no comments on this title.