Synthesis and X-ray diffraction of derivatives 2,4-dimethyl-6-oxo-1,6-dihydropyridin-3-carboxamide

Abstract

Based on the synthesized starting 2,4-dimethyl-6-oxo-1,6-dihydropyridin-3-carboxamide crystallizing as a dihydrate, 9 derivatives of it including O- and N-phenacyl substituted products were obtained through original rearrangements and cyclizations. The corresponding oxazolopyridinium perchlorate was obtained from the latter preparation in the presence of acid, from which indolysin was obtained under the action of a nitrogenous base. The obtained molecular and crystal structures of all the compounds were studied by single crystal diffraction: 2,4-dimethyl-6-oxo-1,6-dihydropyridine-3-carboxamide dihydrate, 6-hydroxy-2,4-dimethyl-3-carbamoyl-pyridinium chloride monohydrate, 2,4-dimethyl-6-methoxypyridine-3-carboxamide, 1-[2-(4-methylphenyl)-2-oxoethyl]-2,4-dimethyl-6-oxo-1,6-dihydropyridine-3-carboxamide, 2,4-dimethyl-6-oxo-1-[2- (4-[chlorophenyl)-2-oxoethyl]-1,6-dihydropyridine-3-carboxamide, 2,4-dimethyl-6-[2-(4-methylphenyl)-2-oxo-ethoxy]pyridin-3-carbox-amide, 2,4-dimethyl-6-[2-(4-chlorophenyl)-2-oxoethoxy] pyridin-3-carb xamide, 6-carbamoyl-2-(4-chlorophenyl)-5,7-dimethyl[1,3]oxazolo[3,2-a]pyridin-4 perchlorate, 7-methyl-5-morpholin-4 -yl-2-(4-chlorophenyl) indolysin-8-carboxamide. A structural analysis of the by-products of 1,4-bis (4-methylphenyl) butane-1,4-dione and 1,4-bis(4-chlorophenyl) butane-1,4-dione was also carried out. The synthesis methods of each of them are given. A comparative analysis of bond lengths, valence and torsion angles in similar fragments of molecules is carried out. Hydrogen bonds were revealed in the structures and their influence on the strength of molecular packing in crystals was shown. All structures of the studied compounds, in addition to XRD, are characterized by 1H NMR spectra.