Synthesis and Intramolecular Heterocyclization of Selected Isonicotinic Acid Thiocarbazides

Synthesis and Structure of Diethyl-2,6-Dimethyl-Pyridin-3,5-Dicarboxylate

“…In the 13 The structure of compound 1 was also confirmed by the methods of two-dimensional NMR spectroscopy COSY ( 1 H-1 H) and HMQC ( 1 H-13 C), which allows one to establish spin-spin interactions of a homo-and heteronuclear nature (Figs. 1 and 2).…”

“…The reaction time was monitored by TLC. As a result of the reaction, after 1 h of boiling the mixture, a light yellow precipitate formed, which after filtration did not require additional purification, since According to the 1 H and 13 C NMR spectra, it turned out to be analytically pure product In the 1 H NMR spectrum of compound 1, the equivalent methyl protons H-15, 15, 15, 18, 18, 18 of the ethyl carboxylate groups appeared as a six-proton triplet at 1.14 ppm with 3 J 7.2 Hz. The neighboring equivalent methylene protons H-14, 14, 17, 17 of the ethyl carboxylate substituent resonated with a fourproton quadruplet signal at 4.01 ppm, respectively with 3 J 6.8 Hz.…”

“…In the spectra of 1 H-1 H COSY compounds, spin-spin correlations are observed through three bonds of the neighboring methyl and methylene protons of the ethyl carboxylate fragments H 15,18 -H 14,17 with coordinates at 1.11, 4.01 and 4.00, 1.14 ppm. Heteronuclear interactions of protons with carbon atoms through one bond were established using 1 H- 13 C HMQC spectroscopy for all pairs present in the compound: H 15,18 -C 15,18 (1.14, 14.92), H 7,12 -C 7,12 (2.06, 18.47) , H 4 -C 4 (3.06, 25.24) and H 14,17 -C 14,17 In the 1 H NMR spectrum of compound 2, the equivalent methyl protons H-15, 15, 15, 18, 18, 18, 18 of the ethyl carboxylate groups showed a six-proton triplet at 1.28 ppm with 3 J 6.8 Hz (Fig. 3).…”

“…It is known that the derivatives of the Ganch reaction -1,4-dihydropyridines, are of great interest not only in terms of their possible preparative modification and possessing a wide range of pharmacological activity, but also the constant detection and identification of derivatives of new forms of biological activity among this class of derivatives [1][2][3][4][5][6][7][8][9][10][11][12]. The chemical oxidation reaction of 1,4-dihydropyridines has been well studied; a number of both organic and inorganic reagents are used as oxidizing agents [13][14][15][16][17][18][19].…”

“…Methods 1 H and 13 C NMR spectra of compounds 1, 2 were recorded in DMSO-d 6 on a JNM-ECA 400 spectrometer (399.78 and 100.53 MHz on 1 H and 13 C nuclei, respectively) of the Jeol company from Japan. The survey was carried out at room temperature using a DMSO-d 6 solvent.…”