Synthesis of 2-(1,3-Diphenyl-1 H -1,2,4-triazol-5-yl)-2,2-dinitroacetonitrile and Its Reaction with Diazomethane
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hesis of 2-(1,3-Diphenyl-1H-1,2,4-triazol-5-yl)-2,2dinitroacetonitrile and Its Reaction with Diazomethane A. G. Tyrkova,* and E. A. Yurtaevab a
b
Astrakhan State University, Astrakhan, 414000 Russia Vologograd State Medical University, Branch of Pyatigorsk Medical and Pharmaceutical Institute, Pyatigorsk, 357532 Russia *e-mail: [email protected] Received March 26, 2020; revised May 14, 2020; accepted May 15, 2020
Abstract—A method for the synthesis of 2-(1,3-diphenyl-1H-1,2,4-triazol-5-yl)-2,2-dinitroacetonitrile was developed, and its reaction with diazomethane was investigated to show the reaction involves 1,3-dipolar cycloaddition and forms a separable mixture of 4-[(1,3-diphenyl-1H-1,2,4-triazol-5-yl)dinitromethyl]-2H-1,2,3-triazoles. The latter react with KOH in ethanol to form potassium salts of 4-[(1,3-diphenyl-1H-1,2,4-triazole-5-yl)aci-nitromethyl]1,2,3-triazoles. Keywords: 2-(1,3-diphenyl-1H-1,2,4-triazole-5-yl)-2,2-dinitroacetonitrile, cyanogen bromide, diazomethane, 1,3-dipolar cycloaddition, 4-[(1,3-diphenyl-1H-1,2,4-triazole-5-yl)dinitromethyl]-2H-1,2,3-triazoles, potassium salts of 4-[(1,3-diphenyl-1H-1,2,4-triazole-5-yl)aci-nitromethyl]-1,2,3-triazoles
DOI: 10.1134/S1070428020080114 The chemical transformations of hetaryl derivatives of dinitroacetonitrile have been insufficiently studied. It is only known that 2,2-dinitro-2-(3-phenyl-1,2,4-oxadiazol-5-yl)acetonitrile and 2,2-dinitro-2-(2-methyl-2Htetrazol-5-yl)acetonitrile react with diazomethane by way of 1,3-dipolar cycloaddition to give dinitro[3-phenyl1,2,4-oxadiazol-5-yl)-1,2,3-triazol-4-yl]methanes and 5-[dinitro(1,2,3-triazol-4-yl)methyl]-2-methyltetrazoles, respectively [1, 2]. To assess the degree of generality of the previously accomplished reaction resulting in the synthesis of hetaryl derivatives of dinitroacetonitrile, for example, 2,2-dinitro-2-(3-phenyl-1,2,4-oxadiazol-5-yl)acetonitrile and 2,2-dinitro-2-(2-methyl-2H-tetrazol-5-yl)acetonitrile, we made an attempt to extend this reaction to a new dinitroacetonitrile compound, specifically 2-(1,3-diphenyl-1H1,2,4-triazol-5-yl)-2,2-dinitroacetonitrile 3. Compound 3 was synthesized via introducing a cyano group into the dinitromethyl fragment of the silver salt of 5-dinitromethyl-1,3-diphenyl-1H-1,2,4-triazole (2), obtained from the potassium salt of azole 1 (Scheme 1). The structure of silver salt 2 was established by IR and 13C NMR spectroscopy and its composition, by elemental
analysis. The IR spectrum displays a group of absorption bands at 1540, 1490, 1462, 1370, 1260, and 1143 cm–1, the complicated pattern of which may be associated, in agreement with [3], with the C(NO2)2– fragment. This is also consistent with the close chemical shifts of the signal of the central carbon atom in the 13C NMR spectrum of salt 2 in water (δC 136.1 ppm) and the signal of the carbon atom of the gem-dinitromethyl group of the silver salt of 5-(dinitromethyl)-2-methyl-2H -tetrazole (δ 136.2 ppm) [4]. Treatment of salt 2 with excess cyanogen bromide at 40°C for 20 h leads to C-alkylation to form dinit
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