Reactions of 3-nitro-1,2,4-triazole derivatives with alkylating agents. 8*. Alkylation of 3-nitro-5-R-1,2,4-triazoles with derivatives of diethylene glycol in the presence of alkali

The interaction of 3-nitro-1,2,4-triazole and 5-methyl-3-nitro-1,2,4-triazole with bifunctional agents ‒ β,β′-dichloro- and β,β′-(dinitroxy)diethyl ethers ‒ in the presence of alkali proceeds with the formation of a mixture of products substituted at the N(1) and N(2) atoms of the heterocycle, consisting of three reaction products, the N(1),N′(1)-, N(1),N′(2)-, and N(2),N′(2) isomeric derivatives of nitrotriazoles. Replacement of the Cl leaving group in the alkylating agent by a NO₂ group does not lead to a substantial change in the degree of conversion and overall yield of alkylation products. The ratio of N(1),N′(1):N(1),N′(2):N(2),N′(2) isomeric reaction products from 3-nitro-1,2,4-triazole was (82.0-85.7): (7.7-9.9):(6.6-8.1), and from 5-methyl-3-nitro-1,2,4-triazole was (76.9-79.8):(10.1:11.4):(10.1-11.7) respectively.     

Theoretical studies on a series of 1,2,3-triazoles derivatives as potential high energy density compounds

Based on the full-optimized molecular geometric structures at B3LYP/6-31G* and B3P86/6-31G* levels, the densities (ρ), detonation velocities (D), and pressures (P) for a series of 1,2,3-triazole derivatives, as well as their thermal stabilities, were investigated to look for high energy density compounds (HEDCs). The heats of formation (HOFs) are also calculated via designed isodesmic reactions. The calculations on the bond dissociation energies (BDEs) indicate that the BDEs of the initial scission step are between 53 and 70 kcal/mol, and 4-nitro-1,2,3-triazole is the most reactive compound, while 1-(2′,4′-dinitrophenyl)-5-nitro-1,2,3-triazole is the least reactive compound for 1,2,3-triazole derivatives studied. The condensed phase heats of formation are also calculated for the title compounds. These results would provide basic information for the further studies of HEDCs. The detonation data of 1-(3′,4′-dinitrophenyl)-4-nitro-1,2,3-triazole and 1-(2′,4′-dinitrophenyl)-4-nitro-1,2,3-triazole show that they meet the requirement for HEDCs.     

Reactions of 1,2,4-triazole derivatives with a “model” thiirane

Reactions of 3-mono- and 3,5-disubstituted 1,2,4-triazoles with a “model” thiirane, 8-bromo-1,3-dimethyl-7-(thiiran-2-ylmethyl)-3,7-dihydro-1H-purine-2,6-diones proceed at the positions N¹ and N² of the triazole ring and yield 7-(5-R-3-R′-1,2,4-triazol-1-yl)methyl- and/or 7-(5-R′-3-R-1,2,4-triazol-1-yl)methyl-1,3-dimethyl-6,7-dihydro[1,3]thiazolo[2,3-f]-purine-2,4-(1H,3H)-diones. 3-Methylsulfonyl-1,2,4-triazole reacted regiospecifically at the position N¹ forming 1,3-dimethyl-7-[(3-methyl-sulfonyl-1,2,4-triazole-1-yl)-methyl]-6,7-dihydro[1,3]thiazolo-[2,3-f]purine-2,4(1H,3H)-dione.     

Thermal decomposition mechanisms of nitro-1,2,4-triazoles: A theoretical study

Possible decomposition mechanisms of C-nitro-and N-nitro-1,2,4-triazoles were simulated. We showed that in addition to the experimentally detected thermolysis products including N₂, N₂O, NO, CO₂, HCN, HNCO, 1,2,4-triazole, 3(5)-nitroso-1,2,4-triazole, and 1,2,4-triazolone, some other decompositon products (H₂O, CO, NO₂, cyanamide, cyanuric acid, and melamine) can be formed. Using the density functional approach (B3LYP/6-31G* approximation), we assessed the most favorable thermal decomposition pathways of nitrotriazoles and studied the relationships between the thermolysis pathways of these substances and their molecular and electronic structures. We found a correlation between the energy gap width (energy difference between the frontier molecular orbitals) and the stabilities of the C-nitro-1,2,4-triazole tautomers to thermal decomposition. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1338–1358, August, 2006.     

Synthesis and structure of new ditopic ligands containing tetrazole and 3-nitro-1,2,4-triazole fragments

Alkylation of 3-nitro-1,2,4-triazole with haloalkyltetrazoles has afforded in high yields previously unknown 1-[2-(3-nitro-1H-1,2,4-triazol-1-yl)ethyl]-1H-tetrazole and 2-tert-butyl-5-(3-nitro-1H-1,2,4-triazol-1-ylmethyl)-2H-tetrazole. The molecular and crystal structure of these compounds has been established by X-ray diffraction analysis (XRD).     

Nitraminomethylation of silylated polynitrogen heterocyclic compounds in nonaqueous solutions

Trimethylsilyloxy derivatives of 1,2,4-triazole, 3(5)-nitro-1,2,4-triazole, and tetrazole are inert toward 2-nitro-1-trimethylsilyloxy-2-azapropane, but they react with 1-chloro-2-nitro-2-azapropane to give the corresponding nitraminomethyl derivatives. Silyiated 1,2,4-triazole undergoes bis-nitraminomethylation to give a triazolium salt.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1666–1668, September, 1993.     

Reaction Of 3-Nitro-1,2,4-triazolederivatives with Alkylating Agents. 1. Alkylation in the Presence of Alkali

Alkylation of 3-nitro-1,2,4-triazole and 5-methyl-3-nitro-1,2,4-triazole with dialkyl sulfates or alkyl halides in the presence of alkali proceeds with a low selectivity for the alkylating agent with the formation of two regioisomers at the N₍₁₎ and N₍₂₎ atoms of the heterocycle. Depending on the reaction conditions the proportion of the N₍₂₎ isomer was 14.6-33.8%. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 1020–1025, July, 2005.     

2-Nitroguanidine Derivatives: IX. Reaction of 1-Amino-2-nitroguanidine with Oxalic Acid as a Method of Synthesis of 3(5)-Nitroamino-1,2,4-triazole-5(3)-carboxylic Acid and 5,5′-Bi(3-nitroamino-1,2,4-triazole) Salts

A new procedure for the synthesis of 5(3)-nitroamino-1,2,4-triazole-3(5)-carboxylic acid and 5,5′ -bi(3-nitroamino-1,2,4-triazole) potassium salt has been developed. It includes cyclization of [2-(N²-nitro-carbamimidoyl) hydrazino]oxoacetic acid and 2,2′-bis(N ²-itrocarbamimidoyl)oxalohydrazide, respectively, which are prepared by reaction of 1-amino-2-nitroguanidine with oxalic acid. The reaction of 5(3)-nitroamino-1,2,4-triazole-3(5)-carbohydrazide with 1-methyl-2-nitro-1-nitrosoguanidine leads to N′ -(N ²-nitrocarbamimidoyl)-5(3)-nitroamino-1,2,4-triazole-3(5)-carbohydrazide whose intramolecular cyclization in the presence of bases may be regarded as a new method of synthesis of 5,5′-bi(3-nitroamino-1,2,4-triazole) salts.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 3, 2005, pp. 447–450.Original Russian Text Copyright © 2005 by Metelkina, Novikova, Berdonosova, Berdonosov.For communication VIII, see [1].     

Reactions of 3-nitro-1,2,4-triazoles with alkylating agents. 6*. Alkylation of a neutral heterocycle by alcohols in acid media*

Reaction of 3-nitro-1,2,4-triazole and 5-methyl-3-nitro-1,2,4-triazole with secondary and tertiary alcohols in conc. H₂SO₄ takes place at the N(2) atom. Alkylation by 2-propanol occurs regioselectively to form the 1-isopropyl-3-nitro-and 1-isopropyl-3-methyl-5-nitro-1,2,4-triazoles. As a consequence of isomerization the alkylation using cyclohexyl or tert-butyl alcohols gives respectively a mixture of regioisomers substituted at atom N(1) (1-cyclohexyl-3-nitro-and 1-cyclohexyl-5-methyl-3-nitro-1,2,4-triazoles) and at atom N(2) (5-nitro-1-cyclohexyl-and 1-cyclohexyl-3-methyl-5-nitro-1,2,4-triazoles) and, in the second case, to 1-tert-butyl-3-nitro-1,2,4-triazole. * For Communication 5 see [1]. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1680–1687, November, 2008.     

Reaction of thiosemicarbazide with n-cyanoguanidine: synthesis of 3,5-diamino-1-thiocarbamoyl-and 3,5-diamino-1-thiazol-2-yl-1,2,4-triazoles

The reaction of thiosemicarbazide with N-cyanoguanidine in an acidic medium afforded 3,5-diamino-1-thiocarbamoyl-1,2,4-triazole, whose condensation with α-halo ketones gave 3,5-diamino-1-thiazol-2-yl-1,2,4-triazoles 7a–d. The latter were also prepared by the independent synthesis from 2-hydrazinothiazoles and N-cyanoguanidine. Acylation of compounds 7a,d under mild conditions and their condensation with aldehydes occur at the C(3′)NH₂group. The structure of aroyl derivative 11c was established by X-ray diffraction. Acylation of diaminothiazolyltriazole 7a in boiling Ac₂O afforded 3,5-diacetylamino-1-(4-phenylthiazol-2-yl)-1,2,4-triazole. Hydrogenation of arylidene derivatives 14b,c and aroyl derivative 11c gave the corresponding benzylaminotriazoles 15a,b. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 329–334, February, 2006.     

Heterocyclic nitro compounds. 26. Reaction of 1-substituted 3,5-dinitro-1,2,4-triazoles with anions of heterocyclic NH acids

1-Substituted 3-nitro-5-(N-azolyl)-1,2,4-triazoles mixed with 1-substituted 3-nitro-1,2,4-triazol-5-ones are obtained in the reaction of 1-substituted 3,5-dinitro-1,2,4-triazoles with anions of heterocyclic NH acids (1,2,4-triazole, 1,2,3-triazole, pyrazole, benzotriazole, benzimidazole, and indazole derivatives). 1-Methyl-3-nitro-5-amino-1,2,4-triazole is formed instead of the expected 5-tetrazolyl derivative in the reaction of 1-methyl-3,5-dinitro-1,2,4-triazole with tetrazole in alkaline media. See [1] for communication 25. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 257–261, February, 1980.     

Synthesis of certain 1,2,4-triazole nucleoside derivatives

The syntheses of 3-amino-4-methyl-1-(β-D-ribofuranosyl)-1,2,4-triazolin-5-one ( 8a ) and its 2′-deoxy analog 8b as well as 5-amino-2-methyl-1-(β-D-ribofuranosyl)-1,2,4-triazolin-3-one ( 12 ) have been accomplished. Compounds 8a and 8b were synthesized via glycosylation of 3-bromo-5-nitro-1,2,4-triazole which was followed by replacement in three steps of the 3-bromo function to yield 3-nitro-1-(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)-1,2,4-triazolin-5-one ( 4a ) and its 2′-deoxy analog 4b . Compounds 4a and 4b were methylated at N², hydrogenated and deblocked to give 3-amino-4-methyl-1-(β-D-ribofuranosyl)-1,2,4-triazolin-5-one ( 8a ) and the 2′-deoxy analog 8b . Compound 12 was synthesized by glycosylation of 3-amino-1-methyl-1,2,4-triazolin-5(2H)-one ( 10 ). The structures of 8b and 12 were confirmed by single crystal X-ray diffraction analysis.     

Determination of the products of the transformation of unsymmetrical dimethylhydrazine in soils using chromatography/mass spectrometry

An approach is proposed for the simultaneous determination of formic acid N,N-dimethylhydrazide and 1-methyl-1-H-1,2,4-triazole (ecotoxicants formed upon the oxidative transformation of unsymmetrical dimethylhydrazine) in soils in the concentration range 0.05–50 mg/kg using gas chromatography/mass spectrometry. The conditions for the quantitative extraction of the components by continuous periodic extraction with methanol have been found. The adsorption of formic acid N,N-dimethylhydrazide and 1-methyl-1-H-1,2,4-triazole from solutions by soils of different types has been studied and a method has been proposed for preparing uniform model soil samples with the required contaminant concentrations.     

Synthesis and characterization of mono- and bicyclic heterocyclic derivatives containing 1,2,4-triazole, 1,3,4-thia-, and -oxadiazole rings

A series of new N- and S-substituted 1,3,4-oxadiazole derivatives were synthesized. 5-Pyridin-3-yl-3-[2-(5-thioxo-4,5-dihydro-l,3,4-thiadiazol-2-yl)ethyl]-1,3,4-oxadiazole-2(3H)-thione and 5-[(5-(pyridin-3-yl)-1,3,4-oxadiazol-2-ylthio)methyl]-N-phenyl-1,3,4-thiadiazol-2-amine were formed by cyclization of 3-(5-pyridin-3-yl-2-thioxo-1,3,4-oxadiazol-3(2H)-ylpropanimidohydrazide and 2-[(5-pyridin-3-yl-1,3,4-oxadiazol-2-yl)thio]thiosemicarbazide with CS₂ and H₂SO₄. On the other hand, a number of new bicyclic 1,2,4-triazolo[3,4-b][1,3,4]thiadiazole derivatives were synthesized. 6-Pyridin-3-ylbis[1,2,4]‐triazolo[3,4-b:4′,3′-d][1,3,4]thiadiazole-3(2H)-thione was synthesized by reaction of 6-(hydrazino)-3-pyridine-3-yl[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole with CS₂/KOH/EtOH. The structures of the newly synthesized compounds were elucidated by the spectral and analytical data IR, Mass, and ¹H NMR spectra. Correspondence: Adel A.-H. Abdel-Rahman, Department of Chemistry, Faculty of Science, Menoufia University, Shebin El-Koam, Egypt; Wael A. El-Sayed, National Research Centre, Department of Photochemistry, Cairo, Egypt.     

Spectroscopic identification of some derivatives of 3,4-diamino-4H-1,2,4-triazole and 3-Hydrazino-4H-1,2,4-triazole

Spectroscopic methods (ir, ¹H- and ¹³C-nmr, ms and uv) have been used for the structural elucidation and identification of different isomeric 1,2,4-triazole derivatives, obtained by cyclisation reactions from appropriate diaminoguanidines. The four compounds 3,4-diamino-4H-1,2,4-triazole, 3-hydrazino-4H-1,2,4-triazole, 3-amino-4-(2,6-dichlorobenzylideneamino)-4H-1,2,4-triazole and 3-(2,6-dichlorobenzylidenehydrazino)-4H-1,2,4-triazole, were chosen as representative structures to illustrate the general spectroscopic properties for 3,4-diamino- and 3-hydrazino-substituted 4H-1,2,4-triazoles and the corresponding hydrazones, with different substituents in the 5-position of the triazole ring (alkyl-, aralkyl-, mercapto-, hydroxy- and amino-groups). Nmr and uv spectroscopy were found to be the best methods for confirmation of the different series of hydrazones, while ir and nmr were found to be suitable for the structural elucidation of compounds in the series of 3,4-diamino- and 3-hydrazino-4H-1,2,4-triazoles, respectively.     

Synthesis of azoles from 3,3′-[(4-alkoxyphenyl)imino]bis(propanoic acid hydrazides)

Abstract  

Reaction of 3,3′-[(4-alkoxyphenyl)imino]bis(propanoic acid hydrazides) with CS₂ in alkaline solution and subsequent acidification gave 5,5′-[[(4-alkoxyphenyl)imino]diethane-2,1-diyl]bis(1,3,4-oxadiazole-2(3H)-thiones). The same dihydrazides on reaction with phenyl isocyanates or phenyl isothiocyanates were converted to bis[N′-(phenylaminocarbonyl)propanoic acid hydrazides] and bis[N′-(phenylaminocarbonothioyl)propanoic acid hydrazides], which underwent cyclization in alkaline medium to produce 5,5′-[[(4-alkoxyphenyl)imino]diethane-2,1-diyl]bis(4-phenyl-2,4-dihydro-3H-1,2,4-triazol-3-ones) and their 3-thio analogues, whereas in sulfuric acid or POCl₃ 5,5′-[[(4-alkoxyphenyl)imino]diethane-2,1-diyl]bis(N-phenyl-1,3,4-oxadiazol-2-amines) and 5,5′-[[(4-alkoxyphenyl)imino]diethane-2,1-diyl]bis(N-phenyl-1,3,4-thiadiazol-2-amines) were obtained.     

Heterocyclic nitro compounds

Ketones of the 3-nitro-5-R-1,2,4-triazole series react with hydrazoic acid in concentrated sulfuric acid to give triazolyl-substituted acetamides. Acid hydrolysis of the latter leads to 1-aminoalkyl-3-nitro-5-R-1,2,4-triazoles. Intramolecular cyclization with the elimination of HNO₂ and the formation of 2-nitro-5,6-dihydro-1H-imidazo[2,3-b]-1,2,4-triazole was noted in the case of 1-(2-aminoethyl)-3,5-dinitro-1,2,4-triazole.See [1] for communication XX.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1271–1273, September, 1977.     

Adamantylation of 3-Nitro- and 3-Ethoxycarbonyl-1,2,4-triazolo[5,1-c]-1,2,4-triazin-4-ones

Reaction of 3-nitro- and 3-ethoxycarbonyl-1,2,4-triazolo[5,1-c]-1,2,4-triazin-4-ones with 1-adamantanol (or 1-adamantyl nitrate) in concentrated sulfuric acid or with 1-bromoadamantane in sulfolane affords N-adamantyl derivatives. The adamantylation of 3-nitro-1,4-dihydro-7H-1,2,4-triazolo[5,1-c]-1,2,4-triazin-4-one yields a mixture of N⁸- and N¹-isomers that undergo interconversion in concentrated sulfuric acid along intermolecular mechanism.     

The synthesis of azole derivatives from 3-[(4-methylphenyl)amino]propanehydrazide and its N′-phenylcarbamoyl derivatives, and their antibacterial activity

Abstract  

5-[2-[(4-Methylphenyl)amino]ethyl]-1,3,4-oxadiazol-2(3H)-thione, 5-[2-[(4-methylphenyl)amino]ethyl]-1,3,4-oxadiazol-2(3H)-one, N-(2,5-dimethyl-1H-pyrrol-1-yl)-3-[(4-methylphenyl)amino]propanamide, and a series of N-[(phenylcarbamoyl)amino]-3-[(4-methylphenyl)amino]propanamides and 3-[(4-methylphenyl)(phenylcarbamoyl)amino]-N-[(phenylcarbamoyl)amino]propanamides, and their thio analogues were synthesized from 3-[(4-methylphenyl)amino]propanehydrazide. 1,3,4-Oxadiazole-2(3H)-thione was converted to 4-amino-2,4-dihydro-5-[2-[(4-methylphenyl)amino]ethyl]-3H-1,2,4-triazole-3-thione, whereas cyclization of N′-phenylcarbamoyl derivatives provided thiazole, oxadiazoles, and thiadiazole, as well as triazole derivatives. Two of the synthesized compounds exhibited good antibacterial activity against Rhizobium radiobacter.     

Poly(<Emphasis Type="Italic">N</Emphasis>-vinylimidazole) as an efficient and recyclable catalyst of the aza-Michael reaction in water

Poly(N-vinylimidazole) effectively catalyzed Michael addition of 1H-1,2,4-triazole, 3,5-dimethyl-1H-1,2,4-triazole, uracil, oxazolidin-2-one, and succinimide to but-3-en-2-one, cyclohex-2-en-1-one, methyl acrylate, and methyl vinyl sulfone in water at room temperature. The catalyst can readily be regenerated and repeatedly used at least five times without loss in activity, as shown in the reaction of 1H-1,2,4-triazole with but-3-en-2-one as an example.