Regioselective addtion of 5-amino-3-benzylthio-l,2,4-triazole and its analogues with aryl isocyanates

The orientation of the addition of 5-amino-3-benzylthio-1,2,4-triazole and its analogues (pyrazole) (1) with the aryl isocyanate can be directed by controlling the reaction temperature and one of the product, 5-amino-1-arylaminocarbonyl-3-benzylthio-1,2,4-triazole (pyrazole) (2), can rearrange at 170C to another product, 5-arylureylene-3-benzylthio-1,2,4-triazole (pyrazole) (3). A plausible mechanism explanation for this rearrangement reaction was presented. It was suggested that the rearrangement reaction could be referred to the thermodynamics transposition leading to the predominant 5-arylureylene-3-benzylthio-1,2,4-triazole energy preferentially.     

Methods for controlling the regioselection in the reaction of 3-amino-5-benzylthio-1,2,4-triazole with acetylacetaldehyde dimethyl acetal

The reaction of 3-amino-5-benzylthio-1,2,4-triazole with acetylacetaldehyde dimethyl acetal affords 2-benzylthio-5-methyl-1,2,4-triazolo[1,5a]pyrimidine or 2-benzylthio-7-methyl-1,2,4-triazolo[1,5a]pyrimidine regioselectively depending on the reaction conditions.     

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.     

含磷稠杂环的合成及其生物活性(Ⅴ)

研究了氯代膦酰基异氰酸酯与5-氨基-3-苄硫基-1,2,4-三唑及其类似物的成环反应,合成了12个7-芳基(烷氧基)-2苄硫基-5,7-二氧代-4,5,6,7-四氢-7-磷杂-1,2,4-三唑[1,5a]三嗪,利用¹HNMR、³¹PNMR确定其Z型,生物活性测定结果表明,部分化合物具有一定的除草活性。     

Regioselection in the reaction of 3-amino-5-benzylthio-1,2,4-triazole with unsymmetrical 1,3-diketones

The results of a study of the regioselection in the reaction of 3-amino-5-benzylthio-1,2,4-triazole with several unsymmetrical 1,3-diketones are reported. The 1,3-diketones studied are 1,1,1-trifluoro-2,4-pentanedione, benzoylacetone and 2-acetylcyclopentanone. Chemical, spectroscopic and X-ray crystallographic data are presented to support structural assignments of the major reaction products.     

Syntheses of some new 4-amino-5-(N-methyl-arylsulfonamido)methyl-1,2,4-triazole-3-thiones and their derivatives

The cyclization of 4-amino-5-(N-methyl-arylsulfonamido)methyl-1,2,4-triazole-3-thiones II , synthesized by the Reid and Heindel approach, with α-chloroacetophenone yields 7II-6-aryl-3-(N-methyl-arylsulfon-amido)methyl-s-triazolo[3,4-b][1,3,4]-thiazines III . Novel compounds II also react with benzyl chloride to afford 4-amino-3-benzylthio-5-(N-methyl-arylsulfonamido)methyl-1,2,4-triazole IV . © 1996 John Wiley & Sons, Inc.     

Die Acylierung von 5-Amino-1 H-1, 2, 4-triazolen. Eine 13C-NMR.-Studie

The Acylation of 5-Amino-1 H-1,2,4-triazoles. A ¹³C-NMR. Study The acylation of 3-substituted-5-amino-1 H-1,2,4-triazoles (1) with methyl chloroformate or dimethylcarbamoyl chloride yielded mainly 1-acyl-5-amino-1,2,4-triazoles ( 2 and 3 ). Acylation of 3-methyl-, 3-methoxy- and 3-methylthio-5-amino-1 H-1,2,4-triazole ( 1b , 1c and 1d ) with methyl chloroformate gave up to 10% of the 1-acyl-3-amino-1,2,4-triazoles. For the unsubstituted 5-amino-1,2,4-triazole (1a) , a (1:1)-mixture of the 3- and 5-isomers 2a and 4 was obtained in dioxane in the presence of triethylamine. No 4-acylated product was detected in contrast to earlier reports. The structures of the reaction products were determined with the aid of proton coupled ¹³C-NMR. spectra using the corresponding N-methyl-1,2,4-triazoles as reference compounds.     

Solid-phase synthesis of 5-amino-1-(substituted thiocarbamoyl)pyrazole and 1,2,4-triazole derivatives via dithiocarbazate linker

A general method is reported for the parallel solid-phase synthesis of 5-amino-1-(substituted thiocarbamoyl)pyrazole and 1,2,4-triazole derivatives based on the cyclization of polymer-bound dithiocarbazate 3 with various electrophiles, such as 3-ethoxyacrylonitriles 8 and cyanocarboimidates 9. The polymer-bound dithiocarbazate 3, produced by nucleophilic reaction with carbon disulfide and Fmoc-hydrazine on the Merrifield resin, served as the key intermediate for subsequent heterocycle diversification. Further nucleophilic substitution on these polymer-bound 5-amino-1-dithiocarboxypyrazoles 4 and 1,2,4-triazoles 6 with various amines under thermal cleavage condition produced the desired 5-amino-1-(substituted thiocarbamoyl)pyrazoles 5 and 1,2,4-triazoles 7. The progress of reactions could be monitored as polymer-bound intermediates by ATR-FTIR spectroscopy on single bead. The final compounds, obtained in good four-step overall yields and high purities upon cleavage from the resins, were characterized by LC/MS, 1H NMR, and 13C NMR spectroscopy.     

Synthesis of new tetrazene（N-N=N-N）-linked bi（1,2,4-triazole）

The reaction of 4-amino-1,2,4-triazole with sodium dichloroisocyanurate (SDCI) afforded new tetrazene(N-N=N-N)-linked bi(1.2,4-triazole) 2a in excellent yield.Increasing the molar ratio of SDCI to 4-amino-1,2,4-triazole,the chlorinated product 1,5,5′- trichloro-4,4′-azo-1,2,4-triazole (2b) was formed.These new compounds have been characterized by MS,~1H NMR,~(13)C NMR,and elemental analysis.     

含磷稠杂环的合成及其生物活性(Ⅵ)

在阳离子交换树脂D72存在下5-氨基-3-苄硫基-4-氰基(乙氧羰基)吡唑与苯基二氯化膦和芳醛的类Mannich反应,合成了9个2-苄硫基-3-氰基(乙氧羰基)-5-芳基-6-苯基-6-氧-6-磷杂-4,5,6-三氢咪唑[2,3e]吡唑,利用NMR方法确定其为反式构型,初步研究了反应机制。生物活性测试结果表明,部分化合物具有一定的除草活性。     

Convenient synthesis of fused heterocycles from α-ketohydroximoyl chlorides and heterocyclic amines

Nitroso derivatives of imidazo[1,2-a]pyridine ( 11, 13, 14 ), imidazo[1,2-a]pyrimidine ( 15 ), imidazo[1,2-a]pyrazine ( 16 ), imidazo[1,2-b]pyrazole ( 17 ), and imidazo[1,2-b]-1,2,4-triazole ( 19 ) were obtained in good yields from α-ketohydroximoyl chlorides 3 and 2-aminopyridines ( 4–6 ), 2-aminopyrimidine ( 7 ), 2-aminopyrazine ( 8 ), 5-amino-3-phenylpyrazole ( 9 ), and 3-amino-2H-1,2,4-triazole ( 10 ), respectively. Under different conditions, the reaction of 3 with 3-amino-2H-1,2,4-triazole ( 10 ) and 2-aminopyrazine ( 8 ) afforded the noncyclized substitution products 18 and 22 , respectively. The structures of the products were assigned and confirmed on the basis of their elemental analyses, spectral data, and alternate synthesis wherever possible.     

1-芳胺羰基-3-苄硫基-4-乙氧羰基(或氰基)-5-氨基吡唑的合成及生物活性

利用5-氨基-4-乙氧羰基(或氰基)-3-苄硫基吡唑与异氰酸酯的加成反应合成了一系列1-芳胺羰基-3-苄硫基-4-乙氧羰基(或氰基)-5-氨基吡唑。利用分子力学计算,解释了¹HNMR谱中的取代基效应。生物活性测定结果表明部分化合物具有良好的除草活性。     

Molecular and crystal structure of 5-amino-3-(N-<Emphasis Type="Italic">p</Emphasis>-methylbenzoyl-N-<Emphasis Type="Italic">p</Emphasis>-toluenesulfonyl)amino-1-phenyl-1,2,4-triazole

It has been established by X-ray structural analysis that the initial product of the interaction of 5-amino-1-phenyl-3-p-toluenesulfonylamino-1,2,4-triazole with p-methylbenzoyl chloride is 5-amino-3-(N-pmethylbenzoyl-N-p-toluenesulfonyl)amino-1-phenyl-1,2,4-triazole. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 917–921, June, 2007.     

Synthesis and single-crystal X-ray diffraction studies of 1-β-D-ribofuranosyl-1,2,4-triazole-3-sulfonamide and certain related nucleosides

1-β-D-Ribofuranosyl- 21 , 1-(2-deoxy-β-D-erytftro-pento fur anosyl)- 27 and 1-β-D-arabinofuranosyl- 29 derivatives of 1,2,4-triazole-3-sulfonamide ( 19 ) have been prepared. Glycosylation of the silylated 19 with 1,2,3,5-tetra-0-acetyl-β-D-ribofuranose ( 5 ) in the presence of trimethylsilyl triflate gave the corresponding blocked nucleoside ( 20 ), which on ammonolysis afforded 1-β-D-ribofuranosyl-1,2,4-triazole-3-sulfonamide ( 21 ). Stereospecific glycosylation of the sodium salt of 19 with either 1-chloro-2-deoxy-3,5-di-O-p-toluoyl-α-D-erythro-pentofuranose ( 22 ) or 1-chloro-2,3,5-tri-0-benzyl-α-D-arabinofuranose ( 23 ) provided the corresponding protected nucleosides 26 and 28. Deprotection of 26 and 28 furnished 1-(2-deoxy-β-D-erythro-pentofuranosyl)-1,2,4-triazole-3-sulfonamide ( 27 ) and 1-β-D-arabinofuranosyl-1,2,4-triazole-3-sulfonamide ( 29 ), respectively. 2-0-D-Ribofuranosyl-1,2,4-triazole-3(4H)-thione ( 7 ) and 4-β-D-ribofuranosyl-1,2,4-triazole-3(2H)-thione ( 9 ) were also prepared utilizing either an acid catalyzed fusion of 1,2,4-triazole-3(1H,2H)-thione ( 4 ) with 5 , the reaction of 5 with silylated 4 in the presence of trimethylsilyl triflate, or by ring closure of 4-(2,3,5-tri-0-benzoyl-β-D-ribofuranosyl)thiosemicarbazide ( 10 ) with mixed anhydride and subsequent deacylation. The synthesis of 1-β-D-ribofuranosyl-3-benzylthio-1,2,4-triazole ( 15 ) has also been accomplished by the silylation procedure employing 3-benzylthio-1,2,4-triazole ( 13 ) and 5 to give 1-(2,3,5-tri-0-acetyl-β-D-ribofuranosyl)-3-benzylthio-1,2,4-triazole ( 14 ). Deacetylation of 14 furnished 15 . The structural assignments of 7, 14 and 21 were made by single-crystal X-ray diffraction analysis and their hydrogen bonding characteristics have been studied. The sulfonamido-1,2,4-triazole nucleosides are devoid of any significant antiviral or antitumor activity in cell culture.     

N-Nitroimines: I. Synthesis,Structure, and Properties of 3,5-Diamino-1-nitroamidino-1,2,4-triazole

The reaction of 3,5-diamino-1,2,4-triazole with 2-methyl-1-nitroisothiourea gives 3,5-diamino-1-nitroamidino-1,2,4-triazole instead of the expected 1-[5(3)-amino-1,2,4-triazol-3(5)-yl]-2-nitroguanidine. Almost planar structure of the molecule of 3,5-diamino-1-nitroamidino-1,2,4-triazole gives rise for direct polar conjugation which is responsible for the low basicity of the amino groups.     

Unusual reaction of 3-amino-1,2,4-triazole with 1,3-diiodopropan-2-one

3-Amino-1,4-bis(2-oxopropyl)-4H-1,2,4-triazolium triiodide is the product of the reaction of 3-amino-1,2,4-triazole with 1,3-diiodopropan-2-one in acetone in the absence of bases and phase-transfer catalysts. In dimethyl sulfoxide, conversely, a water soluble polyionene consisting of three aminotriazole rings bound by 1,3-dimethylenecarbonyl bridges is formed. The effect of the solvent on the alkylation of 3-amino-1,2,4-triazole with 1,3-diiodopropan-2-one was studied.     

Synthesis and photochemical degradation of N-arylmethyl derivatives of the herbicide 3-amino-1,2,4-triazole

Reaction of an arylmethyl halide with 3-amino-1,2,4-triazole ( 1 ) allows the preparation of the three N-aryl-methyl derivatives of 1 bearing the substituent on the heterocyclic nitrogen atoms. In basic medium (methoxide anion in DMF or methanol, or in benzene by phase transfer catalysis), the isomers 3 and 5 substituted at N-1 and N-2 respectively are obtained, while the isomer 4 is isolated from neutral medium (DMF). The isomers 3 and 4 may be also prepared by cyclization of appropriate formylguanidinium derivatives. 3-Arylmethylamino-1,2,4-triazoles 2 may be obtained through reaction of 3-chloro-1,2,4-triazole ( 6 ) with arylmethylamines. Photolysis of the N-arylmethyl-3-amino-1,2,4-triazoles 2-5 in methanol or water-methanol mixture, induces homolytic and heterolytic cleavage of the arylmethyl-C-N bond giving rise to 3-amino-1,2,4-triazole ( 1 ). Thus, compounds 2-5 with arylmethyl groups able to absorb solar light may be considered as potential photoactivatable herbicides.     

N-isopropenylazoles: III. Quantum-chemical analysis of the reaction of azoles with allene and propyne in the gas phase

Reactions of pyrrole, imidazole, pyrazole, and 1,2,4-triazole with allene and propyne in the gas phase with formation of the corresponding N-isopropenylazoles were simulated at the RHF/6-31G**, B3LYP/6-31G**, and MP2(full)/6-31G** levels. Dissociation of the N-H bond to give azolate ion is the main constituent of the reaction coordinate. All the examined azoles react preferentially with allene rather than with propyne; their reactivity decreases in the series pyrrole > imidazole > pyrazole > 1,2,4-triazole due to participation of the pyridine type nitrogen atoms in the prototropic propyne-allene rearrangement.     

Synthesis of some sym-triazole derivatives

3,5-Di(hydroxyalkyl) derivatives of 4-amino-1,2,4-triazole and the corresponding derivatives of 1,2,4-triazole obtained by diazotizing them are converted by reaction with SOCl₂ into the hydrochlorides of 4-amino-3,5-di(chloroalkyl)-1,2,4-triazoles and 3,5-di(chloroalkyl)-1, 2,4-triazoles. The dinitrate of 3,5-di(hydroxymethyl)-1,2,4-triazole has been prepared. When the cyanohydrazide of glycolic acid is heated with hydrazine hydrate, 4,5-diamino-3-hydroxymethyl-1, 2,4-triazole is formed.     

Alkylation of acyl and sulfonyl derivatives of 3,5-diamino-1-phenyl-1,2,4-triazole

Alkylation of 3-acylamino-, 5-amino-1-phenyl-3-tosylamino-1,2,4-triazoles and 3,5-diacetylamino-1-phenyl-1,2,4-triazole in the presence of an equimolar amount of sodium methylate in DMSO occurs regioselectively at the amide (sulfamide) group nitrogen atom. The benzylation of 3-acetylamino-5-amino-1-phenyl-1,2,4-triazole with excess base and benzyl chloride also alkylates the amino group at position 5. Alkylamino-1-R-1,2,4-triazoles can be conveniently prepared by alkylation of the corresponding acetylamino-1,2,4-triazoles in the presence of base and subsequent acid hydrolysis of the N-acetyl-N-alkyl derivatives. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 557–567, April, 2009.