Derivatives of 4-amino-4H-1,2,4-triazole-3-thiols linked to the pyrrole cycle and some products of their S-alkylation

This study offers an access to 21 new heterocyclic compounds representing pyrrole derivatives of 4-amino-4H-1,2,4-triazole-3-thiols or 1,3,4-oxadiazole-2-thiols. The principal synthetic approach is based on the cyclization of substituted potassium 2-(pyrrolecarbonyl)hydrazine-1-carbodithionate with hydrazine hydrate to 5-(substituted pyrrolyl)-4-amino-4H-1,2,4-triazole-3-thiols, followed by S-alkylation with methyl iodide or benzyl chloride. Among the resulted thirteen S-alkyl derivatives, five 1,3,4-oxadiazole derivatives have been isolated as secondary products and their formation is explained as being the result of S-alkylation of intermediate 1,3,4-oxa-diazole-2-thiols, generated in the alkaline medium. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 383–391, March, 2007.     

Synthesis of 3-Alkyl-6-aryl(arylamino)-7H-[1,2,4]triazolo- [3,4-b][1,3,4]thiadiazines

Starting from 5-alkyl-4-amino-4H-1,2,4-triazole-3-thiols and substituted chloroacetanilides, the corresponding (5-alkyl-4-amino-4H-1,2,4-triazol-3-ylsulfanyl)acetanilides were synthesized. The products underwent intramolecular cyclization in boiling phosphoryl chloride to afford 3-alkyl-6-arylamino-7H-[1,2,4]-triazolo[3,4-b][1,3,4]thiadiazines. 3-Alkyl-6-aryl-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazine hydrobromides were obtained by reaction of 5-alkyl-4-amino-4H-1,2,4-triazole-3-thiols with substituted phenacyl bromides.     

Synthesis of some new 4,5-substituted-4H-1,2,4-triazole-3-thiol derivatives

In this study appropriate hydrazide compounds, furan-2-carboxylic acid hydrazide (1) and phenylacetic acid hydrazide (2) were converted into 1,4-substituted thiosemicarbazides 4a-e and 5a-e and 4-amino-5-(furan-2-yl or benzyl)-4H-1,2,4-triazole-3-thiols 7 and 10. The 1,4-substituted thiosemicarbazides were then converted into 5-(furan-2-yl or benzyl)-4-(aryl)-4H-1,2,4-triazole-3-thiols 8a-e and 9a-e. In addition, the azomethines 11a-d and 12a-d were prepared from the corresponding arylaldehydes and the 4-amino-5-(furan-2-yl or benzyl)-4H-1,2,4-triazole-3-thiols 7 and 10. The structures of all the synthesized compounds were confirmed by elemental analyses, IR, (1)H-NMR and(13) C-NMR spectra.     

Inorganic base-catalyzed formation of antivirally active N-substituted benzamides from α-amido sulfones and N-nucleophile

Background

Heteronucleophiles as well as carbanionic reagents can be used to react with α-amido sulfones, thus giving the opportunity to prepare a large array of amino derivatives. Since, novel 1,3,4-oxadiazole-2-thiol derivatives can serve as potent nucleophiles, we employed 5-subsititued phenyl-1,3,4-oxadiazole-2-thiols as the nucleophilic source of nitrogen in the reaction with α-amido sulfones.

Results

A series of N-substituted benzamides bearing 1,3,4-oxadiazol unit were prepared for the first time by the reaction of in situ generated protected imine from α-amido sulfones with 5-subsititued phenyl-1,3,4-oxadiazole-2-thiols as the source of nitrogen nucleophile. Some of the synthesized products displayed favourable antiviral activity against cucumber mosaic virus (CMV) in preliminary antiviral activity tests. The title compounds 5c, 5o and 5r revealed curative activity of 42.2%, 48.7% and 40.5%, respectively against CMV (inhibitory rate) compared to the commercial standard Ningnanmycin (53.4%) at 500 μg/mL.

Conclusion

A practical synthetic route to N-benzoyl-α-amido sulfones by the reaction of 5-subsititued phenyl-1,3,4-oxadiazole-2-thiols as the source of nitrogen nucleophiles with in situ generated protected imine from N-benzoyl-α-amido sulfones is presented. The reaction catalyzed by an inorganic base has considerable significance to exploit the potential of α-amido sulfones in organic synthesis.     

Synthesis of New Substituted 1,2,4-Triazoles and 1,3,4-Thiadiazoles and Their Effects on DNA Methylation Level

Russian Journal of General Chemistry - Continuing the search for biologically active compounds among functionally substituted azoles, new 1,2,4-triazole-3-thiols and 1,3,4-thiadiazoles derivatives...     

Solid Acid Induced Cyclocondensation: A Facile,One-Pot Synthesis of 7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazines

7H-[1,2,4]Triazolo[3,4-b][1,3,4]thiadiazines are synthesized in good yields by the catalytic action of sulfuric acid adsorbed on sillica gel. Starting from 4-amino-5-substituted-1,2,4-triazole-3-thiones and employing cyclocondensation reaction with f -chloroacetonitrile and f -haloketones, the desired triazolothiadiazines have been synthesized satisfactorilly.     

5-(4,6-Diphenyl-2-pyrimidinyl)-1,3,4-oxadiazole-2-thione with Some C-Electrophiles and N-Nucleophiles

5-(4,6-Diphenyl-2-pyrimidinyl)-1,3,4-oxadiazole-2-thione reacted with haloalkanes or their derivatives containing side chain oxo group to give S-alkylated compounds. Aminomethylation and acylation of the thione yielded N₍₃₎-derivatives. Treatment of the title compound with hydrazine hydrate in butanol resulted in 4-amino-5-(4,6-diphenyl-2-pyrimidinyl)-1,2,4-triazole-3-thione via a recyclization reaction. Reaction of the title compound with hydrazine hydrate or phenylhydrazine in dioxane led to formation of the corresponding thiocarbohydrazides. The latter in the presence of a base were cyclized to 4-amino-1,2,4-triazole-3-thiones.     

The synthesis of 4-substituted-4H-1,2,4-triazole-3-thiols and 3-methylthio-4-substituted-4H,2,4-triazoles

The synthesis of 4-substituted-4H-1,2,4-triazole-3-thiols and 3-methylthio-4-substituted-4H-1,2,4-triazoles by the condensation of 4-substituted-3-thiosemicarbazides with dimethylformamide dimethyl acetal or dimethylacetamide dimethyl acetal is described. A discussion of the mechanistic pathway is included.     

3-（5-H/CH3-苯并咪唑-2-亚甲硫基）-5-取代-[1,2,4]三唑-4-胺衍生物的合成、结构和生物活性

利用3-巯基-4-氨基-5-取代-1,2,4-三唑和2-氯甲基-5-取代-苯并咪唑在氢氧化钠溶液中反应,得到17个3-(5-H/CH3-苯并咪唑-2-亚甲硫基)-5-取代-[1,2,4]三唑-4-胺衍生物.所有目标化合物经元素分析、红外光谱、核磁共振氢谱确定结构;采用溶液法得到化合物3f与Co2+形成的配合物,通过X射线单晶衍射确定结构.初步的生物活性测试结果表明,所合成的化合物对小麦芽鞘和绿豆发芽有着较好的生长调节作用;化合物3d,3i对金黄色葡萄球菌具有一定的抑制作用.     

Novel Fused Heterocycles: Synthesis and Activity of 5,6-Dihydro-7-thia-1,3,3a,5-tetraazainden-4-one and 1-Thia-3,4a,9-triazafluoren-4-one Derivatives

 Thiatetraazaindenone derivatives were synthesized by reaction of 3-substituted 1,2,4-triazole-5-thiols with N-substituted N-chloromethyl carbamoyl chlorides. A series of thiatriazafluorenone derivatives were also prepared by reaction of benzimidazole derivatives with the same substrate. Some of the new compounds show fungicidal, herbicidal, and insecticidal activity.     

Non-catalyzed addition of heterocyclic thiols and 5-substituted-1H-tetrazoles to vinyl ethers

The alkylation of 1-substituted 1H-tetrazole-5-thiols and 4-substituted 4 H-1,2,4-triazole-3-thiols with alkyl halides or sulfonates lead to the formation of S-alkylated products regardless of the substituent on the heterocycle. In this work, we found that substituted 1H-tetrazole-5-thiols and 4 H-1,2,4-triazole-3-thiols readily reacted with vinyl ethers in the absence of a catalyst to exclusively form N-substituted 1H-tetrazole-5(4H)-thiones and 1H-1,2,4-triazole-5(4H)-thiones, respectively. Furthermore, the reactions of 5-substituted-1H-tetrazoles with vinyl ethers under the same conditions selectively yielded 2,5-disubstitued tetrazoles.     

Synthesis of 1,2,4-triazole, 1,2,4-triazolo[3,4-b][1,3,4]thiadiazole and 1,2,4-triazolo[3,4-b][1,3,4]thiadiazine derivatives of benzotriazole

A novel series of 1-(1-carbonylmethyl-1H-benzotriazole) thiosemicarbazides 3a-e was synthesized and then cyclized with sodium hydroxide to afford 1-(4-substituted-4H-1,2,4-triazole-3-thion-5-yl)methyl-1H-benzotriazoles 4a-e , which were alkylated with ethyl iodide to l-(3-ethylthio-4-substituted-4H-1,2,4-triazol-5-yl)-methyl-1H-benzotriazoles 5b-e . The reaction of 1H-benzotriazol-1-acetic acid hydrazide ( 2 ) with carbon disulphide and potassium hydroxide followed by hydrazine hydrate gave 1-(4-amino-4H-1,2,4-triazole-3-thion-5-yl)methyl-1H-benzotriazole ( 6 ). Its subsequent condensation with carboxylic acids in the presence of phosphorus oxychloride or with phenacyl bromides afforded two series of fused heterocycles namely; 6-substituted-3-[1-(1H-benzotriazole)methyl]-1,2,4-triazolo[3,4-b][1,3,4]thiadiazoles 7a-e and 6-substituted phenyl-3-[1-(1H-benzotriazole)methyl]-7H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazines 8a-e respectively. The structure of the newly synthesized compounds was elucidated by elemental analyses, ir and nmr spectra.     

Synthesis and pharmacological evaluation of 3-diphenylmethyl-6-substituted-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazoles: A condensed bridgehead nitrogen heterocyclic system

A series of 3-diphenylmethyl-6-substituted-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole derivatives (4a–j and 5a–d) were synthesized by condensation of 4-amino-5-diphenylmethyl-4H-1,2,4-triazole-3-thiol with various substituted aromatic acids and aryl/alkyl-isothiocyanates. The structures of synthesized compounds were characterized by elemental analysis, IR, ¹H NMR, ¹³C NMR and mass spectroscopic studies. These compounds were tested in vivo for their anti-inflammatory activity. The compounds which showed activity comparable to the standard drug ibuprofen were screened for their analgesic, ulcerogenic, lipid peroxidation and hepatotoxic effects. Compounds 6-(4-chlorophenyl)-3-diphenylmethyl-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole (4a) and 6-(2,4-dichlorophenyl)-3-diphenylmethyl-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole(4c) emerged as the most active compounds of the series and were moderately more potent than the standard drug ibuprofen.     

(3-苄基-4-芳酰基-1,2,4-三唑-5-基)(5-本基-1,3,4-噁二唑-2-基)硫醚的合成

通过3-苄基-4-芳酰基-1,2,4-三唑-5-巯基负离子在2-甲磺酰基-5-苯基-1,3,4-噁二唑环2-位上的亲核取代反应,制得13个新的(3-苄基-4-芳酰基-1,2,4-三唑-5-基)(5-苯基-1,3,4-噁二唑-2-基)硫醚衍生物.经元素分析、IR、~1H NMR和MS裂解碎片分析确认结构.初步观察了它们在0.01％浓度时对大肠杆菌繁殖的抑制作用.     

Synthesis of heterocycles based on arylation products of unsaturated compounds: XVII. Arylation of 2-acetylfuran and synthesis of 3-R-6-(5-aryl-2-furyl)-7<Emphasis Type="Italic">H</Emphasis>-[1,2,4]triazolo[3,4-<Emphasis Type="Italic">b</Emphasis>][1,3,4]thiadiazines

Reaction of 2-acetylfuran with arenediazonium chlorides under Meerwein reaction conditions led to the formation of 5-aryl-2-acetylfurans. The bromination of these compounds gave 2-bromo-1-(5-aryl-2-furyl)-ethanones that reacted with 4-amino-4H-5-R-1,2,4-triazole-3-thiols to form 3-R-6-(5-aryl-2-furyl)-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazines.     

A facile one-pot three-component synthesis of benzylideneamino-3,5-dimethyl-1H-pyrazoles

A facile, one-pot three-component protocol for the synthesis of substituted 4-(benzylideneamino)-5-(3,5-dimethyl-1H-pyrazol-1-yl)-4H-1,2,4-triazole-3-thiols have been reported by the reaction of 4-amino-5-hydrazinyl-4H-1,2,4-triazole-3-thiol with acetyl acetone and various substituted benzaldehydes via multi component reaction. The newly synthesized derivatives were characterized by their elemental analysis and spectral data. The current strategy provides heterocyclic compounds in good yields with broad substrate scope.     

Synthesis of 1,2,4-triazole-3-thiols and their S-substituted derivatives

New 1,2,4-triazole-3-thiols were synthesized by reactions of the corresponding carboxylic acid hydrazides with isothiocyanates and subsequent cyclization of intermediate 1,4-substituted thiosemicarbazides. Alkylation of 1,2,4-triazole-3-thiols with benzyl chlorides and bromacetophenones gave only S-substituted derivatives.     

N-2-多氟烷基乙基取代1,3,4-噁二唑-2-硫酮及1,2,4-三唑-5-硫酮类化合物的合成和密度泛函理论研究

为改善二唑及三唑类化合物的生物活性, 设计合成了一系列多氟烷基乙基取代的1,3,4-噁二唑-2-硫酮6a～6l及1,2,4-三唑-5-硫酮类化合物9a～9l. ¹H NMR, ¹⁹F NMR, IR和MS谱以及元素分析表征了它们的结构; 实验结果与Materials Studio 3.0中的Dmol3计算模块理论计算表明了唑环上的NH较之CONH中的NH更易进行烷基化反应.     

Nitrosation of methyl 2-acylamino-3-dimethylaminopropenoates. A simple conversion of n-acylglycines into 5-substituted 1,2,4-Oxadiazole-3-carboxylates

A novel simple synthesis of 5-substituted-1,2,4-oxadiazole-3-carboxylates 5 from N-acylglycines 1 , which are transformed with DMF in the presence of phosphorus oxychloride into 2-substituted-4-dimethyl-aminomethyleneoxazol-5(4H)-ones 2 , followed by opening into 2-aroylamino-3-dimethylamino-propenoates 3 , and nitrosation to give the oximes 4 as intermediates, which cyclize spontaneously into 5-substituted-1,2,4-oxadiazole-3-carboxylates 5 . The compounds 2 can be transformed into 5 without isolation of 3 and 4 .     

Synthesis of 1,2,4,5-Tetrakis(1,2,4-Triazolyl) Benzene and 1,2,4,5-Tetrakis(1,3,4-Oxadiazolyl) Benzene Derivatives

Abstract

A series of 1,2,4,5-tetrakis(1,2,4-triazolyl)benzenes and 1,2,4,5-tetrakis(1,3,4-oxadiazolyl)benzenes was synthesized by nucleophilic addition of sodium salts of 4-phenyl-2,4-dihydro-3H-1,2,4-triazole-3-thiones and 1,3,4-oxadiazole-2(3H)-thiones to 1,2,4,5-tetrakis(bromomethyl)benzene. The structure of the newly synthesized compounds was confirmed by elemental analysis, IR and ¹H and ¹³C NMR spectra.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental resource: 1H and 13C NMR spectra of products (Figures S1-S24).