Microwave-assisted synthesis of 1-{2-[(1-benzyl-1<Emphasis Type="Italic">H</Emphasis>-1,2,3-triazol-4-yl)methoxy]phenyl}-3-(3-aryl-1-phenyl-1<Emphasis Type="Italic">H</Emphasis>-pyrazol-4-yl)prop-2-en-1-ones and their antimicrobial activity

A series of new (E)-1-{2-[(1-benzyl-1H-1,2,3-triazol-4-yl)methoxy]phenyl}-3-(3-aryl-1-phenyl-1H-pyrazol-4-yl)prop-2-en-1-ones (3a–3i) has been synthesized via copper-catalyzed 1,3-dipolar azide-alkyne cycloaddition reaction (CuAAC) of benzyl azide with substituted (E)-3-(3-aryl-1-phenyl-1H-pyrazol-4-yl)-1-[2-(prop-2-ynyloxy)phenyl]prop-2-en-1-ones (2a–2i). The synthesized compounds have been characterized by their IR, ^lH, ¹³C NMR spectra, and mass spectroscopy data. All the compounds have been screened for antimicrobial activity.     

Azolyl-substituted 1,2,3-triazoles

Huisgen reaction of (E)-1,5-diarylpent-2-en-4-yn-1-ones and (E)-1,5-diarylpent-1-en-4-yn-3-ones afforded 1-aryl-3-(5-aryl-1H-1,2,3-triazol-4-yl)prop-2-en-1-ones and 3-aryl-1-(5-aryl-1H-1,2,3-triazol-4-yl)-prop-2-en-1-ones, respectively. (E)-1-Aryl-3-(5-phenyl-1H-1,2,3-triazol-4-yl)prop-2-en-1-ones reacted with hydrazine hydrate and phenylhydrazine to give 72–93% of 4-(3-aryl-4,5-dihydro-1H-pyrazol-5-yl)-5-phenyl-1H-1,2,3-triazoles which underwent dehydrogenation on heating in boiling acetic acid with formation of the corresponding pyrazole derivatives. The molecular structures of (E)-3-phenyl-1-(5-phenyl-1H-1,2,3-triazol-4-yl)prop-2-en-1-one and 4-[3-(4-methylphenyl)-1-phenyl-4,5-dihydro-1H-pyrazol-5-yl]-5-phenyl-1H-1,2,3-triazole were studied by X-ray analysis. 4-(3-Aryl-4,5-dihydro-1H-pyrazol-5-yl)-5-phenyl-1H-1,2,3-triazoles showed toxicity against Daphnia magna.     

3-芳基-1-(吡啶-3-基)-2-(1H-1,2,4-三唑-1-基)-2-丙烯-1-醇的合成及生物活性研究

用硼氢化钠还原3-芳基-1-(吡啶-3-基)-2-(1H-1,2,4-三唑-1-基)丙烯酮, 合成了10个新型含吡啶基的三唑醇类化合物. 所有化合物均经核磁、元素分析确证. 生物活性测试结果表明, 部分化合物具有一定的杀菌活性及植物生长调节活性.     

Synthesis of 8,9-dihydro[1,2,4]triazolo[1,5-a]-quinazolin-6(7H)-one derivatives

Regioselectivity of the reactions of 1H-1,2,4-triazol-3-amines with 2-acyl-5,5-dimethylcyclohexane-1,3-diones and 2-dimethylaminomethylidene-5,5-dimethylcyclohexane-1,3-dione was studied. In all cases, the products were substituted 8,9-dihydro[1,2,4]triazolo[1,5-a]quinazolin-6(7H)-ones whose structure was determined by ¹H and ¹³C NMR spectroscopy.     

Convergent procedure for the synthesis of trifluoromethyl-containing N-(pyridinyl-triazolyl)pyrimidin-2-amines

This study describes a simple and efficient procedure to synthesize a novel series of fourteen 4-substituted N-(5-pyridinyl-1H-1,2,4-triazol-3-yl)-6-(trifluoromethyl)pyrimidin-2-amines, where the 4-substituents are H, CH₃, C₆H₅, 4-FC₆H₄, 4-CH₃C₆H₄, 4-CH₃OC₆H₄ and 2-Furyl; from the cyclocondensation reaction of N-[5-(pyridinyl)-1H-1,2,4-triazol-3-yl]guanidines with 4-alkoxy-4-alkyl(aryl/heteroaryl)-1,1,1-trifluoroalk-3-en-2-ones. The reactions were carried out in ethanol under reflux for 18 h and led to 40-68% yields. N-(Pyridyl-triazolyl)guanidine precursors were further obtained from reactions of cyanoguanidine with nicotinic or isonicotinic acid hydrazides and the halogenated enones from trifluoroacetylation of enolethers or acetals.     

Synthesis and biological activity research of novel ferrocenyl-containing thiazole imine derivatives

A series of novel N-substituted benzylidene-4-ferrocenyl-5-(1H-1,2,4-triazol-1-yl)-1,3-thiazol-2-amine derivatives were synthesized by condensation of substituted-benzaldehydes with 2-amino-4-ferrocenyl-5-(1H-1,2,4-triazol-1-yl)-1,3-thiazole and characterized by ¹H NMR, X-ray diffraction and elemental analysis. The results of bioassay showed that some title compounds exhibited some degree of plant growth regulatory and antifungal activities.     

Synthesis and characterization of some chalcones and their cyclohexenone derivatives

A series of chalcones and their derivatives have been synthesized. Chalcones, 1-(1,3-benzodioxol-5-yl)-3-(aryl)-prop-2-en-1-ones were prepared by the aldol condensation of 1-(1,3-benzodioxol-5-yl)ethanones and aryl aldehydes. Based-catalyzed condensation of 1-(1,3-benzodioxol-5-yl)-3-(aryl)prop-2-en-1-ones with ethyl acetoacetate yields corresponding ethyl 4-(1,3-benzodioxol-5-yl)-6-(aryl)-2-oxocyclohex-3-ene-1-carboxylates. Some of the synthesized chalcones were reported in the literature; the newly synthesized compounds were characterized by single crystal X-ray studies, IR, ¹H-NMR and LCMS mass spectral analysis.     

Ultrasound- and microwave-assisted synthesis of (E)-1-aryl-3-[2-(piperidin-1-yl)quinolin-3-yl]prop-2-en-1-ones and (E)-1-aryl-3-[2-(pyrrolidin-1-yl)quinolin-3-yl]prop-2-en-1-ones,and their antimicrobial activity

Series of new (E)-1-aryl-3-[2-(piperidin-1-yl)quinolin-3-yl]prop-2-en-1-ones and (E)-1-aryl-3-[2-(pyrrolidin-1-yl)quinolin-3-yl]prop-2-en-1-ones have been efficiently prepared via the Claisen-Schmidt condensation of 2-(piperidin-1-yl)quinoline-3-carbaldehyde and 2-(pyrrolidin-1-yl)quinoline-3-carbaldehyde, respectively, with aryl methyl ketones under conditions of ultrasound and microwave irradiation. Structures of the products have been confirmed by IR, ¹H NMR, ¹³C NMR, and mass spectroscopy, as well as by elemental analysis. Evaluation of the in vitro antibacterial activity against bacterial (Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli) and fungal (Aspergillus niger and Candida metapsilosis) strains has revealed good antimicrobial activity of some of the tested compounds.     

Synthesis,characterization, and antimicrobial activity of novel (<Emphasis Type="Italic">E</Emphasis>)-1-(aryl)-3-{3, 5-dimethoxy-4-[(1-(aryl)-1<Emphasis Type="Italic">H</Emphasis>-1,2,3-triazol-4-yl)methoxy]phenyl}prop-2-en-1-ones

The new chalcone derivatives containing the 1,2,3-triazole ring system, namely, (E)-1-(aryl)-3-{3,5-dimethoxy-4-[(1-(aryl)-1H-1,2,3-triazol-4-yl)methoxy]phenyl}prop-2-en-1-ones, were synthesized in 65–88% yield by the “click chemistry” reactions of substituted acetophenones, 4-hydroxy-3,5-dimethoxy-benzaldehyde, and different substituted azides. The structure of the compounds was determined by the FT-IR, ¹H NMR, ¹³C NMR, and mass spectroscopic analyses. Compounds 6a–6l were screened for in vitro antimicrobial activity by the agar disc diffusion method.     

Chemistry of 1,5-diketones: II. Specificity of transformations of polycyclic 1,5-diketones in acid media

2-(1,3-Diaryl-3-oxopropyl)cyclohexan-1-ones underwent carbo-and heterocyclization in a mixture of acetic acid with acetic anhydride in the presence of perchloric acid. The transformation of 2-(1,3-diaryl-3-oxopropyl)cyclohexan-1-ones into 2,4-diaryl-5,6,7,8-tetrahydrochromenylium salts was shown to involve intermediate 2,4-diarylbicyclo[3.3.1]non-2-en-9-ones. The structure of 2,4-diaryl-substituted bicyclo[3.3.1]non-2-en-9-ones and products of their reactions with halogens and hydroxylamine hydrochloride was confirmed by ¹H and ¹³C NMR spectroscopy.     

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.     

Synthesis of 7-(2-R-pyrimidin-4-yl)- and 7-(2-R-[1,2,4]triazolo[1,5-<Emphasis Type="Italic">a</Emphasis>]pyrimidin-7-yl)-2,2,4,6-tetramethyl-1,2,3,4-tetrahydroquinolines

Cyclization of 3-(dimethylamino)-1-(2,2,4,6-tetramethyl-1,2,3,4-tetrahydroquinolin-7-yl)prop-2-en-1-one with carboximidamides, guanidines, and 1,2,4-triazol-5-amines afforded a number of new 2,2,4,6-tetramethyl-7-(2-R-pyrimidin-4-yl)-1,2,3,4-tetrahydroquinolines and 2,2,4,6-tetramethyl-7-(2-R-[1,2,4]triazolo-[1,5-a]pyrimidin-7-yl)-1,2,3,4-tetrahydroquinolines.     

5-substituted 3-nitro-1-trinitromethyl-1,2,4-triazoles

A number of 5-R-substituted 3-nitro-1-trinitromethyl-1H-1,2,4-triazoles (R = Me, Cl, Br, N₃, NH₂, NO₂) were synthesized by nitration of the corresponding ω-(5-R-3-nitro-1H-1,2,4-triazol-1-yl)alkan-2-ones with mixtures of concentrated sulfuric and nitric acids.     

Reaction of polyfluorinated chalcones with guanidine

Reactions of polyfluorinated chalcones with guanidine in the presence of bases are accompanied by elimination of the polyfluorophenyl group. 3-(Pentafluorophenyl)-1-phenylprop-2-en-1-one and its derivatives reacted with guanidine under basic conditions to give 4-phenylpyrimidin-2-amine, polyfluorobenzenes, and Michael adducts, 3-(2-amino-4-phenylpyrimidin-5-yl)-3-(4-R-2,3,5,6-tetrafluorophenyl)-1-phenylpropan-1-ones. 1-(Pentafluorophenyl)-3-phenylprop-2-en-1-one and 1,3-bis(pentafluorophenyl)prop-2-en-1-one were converted into cinnamic acid derivatives whose reaction with guanidine afforded 2-amino-6-aryl-5,6-dihydropyrimidin-4(1H)-ones.     

Synthesis and biological activity of (Z) and (E) isomers of 3-(3,4-diaryl-1,2,4-triazole-5-yl)prop-2-enoic acid

Abstract  (Z)-3-(3,4-diaryl-1,2,4-triazole-5-yl)prop-2-enoic acid derivatives were obtained in the course of the reaction of N ³-substituted amidrazones with maleic anhydride, and isomerized into the (E) isomers by heating under reflux in acetic acid solution. The molecular structure of the compounds obtained was confirmed by IR and ¹H NMR spectroscopy, and by X-ray crystallography for (2E)-3-(4,5-diphenyl-4H-1,2,4-triazol-3-yl)prop-2-enoic acid. The antiviral and immunomodulating activity of several of the compounds was examined. Graphical abstract        

New derivatives of N-vinyltriazoles: 1,3-diaryl-3-(1H-1,2,4-triazol-1-yl)-2-propen-1-ones

We have synthesized previously unknown N-vinyltriazoles:1,3-diaryl-3-(1H-1,2,4-triazol-1-yl)-2 propen-1-ones. We discuss a hypothesis for a probable reaction mechanism. Institute of Chemistry, Academy of Sciences of the Moldavian Republic, Kishinev 277028. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 910–914, July, 1995. Original article submitted March 24, 1995.     

Unusual reaction of chloroacetyl chloride with 1,2-dichloroethene. Synthesis and properties of 2-chlorovinyl dichloromethyl ketone

The reaction of chloroacetyl chloride with 1,2-dichloroethene in the presence of AlCl₃ unexpectedly led to the formation of (E)-1,1,4-trichlorobut-3-en-2-one whose structure was proved by ¹H and ¹³C NMR, IR, and mass spectra and independent synthesis. A probable reaction scheme was proposed, which involves transformation of initially formed 1,2,4-trichloro-3-oxobutan-2-yl cation by the action of AlCl₃. The high reactivity of the vinylic halogen atom in (E)-1,1,4-trichlorobut-3-en-2-one was demonstrated by its reactions with nitrogen-centered nucleophiles (triethylamine, aniline, 3,5-dimethyl-1H-pyrazole) and sodium sulfide. These reactions involved only the C-Cl bond in the vinyl fragment and afforded (4,4-dichloro-3-oxobut-2-en-1-yl)triethylammonium chloride, 1,1-dichloro-4-phenylaminobut-3-en-2-one, 1-(4,4-dichloro-3-oxobut-2-en-1-yl)-3,5-dimethyl-1H-pyrazole, and 4,4′-thiobis(1,1-dichlorobut-3-en-2-one), respectively. The reaction of 1,1,4-trichlorobut-3-en-2-one with benzylhydrazine gave a mixture of 1,3- and 1,5-disubstituted pyrazoles.     

Efficient Synthesis of 6-(1H-1,2,4-Triazol-1-yl)-thieno[2,3-d]pyrimidin-4(3H)-ones via an Iminophosphorane

Ethyl 2-amino-4-methyl-5-(1H-1,2,4-triazol-1-yl)thiophene-3-carboxylate 2, obtained from Gewald reaction of 1-(1H-1,2,4-triazol-1-yl)acetone 1 with ethyl cyanoacetate and sulfur, was transferred into iminophosphorane 3. Further reaction of 3 with aromatic isocyanates gave carbodiimides 4, which were treated subsequently with a secondary amine to give 6-(1H-1,2,4-triazol-1-yl)-thieno[2,3-d]pyrimidin-4(3H)-ones 6 in good yields in the presence of a catalytic amount of sodium ethoxide.     

A chemoselective hydroxymethylation: new route for the synthesis of 6-aroyl-4-(4H-triazol-3-yl)thiomorpholin-3-ones

Treatment of 2-(2-oxo-2-arylethylthio)-N-(4H-1,2,4-triazol-3-yl)acetamides with paraformaldehyde in the presence of a base has led to a tandem chemoselective hydroxymethylation followed by cyclization yielding a set of novel 6-aroyl-4-(4H-triazol-3-yl)thiomorpholin-3-ones. The thiomorpholine ring has been found to have a boat like conformation in these compounds as evidenced by NOESY NMR spectrum.     

Halocyclization of 3-{[2-methyl(bromo)prop-2-en-1-yl]-sulfanyl}-5<Emphasis Type="Italic">H</Emphasis>-[1,2,4]triazino[5,6-<Emphasis Type="Italic">b</Emphasis>]indoles

Reactions of 3-[(2-bromoprop-2-en-1-yl)sulfanyl]-5H-[1,2,4]triazino[5,6-b]indole with bromine and of 3-[(2-methylprop-2-en-1-yl)sulfanyl]-5H-[1,2,4]triazino[5,6-b]indole with iodine and bromine afforded 3-halomethyl-10H-[1,3]thiazolo[3′,2′: 2,3][1,2,4]triazino[5,6-b]indol-4-ium halides whose structures were determined by ¹H NMR and X-ray analysis.