Synthesis of 4,5-dichloro-1-(4,5-dichloropyridazin-3-yl)pyridazin-6-one

This paper presents the synthesis of 4,5-dichloro-1-(4,5-dichloropyridazin-3-yl)pyridazin-6-one from 4,5-dichloropyridazin-6-one.     

Synthesis of 3-(pyridine-2-yl)-4,5-dihydro-1H-pyrazole-1-thiocarboxamides and their copper(II) complexes

New organic ligands 3-(pyridine-2-yl)-4,5-dihydro-1H-pyrazole-1-thiocarboxamides (L) have been synthesized by a two or three step reaction sequence starting from substituted benzaldehydes and 2-acetyl pyridine. Copper(II) complexes with LCuCl₂ composition were obtained by the reactions of these ligands with CuCl₂·2H₂O. The crystal structure of two synthesized complexes has been determined by X-ray analysis. Copper atoms located in a strongly distorted square piramidal environment and coordinated by pyrazoline and pyridine nitrogen atoms, thiocarbamoyl sulfur atom and two chloride-anions. All complexes undergo reversible or quasi-reversible electrochemical reduction at 0.45–0.28 V with the formation of Cu(I) containing intermediates. The cytotoxicity of copper containing complexes, comparable to cisplatin and doxorubicin, was demonstrated using cancer cell lines MCF-7, A549 and HEK293.     

Synthesis and Characterization of Novel 2-(1,2,3-Triazol-4-yl)-4,5-dihydro-1H-pyrazol-1-yl)thiazoles and 2-(4,5-Dihydro-1H-pyrazol-1-yl)-4-(1H-1,2,3-triazol-4-yl)thiazoles

Reactions of 1-(5-methyl)-1H-1,2,3-triazol-4-yl)ethan-1-ones and benzaldehydes in ethanol under basic conditions gave the corresponding chalcones. Reactions of the chalcones combined with thiosemicarbazide in dry ethanol containing sodium hydroxide afforded the corresponding pyrazolin-N-thioamides. Reactions of the synthesized pyrazolin-N-thioamides and several ketones (namely, ethyl 2-chloro-3-oxobutanoate, 2-bromoacetylbenzofuran, and hydrazonoyl chloride) gave the corresponding novel 2-(1,2,3-triazol-4-yl)-4,5-dihydro-1H-pyrazol-1-yl)thiazoles in high yields (77–90%). Additionally, 2-(4,5-dihydro-1H-pyrazol-1-yl)-4-(1H-1,2,3-triazol-4-yl)thiazoles were obtained in high yields (84–87%) from reactions with N-pyrazoline-thioamides and 4-bromoacetyl-1,2,3-triazoles under basic conditions. The structures of six of the newly synthesized heterocycles were confirmed by X-ray crystallography.     

4,5-二苯基-2-(9-苯基-9H-3-咔唑基)-1H-咪唑的合成及其性能

以联苯甲酰、对溴苯甲醛和乙酸铵为原料,经缩合反应制得2-(4-溴苯基)-4,5-二苯基咪唑(1); 1与N-苯基-3-咔唑硼酸经Suzuki偶联反应合成了一种具有D-π-A结构的新型咪唑衍生物4,5-苯基-2-(9-苯基-9H-3-咔唑基)-1H-咪唑(2）,其结构经¹H NMR, ¹³C NMR, IR和MS(EI)表征。采用FL, UV-Vis,循环伏安法（CV）和理论计算对2的光电性能进行了研究。结果表明：2的最大吸收波长为302 nm和326 nm,荧光发射波长为395 nm和412 nm, HOMO和LUMO轨道能级分别为5.35 eV和2.14 eV。     

Luminescent zinc(II) and cadmium(II) complexes based on 2-(4,5-dimethyl-1H-imidazol-2-yl)pyridine and 2-(1-hydroxy-4,5-dimethyl-1H-imidazol-2-yl)pyridine

Complexes ZnL¹Cl₂, CdL¹Cl₂, ZnL ₂ ¹ Cl₂ ^·1.5H₂O, CdL ₂ ¹ Cl₂ ^·2H₂O, CdL ₂ ¹ Cl₂ ^·MeOH·H₂O [L¹ = 2-(4,5-dimethyl-1H-imidazol-2-yl)pyridine] and inner-complex compounds ZnL ₂ ² ·2H₂O, CdL ₂ ² [HL² = 2-(1-hydroxy-4,5-dimethyl-1H-imidazol-2-yl)pyridine] were synthesized. The complexes exhibit bright photoluminescence in the blue region of the spectrum, with the intensity exceeding this characteristic of the compounds L¹ and HL². Compound L¹ in aqueous solution is a potential chemosensor for the determination of zinc and cadmium.     

Synthesis,structural characterization and anticancer properties of p-cymene Ru(II) complexes with 2-(N-methyl-1H-1,2,4-triazol-3-yl)pyridines

Transition Metal Chemistry - The structures of new p-cymene Ru(II) complexes with 2-(1-methyl-1H-1,2,4-triazol-3-yl)pyridine and 2-(1-methyl-1H-1,2,4-triazol-5-yl)pyridine were established based on...     

Synthesis of 3-(3-Alkyl-5-thioxo-1H-4,5-dihydro-1,2,4-triazol-4-yl)aminocarbonylchromones

A series of 3-(3-alkyl-5-thioxo-1H-4,5-dihydro-1,2,4-triazol-4-yl)aminocarbonylchromones has been prepared by oxidation of 3-formylchromone with Jones' reagent followed by reaction with 3-alkyl-4-amino-4,5-dihydro-1,2,4-triazole-5(1H)-thione in the presence of POCl³. The structures of the compounds were confirmed by IR, LC-MS, and ¹H NMR spectra and elemental analyses.     

Synthesis of 3-(2-(4,5-Dihydro-3,5-diphenylpyrazol-1-yl)thiazol-4-yl)-2H-chromen-2-one Derivatives via Multicomponent Approach

An efficient synthesis of 3-(2-(4,5-dihydro-3,5-diphenylpyrazol-1-yl)thiazol-4-yl)-2H-chromen-2-one derivatives by a simple, atom-economical, and multicomponent reaction of chalcones, thiosemicarbazide, and 3-(2-bromoacetyl) coumarins in the presence of aqueous sodium hydroxide in refluxing ethanol is reported. The structures of newly prepared compounds have been confirmed by their analytical and spectral (IR, ¹HNMR, ¹³CNMR and mass) data.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]     

Synthesis, antibacterial and antifungal activities of 3-aryl-5-(pyridin-3-yl)-4,5-dihydropyrazole-1-carbothioamide derivatives

A new series of 3-aryl-5-(pyridin-3-yl)-1-thiocarbamoyl-2-pyrazoline derivatives (4a-j) were prepared by the reaction of azachalcons 3a-j with thiosemicarbazide in ethanolic sodium hydroxide. The structure of synthesized compounds were confirmed by ¹H NMR and Mass spectral data. Their antibacterial activities against Escherichia coli (CTP 7624), Staphylococcus aureus (ATCC 6538), Staphylococcus epidermidis (ATCC 12229), Pseudomonas aeruginosa (ATCC 9027), Bacillus subtilis (ATCC 1156) and Micrococcus luteus (ATCC 9341) were investigated. Antifungal activity of compounds against Candida albicans and Candida globrata were found to be inactive. Compounds 4a-j were also evaluated for antituberculosis activity against Mycobacterium tuberculosis H ₃₇ Rv (ATCC 27294) in BACTEC 12B using a broth microdilution assay and Microplate Alamar Blue Assay (MABA). The preliminary results showed that compounds 4e, 4d and 4g had 87%, 93% and 92% inhibitory effect respectively.     

Synthesis of 5-(thiazol-5-yl)-4,5-dihydroisoxazoles from 3-chloropentane-2,4-dione

Condensation of 3-chloropentane-2,4-dione with thioamides gives 1-(thiazol-5-yl)ethanones and subsequent Wittig olefination, followed by nitrile oxide 1,3-dipolar cycloaddition to the resulting prop-1-en-2-yl moiety, delivers racemic 5-(thiazol-5-yl)-4,5-dihydroisoxazoles. When this thiazole and isoxazoline diheterocyclic scaffold has a carboethoxy substituent at C2 of the thiazole ring, aminolysis provides for effective diversification. A 50-member library of various 5-(thiazol-5-yl)-4,5-dihydroisoxazoles is reported.     

Reaction of 3-(alken-1-yl)-4,5-dihydro-3H-pyrazoles with sodium nitrite in acetic acid

3-Vinyl-4,5-dihydro-3H-pyrazole reacted with sodium nitrite in acetic acid to give 3-vinyl-1-nitroso-4,5-dihydro-1H-pyrazole, whereas 3-isopropenyl-4,5-dihydro-3H-pyrazole under analogous conditions was unexpectedly converted into a nitro derivative, 3-(1-methyl-2-nitrovinyl)-4,5-dihydro-1H-pyrazole.     

Synthesis,characterization and antimicrobial activity of a Zn(II) complex with 1-(1H-benzoimidazol-2-yl)-ethanone thiosemicarbazone

A new Zn(II) complex with 1-(1H-benzoimidazol-2-yl)-ethanone thiosemicarbazone [Zn(NO₃)(H₂O)(C₁₀H₁₁N₅S)]NO₃ was prepared and characterized by elemental analyses, FT-IR, ¹H NMR spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD), and single-crystal X-ray diffraction analysis. The coordination geometry of the pentacoordinated zinc is a distorted square pyramid. The antimicrobial activity of the complex was evaluated using a broth micro-dilution method against a panel of human pathogenic Gram positive, Gram negative bacteria and the yeast Candida albicans. The best inhibitory effect was observed against Enterobacter aerogenes (MIC = 0.031 mg mL^?1).     

From Levulinic Acid to Biheterocycles: Synthesis of 1-[(5-Hydroxy-5-trifluoromethyl-3-substituted-4,5-dihydro-1H-pyrazol-1-yl)-3-(5-trifluoromethyl-1H-pyrazol-3-yl)propan-1-ones

We develop an efficient method to synthesize novel propionyl-spaced bisheterocyclic compounds. It entails cyclocondensation of 3-(5-trifluoromethyl-1H-pyrazol-3-yl)propanoyl hydrazide obtained from levulinic acid, with 1,1,1-trifluoro-4-methoxy-3-alken-2-ones proceeding regiospecifically to 1-[(5-trifluoromethyl-5-hydroxy-3-substituted-4,5-dihydro-1H-pyrazol-1-yl)-3-(5-trifluoromethyl-1H-pyrazol-3-yl)propan-1-one derivatives.     

Synthesis of 3-(Benzotriazol-1-yl)naphthoquinone Derivatives

2,3-Bis(benzotriazol-1-yl)-1,4-naphthoquinone reacts with aliphatic and aromatic amines to give the corresponding 2-amino-3-(benzotriazol-1yl)-1,4-naphthoquinones, and its reaction with alkali gives 2-hydroxy-3-(benzotriazol-1-yl)-1,4-naphthoquinone.     

Synthesis and photochromism of dimers of 4,5- diaryl-2-(2,5-dimethylthiophen-3-yl)imidazolyl

4,5-Diphenyl, 4,5-di(4-methylphenyl), 4,5-di(4-methoxyphenyl)-2-(2,5-dimethylthioph-en-3-yl)imidazoles were synthesized. Oxidation of the obtained imidazoles with potassium ferricyanide in water-alcohol solution of alkali gave the corresponding dimers. The structures were characterized by IR, 1H NMR, mass spectroscopy and elemental analysis. The dimers showed photochromism in solution on irradiation.     

Synthesis of 1-(1,2,4-triazol-3-yl)-1,2,3-triazoles

1-(1,2,4-Triazol-3-yl)-1,2,3-triazoles were obtained by 1,3-dipolar cycloaddition of 3-azido-1,2,4-triazole to acetylene derivatives. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 262–264, February, 1980.     

Synthesis and structures of two novel non-centrosymmetric metal-organic polymers containing 2-(pyridin-4-yl)-1H-imidazole-4,5-dicarboxylic acid ligands

Two novel non-centrosymmetric coordination polymer, [Zn₂(PIDC)(H₂O)Cl]_n (1) and {[Mn(HPIDC)H₂O]·2H₂O}_n (2) have been synthesized through hydrothermal method and characterized by IR, elemental analysis and single-crystal X-ray diffraction. Complex 1 crystallized in a chiral space group P2₁2₁2₁ has a 2D network structure. Complex 2 is a 3D open framework with 1D channel where 1D zigzag water chains are reside through hydrogen-bonding interactions and crystallized in a chiral space group C_c. Both 1 and 2 display a strong second harmonic generation (SHG) response.     

Synthesis of functional derivatives of isothiazole and isoxazole basing on (5-arylizoxazol-3-yl)- and (4,5-dichloroisothiazol-3-yl)arylmethanol

From (4,5-dichloroisothiazol-3-yl)phenylmethanol by Ritter reaction a substituted acetamide was synthesized that at hydrolysis with HCl afforded (4,5-dichloroisothiazol-3-yl)phenylmethylamine hydrochloride. By reaction of (5-arylisoxazol-3-yl)- and 4,5-dichloroisothiazol-3-yl)arylmethanol with thionyl chloride the corresponding (1,2-azol-3-yl)arylchloromethanes were obtained. At treatment with O- and N-nucleophiles chlorine atom in chloromethylеne fragment of obtained compounds was substituted by residues of benzylamine, morpholine, vanillin, and ethoxy group.     

Synthesis of photosensitizer pairs containing Ru(bpy)3 2+ and an electron acceptor (viologen) linked by a hydrocarbon chain

Conclusions Two Ru(bpy)₃ ²⁺-viologen complexes, in which the components are linked by a hydrocarbon chain, were synthesized and characterized by PMR, visible, and UV spectrophotometry.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 700–703, March, 1989.