Synthesis of novel 1,2,3-thiadizoles and 1,2,3-selenadiazoles as new antimicrobial agents

Abstract

A series of novel 1,2,3-thiadiazoles and 1,2,3-selenadiazoles having a long alkyl chain were synthesized by reacting semicarbazones with SOCl₂ and SeO₂, respectively. The structures of the target compounds 5–12 were confirmed by spectroscopy (IR, ¹H NMR, ¹³C NMR, and MS) and elemental analysis. Their antibacterial and antifungal activities were evaluated against six bacteria (Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Enterococcus faecalis, Staphylococcus epidermidis, Staphylococcus aureus) and three fungi (Candida albicans, Candida parapsilosis, Candida tropicalis). The results of bioassays indicated that the compounds 5-Dodecyl-4-(4-methoxy-phenyl)-[1-3]selenadiazole (7), 4-Methyl-5-tetradecyl-[1-3]selenadiazole (8) and 5-Dodecyl-4-(4-methoxy-phenyl)-[1-3]thiadiazole (11) displayed moderate antibacterial activity against S. Epidermidis. On the other hand, according to antifungal screening results, compounds 5-Dodecyl-4-phenyl-[1-3]selenadiazole (5), 4-p-Tolyl-5-undecyl-[1-3]selenadiazole (6), and 5-Dodecyl-4-(4-methoxy-phenyl)-[1-3]selenadiazole (7) exhibited significant antifungal activities studied yeast strains.     

A new synthesis of 3,4-disubstituted 1,2,5-thiadiazoles

A simple and convenient reduction of 3,4-diamino derivatives of 2,5-thiadiazole-1-oxide to the corresponding 1,2,5-thiadiazoles has been accomplished using Ph₃P and CCl₄ in dichloromethane.     

Reaction of 5-Hydrazono-1,2,3-thiadiazoles with Toluene and Xylene in the Presence of PCl5

The treatment of 5-hydrazono-1,2,3-thiadiazoles by phosphorus pentachloride in toluene or xylene leads to an anomalous Dimroth rearrangement and the reaction of the mercapto function formed with the methyl group of the solvent to give 5-benzylmercapto-1,2,3-triazole.     

A new synthetic method for the 2H-[1,2,3]thiadiazolo[5,4-b]indoles

The systematic study of oxidative cyclization of 3-hydrazono-1,3-dihydroindole-2-thiones has been carried out and a series of new 2H-[1,2,3]thiadiazolo[5,4-b]indoles has been prepared. The elaborated reaction represents an efficient method for the synthesis of fused 1,2,3-thiadiazoles.     

Synthesis of tetrazole containing 1,2,3-thiadiazole derivatives via U-4CR and their anti-TMV activity

A series of novel tetrazole containing 1,2,3-thiadiazole derivatives were designed and synthesized via Ugi reaction. Their structures were confirmed by melting points, IR, 1H NMR, and HRMS (ESI). Preliminary bioassay indicated that most target compounds exhibited very good direct anti-TMV activity at 100 μg/mL, which was equal to or higher than that of ribavirin. Among them, compounds 4b, 4c and 4i also showed equivalent protection effect to ribavirin in vivo at 100 μg/mL.     

Efficient,mild synthesis of N-unsubstituted 1,2,3-triazoles from methanolysis of 1-sulfonyl-1,2,3-triazoles

A small library of diverse N-unsubstituted 1,2,3-triazoles was prepared from the corresponding 1-sulfonyl-1,2,3-triazoles, which were treated only with MeOH at reflux temperature. This process was carried out in good yields showing high efficiency and good functional group tolerance.     

Metal-free synthesis of 1,2,3-benzotriazines

The recent molecular iodine catalyzed [1,2]-rearrangement of aryl amines and 3-amino-1H-indazolesfor the synthesis of 1,2,3-benzotriazines is highlighted.     

Antitumor Activity of Some Novel 1,2,5-Thiadiazole Derivatives

Some novel thiourea,1,2,4-triazole, quinazoline, thieno[2,3-d]pyrimi-dine, and thiazolidine derivatives were synthesized to evaluate their antitumor activity. Compound (3f) is nearly as active as reference drug, (Doxorubicin) as positive control.     

Synthese Des 2,3-Di(Pyrazolyl,Isoxazolyl et 1,2,3-Triazolyl) Methylsulfanylquinoxalines

Abstract

A one pot synthetic approach to the novel (pyrazolyl, isoxazolyl, triazolyl) methylsulfanylquinoxaline system respectively by 1,3-dipolar cycloaddition of diphenylnitrilimine, benzonitriloxide and benzylazide to 2,3-dipropargylmercaptoquinoxaline, is described. The structures of the obtained adducts have been assigned by means of spectroscopic measurements.     

An effcient and facile synthesis of novel 1,2,3-triazolyl-N- acylpyrazoline hybrids简

An efficient and facile synthesis of a library of hitherto novel 1,2,3-triazolyl-N-acetyl/N-propionylpyrazoline hybrids(16 examples) in excellent yields(90%–96%) has been accomplished from easily accessible 1,2,3-triazolyl chalcone precursors.     

Synthesis and Biological Activities of Novel 1,2,4-Triazole Derivatives Containing 1,2,3-Thiadiazole Ring

A series of novel 1,2,4-triazole derivatives containing 1,2,3-thiadiazole ring was designed and synthesized. Their structures were confirmed by IR, 1^H NMR, high resolution mass spectrometer（HRMS） and electrospray ionization-mass spectromcter（ESI-MS） combined with melting points and elemental analysis. Preliminary bioassays indi- cate that these compounds exhibit good insecticidal activity against Aphis laburni at 100 μg/mL, especially compound 6b shows mortality of no less than 95%. Most of the compounds show good activities against tobacco mosaic virus（TMV） with different modes in vivo at 100 μg/mL. Compound 6d standed out, showing a good insecticidal activity and very high induction effects against TMV in vivo. Collectively, our data demonstrate a new strategy for insect and virus control.     

含噻唑和1,2,3-三唑环的硫代磷酸肟酯的合成与生物活性

为了寻找高效、低毒的新型农用化学品,以2-氯-5-(氯甲基)噻唑为起始原料,设计合成了一系列新型含1,2,3-三唑和噻唑杂环的肟醚硫代磷酸酯衍生物,采用IR, 1H NMR, 31P NMR, MS和元素分析对其进行了结构表征。初步生物活性测试结果表明：该系列化合物具有中等程度的杀虫和杀菌活性。     

Regiospecific solid-phase synthesis of substituted 1,2,3-triazoles

A traceless and regiospecific solid-phase synthesis of substituted 1,2,3-triazoles is developed using polystyrene-sulfonyl hydrazide resin. The chemistry is applicable to combinatorial library synthesis.     

Metal-free and azide-free synthesis of 1,2,3-triazoles derivatives

1,2,3-Triazoles, significant five-membered ring N-heterocycles, are main structural moieties in well-designed materials, pharmaceutical agents, bioactive products, and synthetic intermediates. In the research of life sciences and pharmaceuticals, by seeing the spacious applications of 1,2,3-triazoles, the progress of metal-free method is exceedingly desirable to evade the heterocyclic product metal contamination. Moreover, on a larger scale, the toxicity and explosiveness of azides makes azides discommode and hard to hold, to synthesize 1,2,3-triazoles. The need to steer the development of the synthesis of 1,2,3-triazoles toward more maintainable synthesis is a pressing issue. There are rare methods to construct 1,2,3-triazoles under azide-free and metal-free environments. These rare methods are compiled in this review. The afford of the collection and compilation of azide-free and metal-free synthesis methodologies of 1,2,3-triazole in single podium is supportive and crucial for synthetic chemist to extend the diversity of the synthesis of 1,2,3-trizoles through green protocol.     

Determination of the elastic constants of nematic liquid crystals by means of the affine transformation model

In this paper the affine connection approach will be used to calculate the elastic constants of nematic liquid crystals. Following this approach, which was originally conceived to compute the nematic viscosity coefficients, an expression for the elastic constants, without adjustable free parameters, will be formulated in terms of a temperature dependent metric, whose non‐isotropic part is proportional to the tensorial order parameter of the nematic phase. The dependence of the elastic constants on the scalar order parameter, in the geometry of the nematic molecules, and in the anisotropic part of the molecular interaction, will be determined.     

Reactions of 5-dialkylamino-1,2,3-thiadiazole-4-carbaldehydes with amines as a method for the synthesis of 1,2,3-triazole-4-carbothioamides

A method for the synthesis of previously inaccessible 5-dialkylamino-substituted 1,2,3-thiadiazole-4-carbaldehydes was developed. Ring transformation in these compounds induced by primary aliphatic and aromatic amines, hydroxylamines, and N-substituted hydrazines resulted in the synthesis of a broad range of 1,2,3-triazole-4-carbothioamide.     

Recent advances in the synthesis,structural diversity,and applications of mesoionic 1,2,3-triazol-5-ylidene metal complexes

Beyond the classic N-heterocyclic carbenes (NHCs) there is a subclass of NHCs called mesoionic carbenes (MICs). This review focuses on recent advances in the area of 1,2,3-triazol-5-ylidenes as the most abundant class of MICs and their metal complexes. The study of mesoionic 1,2,4- and 1,3,4-trisubstituted 1,2,3-triazol-5-ylidene transition metal complexes is a research area with a history of just ～10 years. During this relatively short period, hundreds of these complexes have appeared in the literature, reflecting their high stability and simpler synthesis compared with NHCs. Specifically, this review is focused on advances in the synthesis of 1,2,3-triazol-5-ylidene metal complexes derived from palladium, silver, gold, ruthenium, iridium, rhodium, iron, molybdenum, cobalt, nickel, platinum, and osmium, together with their catalytic, medicinal, and photophysical applications.     

Application of the hurd-mori-reaction for the synthesis of tricyclic annelated 1,2,3-thiadiazoles

The synthesis of methyl naphtho[1,2-d][1,2,3]thiadiazole-4-carboxylate 1a as well as the corresponding thienobenzo[1,2,3]thiadiazoles 1b and 1c is reported using the Hurd-Mori reaction in the key step. Treatment of the readily available tosylhydrazones 10a-c with thionyl chloride surprisingly affords the fully aromatic products 1a-c , instead of the expected annelated 4,5-dihydro[1,2,3]thiadiazoles 2a-c . Based on these results a mechanism for the aromatization step with thionyl chloride is proposed.     

Functionalized graphene oxide supported copper (I) complex as effective and recyclable nanocatalyst for one‐pot three component synthesis of 1,2,3‐triazoles

Efficient, one pot three‐component reaction of alkyl halides, sodium azide with terminal alkynes can be catalyzed by functionalized graphene oxide with copper(I) under thermal conditions. A series of 1,4‐disubstituted 1,2,3‐triazoles were obtained by this one‐pot strategy. The catalyst was prepared and characterized by Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), emission scanning electron microscopy (FE‐SEM) and energy dispersive X‐ray (EDX). The catalyst can be reused at least five times without significant deactivation.