Novel thiosemicarbazone derivatives containing benzimidazole moiety: Green synthesis and anti-malarial activity

A series of (E)-2-[5-chloro-1-(1H-benzo[d]imidazol-2-yl)ethylidene] N-(substituted) hydrazine carbothioamide (7a–7t) and (E)-2-[1-(1H-benzo[d]imidazol-2-yl)ethylidene] N-(substituted) hydrazine carbothioamide (8a–8t) were prepared via the synthesis of 1-(substituted-1H-benzimidazol-2-yl) ethanol (3a–3b) which was synthesized by the condensation of substituted o-phenylenediamine (2a–2b) with dl-lactic acid (1) followed by oxidation with sodium hypochlorite in mild acidic condition to form the corresponding ketones 4a–4b. Final compounds were formed by condensation of 4a–4b with different thiosemicarbazides 6a–6t. A total of 40 compounds were synthesized and characterized by FT-IR, ¹H NMR, ¹³C NMR, Mass spectral technique and elemental analysis, in addition they were evaluated for anti-malarial properties. Among the compounds tested 7o, 7p, 7q, 7r, 7s, 8e and 8h exhibited good antimalarial activity in vitro.     

Novel pyrethrin derivatives containing an 1,3,4-oxadiazole thioether moiety: Design,synthesis, and insecticidal activity

In this study, a series of novel pyrethrin derivatives containing an 1,3,4-oxadiazole thioether moiety were designed and synthesized. Bioassay results revealed that some of the target compounds possessed excellent insecticidal activities against Plutella xylostella (P. xylostella), Vegetable aphids (V. aphids), and Empoasca vitis (E. vitis), respectively. In particular, compound 4l revealed the best insecticidal activities against P. xylostella and V. aphids, with the 50% lethal concentration (LC₅₀) values of 1.78 and 1.61 mg/L, respectively, meanwhile, compound 4k revealed the best insecticidal activity against E. vitis, with the LC₅₀ value of 1.06 mg/L, which were superior to those of the commercial insecticidal agents of chlorpyrifos, beta cypermethrin, spinosad, and azadirachtin. These results indicated that novel pyrethrin derivatives containing an 1,3,4-oxadiazole thioether moiety could effectively inhibit P. xylostella, V. aphids, and E. vitis.     

Design,synthesis and antiproliferative activities of diaryl urea derivatives bearing N-acylhydrazone moiety

A new series of diaryl urea derivatives bearing N-acylhydrazone moiety were designed and synthesized.All the target compounds were evaluated for their antiproliferative activities against human leukemia cell line(HL-60),human lung adenocarcinoma epithelial cell line(A549) and human breast cancer cell line(MDA-MB-231) in vitro by standard MTT assay.The pharmacological results indicated that some compounds exhibited promising antitumor activities.Compound 1j showed the most potent antiproliferative activity against the tested three cell lines with IC values of 0.13 mmol/L,0.7 mmol/L and 0.5 mmol/L,respectively.     

Two oxovanadium complexes incorporating thiosemicarbazones: synthesis,characterization, and DNA-binding studies

An oxovanadium complex [VO(satsc)(phen)] (1) (satsc?=?salicylaldehyde thiosemicarbazone, phen?=?phenanthroline) and its derivative [VO(3,5-dibrsatsc)(phen)] (2) (3,5-dibrsatsc?=?3,5-dibromosalicylaldehyde thiosemicarbazone) have been synthesized and characterized by elemental analysis, infrared, electrospray-mass spectra, ¹H NMR, and magnetic susceptibility measurements. The DNA-binding behaviors of these complexes with calf-thymus DNA (CT-DNA) were investigated by UV-Vis absorption titration, fluorescence spectra, viscosity measurements, thermal denaturation, and circular dichroism. Both 1 and 2 bind to CT-DNA by intercalation and 1 exhibits much stronger binding affinity to CT-DNA than 2.     

Soluble aromatic polyamide bearing ether linkages: synthesis and characterization

Soluble aromatic polyamide chains were prepared by reacting 4–4′-oxydianiline with isophthaloyl chloride in dimethylacetamide. To quench the HCl produced during the polymerization reaction, a stoichiometric amount of triethylamine was added. The precipitates formed were separated leaving behind clear polyamide resin. Thin and transparent film was obtained by evaporating the solvent and was subjected for Fourier transform infrared (IR), nuclear magnetic resonance (NMR), gel permeation chromatography, thermogravimetric analysis, differential scanning calorimetry, water absorption, and mechanical analyses. The transparent film was found to be soluble in dimethylacetamide, dimethyl sulfoxide, and dimethylformamide. IR and NMR spectroscopic analyses confirmed the structure of the polyamide while the gel permeation chromatography revealed the formation of a high-molecular-weight polymer. Thermogravimetry, differential scanning calorimetry, water absorption, and mechanical testing were also performed to further verify its physical properties. A soluble aromatic polyamide was successfully synthesized by solution polymerization and characterized. The polyamide has film-forming property, and the film is transparent, mechanically strong, and thermally stable.     

Substituted-nicotinyl thiourea derivatives bearing pyrimidine moiety: synthesis and biological evaluation

A series of substituted-nicotinyl thiourea derivatives containing pyrimidine ring were synthesized in good to excellent yield using PEG-400 as solid?Cliquid phase transfer catalyst under ultrasonic irradiation. The structures of all newly synthesized compounds were elucidated and confirmed by IR, ¹H NMR and elemental analysis. The preliminary biological tests show that some of the target compounds present good inhibitory activities against the root and stalk of dicotyledon plants and are safe for monocotyledon plants.     

Novel 1,3,4-oxadiazole thioether and sulfone derivatives bearing a flexible N-heterocyclic moiety: Synthesis,characterization, and anti-microorganism activity

In the search for more efficient and versatile anti-phytopathogen agents, a series of new 1,3,4-oxadiazole thioether/sulfone analogues bearing a flexible N-containing heterocyclic pattern were elaborately prepared, and their bioactivities against plant pathogenic microorganisms were systematically evaluated. Bioassay screening results demonstrated that compounds 32 and 33 significantly inhibited the growth of Xanthomonas oryzae pv. oryzae (Xoo) in vitro (32, EC₅₀ = 5.17 mg L^?1; 33, EC₅₀ = 1.19 mg L^?1), which were significantly surpass commercial bismerthiazol (BT) and thiodiazole copper (TC). Meanwhile, pot experiments confirmed the prospective applications of compound 33 in managing rice bacterial leaf blight and its good safety toward rice plants. Further studies showed that compound 33 interfered with the formation of bacterial biofilms and inhibited bacterial virulence factors. Furthermore, an in vitro antifungal bioassay showed that compound 32 possessed remarkable growth inhibitory activity against Sclerotinia sclerotiorum (S.s., EC₅₀ = 22.16 mg L^?1) and Verticillium dahlia (V.d. EC₅₀ = 32.78 mg L^?1). These results all confirmed that the designed 1,3,4-oxadiazole compounds displayed potential for managing plant microbial diseases through targeting dihydrolipoamide S-succinyltransferase (DLST).     

Design,synthesis, and insecticidal activity of novel isoxazole derivatives containing bisamide moiety

In this study, a total of 31 novel isoxazole derivatives containing bisamide moiety were synthesized and evaluated for their insecticidal activity against Plutella xylostella (P. xylostella). Bioassays indicated that some of the target compounds exhibited good insecticidal activity against P. xylostella. In particular, compound E26 revealed excellent insecticidal activity against P. xylostella, with a 50% lethal concentration (LC₅₀) value of 4.6 μg/mL, which was even better than those of chlorpyrifos (7.7 μg/mL), beta‐cypermethrin (12.8 μg/mL), and azadirachtin (10.2 μg/mL). These results indicated that isoxazole derivatives containing bisamide moiety could be developed as novel and promising insecticides. To the best of our knowledge, it is the first report on the insecticidal activity of this series of novel isoxazole derivatives containing bisamide moiety.     

Design, synthesis and in vitro antitumor evaluation of novel diaryl urea derivatives bearing sulfonamide moiety

A novel series of diaryl urea derivatives bearing sulfonamide moiety have been designed and synthesized.Their in vitro antitumor effect against human cancer cell lines MX-1,A375,HepG2,Ketr3 and HT-29 was screened and evaluated by the standard MTT assay with sorafenib as the positive control.Some of the compounds showed significant inhibitory activity against multiple cell lines compared to sorafenib.In particular,2,6-dimethyl-4-{6-[3-(4-chloro-3-(trifluoromethyl)phenyl)urea]naphthalen-2-yl}sulfonyl morpholine(10d)was found to be the most potent against A375,HepG2 and Ketr3 with IC50values of 0.65–0.97mol/L,which were 5–20-fold more potent than sorafenib.Compound 10d emerged as a valuable lead for further optimization.     

酰胺类喹唑啉酮衍生物的合成及抗菌活性

本文设计并合成了23个含酰胺结构单元的新型喹唑啉酮类化合物,经1 H NMR、13 C NMR和HRMS确证结构.在100μg·mL-1和50μg·mL-1浓度下,评价了它们对水稻白叶枯病菌、猕猴桃溃疡病菌和柑橘溃疡病菌的抑菌活性.结果表明,化合物对柑橘溃疡病菌有较强的抑制活性,并测定了6个化合物对柑橘溃疡病菌的EC5...     

Crystal structures of organomercury(II) derivatives of cyclohexanone and benzaldehyde thiosemicarbazones

The crystal and molecular structures of the organomercury(II) complexes [Hg(C₆H₅)(chtsc)], 1, and [Hg(C₆H₅C₅H₄N)(btsc)], 2, obtained from the reaction of phenylmercury(II) acetate with cyclohexanone thiosemicarbazone (Hchtsc) and that of [2-(pyridin-2′-yl)]phenyl]mercury(II) acetate with benzaldehyde thiosemicarbazone (Hbtsc), respectively, are described. Both 1 and 2 are monoclinic, space group C2/c. Complex 1 has a distorted T-shaped geometry {C-Hg-S, 161.91(10)°} and 2 can be considered to have a distorted seesaw geometry {C-Hg-S, 171.2(10)°}. In both complexes the ligands act as bidentate chelating anions bonding through azomethine N¹ and thiolato S atoms.     

Facile,one-pot synthesis of new phenanthridine derivatives through 1,4-dipolar cycloaddition of phenantridine,activated acetylenes,and aromatic aldehydes

A facile, one-pot synthesis of new phenanthridine derivatives by a three-component reaction between phenantridine, dialkyl acetylenedicarboxylates（DAADs）, and aromatic aldehydes is described. The reaction is characterized by mild conditions, high selectivity, and tolerance to various functional groups.     

Antimony(III) complexes with pyridine-derived thiosemicarbazones: Structural studies and investigation on the antitrypanosomal activity

The antimony(III) complexes [Sb(2Fo4Ph)Cl₂] (1), [Sb(2Ac4Ph)Cl₂] (2) and [Sb(2Bz4Ph)Cl₂] (3) were prepared with N(4)-phenyl-2-formyl- (H2Fo4Ph), 2-acetyl- (H2Ac4Ph) and 2-benzoylpyridine (H2Bz4Ph) thiosemicarbazones. The antimony(III) complexes presented antitrypanosomal activity against the epimastigote and trypomastigote forms of Trypanosoma cruzi. Complexes (1) and (2) exhibited higher activity than the reference drugs benznidazole and nifurtimox.     

Synthesis and antimicrobial activity of some acridone derivatives bearing 1,3,4-oxadiazole moiety

Novel acridone derivatives bearing 1,3,4-moiety were synthesized by intramolecular cyclization of N´-[2-(9-oxoacridin-10(9H)-yl)acetyl]arylhydrazides. Study of antimicrobial activity of the synthesized compounds reveals that some of them are more active than the comparator drug rivanol.     

Transformation of aromatic bromides into aromatic nitriles with n-BuLi,pivalonitrile, and iodine under metal cyanide-free conditions

Various aromatic nitriles could be obtained in good yields by the treatment of aryl bromides with n-butyllithium and then pivalonitrile, followed by the treatment with molecular iodine at 70 °C, without metal cyanides under transition-metal-free conditions. The present reaction proceeds through the radical β-elimination of imino-nitrogen-centered radicals formed from the reactions of imines and N-iodoimines under warming conditions. © 2019 Elsevier Science. All rights reserved.     

Novel pyrethrin derivatives containing hydrazone and 1,3,4-oxadiazole thioether moieties: Design,synthesis, and insecticidal activity

Abstract

A series of novel pyrethrin derivatives containing hydrazone and 1,3,4-oxadiazole thioether moieties were designed, synthesized, and evaluated for their insecticidal activity. Bioassays indicated that some of the target compounds exhibited good insecticidal activities against Plutella xylostella (P. xylostella), Vegetable aphids (V. aphids), and Empoasca vitis (E. vitis). In particular, compound (E)-2-((5-(2,2-dimethyl-3-(2-methylprop-1-en-1-yl)cyclopropyl)-1,3,4-oxadiazol-2-yl)thio)-N'-(4-(trifluoromethyl)benzylidene)acetohydrazide (6s) revealed excellent insecticidal activities against P. xylostella, V. aphids, and E. vitis with the 50% lethal concentration (LC₅₀) values of 5.23, 7.07, and 1.61?mg/L, respectively, which were similar to or even better than those of chlorpyrifos, beta cypermethrin, spinosad, and azadirachtin. These results indicated that novel pyrethrin derivatives containing hydrazone and 1,3,4-oxadiazole thioether moieties could be developed as novel and promising insecticides.     

Novel aroylhydrazine-amide derivatives bearing pyridine core: synthesis,characterisations and selective colorimetric recognition properties

Four aroylhydrazine-amides receptors AR1-4 with a hydrazine spacer have been designed, synthesised and characterised as novel colorimetric chemosensors by typical spectroscopic techniques. The receptors AR1–3 exhibited certainly selectivity and sensitivity towards F^?  and AcO^? , forming 1:1 stoichiometry complex by hydrogen-bond interaction. Furthermore, AR4 has especially shown obvious colour change in the presence of these two important biologically anions.     

Synthesis and in vitro antimicrobial activity of N-arylquinoline derivatives bearing 2-morpholinoquinoline moiety

A new series of N-arylquinoline derivatives 5a-x bearing 2-morpholinoquinoline moiety has been synthesized by one pot base catalyzed cyclocondensation reaction of 2-morpholinoquinoline-3-carbaldehydes 2a-c,malononitrile 3 andβ-enaminones 4a-h. All the synthesized compounds were screened for their in vitro antimicrobial activity against six bacterial pathogens,namely Streptococcus pneumoniae,Clostridium tetani,Bacillus subtilis,Salmonella typhi,Vibrio cholerae,Escherichia coli and against two fungal pathogens,Aspergillus fumigatus and Candida albicans using broth microdilution MIC method.Of the compounds studied,majority of the compounds were found to active against C.tetani,B.subtilis and C.albicans as compared to first-line standard drugs.     

One-pot synthesis of polyfunctionalized 4H-pyran derivatives bearing fluorochloro pyridyl moiety

Polyfunctionalized 4H-pyran derivatives bearing fluorochloro pyridyl moiety were readily prepared in high yields via one-pot multicomponent reaction catalyzed by piperidine. This present protocol provides an efficient synthetic route to the target compounds with the characteristics of short reaction time, high yield, and easy separation of the products.