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Two pyrazol-4-carboxamides, 3-(difluoromethyl)-N-(mesitylcarbamoyl)-1-methyl-1H-pyrazole-4-carboxa-mide (7a) and 3-(difluoromethyl)-N-((3,5-dimethylphenyl) carbamoyl)-1-methyl-1H-pyrazole-4-carboxamide (7b) were synthesized and their structures were confirmed by the aid of 1H NMR and HRMS analyses. The structure of the pyrazole-4-carboxamide, 7a was also determined by X-ray diffraction. The preliminary activity results demonstrate that these two compounds exhibit good inhibitory activity against Botrytis cinerea. Further docking results indicated that the key active group is difluoromethyl pyrazole moiety.

Natural products are a source for pesticide or drug discovery. In order to discover lead compounds with high fungicidal or herbicidal activity, new niacinamide derivatives derived from the natural product niacinamide, containing chiral flexible chains, were designed and synthesized. Their structures were confirmed by 1H NMR, 13C NMR and HRMS analysis. The fungicidal and herbicidal activities of these compounds were tested. The fungicidal activity results demonstrated that the compound (S)-2-(2-chloronicotinamido)propyl-2-methylbenzoate (3i) exhibited good fungicidal activity (92.3% inhibition) against the plant pathogen Botryosphaeria berengriana at 50 μg/mL and with an EC50 of 6.68 ± 0.72 μg/mL, which is the same as the positive control (fluxapyroxad). Compound 3i was not phytotoxic and could therefore be used as a fungicide on crops. Structure-activity relationships (SAR) were studied by molecular docking simulations with the succinate dehydrogenase of the fungal mitochondrial respiratory chain. [ABSTRACT FROM AUTHOR]

A series of pyrazole derivatives was designed according to prodrug strategy. These compounds were synthesized via eight steps and their structures were confirmed by 1H NMR spectroscopy and MS. The preliminary herbicidal bioassay results indicated that the title pyrazole ketone compounds exhibited low herbicidal activity against six weeds at 150 g/ha, which is weaker than that of the commercial HPPD herbicide topramezone. The docking results showed that the binding mode of the key intermediate (3-(2-(2-fluorophenoxy)ethoxy)-2-methyl-4-(methylsulfonyl)phenyl)(5-hydroxy-1,3-dimethyl-1H-pyrazol-4-yl)methanone is the same as the reported inhibitor DAS689 in the complex. [ABSTRACT FROM AUTHOR]

A series of new acyl thiourea derivatives containing difluoromethyl pyrazole moiety were designed and synthesized. Their structures were confirmed by 1H NMR, 31C NMR, MS and HRMS. The bioassay results showed that some of title compounds exhibited good in vivo fungicidal activity against Botrytis cinerea and Fusarium oxysporum and good antibacterial activity against Pseudomonas syringae pv. Lachrymans at 50 mg/L respectively. [ABSTRACT FROM AUTHOR]

BACKGROUND Quinoline derivatives possess excellent fungicidal activity against rice blast, but quinoline derivatives have not been thoroughly explored as fungicides. In the process of designing new fungicides, the 1,1,1,2,3,3,3-heptafluoropropan-2-yl group was introduced in order to find new structure quinoline derivatives. RESULTS Seventeen new quinoline derivatives containing 1,1,1,2,3,3,3-heptafluoropropan-2-yl moiety were designed and synthesised. In vivo fungicidal activities of these compounds were tested against rice blast. Some of the compounds provided effective control at 100 mg L−1, and a few compounds were effective at 10 mg L−1. Furthermore, a density functional theory study established the structure-activity relationships of the synthesised compounds. CONCLUSION Quinoline derivatives, especially benzyl (2,3,8-trimethyl-6-(perfluoropropan-2-yl)quinolin-4-yl) carbonate, which possess good control effective against rice blast and cucumber powdery mildew, may become new lead compounds for the development of fungicides with further structure modification. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

BACKGROUND Aedes aegypti is a major mosquito vector for the transmission of serious diseases, especially dengue and yellow fever. More than 1 billion people in developing countries are at risk. The widespread and continual use of pesticides can lead to resistant mosquitoes. In order to maintain mosquito control gains, it is critical to develop and evaluate novel bioactive molecules that differ in mode of action from currently used products. RESULTS A series of novel pyrimidine derivatives were designed and synthesized. Their structures were elucidated by proton nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry. The biological activities of these compounds were tested against Ae. aegypti. Many of them exhibited insecticidal activity against adult and larval mosquitoes. Compound 4d displayed relatively good activity to reach 70% mortality at 2 µg mL−1. Furthermore, density functional theory calculations were established to study the structure-activity relationship of these novel compounds. CONCLUSION A practical synthetic route for pyrimidine derivatives is presented. This study suggests that these pyrimidine derivatives exhibit some activity against the yellow fever mosquito and, with further structure modification, could be novel lead compounds for the development of insecticides against mosquitoes. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Some new sulfoxide compounds containing 1,2,3-thiadiazole moiety were synthesized from diethyl carbonate and hydrazine hydrate by multi-step reactions. Their structures were confirmed by NMR, MS, and elemental analysis. One of the title compounds, 5-(4-cyclopropyl-5-((3-fluorobenzyl)sulfinyl)-4H-1,2,4-triazol-3-yl)-4-methyl-1,2,3-thiadiazole (C15H14FN5OS2), was structurally determined by a single crystal X-ray diffraction study. The biological activity of the title compound was determined, and the results showed that it displays moderate biological activities. [ABSTRACT FROM PUBLISHER]

BACKGROUND 1,2,4-Triazolo[4,3-a]pyridine derivatives represent a new series of compounds that possess good herbicidal activity against Echinochloa crusgalli (L.) Beauv., Setaria faberii, Digitaria sanguinalis (L.) Scop., Brassica juncea Coss., Amaranthus retroflexus L. and Eclipta prostrata L. RESULTS A total of 23 novel 1,2,4-triazolo[4,3- a]pyridine derivatives were synthesised and identified by 1H NMR, IR, single-crystal X-ray diffraction, mass-spectroscopic and elemental analysis, and their herbicidal activities were tested against E. crusgalli (L.) Beauv., S. faberii, D. sanguinalis (L.) Scop., B. juncea Coss., A. retroflexus L. and E. prostrata L. at 150 g a.i. ha−1. It was found that the title compound 8-chloro-3-(4-propylphenyl)-[1,2,4]-triazolo[4,3- a]pyridine possesses high herbicidal activity and a broad spectrum against the 22 test weeds, with an inhibition effect of about 50% at a dosage of 37.5 g a.i. ha−1, and is safe for corn, cotton and rice at a dosage of 150 g a.i. ha−1. Furthermore, comparative molecular field analysis contour models were established to study the structure-activity relationship of the title compounds. CONCLUSION It is possible that, with further structure modification, 1,2,4-triazolo[4,3- a]pyridine derivatives, which possess good herbicidal activities, may become novel lead compounds for the development of herbicides against dicotyledonous weeds. © 2014 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

A new 1,2,3-thiadiazole compound containing 1,2,4-triazole moiety, C15H14FN5O2S2, has been synthesized and the crystal structure was determined by single crystal X-ray diffraction study. The biological activity of the title compound was determined and the results showed that title compounds10showed higher inhibition abilities of rape root than the control cyclopropane-1,1-dicarboxylic acid at 100 μg/mL (73%) and weak activity against Echinochloa crusgalli (28%) and KARI (35%) at 100 μg/mL. [Supplementary materials are available for this article. Go to the publisher's online edition ofPhosphorus, Sulfur, and Silicon and the Related Elementsfor the following free supplemental files: additional text, figures, tables.] [ABSTRACT FROM AUTHOR]

A new 1,2,3-thiadiazole compound, C18H18Cl2N4O2S, has been synthesized and the crystal structure was determined by single crystal X-ray diffraction study. The fungicidal activity of the title compound was determined and the results showed that it displays moderate fungicidal activity. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. [ABSTRACT FROM PUBLISHER]

A new triazole compound, C46H46N10O2S2, has been synthesized, and the crystal structure was determined by a single crystal X-ray diffraction study. The fungicidal activity of the title compound was determined, and the results showed that it displays moderate fungicidal activity. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. GRAPHICAL ABSTRACT[image omitted] [ABSTRACT FROM AUTHOR]

A series of novel substituted 8-chloro-6-(trifluoromethyl)-[1,2,4]triazolo[4,3-a]pyridines are synthesised from 2,3-dichloro-5-(trifluoromethyl)pyridine, hydrazine hydrate as starting materials by multi-step reactions under microwave irradiation. Their chemical structures can be characterised by 1H NMR, MS and elemental analysis. The title compounds exhibit weak antifungal activity. [ABSTRACT FROM AUTHOR]

Abstract Fifteen novel stilbene analogues containing thiazole moiety were designed and synthesized. The structure of the synthesized compounds was confirmed by 1H NMR, 13C NMR and ESI-HRMS. These compounds were screened for their topoisomerase I inhibitory activity using Top1-mediated relaxation assay, and compound 6n displayed promising Top1 inhibitory activity. Molecular docking was established to study the structure-activity relationship of the title compounds and a good correlation was observed between Top1 inhibitory activity and molecular docking study. Furthermore, in vitro antifungal activities of these compounds were evaluated against FusaHum graminearum, Mycosphaerella melonis and Thanatephorus cucumeris respectively. Some compounds possessed moderate antifungal activity at 50 mg/L, while compound 6i displayed 70.1% inhibition against F. graminearum and 6o showed 61.6% inhibition against M. melonis. Graphical abstract A series of novel stilbene analogues containing thiazole moiety have been synthesized and evaluated for their Top1 inhibitory activity and in vitro antifungal activity. The mode of action was also investigated by molecular docking study. Image 1 Highlights • Novel stilbene analogues containing thiazole moiety were designed and synthesized. • Evaluated for their Top1 inhibitory activity and in vitro antifungal activity. • Compound 6n displayed promising Top1 inhibitory activity. • The mode of action was investigated by molecular docking study. • Some compounds possessed moderate antifungal activity at 50 mg/L. [ABSTRACT FROM AUTHOR]

Thirteen novel trifluoromethylpyrazole acyl urea derivatives were designed and synthesized. In vivo fungicidal activities of these compounds were tested against Fusarium oxysporum, Corynespora mazei, Botrytis cinerea and Pseudomonas syringae respectively, particularly compounds exhibited significant control effective at 100 mg/L. More importantly, some compounds showed the good control effective at 10 mg/L. Furthermore, docking was established to study the structure-activity relationship of the title compounds. It is possible that trifluoromethylpyrazole acyl urea derivatives, which possess good control effective against Fusarium oxysporum, Corynespora mazei and Botrytis cinerea , may become novel lead compounds for the development of fungicides with further structure modification. [ABSTRACT FROM AUTHOR]