Synthesis and insecticidal activities of novel 1,3,4-thiadiazole 5-fluorouracil acetamides derivatives: an RNA interference insecticide

Efficient Synthesis and Bioactivity of Novel Triazole Derivatives

Triazole pesticides are organic nitrogen-containing heterocyclic compounds, which contain 1,2,3-triazole ring. In order to develop potential glucosamine-6-phosphate synthase (GlmS) inhibitor fungicides, forty compounds of triazole derivatives were synthesized in an efficient way, thirty nine of them were new compounds. The structures of all the compounds were confirmed by high resolution mass spectrometer (HRMS), ¹H-NMR and ¹³C-NMR. The fungicidal activities results based on means of mycelium growth rate method indicated that some of the compounds exhibited good fungicidal activities against P. CapasiciLeonian, Sclerotinia sclerotiorum (Lib.) de Bary, Pyricularia oryzae Cav. and Fusarium oxysporum Schl. F.sp. vasinfectum (Atk.) Snyd. & Hans. at the concentration of 50 µg/mL, especially the inhibitory rates of compounds 1-d and 1-f were over 80%. At the same time, the preliminary studies based on the Elson-Morgan method indicated that the compounds exhibited some inhibitory activity toward glucosamine-6-phosphate synthase (GlmS). These compounds will be further studied as potential antifungal lead compounds. The structure-activity relationships (SAR) were discussed in terms of the effects of the substituents on both the benzene and the sugar ring.

Design, synthesis and bioactivity of novel glycosylthiadiazole derivatives

A series of novel glycosylthiadiazole derivatives, namely 2-phenylamino-5-glycosyl-1,3,4-thiadiazoles, were designed and synthesized by condensation between sugar aldehydes A/B and substituted thiosemicarbazide C followed by oxidative cyclization by treating with manganese dioxide. The original fungicidal activities results showed that some title compounds exhibited excellent fungicidal activities against Sclerotinia sclerotiorum (Lib.) de Bary and Pyricularia oryzae Cav, especially compounds F-5 and G-8 which displayed better fungicidal activities than the commercial fungicide chlorothalonil. At the same time, the preliminary studies based on the Elson-Morgan method indicated that many compounds exhibited some inhibitory activity toward glucosamine-6-phosphate synthase (GlmS). The structure-activity relationships (SAR) are discussed in terms of the effects of the substituents on both the benzene and the sugar ring.

Synthesis and Insecticidal Evaluation of Aryl Pyrazole 5-Fluorouracil Compounds

Twenty eight aryl pyrazole derivatives containing 5-fluorouracil were designed and synthesised via the key intermediate 1-aryl-3-methyl-1 H-pyrazole-5-carboxylic acid. The structures of target compounds were confirmed by 1H NMR, FT-IR, EA and their insecticidal activities were evaluated. The bioassays revealed that aryl pyrazole derivatives containing 5-fluorouracil exhibited excellent insecticidal activities against Culex pipiens and Musca domestica at a concentration of 0.1%. Some compounds still showed good insecticidal activities even at a concentration of 0.05%.

Synthesis, Insecticidal Evaluation of Novel 1,3,4-Thiadiazole Chrysanthemamide Derivatives formed by an EDCI/HOBt Condensation

A series of novel pesticides with two components derived from a 1,3,4-thiadiazole and chrysanthemic acid were synthesised via an EDCI/HOBt condensation. These 1,3,4-thiadiazole chrysanthemamides were identified by IR, 1H NMR and elemental analyses. Their insecticidal activity was also evaluated.