A series of new 3-substitutedphenyl-4-substitutedbenzylideneamino-1,2,4-triazole Mannich bases and bis-Mannich bases were synthesized through Mannich reaction with high yields. Their structures were confirmed by means of IR, 1H NMR, 13C NMR and elemental analysis. The preliminary bioassay indicated that compounds 7g, 7h and 7l exhibited potent in vitro inhibitory activities against ketol-acid reductoisomerase (KARI) with Ki value of (0.38 ± 0.25), (6.59 ± 2.75) and (8.46 ± 3.99) μmol/L, respectively, and were comparable with IpOHA. They could be new KARI inhibitors for follow-up research. Some of the title compounds also exhibited obvious herbicidal activities against Echinochloa crusgalli and remarkable in vitro fungicidal activities against Physalospora piricola and Rhizoctonia cerealis. The SAR of the compounds were analyzed, in which the molecular docking revealed the binding mode of 7g with the KARI, and the 3D-QSAR results provided useful information for guiding further optimization of this kind of structures to discover new fungicidal agents towards Rhizoctonia cerealis.Download high-res image (73KB)Download full-size image

A series of fluorine- and piperazine-containing 1,2,4-triazole thione derivatives were synthesized by the Mannich reaction of triazole intermediates with various substituted piperazines and formaldehyde in high yields. Structures of title compounds were confirmed by melting points, IR, 1H NMR, 13C NMR and elemental analysis. The preliminary bioassays for 17 novel title compounds showed that several compounds have significant fungicidal activity against Cercospora arachidicola, Physalospora piricola and Rhizoctonia cerealis at 50 μg/mL.A series of novel fluorine- and piperazine-containing 1,2,4-triazole thione derivatives were synthesized by the Mannich reaction of triazole intermediate in high yields. Their herbicidal and fungicidal activities were evaluated.

⿢27 novel phenylpyrazole- and piperazine-containing (bis)1,2,4-triazole thiones were synthesized.⿢Several compounds exhibited significant fungicidal activities.⿢The compounds with two CF3 groups on triazole and pyrazole rings had excellent fungicidal activities.⿢VIIIg, IXi, IXo and IXp could be used as new fungicide lead compounds.A series of novel 1,2,4-triazole thione and bis(1,2,4-triazole thione) derivatives containing phenylpyrazole and substituted piperazine moieties have been conveniently synthesized via Mannich reaction using various 1,2,4-triazole thiols, substituted piperazines, and formaldehyde at room temperature in short time. Their structures were confirmed by IR, 1H NMR, 13C NMR and elemental analysis. The preliminary bioassays for 27 new title compounds have shown that some of them possess certain herbicidal activities against Echinochloa crusgalli at 100 μg/mL concentration. Some of the compounds exhibited significant in vitro fungicidal activities, especially against Cercospora arachidicola and Rhizoctonia cerealis at the concentration of 50 μg/mL, and were comparable with that of control Triadimefon. Meanwhile, IXp held the control efficacy of 60% against Puccinia sorghi Schw. at 200 μg/mL concentration in the in vivo test. The SAR analysis has indicated that compounds with two CF3 groups both on triazole and pyrazole rings are more effective than compounds with one CF3 group or two CH3 groups according to their fungicidal activity data. On the whole, compounds VIIIg, IXi, IXo and IXp could be used as novel lead structures for the design and discovery of new fungicides.A series of novel phenylpyrazole- and piperazine-containing (bis)1,2,4-triazole thiones were synthesized via Mannich reaction in high yields. The compounds with two CF3 groups exhibited excellent fungicidal activities.

A series of novel 5-substituted-1,3,4-oxadiazole Mannich bases and bis-Mannich bases have been conveniently synthesized in good yields. Their structures were characterized by IR, 1H NMR, 13C NMR and elemental analysis. The preliminary bioassay results indicated that some of the compounds showed promising in vitro fungicidal activities towards several test plant fungi; some of them exhibited significant herbicidal activities against Brassica campestris and excellent in vitro inhibitory activities against rice ketol-acid reductoisomerase (KARI). Among 14 novel compounds, 8c, 8d and 8m showed potent KARI inhibitory activities with Ki value of (0.96 ± 0.42), (3.86 ± 0.49) and (3.10 ± 0.71) μmol/L, respectively, and were comparable with IpOHA. These compounds could be novel KARI inhibitors for further investigation. The density functional theory (DFT) calculations and molecular docking were carried out to study the structure–activity relationship (SAR) of the active inhibitors in this Letter.

Two series of novel anthranilic diamides containing oxime ester and diacylhydrazine moieties were designed and synthesized. Their structures were characterized by melting points, 1H NMR, 13C NMR and high resolution mass spectrometry(HRMS). The single crystal structure of compound 7e was determined by X-ray diffraction and their evaluated insecticidal activity against oriental armyworm(Mythimna separata) indicates that some of the compounds exhibited moderate insecticidal activities. Among the 20 compounds, 6a and 6b show 100% larvicidal activity against Mythimna separate Walker at the test concentration of 100 mg/L.