BACKGROUND 4‐Hydroxyphenylpyruvate dioxygenase (HPPD, EC 1.13.11.27) has been a good target for herbicide discovery. In order to discover novel HPPD herbicides, a series of pyrazole aromatic ketone analogs were designed and synthesized. RESULTS The 25 pyrazole aromatic ketone analogs synthesized were tested for herbicidal activity and compounds A1, A3, A4, A17, A20 and A25 displayed excellent herbicidal activity against Chenopodium serotinum, Stellaria media and Brassica juncea at 37.5 g ha−1. In addition, compounds A1, A5, A9, A10, A16, A17, A20 and A25 exhibited good crop selectivity for wheat, maize and rice at 150 g ha−1. Inhibition activities against AtHPPD proved the compounds were HPPD inhibitors. The structure–activity relationship of these pyrazole aromatic ketone analogs was studied using molecular docking. CONCLUSION These pyrazole aromatic ketone derivatives could be used as lead structures for development of HPPD herbicides against dicotyledonous weeds with further structure modification. © 2019 Society of Chemical Industry

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A series of 3-arylisoxazoline-pyrazole-5-carboxamide derivatives derived from ethyl 5,5-dimethoxy-2,4dioxopentanoate were designed, synthesized, and characterized by 1 H NMR, 13 C NMR and HRMS. The preliminary bioassay indicated that most title compounds exhibited positive potency against Mythimna separate (Walker) at 500 mg/L. At the concentration of 100 mg/L, three compounds were still moderately active against Mythimna separate (Walker) (lethal rate≈ 60%). At 500 mg/L, four compounds were also active against Aphis craccivora. The results indicated that the potential of these 3-arylisoxazoline-pyrazole-5-carboxamide derivatives can be utilized in insecticide research with further optimization.

9-Nitrocamptothecin has shown potent antitumor activity against many types of human cancers. A practical scale-up procedure for this compound is reported by selective reduction of corresponding sulfonate.