Novel HPPD inhibitors: triketone 2H-benzo[b][1,4]oxazin-3(4H)-one analogs.

BACKGROUND: Herbicides that inhibit 4-hydroxyphenylpyruvate dioxygenase (HPPD, EC 1.13.11.27) are very important for grass weed control. In order to discover novel HPPD herbicides, a series of triketone 2H-benzo[b] oxazin-3(4H)-one analogs was designed and synthesized.

RESULTS: In comparison with the commercial triketone HPPD herbicide mesotrione (IC50 = 0.252 μM), some of these new triketone analogs displayed excellent HPPD inhibitory potency in vitro, for example B39 (IC50 = 0.172 μM) and B41 (IC50 = 0.156 μM). In addition, some of these compounds exhibited pre- and post-emergence herbicidal activity similar to mesotrione when applied at 375 g/ha.

CONCLUSION: Many of the title compounds described in this paper could be important lead structures for the further development of novel HPPD herbicides. © 2017 Society of Chemical Industry.