Discovery of a novel uracil herbicide by using intermediate derivatization approach

The resistance to herbicides has developed more and more seriously and widely around the world, especially the resistance to glyphosate that is the most successful herbicide in history. So, the resistance management for herbicides has become an aporia to be solved for researchers in the world, and thus to search for new herbicides is already an imminent question. Uracil herbicide saflufenacil discovered by BASF SE with good control against broadleaf weeds only was selected as a template to discover a new herbicide with high efficacy and broad spectrum to effectively control glyphosate-resistant weeds. A series of uracil derivatives containing an isoxazoline moiety were designed and discovered by means of the intermediate derivatization method using a key intermediate of saflufenacil as starting material. Bioassays demonstrated that some of the title compounds exhibited good herbicidal activities, especially, compound 2b can efficiently and effectively control both broadleaf weeds and grassy weeds at lower doses, especially glyphosate-resistant weeds: Conyza canadensis and Eleusine indica, and 2b also displayed outstanding synergism with glyphosate on resistant weeds above. The study showed that compound 2b was a promising herbicide candidate for further development.