Design, Synthesis and Herbicidal Activity of Novel Benzothiazole-Pyrimidinediones Compounds

Based on the benzothiazole-pyrimidinedione derivatives discovered in the our previous report, a series of novel pyrimidinedione derivatives with benzothiazole as the scaffold, which have not been reported in the literature, were designed and synthesized by the strategy of replacing sulfur bridge with oxygen bridge. All of the target compounds were evaluated for their herbicidal activity in the greenhouse assay at a dose of 150 g a.i./ha, and the results showed that some compounds exhibited good herbicidal activity against the tested six weeds. In particular, ethyl 2-((6-fluoro-5-(3-methyl-2,6-dioxo-4-(trifluoro-methyl)-3,6-dihydropyrimidin-1(2H)-yl)benzo[d]thiazol-2-yl)oxy)acetate (9ac) showed a broad-spectrum herbicidal activity with more than 85% efficacy against the weeds tested.