N-Fluorinated phenyl-N＇-pyrimidyl urea derivatives： Synthesis,biological evaluation and 3D-QSAR study

With the increase of herbicide-resistant weeds, novel, more selective and even more potent herbicides to control weeds are needed. In this paper, a series of N-fluorinated phenyl-N＇-pyrimidyl urea derivatives were synthesized and screened for their herbicidal activities against Amaranthus retroflexus （AR） and Setaria viridis （ SV）. Compound 2S （N-（3-trifluoromethylphenyl）-N＇-（2-amino-4-chloro-6-methylpyr- imidyl） urea） exhibited marked herbicidal activity against SV（IC50 =11.67 mg/L） and is more potent than bensulfuron （IC50= 27.45 mg/L）, a commercially available herbicide. A statistically significant CoMFA model with high prediction abilities （q2 = 0.869, r2 = 0.989） was obtained.