Synthesis and Herbicidal Activities of Potassium Methyl 1-(Substituted Phenoxyacetoxy)alkylphosphonate

A series of potassium methyl 1-(substituted phenoxyacetoxy)alkylphosphonates(9a―9o) was designed and synthesized. The results of preliminary bioassays indicate that most of the title compounds possess excellent pre-emergence and post-emergence herbicidal activities against Brassica napus, Amaranthus mangostanus, Medicago sativa, Echinochloa crusgalli, and Digitaria sanguinalis at a dosage of 1500 g/ha(1 ha=10000 m²). Especially, potassium methyl 1-(2,4-dichlorophenoxyacetoxy)-1-(4-methylphenyl)methylphosphonate(9g) and potassium methyl 1-(2,4-dichlorophenoxyacetoxy)-1-(furan-2-yl)methylphosphonate(9j) show the best herbicidal activity against five tested weeds with more than 85% inhibitory rate in pre-emergence.