Design, synthesis, crystal structure and bioactivity evaluation of novel diethyl (arylfuranyl)(arylpyrazolylamino)methanephosphonates

A series of novel arylpyrazole derivatives containing aminomethanephosphonate and phenylfuran moieties were designed, synthesized and characterized by 1H NMR, 31P NMR and IR spectroscopy and elemental analyses. The single crystal structure of diethyl [5-(4-chlorophenyl)furan-2-yl][3-cyano-1-(2,3,4-trifluorophenyl)-1H-pyrazol-5-ylamino]methanephosphonate (4l) was determined by X-ray diffraction. Preliminary bioassays showed that these phosphonates exhibit satisfactory insecticidal activities against Culexpipiens and Musca domestica at 0.1%. In particular, compound 4l exhibited a most promising KT50 value, which is superior to that of Dextraltetramethrin® and similar to Prallehtrin®. The structure-activity relationship was also preliminarily investigated.