SYNTHESIS AND HERBICIDAL ACTIVITY OF 1-(P Y-3-ARYL-1,4,2-DIAZAPHOSPHOLIDIN-5-THIONE-2-OXIDES

1-Phenyl-3-(p-toluenesufonyl)thiourea was reacted with triphenylphosph ite and substituted benzaldehydes to give 2-phenoxy-3-aryl-1,4,2-diaza phospholidin-5-thiones in anhydrous toluene. The by-reactions of the p reparation process were discussed. The structures of new compounds wer e confirmed by elementary analysis, H-1 NMR, P-31 NMR, MS and IR spect ra. The results of preliminary bioassay show that they possess a herbi cidal activity at 1.5 kg/ha in post-emergent tests against six kinds o f plants including Barnyard-grass, Oat, Rape, and Alfalfa, etc.