Organophosphorus Compounds as Potential Fungicides. Part V.1 the Preparation and Properties of Some Novel N,n,n',n'-Tetramethyl-N''-(1-Substituted-2,2,2-Trichloroethyl) Phosphoric Triamides

A series of N,N,N',N'-tetramethyl-N''-(1-substituted-2,2,2-trichloroethyl)phosphoric triamides has been prepared in which the 1-substituent is an amido group, NHCOR (R = H, Me, CH2Cl, CCl3, 2,4-dichlo-rophenyl, 2-methylfuran-3-yl, 5,6-dihydro-2-methyl-1,4-oxathiin-3-yl), an alkoxy group (OMe, OEt, OBu, OC12H25), or a substituted acetamido group (NHCOCH2Y), in which Y is triazolyl, N,N-di-methyldithiocarbamato, N,N-diethyldithiocarbamato, diethyl xanthato, diethoxythiophosphorylthio, or dodecylthio. The compounds in general showed low activity as fungicides when tested against a range of organisms at 300 ppm in vitro. However, certain compounds (the 1-formamido, 1-acetamido, and 1-chloroacetamido derivatives) showed 55–77% of the activity of the reference fungicide (guazatine) in vivo, when applied as seed-dressings at 400 ppm for the control of Drechslera teres. No adverse effect on seed germination was observed.