Organophosphorus compounds as potential fungicides. Part VI. Preparation, characterization, and biological activity of analogues and derivatives of 1-aminopropanephosphonic acid

alpha -Aminopropane-phosphonous, -methylphosphinic, and -phenylphosphinic a cids do not exhibit comparable antifungal activity to that shown by alpha - aminopropanephosphonic acid (ampropylfos) against Drechslera teres, when ap plied as seed dressings, It is concluded that the phosphonic acid function is necessary for this type of activity. Moderate activity against several o rganisms was nevertheless shown by alpha -aminopropane- and alpha -aminoeth ane-phosphonous acids in foliar spray tests, although longer chain compound s were found to be inactive. alpha -Ureidopropanephosphonate (ammonium salt ) also showed activity in foliar tests at 1000 ppm. A range of new ureylene - and thioureylene-bisphosphonates, prepared as potential profungicides of ampropylfos, proved to be inactive as seed dressings although tetrakis(2,2, 2-trifluoroethyl) thioureylenebis(1-propylphosphonate) gave 75-100% control of Puccinia recondita as a foliar spray (1000 ppm). Characterization of th e various compounds by nmr spectroscopy and mass spectrometry is discussed.