ORGANOPHOSPHORUS COMPOUNDS AS POTENTIAL FUNGICIDES .2. AMINOALKANE-, GUANIDINOALKANE-, AND THIOUREIDOALKANE-PHOSPHONIC ACIDS - PREPARATION,SPECTROSCOPY, AND FUNGICIDAL ACTIVITY

A range of alpha-amino-, omega-amino-, alpha-guanidino-, and omega-gua nidinoalkanephosphonic acids has been prepared for the purpose of stud ying their spectroscopic features and fungicidal activity. In addition , alpha-thioureido-octanephosphonic acid and thioureylene-1,1-bis(1-oc tanephosphonic acid) were isolated during the preparation of alpha-gua nidino-octanephosphonic acid. P-31, H-1, and C-13 nmr spectral data wh ich were obtained for solutions of the amino- and guanidino-compounds in D2O or D2O/D2SO4, and for the thioureido compounds in DMSO-d(6), ar e discussed together with previously reported data for the aminophosph onic types. FAB mass spectrometry generally gives strong pseudomolecul ar ions [MH](+) for the zwitterionic amino- and guanidino-compounds wi th relatively simple fragmentations. Fungicidal activity of the alpha- aminophosphonic acids was found to be greater than for the omega-amino compounds, with maximum activity at a chain length of three carbon at oms when used as a seed dressing for the control of Drechslera spp. Mo derately good activity was shown by the thioureido compounds against a number of fungal organisms in vitro but the guanidino-compounds exhib ited low activity.