Abstract
The preparation, physical and spectroscopic properties of l-amino-2-arylethylphosphonic, and -phosphinic acids as well as -phosphine oxides, the phosphorus analogues of phenylalanine are described, and the reactions of l-amino-2-(4-fluorophenyl) ethylphosphonates with acetals, isocyanides, esters, acid anhydrides, activated aromatic nitro- and halogen compounds, and with N-protected alanine are reported. It is shown that several of the 1-amino-2-arylethylphosphonic acids are strong inhibitors of PAL and anthocyanin synthesis and also are quite active botryticides. Among the active compounds were l-amino-2-(4-fluorophenyl)ethylphosphonic acid, 3f, and the methyl-substituted compounds 3k, 31, and 3m. The fluoroderivative 3f was also effective as a seed-dressing agent in barley showing a 100% protection against the fungus Fusarium nivale at 600 ppm.