STUDIES OF THE NEW HERBICIDE KIH-6127 .3. SYNTHESIS AND STRUCTURE-ACTIVITY STUDIES OF ANALOGS OF KIH-6127 AGAINST BARNYARD GRASS (ECHINOCHLOA-ORYZICOLA)

The previously evaluated prototype, methyl etyl-2-[(4,6-dimethoxypyrim idin-2-yl)oxy]benzoate, was modified by the introduction of an oximino group. Further extensive synthetic modifications were then made to th e B-alkyl moiety (R(1)), the ester moiety (R(2)), th, alkoxyimino moie ty (R(3)), th, bridge-atom (X) and the 4,6-disubstituted-pyrimidine mo iety (A, B, Z). Structure-activity relationships of the synthesized co mpounds were studied by examining their herbicidal activity against Ba rnyard grass (Echinochloa oryzicola) in paddy rice at various growth s tages, including pre-emergence. The novel herbicide methyl midin-2-yl) oxy]-6-[1-(methoxyimino)ethyl]benzoate, (KIH-6127) was found to be the most effective compound. The commercial development of this compound is currently in progress.