Photosynthetic electron transport inhibitory and herbicidal activities of 2-(fluorinated methyl)-4-benzylamino-6-methyl-1,3,5-triazines.
To investigate the substitution effect of the fluorine atom on the methyl group, a methyl group of 2-benzylamino-4,6-dimethyl-1,3,5-triazines was replaced with fluoromethyl, difluoromethyl and trifluoromethyl groups and photosynthetic electron transport (PET) inhibitory and herbicidal activities of these (fluorinated methyl)-1,3,5-triazine compounds were evaluated against Echinochloa crus-galli, Digitaria ciliaris, Chenopodium album, Polygonum longisetum, Amaranthus lividus [Amaranthus blitum], Monochoria vaginalis, Scirpus juncoides var. hotarui and Rotala indica. Following an increase in the number of fluorine atoms of fluorinated methyl group, PET inhibitory activity became higher. Furthermore, after introducing a halogen atom to the 4-position of the benzyl group, PET inhibitory activity was greatly improved compared to triazines having an un-substituted benzylamino group. The (fluorinated methyl)-1,3,5-triazine derivatives with a higher PET inhibitory activity were more potent herbicides in soil and foliar application tests.