Herbicidal Activity and Phytotoxic Properties of N-Alkyl-N′-(α,α–dimethylbenzyl)-2,4-diamino-6-chloro-s-triazines

Abstract

N-alkyl-N′-(α,α,dimethylbenzyl)-2,4-diamino-6-chloro-s-triazines were synthesized, and their phytotoxicity against paddy weeds and rice plants was evaluated. The α-branched alkyl group played an important role in increasing the phytotoxicity against barnyardgrass. Among these compounds, N-sec-butyl-N′-(α,α-dimethylbenzyl)-2,4-diamino-6-choloro-s-triazine (9) and N-(1-ethylpropyh-N′-(α,α-dimethylbenzyl)-2,4-diamino-6-chloros-s-triazine (13) were found to have high herbicidal activity against barnyardgrass with safety for directly sown rice plants during pot testing. These two compounds (9 and 13) also showed high selectivity between rice plants and barnyard millet from the petri dish test, and scarcely inhibited the photosynthesis of leaf slices of pokeweed (Phytolacca americana L.). These compounds seem to have a different mode of action from that of atrazine.