The synthesis and test results on the herbicidal and fungicidal activities of a large number of 2,1,3‐benzothiadiazoles, mainly 4,5,7‐trisubstituted derivatives, are described and discussed.
Summary. A large number of substituted benzothiadiazoles (2,1,3) was synthesized. In this report, the herbicidal activities of some halo‐ and alkyl‐substituted benzothiadiazoles (2,1,3) are described. It was found experimentally that at least one of the positions 5 and 6 in the molecule must be unsubstituted. Some di‐ and tri‐substituted derivatives had excellent herbicidal activities, in contrast to tetra‐substituted benzothiadiazoles (2,1,3).
Relation entre la structure et I'activité herbicide des (2,1,3) benzothiadiazoles substitués
In view of their herbicidal properties a number of similarly or differently 2,4-substituted dchloro-l,3,5-triazines was synthesized. Their herbicidal properties are briefly discussed.The strong phytotoxic action of some 2-alkyloxy-and 2-alkylthio-4,6-dichloro-l,3,5-triazines led us to investigate the influence of the substitution of a chlorine atom in the above mentioned compounds by an alkylamino, alkyloxy or alkylthio group.Many derivatives of 2,4-diamino-6-chloro-1,3,5-triazine * ~~~~ are known. Where the substituents were identical they were synthesized by reaction of two equivalents of amine with cyanuric chloride in the presence of an acid acceptor usually the amine. Where the substituents were different the compounds were prepared by reaction of one equivalent of amine with 2-amino-4,6-dichloro-1,3,5-triazine.Dudley and Thurston 5 ' succeeded in preparing 6-chloro-2.4-dimethoxy-l,3,5-triazine from cyanuric chloride and methanol with sodium bicarbonate as the acid acceptor. The corresponding synthesis of 2,4-diallyloxy-6-chloro-l,3,5-triazine failed however.
An improved synthesis of 4,6-dichloro-2-phenoxy-l,3,5.-triazine from cyanuric chloride and phenol in the presence of collidine (2,4,6-trimethylpyridine) induced us to investigate the scope and limitation of the substitution of one chlorine atom in cyanuric chloride and the influence of the base used as an acid acceptor. Phenols, thiophenols, alcohols, thiols and oximes generally reacted with cyanuric chloride in the presence of collidine giving good yields of the corresponding substitution derivatives. The herbicidal and fungicidal properties of the compounds are dealt with and are briefly discussed. The influence of the alkyl or aryl side chain on the biological activity was determined. For this reason some derivatives mentioned in the literature were included for comparison in our biological tests.From the 2-alkoxy-4,6-dichloro-l,3,5-triazines the methoxy and the ethoxy derivatives are known in the literature. These compounds were synthesized from cyanuric chloride and the corresponding alcohol in the presence of sodium bicarbonate2.s or by dropping a sodium meth-* ** 1 t J Present address: N.V.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.