Abstract
With diaminomaleonitrile (DAMN) as starting material, 14 kinds of esters (II-a and II-b series) and two kinds of amides (III-a and III-b) were prepared from 2, 3-dimethyl-5-(2, 5-dimethyl- and 2, 5-dichloro-phenylaminocarbonyl)-6-pyrazinecarboxylic acids (I-a and I-b). Seventeen kinds of N-alkylamides (V-a, V-b and V-c series) were prepared from I-a, I-b and I-c having a 2, 5-dimethoxyphenylaminocarbonyl group at 5 position, respectively. Five kinds of N, N-dialkylamides (VI-a series) were also prepared from I-a through its acid chloride (IV-a). All the compounds were examined for phytotoxicity, and several N-alkylamides (V-a series, R1=Pr, iso-Pr, Bu, iso-Bu, sec-Bu and iso-Am) were found to have a certain phytotoxic action against Cos lettus and American millet in germination tests and a certain herbicidal activity against paddy field plants.
