Synthesis and Herbicidial Activity of 6-Phenyl-5-Propylamino-2-Pyrazinecarbonitriles and Related Compounds
6-Phenyl- and 5-phenyl-2-pyrazinecarbonitriles with or without a propylamino group at the 3-, 5- or 6-position of the pyrazine ring were prepared together with some related compounds from the corresponding 2,3-pyrazinedicarbonitriles.Their hebicidial activities against barnyardgrass and broadleaf weeds were examined in pot tests.The 6-phenyl-2-pyrazinecarbonitriles were relatively potent compared with the 5-phenyl derivatives.Moreover, the presence of a propylamino group at the 5-position of the 6-phenyl-2-pyrazinecarbonitriles was closely related to an increase in activity.