Studies on herbicidal 2,3-dicyanopyrazines. Part II. Structure-activity relationships of herbicidal 5-ethylamino- and 5-propylamino-2,3-dicyanopyrazines.

Abstract

Sixty-eight 6-substituted 5-ethylamino and 5-propylamino-2, 3-dicyanopyrazines were synthesized and their herbicidal activities against barnyard grass were measured in pot tests.The most active compound was 2, 3-dicyano-5-propylamino-6-(m-chloro phenyl) pyrazine.The activities of the two series of compoundswere analyzed quantitatively using the hydrophobic and steric parameters of substituents at the 6-position of the pyrazine ring and an indicator variable.