Fungicidal Activity of N-Benzoylanthranilates and Related Compounds

Methyl N-(substituted benzoyl)anthranilates were found to possess inhibitory activity against the powdery mildew of cucumber caused by Sphaerotheca fuliginea. Both the anthranilate and the N-benzoyl moieties were essential for this type of fungicidal activity. Substitution at the 2- and 4-positions of the N-benzoyl group was unfavorable to the activity except for the 4-methoxy group. Substitution at the 3-position varied the fungicidal activity to various extents. The variation in the activity of 3-substituted derivatives was analyzed quantitatively with substituent parameters and regression analysis indicating that the variation in the steric dimension of substituents was most responsible for the activity.