Synthesis and fungicidal activities of 3-(alpha-alkoxyiminobenzyl)isoxazole derivatives

A series of 3-(alpha-alkoxyiminobenzyl)isoxazole derivatives were synthesiz ed and their fungicidal activities against crop diseases were assessed. Stu dies of the structure-activity relationships revealed the strongest fungici dal activity when the alkoxyimino moiety was substituted with a methyl grou p. When the position-2 of the benzene ring on the benzyl moiety was substit uted with a phenoxymethyl group, a good fungicidal activity was obtained. A mong the compounds examined, 3-[2-(2,5-dimethylphenoxymethyl)-alpha-methoxy iminobenzyl] isoxazole (27) showed potent fungicidal activity against cucum ber powdery mildew, wheat powdery mildew and wheat eye spot.