Abstract
N-Phenylcarbamates with various substituents on the benzene ring and at the ester moiety were prepared, and their fungicidal activity against Botrytis cinerea (gray mold of cucumber) and Cercospora beticola (cercospora leaf spot of sugar beet), which are resistant to benzimidazole fungicides, was determined by foliar application in pot tests. The 3, 4-diethoxy group on the benzene ring of methyl N-phenylcarbamates and the isopropyl group at the ester moiety of N-(3, 4-diethoxyphenyl) carbamates were favorable for high activity against B. cinerea. Modification of N-(3, 4-diethoxyphenyl) carbamates into thiocarbamate, urea and amide analogs and N-substitution with acyl and methyl groups resulted in reduced activity. Isopropyl N-(3, 4-diethoxyphenyl) carbamate (diethofencarb) showed systemicity and fungicidal activity against C. beticola as well as B. cinerea.
