STRUCTURE-ACTIVITY-RELATIONSHIPS OF N-(1,1,3-TRIMETHYLINDAN-4-YL)CARBOXAMIDE FUNGICIDES

A number of N-(1,1,3-trimethylindan-4-yl)aryl- or heteroaryl-carboxamides were synthesized and their structure-activity relationships studied. A series of compounds showed potent fungicidal activity against grey mold caused by Botrytis cinerea, in addition to rice sheath blight caused by Rhizoctonia solani. Pyridine-3-carboxamides substituted by Cl, Br, CH3 or CF3 at 2-position exhibited high activity against both diseases. Monosubstituted pyrazine-3-carboxamides, furan-3-carboxamides, pyrazole-4-carboxamides and thiazole-5-carboxamides gave as high activity against both diseases in pot tests and SDC of Botrytis cinerea in an enzyme test as the 2-substituted pyridine-3-carboxamides. 2,5-Dimethylfuran-3-carboxamide gave activity against both diseases and SDC as high as 2-methylfuran-3-carboxamide, whereas the activities of 2,4-dimethyl and 2,4,5-trimethylfuran derivatives were extremely low against grey mold in a pot test. Pyrazole-4-carboxamides and thiazole-5-carboxamides showed the same substituent effects as the furan derivatives. Among the compounds of this series, 4-methylthiazole-5-carboxamide (BC340) and 2-chloropyridine-3-carboxamide (BC723) were most potent against both diseases.