Use of dithiin-tetracarboximide compounds (I) and dithiin-diisoimide compounds (V) for treating phytopathogenic fungi, is claimed. Use of dithiin-tetracarboximide compounds of formula (I) and dithiin-diisoimide compounds of formula (V) for treating phytopathogenic fungi, is claimed. R 1>；, R 2>； : H, 1-8C-alkyl (optionally substituted by halo, OR 3>； or COR 4>；), 3-7C-cycloalkyl (optionally substituted by halo, 1-4C-alkyl or 1-4C-haloalkyl), aryl (optionally substituted by halo, 1-4C-alkyl, 1-4C-haloalkyl, COR 4>； or sulfonylamino) or aryl-(1-4C-alkyl)； R 3>； : H, 1-4C-alkyl, 1-4C-alkyl carbonyl or aryl (optionally substituted by halo, 1-4C-alkyl or 1-4C-haloalkyl)； R 4>； : OH, 1-4C-alkyl or 1-4C-alkoxy； and n : 0 or 1. Independent claims are included for: (1) an agent for combating phytopathogenic fungi comprising (I), diluents and/or surface active materials； (2) the dithiin-tetracarboximide compounds of formula (Ic)； and (3) the dithiin-diisoimide compounds of formula (Va). R1a, R2a : 1-8C-alkyl substituted by F, OR3a or COR4a, 3-7C-cycloalkyl substituted by halo, 1-4C-alkyl or 1-4C-haloalkyl, or aryl-(1-4C-alkyl) substituted by COR4a in alkyl portion, preferably 1-4C-alkyl (optionally substituted by F, OH, CH 3O, C 2H 5O, methylcarbonyloxy, or carboxyl), 3-7C-cycloalkyl (optionally substituted by Cl, CH 3 or CF 3), 1-phenethyl or 2-phenethyl； R3a : 1-4C-alkyl, 1-4C-alkylcarbonyl or aryl (optionally substituted by halo, 1-4C-alkyl or 1-4C-haloalkyl), preferably CH 3, methylcarbonyl or phenyl； R4a : OH, 1-4C-alkyl or 1-4C-alkoxy, preferably OH or CH 3O； and r : 0 (preferred) or 1. Where R1a and R2a are not simultaneously acetoxymethyl (preferred) or methoxymethyl. [Image] [Image] ACTIVITY : Fungicide； Nematocide； Anthelmintic； Insecticide； Acaricide； Antibacterial； Virucide. MECHANISM OF ACTION : None given.
