Patent EA-002606-B1 (EA)
Title: Fungicidal 2-methoxybenzophenones
Inventor: CURTZE JUERGEN
IPC: C07C205/45
Filed: 1998-08-19
Abstract: 1. A compound of formula I:   wherein R<1> represents a halogen atom or an alkyl C1-C10 group; R<2> represents a hydrogen or halogen atom, or an C1-C10 alkyl, C1-C10 alkoxy or nitro group; or R<1> and R<2> together represent a group of formula --CH.dbd.CH--CH.dbd.CH--; R<3> and R<4> each independently represent an optionally substituted C1-C10 alkyl or benzyl group, optionally substituted by one or several halogen atoms, nitro- or cyano group, cyclo C1-C10 alkyl, halogenC1-C10 alkyl, halogencycloC1-C10 alkyl, C1-C10 alkoxy, halogen C1-C10 alkoxy, phenyl, halogen- or dihalogen-phenyl or pyridyl and n is an integer from 0 to 3. 2. A compound as claimed in claim 1, wherein R<1> represents a chloro atom or a methyl group; R<2> represents a hydrogen, chloro or bromo atom; R<3> represents a C1-5 alkyl group; R<4> represents a C1-5 alkyl group or benzyl group, being optionally substituted by at least halogen atom, or C1-4 alkyl or alkoxy group; and n is 0. 3. A compound as claimed in claim 2 being selected from the group consisting of 6,6'-dimethyl-2,2',3',4'-tetramethoxy-benzophenone, 6,6'-dimethyl-3'-pentoxy-2,2',4'-trimethoxy-benzophenone, 5-bromo-6,6'-dimethyl-2,2',3',4'-tetramethoxy-benzophenone, 5-chloro-6,6'-dimethyl-2,2',3',4'-tetramethoxy-benzophenone, 5-iodo-6,6'-dimethyl-2,2',3',4'-tetramethoxy-benzophenone, 6-chloro-6'-methyl-2,2',3',4'-tetramethoxy-benzophenone, 5-bromo-6-chloro-6'-methyl-2,2',3',4'-tetramethoxy-benzophenone, 6-chloro-5,6'-dimethyl-2,2',3',4'-tetramethoxy-benzophenone, 2'-butoxy-6-chloro-6'-methyl-2,3',4'-trimethoxy-benzophenone, 2'-butoxy-6-chloro-5,6'-dimethyl-2,2',3'-trimethoxy-benzophenone, 6-chloro-2'-(2-fluorobenzyloxy)-6'-methyl-2,3',4'-trimethoxy-benzophenone, 6-chloro-2'-(4-fluorobenzyloxy)-6'-methyl-2,3',4'-trimethoxy-benzophenone, 5-bromo-6,6'-dimethyl-3'-pentyloxy-2,2',4'-trimethoxy-benzophenone, 6-chloro-6'-methyl-2'-pentyloxy-2,3',4'-trimethoxy-benzophenone, 6-chloro-2'-(3-methylbutyloxy)-6'-methyl-2,3',4'-trimethoxy-benzophenone, 2'-benzyloxy-6-chloro-6'-methyl-2,3',4'-trimethoxy-benzophenone, 6-chloro-2'-(3-methylbenzyloxy)-6'-methyl-2,3',4'-trimethoxy-benzophenone, 6-chloro-2'-(4-methylbenzyloxy)-6'-methyl-2,3',4'-trimethoxy-benzophenone, 6-chloro-2-difluoromethoxy-6'-methyl-2',3',4'-trimethoxy-benzophenone, 1-(6'-methyl-2',3',4'-trimethoxybenzoyl)-2-methoxynaphthalene, and 1-(6'-methyl-,2',3',4'-trimethoxybenzoyl)-2-difluoromethoxynaphthalene. 4. A process for the preparation of the compound of claim 1, wherein n is 0, which comprises reacting a compound of formula II:   wherein R<1>, R<2>, R<3> and R<4> are as described in claim 1, and X represents a fluoro or chloro atom, with an alkali methanolate. 5. A process for the preparation of the compound of claim 1, which comprises (a) reacting a compound of formula III:   wherein R<1>, R<2> and n are as described in claim 1, and Y represents a leaving group or a hydroxy group, with a compound of formula IV:   wherein R<3> is as described in claim 1, in the presence of a Lewis acid or a dehydrating agent; and (b) optionally treating the product obtained with a compound of formula V: R<4>O-Met             (V) wherein R<4> represents an C1-C10 alkyl or benzyl optionally subsituted by one or several several halogen atoms, nitro- or cyano group, cycloalkyl, halogenalkyl, halogencycloalkyl, alkoxy, halogenalkoxy, phenyl, halogen- or dihalogen-phenyl or pyridyl and with the proviso that the alkyl group is not methyl, and Met denotes an alkali metal atom. 6. A process for the preparation of a formula III compound of claim 5, wherein R<2> represents a halogen atom, which comprises (a) reacting a compound of formula VI:   wherein R<1> and n are as described in claim 1, and R" represents a hydrogen atom or an alkyl group, with a halogenating agent. 7. A process for the preparation of a formula III compound of claim 5, wherein R<2> represents a halogen atom, which comprises (a) reacting a compound of formula VI:   wherein R<1> and n are as described in claim 1, and R" represents an alkyl group, with a halogenating agent; (b) optionally hydrolyzing the resulting halogenated alkyl benzoate; and (c) optionally treating the resulting halogenated alkyl benzoic acid with thionyl chloride. 8. A composition which comprises a fungicidally effective amount of at least one compound of Claim 1, and a carrier. 9. A method of combating fungus or a fungal plant disease at a locus, which comprises treating the locus with a compound of claim 1. 10. A method of combating fungus or a fungal plant disease at a locus, which comprises treating the locus with the composition of claim 8. 11. The method of claim 9 wherein the fungal plant disease is caused by ascomycetes. 12. The method of claim 10 wherein the fungal plant disease is caused by ascomycetes. 13. The method according to claim 9 wherein the fungus is a member of the subgroup Bysiphales. 14. The method of Claim 13 wherein the fungus is selected from Erysiphe graminis. Erysiphe cichoracearum, Podosphaera leucotricha or Uncinula necator. 15. The method according to claim 10 wherein the fungus is a member of the subgroup Erysiphales. 16. The method of claim 15 wherein the fungus is selected from Ersiphe graminis, Erysiphe dchoraceamm, Podosphaera leucotricha or Uncinula necator. 17. A process for the preparation of a formula III compound of claim 6, wherein R<2> represents a bromo atom, which comprises (a) reacting a compound of formula VI, wherein R<1> represents an alkyl group, n is 0 and R" represents a hydrogen atom with bromine. 18. A process for the preparation of a formula III compound of claim 17, which comprises reacting the compound of formula VI and brominein the presence of a polar protonic solvent. 19. A compound of the formula   wherein R<1> is an alkyl group.