Patent EA-001102-B1 (EA)
Title: 1.3-oxazin-4-one derivatives as herbicides
Inventor: CRAMP Michael
IPC: C07D413/06
Filed: 1996-12-04
Abstract: 1. 1,3-oxazin-4-one derivatives of formula (I):    wherein: R<1> represents phenyl or thienyl optionally substituted by one or more groups, which are selected from halogen, C1-4 alkyl, and C1-4 haloalkyl; R<2> represents a straight or branched-chain alkyl group containing from one to six carbon atoms; R<3> represents: -(CH2)r- (phenyl group, optionally substituted with one-two groups, selected from halogen or alkyl); thienyl, furyl, benzthiazolyl or piridyl, optionally substituted with halogen or (optionally halogenated) methyl; a straight or branched-chain optionally halogenated alkyl group, alkenyl or alkynyl, containing up to eight carbon atoms, optionally substituted by cycloalkyl containing from three to six carbon atoms; or cycloalkyl containing from three to six carbon atoms, and R<4>  and R<5> represent methyl; r is zero, one or two; azide; Q represents -C(=O)-; or an agriculturally acceptable salt thereof. 2. A compound according to claim 1 in which R<2> represents methyl. 3. A compound according to claim 1 in which R<3> is cyclopentyl. 4. A compound according to claim 2 in which R<3> is cyclopentyl. 5. A compound according to claim 1 in which R<3> is n-butyl or butenyl. 6. A compound according to claim 2 in which R<3> is n-butyl or butenyl. 7. A compound according to claim 1 in which R<1> represents phenyl optionally substituted by halogen. 8. A compound according to claim 2 in which R<1> represents phenyl optionally substituted by halogen. 9. A compound according to claim 3 in which R<1> represents phenyl optionally substituted by halogen. 10. A compound according to claim 4 in which R<1> represents phenyl optionally substituted by halogen. 11. A compound according to claim 5 in which R<1> represents phenyl optionally substituted by halogen. 12. A compound according to claim 1 in which R<1> represents phenyl or thienyl optionally substituted by halogen or methyl. R<3> represents -(CH2)r-(phenyl, optionally substituted with one-two groups, selected from halogen or optionally halogenated alkyl group, containing one or two carbon atoms); a straight or branched-chain alkyl or alkenyl group containing up to six carbon atoms; or cycloalkyl containing from three to six carbon atoms, and r is zero or one. 13. A compound according to claim 1 in which R<1> represents phenyl or thienyl optionally substituted by halogen or methoxy. 14. A compound according to claim 1 which is: 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2,4-dimethylpentan-3-one; 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3)-oxazin-3-yl)-2-methylheptan-3-one; 1-(3,5-difluorophenyl)-2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropan-1-one; 1-(2-fluoro-5-trifluoromethylphenyl)-2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropan-1-one; 1-(3-chlorophenyl)-3-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-3-methylbutan-2-one; 1-(3-fluoromethylphenyl)-3-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-3-methylbutan-2-one; 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylhex-5-en-3-one; 4-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-4-methylpent-1-en-3-one; 1-(4-fluorophenyl)-2-[5-(2-fluorophenyl)-2,3-dihydro-6-methyl-4-oxo-4H-1,3-oxazin-3-yl]-2-methylpropan-1-one; 4-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-4-methylpent-1-yn-3-one; 2-[5-(2-fluorophenyl)-2,3-dihydro-6-methyl-4-oxo-4H-1,3-oxazin-3-yl]-1-(2-methylphenyl)-2-methylpropan-1-one; 1-(4-fluoro-3-methylphenyl)-2-[5-(2-fluorophenyl)-2,3-dihydro-6-methyl-4-oxo-4H-1,3-oxazin-3-yl]-2-methylpropan-1-one; 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methyl-1-(2-methylphenyl)propan-1-one; 1-(4-fluorophenyl)-2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropan-1-one; 1-(4-fluoro-3-methylphenyl)-2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropan-1-one; 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methyl-1-phenylpropan-1-one; 1-(2-chlorophenyl)-2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropan-1-one; 1-(3-chlorophenyl)-2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropan-1-one; 1-(4-chlorophenyl)-2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropan-1-one; 1-(3-trifluoromethylphenyl)-2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropan-1-one; 1-(3,5-dichlorophenyl)-2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropan-1-one; 3-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-3-methylbutan-2-one; 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylhexan-3-one; 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2,5-dimethylhexan-3-one; 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpentan-3-one; 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylundecan-3-one; 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2,4-dimethylhexan-3-one; 1-cyclopropyl-2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropan-1-one; 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2,4,4-trimethylpentan-3-one; 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methyl-1-(2-thienyl)propan-1-one; 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-1-(3-furyl)-2-methylpropan-1-one; 1-(2-benzthiazolyl)-2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropan-1-one; 1-(3,4-dichlorophenyl)-3-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-3-methylbutan-2-one; 1-(3,5-dichlorophenyl)-3-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-3-methylbutan-2-one; 3-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-1-(3,5-dimethylphenyl)-3-methylbutan-2-one; 1-(4-chlorophenyl)-3-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-3-methylbutan-2-one; 1-cyclopentyl-2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropan-1-one; 3-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-3-methyl-1-(3-methylphenyl)butan-2-one; 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylnonan-3-one; 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methyloctan-3-one; 3-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-3-methyl-1-(phenyl)butan-2-one; 1-(3,5-difluorophenyl)-3-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-3-methylbutan-2-one; 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methyl-1-(6-methylpyrid-2-yl)propan-1-one; 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2,6-dimethylheptan-3-one; 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methyl-1-(4-trifluoromethylpyrid-2-yl)propan-1-one; 1-(2,5-difluorophenyl)-3-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-3-methylbutan-2-one; 1-(2,3-chlorophenyl)-3-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-3-methylbutan-2-one; 1-(2,4-difluorophenyl)-3-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-3-methylbutan-2-one; 1-(4-fluorophenyl)-3-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-3-methylbutan-2-one; 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylhept-6-en-3-one; 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2,4-dimethylheptan-3-one; 2-[2,3-dihydro-5-(2-fluorophenyl)-6-methyl-4-oxo-4H-1,3-oxazin-3-yl]-2-methylheptan-3-one; 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylhept-5-en-3-one; 2-[2,3-dihydro-5-(2-fluorophenyl)-6-methyl-4-oxo-4H-1,3-oxazin-3-yl]-2-methylhexan-3-one; 2-[2,3-dihydro-5-(2-methoxyphenyl)-6-methyl-4-oxo-4H-1,3-oxazin-3-yl]-2-methylhexan-3-one; 2-[2,3-dihydro-5-(2-methoxyphenyl)-6-methyl-4-oxo-4H-1,3-oxazin-3-yl]-2-methylheptan-3-one; 2-[2,3-dihydro-5-(2-methoxyphenyl)-6-methyl-4-oxo-4H-1,3-oxazin-3-yl]-2-methylhept-6-en-3-one; 1-cyclohexyl-2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropan-1-one; 2-[2,3-dihydro-6-methyl-4-oxo-5-(2-thienyl)-4H-1,3-oxazin-3-yl]-2-methylhexan-3-one; 2-[2,3-dihydro-6-methyl-4-oxo-5-(2-thienyl)-4H-1,3-oxazin-3-yl]-2-methylheptan-3-one; 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2,5-dimethylheptan-3-one; 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2,6,6-trimethylheptan-3-one; 2-(2,3-dihydro-6-metbyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-4-ethyl-2-methylhexan-3-one; 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2,5,5-trinethylhexan-3-one; 2-[2,3-dihydro-6-methyl-4-oxo-5-(2-thienyl)-4H-1,3-oxazin-3-yl]-2-methylhept-6-en-3-one, 1-cyclopentyl-2-[2,3-dihydro-6-methyl-4-oxo-5-(2-thienyl)-4H-1,3-oxazin-3-yl]-2-methylpropan-1-one; 1-cyclobutyl-2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropan-1-one; 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methyl-7,7,7-trifluoroheptan-3-one; 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2,6-dimethyloctan-3-one; or 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylhept-6-yn-3-one. 15. A herbicidal composition comprising an effective amount of a 1,3-oxazin-4-one derivative according to any of claims 1-14 or an agriculturally acceptable salt thereof, in association with an agriculturally acceptable diluent or carrier and/or surface active agent. 16. A method for the control of weeds at a locus which comprises applying to said locus a herbicidally effective amount of a 1,3-oxazin-4-one derivative according to any of claims 1-14 or an agriculturally acceptable salt thereof or herbicide composition as claimed in claim 15. 17. A method according to claim 16 wherein the locus is an area used, or to be used, for the growing of crops and the 1,3-oxazin-4-one derivative is applied at an application rate of from 0.001 to 1.0 kg/ha. 18. A process for the preparation of a 1,3-oxazin-4-one derivative of formula (I) as defined in claim 1 or 2 which comprises: (a) when Q represents -C(=O)-, oxidising the corresponding compound of formula (I) in which Q represen