WO1992013846A1

WO1992013846A1 - Pyrimidinyl- and triazinylsalicyl- and -picolinylaldehyde derivatives

Info

Publication number: WO1992013846A1
Application number: PCT/EP1992/000010
Authority: WO
Inventors: Christoph Lüthy; Raymond Fisher
Original assignee: Ciba-Geigy Ag
Priority date: 1991-02-05
Filing date: 1992-01-04
Publication date: 1992-08-20
Also published as: ZA92786B; MX9200468A; AU1153892A; NZ241501A; GB9102423D0; TW222624B

Abstract

Pyrimidinyl- and triazinylsalicyl- and -picolinylaldehyde derivatives of formula (I) in which W is oxygen or NR4; B is nitrogen, methine, or methine which is substituted by fluorine, chlorine, methyl, methoxy, 2-propenyloxy, 2-propynyloxy, difluoromethoxy or benzyloxy; Y is oxygen or sulfur; Z is methine or nitrogen; R1 is chlorine, methyl, methoxy, ethoxy, difluoromethoxy; methylamino, ethylamino or dimethylamino; R2 is methyl, methoxy or difluoromethoxy; R3 is hydrogen, fluorine, chlorine, methyl or methoxy; R4 is C¿1-6?alkyl, or C1-6alkyl which is substituted by up to 3 fluorine atoms, 1 chlorine atom, 1 C1-4alkoxy group, 1 C1-4 alkoxycarbonyl group, 1 dimethylcarbamoyl group, 1 carbamoyl group, 1 cyano group, 1 vinyl group, 1 ethynyl group or 1 phenyl group which is unsubstituted or substituted by fluorine, chlorine, bromine, methyl, trifluoromethyl or methoxy, or is phenyl, or phenyl which is up to trisubstituted by fluorine, chlorine, bromine, methyl, trifluoromethyl, methoxy or nitro, or NR?5R6, or OR7¿; have good pre- and post-emergence-selective herbicidal and growth-regulating properties.

Description

Pyrimidinyl- and triazinylsalicyl- and -picolinylaldehyde derivatives

The present invention relates to novel herbicidally active and plant-growth-regulating pyrimidinyl- and triazinylsalicyl- and -picolinylaldehyde derivatives, to processes for their preparation, to compositions containing them as active substances, and to their use for controlling weeds, mainly selectively in crops of useful plants or for regulating and inhibiting plant growth.

2-Phenoxy- and 2-phenylthiopyrimidines and -triazines which have a herbicidal action are generally known. Compounds of this type are described, for example, in European Patent Applications No. 0223 406, 0287 079, 0249708, 0 336494, 0 374 839 and 0435 186.

Novel herbicidally active and plant-growth-regulating pyrimidinyl- and triazinylsalicyl- and -picolinylaldehyde derivatives have now been found.

The pyrimidinyl- and triazinylsalicyl- and -picolinylaldehyde derivatives according to the invention are those of the formula I

in which

W is oxygen or NR⁴;

B is nitrogen, methine, or methine which is substituted by fluorine, chlorine, methyl, methoxy, 2-propenyloxy, 2-propynyloxy, difiuoromethoxy or benzyloxy; Y is oxygen or sulfur;

Z is methine or nitrogen;

R¹ is chlorine, methyl, methoxy, ethoxy, difluoromethoxy, methylamino, ethylamino or dimethylamino;

R² is methyl, methoxy or difluoromethoxy;

R³ is hydrogen, fluorine, chlorine, methyl or methoxy;

R⁴ is C^alkyl, or C-^alkyl which is substituted by up to 3 fluorine atoms, 1 chlorine atom, 1

group, 1 dimethylcarbamoyl group, 1 carbamoyl group, 1 cyano group, 1 vinyl group, 1 ethynyl group or 1 phenyl group which is unsubstituted or substituted by fluorine, chlorine, bromine, methyl, trifluoromethyl or methoxy, or is phenyl, or phenyl which is up to trisubstituted by fluorine, chlorine, bromine, methyl, trifluoromethyl, methoxy or nitro, orNR⁵R⁶, or OR⁷;

R⁵ is hydrogen or C^alkyl;

R⁶ is hydrogen, C^alkyl, phenyl, pyridyl, 1,3-thiazinyl, pyridazinyl, pyrazinyl, pyrimidinyl, or phenyl which is monosubstituted to trisubstituted or pyridyl which is monosubstituted to disubstituted by C^alkyl, fluorine, chlorine, bromine, trifluoromethyl, methoxy or nitro; or pyridazinyl or pyrazinyl each of which is monosubstituted by methyl, fluorine, chlorine, trifluoromethyl or methoxy; or pyrimidinyl which is monosubstituted to disubstituted by methyl, trifluoromethyl or methoxy; or benzylcarbonyl, pyridylcarbonyl, furylcarbonyl, thiophenylcarbonyl or benzoyl each of which is monosubstituted to disubstituted by fluorine, chlorine, bromine, methyl, trifluoromethyl, methoxy or nitro; or is Ci.galkylcarbonyl, trifluoromethylcarbonyl, C₃.₆cycloalkylcarbonyl, benzylcarbonyl, 2-, 3- or 4-pyridylcarbonyl, 2- or 3-furyl- or thiophenylcarbonyl, benzoyl, or benzoyl which is monosubstituted to disubstituted by fluorine, chlorine, bromine, methyl, trifluoromethyl, methoxy or nitro; or C^alkoxycarbonyl, benzoyloxycarbonyl, aminocarbonyl, aminothiocarbonyl, or aminocarbonyl or aminothiocarbonyl each of which is monosubstituted to disubstituted by phenyl, C^alkyl, C₂_₆-alkenyl or C₂_₆-alkynyl it being possible for the phenyl group to be substituted by fluorine, chlorine, bromine, methyl, trifluoromethyl, methoxy; or is C₁.₆-alkylsulfonyl, phenylsulfonyl or phenylsulfonyl which is monosubstituted to disubstituted by fluorine, chlorine, bromine, methyl, trifluoromethyl, methoxy, cyano or nitro; R⁷ is hydrogen, C_j.₆alkyl or C₂.₆alkenyl, or C₂_₆alkenyl which is substituted by halogen or phenyl, or C^alkoxycarbonyl-C^alkyl or C alkylthiocarbonyl-C alkyl; with the proviso that W is not oxygen when B is unsubstituted or substituted methine; that W is not NOR⁷ when, simultaneously, Z is methine, B is unsubstituted methine and R⁷ is hydrogen, C-^alkyl or C₂_₆alkenyl which can be substituted by halogen or phenyl.

In formula I, the alkyl and alkenyl radicals can be straight-chain or branched. The same is also true for the, or each, alkyl moiety of alkoxy-, alkylthio-, alkoxycarbonyl- and of further alkyl-containing groups.

If there is an asymmetric carbon atom in the compounds of the formula I, the consequence is that the compounds can occur in optically isomeric forms. If there is an aliphatic C=C or C=N double bond, geometric isomerism (for example cis or trans, E form or Z form) can also occur. Some compounds of the formula I can occur in tautomeric forms (for example keto-enol or imine-enamine tautomerism). Formula I therefore also embraces all possible configurational isomers and stereoisomers which are present in the form of E/Z isomers, enantiomers, tautomers, diastereomers or their mixtures.

In the definitions, C₁.₆alkyl or C_j^alkyl is, for example, methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, iso-butyl, tert-butyl, pentyl and the pentyl isomers, and hexyl and the hexyl isomers. The alkyl groups which are present as, or in, the substituents preferably have 1 to 4 carbon atoms.

The C₂.₆alkenyl and C₂.₆alkynyl radicals which occur in the substituents can be straight-chain or branched. Preferred alkenyl radicals are those having a chain length of two to three carbon atoms. Examples of C₂.₆alkenyl radicals are: vinyl, allyl, methallyl, 1 -methyl vinyl, but-2-en-l-yl, pentenyl or 2-hexenyl. Vinyl and allyl are preferred. Examples of C₂.₆alkynyl radicals are: vinyl, propargyl, l-methyl-prop-2-yn-l-yl, l-methyl-but-3-yn-2-yl, 2-hexynyl or 4-pentynyl.

The C₃.₆cycloalkylcarbonyl groups which occur in the definitions of the substituent R⁶ can be unsubstituted or substituted by halogen, methyl, methylthio or methoxy, and they embrace, for example, cyclopropylcarbonyl, 2-fluorocyclopropylcarbonyl, 2,4-difluorocyclopropylcarbonyl, 2-chlorocyclopropylcarbonyl, 2,3-dichlorocyclo- propylcarbonyl, 2-methylcyclopropylcarbonyl, 2-methylthiocyclopropylcarbonyl, 2,3-dimethylcyclopropylcarbonyI, 2-methoxycyclopropyIcarbonyl, cyclobutylcarbonyl, cyclopentylcarbonyl, 3-methylcyclopentylcarbonyl, 3,4-dimethoxycyclopentylcarbonyl, cyclohexylcarbonyl, 3-fluorocyclohexylcarbonyl, 4-methyIcyclohexylcarbonyl or 4-methylthiocyclohexylcarbonyl.

The Ci^alkylcarbonyl groups which occur in the definitions of the substituent R⁶ can be unsubstituted or substituted by halogen, methyl, methylthio or methoxy, and they embrace, for example, chloromethylcarbonyl, dichloromethylcarbonyl, trifluoromethylcarbonyl, methoxymethylcarbonyl or methylthiomethylcarbonyl.

Preferred compounds amongst those of the formula I are those in which the substituent R⁶ ^"is hydrogen, C^a-kyl, phenyl, pyridyl, or phenyl which is monosubstituted to trisubstituted or pyridyl which is monosubstituted to disubstituted by C-^alkyl, fluorine, chlorine, bromine, trifluoromethyl, methoxy or nitro; or is C^alkylcarbonyl, trifluoromethylcarbonyl, C₃.₆cycloalkylcarbonyI, benzylcarbonyl, 2-, 3- or 4-pyridylcarbonyl, 2- or 3-furyl- or thiophenylcarbonyl, benzoyl, or benzoyl which is monosubstituted to disubstituted by fluorine, chlorine, bromine, methyl, trifluoromethyl, methoxy or nitro; or C^alkoxycarbonyl, benzoyloxycarbonyl, aminocarbonyl, aminothiocarbonyl, or aminocarbonyl or aminothiocarbonyl each of which is monosubstituted to disubstituted by phenyl or C-^alkyl, it being possible for the phenyl group to be substituted by fluorine, chlorine, methyl or methoxy.

Further preferred compounds amongst those of the formula I are those in which a) R¹ is chlorine, methyl, methoxy, ethoxy or difluoromethoxy; b) R² is methoxy; c) R¹ and R².are methoxy; d) Y is oxygen; e) Z is methine; f) B is unsubstituted methine or methine which is substituted by methyl, chlorine or methoxy, or is nitrogen, preferably unsubstituted methine; g) R³ is hydrogen; h) W is NR⁴, R⁴ being tert-butyl, phenyl or phenyl which is substituted by halogen, methyl, trifluoromethyl or methoxy; i) R⁴ is an NR⁵R⁶ group in which R⁵ is hydrogen or methyl and R⁶ is C-^alkyl, phenyl, or phenyl which is monosubstituted to disubstituted by halogen, C^alkyl, trifluoromethyl, nitro or methoxy or R⁶ is 2-pyridyl or 2-pyridyl which is monosubstituted by fluorine, chlorine, bromine, methyl or trifluoromethyl; j) R⁴ is an NR⁵R⁶ group in which R⁵ is hydrogen and R⁶ is C^alkyl-, cyclopropyl-, benzyl-, 2- ,3- or 4-pyridyl-, 2-furyl- or phenylcarbonyl or phenylcarbonyl which is monosubstituted or disubstituted by halogen, methyl, trifluoromethyl, methoxy or nitro; k) R⁴ is an NR⁵R⁶ group in which R⁵ is hydrogen and R⁶ is C^alkoxycarbonyl;

1) R⁴ is an NR⁵R⁶ group in which R⁵ is hydrogen or methyl and R⁶ is

2-propenylamino- or phenylaminocarbonyl or -aminothiocarbonyl, or phenylaminocarbonyl which is substituted by halogen, methyl, trifluoromethyl or methoxy. Particularly preferred compounds of the group 1) are those, in which R⁵ is hydrogen and R⁶ is

or phenylaminocarbonyl or phenylaminocarbonyl which is substituted by halogen, methyl or methoxy; m) W is NR⁴, R⁴ being the OR⁷ group and R⁷ being C^alkoxycarbonyl-C^alkyl; n) W is NR⁴; o) Z is methine; p) B is nitrogen or methine which is unsubstituted and R³ is hydrogen, preferred compounds of the group p) are those in which B is methine which is unsubstituted.

In a preferred group of compounds of the formula I: R¹ and R² are methoxy; R³ is hydrogen; Y is oxygen; Z is methine;

B is methine; and R⁴ is C(CH₃)₂CH₂CH₃, C(CH₃)₂C=CH, C(CH₃)₂G≡N, CCH₃(i-Pr)C≡N, C(CH₃)₂CON(CH₃)₂, CH₂COOCH₃, CH(CH₃)COOCH₃, CH(i-Pr)COOCH₃, benzyl, 2-chlorobenzyl, 2-Cl-6-F-benzyl, 4-fluorophenyl, 2-chlorophenyl, 4-bromophenyl, 4-trifluorome.thylphenyl, 2-methoxyphenyl, 4-methoxyphenyl, 3-nitrophenyl, 4-nitrophenyl, o-tolyl, m-tolyl, p-tolyl, 4-tert-butylphenyl, 2,4-dichlorophenyl, 3-CF₃-4-Cl-phenyl, NHCH₂CH=CH₂, NH-2-bromoρhenyl, NH-3-bromophenyl, NH-4-bromophenyl, NH-2-fluorophenyl, NH-4-fluorophenyl, NH-o-tolyl, NH-m-tolyl, NH-p-tolyl, NH-p-(i-Pr)-phenyl, NH-2-trifluoromethylphenyl, NH-4-trifluoromethylphenyl, NH-2-methoxyphenyl, NH-2-nitrophenyl, NH-4-nitrophenyl, NH-o-(3-Cl-tolyl), NH-(3-Cl-p-tolyl), NH-o-(4-Cl-tolyl), NH-m-(4-Cl-tolyl), NH-2,4-xylyl, NH-2,4-Cl₂-(3-Cl)-xylyl, NH-2,4-difluorophenyl, NH-2,5-difluorophenyl, NH-2,4-dichlorophenyl, NH-3,5-dichlorophenyl, NH-3,4-dichlorophenyl, NH-(2-Cl-4-CF₃)-phenyl, NH-(4-Cl-3-CF₃)-phenyl, NH-2-pyridyl, NH-2-(3-CF₃)pyridyl, NH-2-(3-Cl-5-CF₃)pyridyl, NH-2-(3-F-5-Cl)pyridyl, N(CH₃)phenyl, NHCOCF₃, NHCO-m-tolyl, NHCO-p-tolyl, NHCO-4-fluorophenyl, NHCO-4-bromophenyl, NHCO-4-methoxyphenyl, NHCO-3-furyl, NHCOOCH(CH₃)₂, NHCOO-benzyl, NHCONH₂ or NHCSNH₂.

In a particularly preferred group of compounds of the formula I: R¹ is methyl, chlorine, ethoxy or difluoromethoxy; R² is methoxy; R³ is hydrogen;

Y is oxygen; Z is methine;

B is methine; and

R⁴ is 4-chlorophenyl, 3-methoxyphenyl, 3-trifluoromethylphenyl, N(CH₃)₂, NH-3-chlorophenyl, NH-4-chlorophenyl, NH-4-methoxyphenyl, NH-3-nitrophenyl, NH-2,3-xylyl, NH-2-(3-CF₃)pyridyl, NHCOCH₃, NHCO-cyclopropyl, NHCO-benzyl, NHCO-3-chlorophenyl, NHCO-4-chlorophenyl, NHCO-2,3-dichlorophenyl, NHCO-2-pyridyl, NHCO-3-pyridyl, NHCO-4-pyridyl, NHCO-2-furyl, NHCOOCH₂CH₃, NHCONHCH₂CH₃, NHCSNHCH₃, NHCSNHCH₂CH=CH₂, NHCSNH-phenyl or NHCSNH-2-chlorophenyl.

Other compounds of the formula I which are of particular interest are those in which either:

A) R¹ is methyl, methoxy, ethoxy, methylamino or dimethyla ino;

R² is methoxy;

R³ is hydrogen;

Y is oxygen; Z is nitrogen;

B is methine and

R⁴ is tert-butyl, 4-chlorophenyl, 3-methoxyphenyl, 3-trifluoromethylphenyl, N(CH₃)₂, NHC(CH₃)₃, NH-3-chlorophenyl, NH-4-chIorophenyl, NH-4-methoxyphenyl, NH-3-nitrophenyl, NH-2,3-xylyl, NH-2-(3-CF₃-pyridyl), NHCOCH₃, NHCOCH₂CH₃, NHCO-cyclopropyl, NHCO-benzyl, NHCO-3-chlorophenyl, NHCO-4-chlorophenyl, NHCO-2,3-dichlorophenyl, NHCO-2-pyridyl, NHCO-3-pyridyl, NHCO-4-pyridyI, NHCO-2-furyl, NHCONHCH₂CH₃, NHCSNHCH₃, NHCSNHCH₂CH=CH₂, NHCSNH-phenyl or NHCSNH-2-chlorophenyl; or B) R¹ and R² are methoxy; R³ is hydrogen;

Y is sulfur; Z is methine;

B is methine and

R⁴ is tert-butyl, phenyl, 4-chlorophenyl, 3-methoxyphenyl, 3-trifluoromethylphenyl, N(CH₃)₂, NHC(CH₃)₃, NH-3-chlorophenyl, NH-4-chlorophenyl, NH-4-methoxyphenyl, NH-3-nitrophenyl, NH-2,3-xylyl, NH-2-(3-CF₃)pyridyl, NHCOCH₃, NHCOCH₂CH₃, NHCO-cyclopropyl, NHCO-benzyl, NHCO-3-chlorophenyl, NHCO-4-chlorophenyl, NHCO-2,3-dichIorophenyl, NHCO-2-pyridyl, NHCO-3-pyridyl, NHCO-4-pyridyl, NHCO-2-furyl, NHCOOCH₂CH₃, NHCONHCH₂CH₃, NHCSNHCH₃, NHCSNHCH₂CH₃, NHCSNHCH₂CH=CH₂, NHCSNH-phenyl or NHCSNH-2-chlorophenyl; or

C) R¹ and R² are methoxy; R³ is hydrogen;

Z is methine;

Y is oxygen;

B is nitrogen, or methine which is substituted by chlorine, methyl or methoxy, and R⁴ is tert-butyl, phenyl, 4-chlorophenyl, 3-methoxyphenyl, 3-trifluoromethylphenyl, N(CH₃)₂, NHC(CH₃)₃, NH-3-chlorophenyl, NH-4-chlorophenyl, NH-4-methoxyphenyl, NH-3-nitrophenyl, NH-2,3-xylyl, NH-2-(3-F-5-Cl)pyridyl, NH-2-(3-CF₃)pyridyl, NHCOCH₂CH₃, NHCO-cyclopropyl, NHCO-benzyl, NHCO-3-chlorophenyl, NHCO-4-chlorophenyl, NHCO-2,3-dichlorophenyl, NHCO-2-pyridyl, NHCO-3-pyridyl, NHCO-4-pyridyl, NHCO-2-furyl, NHCOOCH₂CH₃, NHCONHCH₂CH₃, NHCSNHCH₃, NHCSNHCH₂CH₃, NHCSNHCH₂CH=CH₂, NHCSNH-phenyl or NHCSNH-2 chlorophenyl; or

D) R¹ and R² are methoxy; R³ is hydrogen;

Y is oxygen; Z is methine;

B is nitrogen, or methine which is substituted by chlorine, methyl or methoxy; W is NOR⁷ and

R⁷ is hydrogen, methyl, ethyl, propyl, i-propyl, n-butyl, i-butyl, s-butyl, CH₂CH₂CH(CH₃)₂, CH₂CH=CH(CH₃), CH₂CH=C(CH₃)C1, CH₂CH=CHphenyl, CH₂COOCH₃, CH(CH₃)COOCH₃, CH(CH₂CH₃)COOCH₃, CH₂COOC(CH₃)₃, CH(i-Pr)COOC(CH₃)₃, CH₂COOCH₂CH=CH₂, CH₂COOCH₂CH₃, CH(CH₃)COOCH₂CH₃, CH₂COSCH₂CH₃ or CH(CH₃)COSCH₂CH₃.

In a very particularly preferred group of compounds of the formula I, R¹ is methyl, chlorine, methoxy, ethoxy or difluoromethoxy; R² is methoxy; R³ is hydrogen;

Y is oxygen; Z is methine; B is methine;

W is NOR⁷; and

R⁷ is CH(CH₃)COOCH₃, CH(CH₂CH₃)COOCH₃, CH(CH₃)COOCH₂CH₃,

CH₂COOCH₂CH=CH₂, CH₂COSCH₂CH₃ or CH(CH₃)COSCH₂CH₃.

A group of compounds of the formula I which excels particularly because of its good biological action is that in which R¹ is methyl, methoxy, ethoxy, methylamino or dimethylamino; R² is methoxy; R³ is hydrogen;

Y is oxygen; Z is nitrogen;

B is methine or nitrogen;

W is NOR⁷; and

R⁷ is hydrogen, methyl, ethyl, propyl, i-propyl, n-butyl, i-butyl, s-butyl,

CH₂CH₂CH(CH₃)₂, CH₂CH=CH(CH₃), CH₂CH=C(CH₃)C1, CH₂CH=CHphenyl,

CH₂COOCH₃, CH(CH₃)COOCH₃, CH(CH₂CH₃)COOCH₃, CH₂COOC(CH₃)₃,

CH(i-Pr)COOC(CH₃)₃, CH₂COOCH₂CH=CH₂, CH₂COOCH₂CH₃,

CH(CH₃)COOCH₂CH₃, CH₂COSCH₂CH₃ or CH(CH₃)COSCH₂CH₃.

The following may be mentioned as preferred individual compounds from the scope of the formula I:

3-[(4,6-dimethoxy-2-pyrimidinyl)oxy]pyridine-2-carboxaldehyde,

4,6-dimethoxy-2-[(α-phenylimino-o-tolyl)oxy]pyrimidine,

4,6-dimethoxy-2-[(α-(α,α,α-trifluoro-m-tolyl)imino-o-toIyl)oxy]pyrimidine,

4,6-dimethoxy-2-[(α-(m-methoxyphenyl)imino-o-tolyl)oxy]pyrimidine, 2-[(α-(p-chlorophenyl)imino)-o-tolyl)oxy]-4,6-dimethoxypyrimidine,

2-[(α-(teπ-butyl)imino-o-tolyl)oxy]-4,6-dimethoxypyrimidine, o-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde phenylhydrazone, o-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde (p-chlorophenyl)hydrazone, o-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde dimethylhydrazone, o-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde tert-butylhydrazone,

3-[(4,6-dimethoxy-2-pyrimidinyl)oxy]pyridine-2-carboxaldehyde phenylhydrazone,

3-[(4,6-dimethoxy-2-pyrimidinyl)oxy]pyridine-2-carboxaldehyde

[(3-trifluoromethyl)-2-pyridyl]hydrazone, o-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde (p-methoxyphenyl)hydrazone, o-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde (m-nitrophenyl)hydrazone, o-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde (2,3-dimethylphenyl)hydrazone, p-chloro-N'-[o-((4,6-dimethoxy-2-pyrimidinyl)oxy)]benzylidene]benzohydrazide,

N^,-[o-((4,6-dimethoxy-2-pyrimidinyl)oxy)]benzylidene]benzohydrazide,

N'-[o-((4,6-dimethoxy-2-pyrimidinyl)oxy)]benzylidene]-o-methoxybenzohydrazide,

N^,-[o-((4,6-dimethoxy-2-pyrimidinyl)oxy)]benzylidene]nicotinohydrazide,

N'-[o-((4,6-dimethoxy-2-pyrimidinyl)oxy)]benzylidene]propionohydrazide,

N'-[o-((4,6-dimethoxy-2-pyrimidinyl)oxy)]benzylidene]-o-nitrobenzohydrazide,

N'-[o-((4,6-dimethoxy-2-pyrimidinyl)oxy)]benzylidene]-2-pyridinecarboxyhydrazide,

N^,-[o-((4,6-dimethoxy-2-pyrimidinyl)oxy)]benzylidene]-m-chlorobenzohydrazide,

N'-[o-((4,6-dimethoxy-2-pyrimidinyl)oxy)]benzylidene]acetohydrazide,

N'-[o-((4,6-o methoxy-2-pyrimidinyl)oxy)]benzylidene]-2-phenylacetohydrazide,

N'-[o-((4,6-ώmethoxy-2-pyrimidinyl)oxy)]benzylidene]-2-furanecarboxyhydrazide,

N^,-[o-((4,6-dimethoxy-2-pyrimidinyl)oxy)]benzylidene]-2-thienylcarboxyhydrazide,

N^,-[o-((4,6-dimethoxy-2-pyrimidinyl)oxy)]benzylidene]-(2,3-dichloro)benzohydrazide,

N'-[o-((4,6-dimethoxy-2-pyrimidinyl)oxy)]benzylidene]-o-trifluoromethylbenzohydrazide,

N'-[o-((4,6-dimethoxy-2-pyrimidinyl)oxy)]benzylidene]cyclopropylcarboxyhydrazide,

Ethyl 3-[o-((4,6-dimethoxy-2-pyrimidinyl)oxy)]benzylidene]carbazate, o- [(4,6-dimethoxy-2-pyrimidinyl)oxy] benzaldehyde 4-methyl-3-thiosemicarbazone, o-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde 4-ethylsemicarbazone, o-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde

4-(o-chlorophenyl)-3-thiosemicarbazone, o- [(4,6-dimethoxy-2-pyrimidinyl)oxy] benzaldehyde

4-(m-chlorophenyl)-3-thiosemicarbazone, o-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde

4-(p-chlorophenyl)-3-thiosemicarbazone, o-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde 4-phenyl-3-thiosemicarbazone, o-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde 4-ethyl-3-thiosemicarbazone, o-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde 4-allyl-3-thiosemicarbazone and 3-[(4,6-dimethoxy-2-pyrimidinyl)oxy]pyridine-2-carboxaldehyde oxime.

The following may be further mentioned as preferred individual compounds from the scope of the formula I:

o-[(4,6^ώmethoxy-2-pyrimidinyl)-oxy]-benzaldehyde-(o-chlorp henyI)-hydrazone, o-[(4,6-dimethoxy-2-pyrimidinyl)-oxy]-benzaldehyde-(p-tert-butyl-phenyl)-hydrazone, o-[(4,6-dimethoxy-2-pyrimidinyl)-oxy]-benzaldehyde-(m-trifluo rmethylphenyl)-hydrazone, o-[(4,6-dimethoxy-2-pyrimidinyl)-oxy]-benzaldehyde-(2,3-dichl orphenyl)-hydrazone, o-[(4,6-dimethoxy-2-pyrimidinyl)-oxy]-benzaldehyde-[(3-chloro

-5-trifluormethyI)-2-pyridyl] -hydrazone, o-[(4,6-dimethoxy-2-pyrimidinyl)-oxy]-benzaldehyde-N-methyl-p henylhydrazone,

3-[(4,6-dimethoxy-2-pyrimidinyl)-oxy]-pyridin-2-carboxyaldehy de-(o-chlorphenyι)-hydrazone.

N'-[o-((4,6-dimethoxy-2-pyrimidinyl)-oxy)-benzylidene]-o-meth ylbenzohydrazide,

N'-[o-((4,6-dimethoxy-2-pyrimidinyl)-oxy)-benzylidene]-4-pyri dincarboxyhydrazide,

N'-[o-((4,6-dimethoxy-2-pyrimidiπyl)-oxy)-benzylidene]-o-meth ylbenzohydrazide,

N'-[3-(o-((4,6^dimethoxy-2-pyrimidinyl)-oxy)-pyridyl)-methyli dene]-2-phenylacetohydrazide, o-[(4,6-dimethoxy-2-pyrimidinyl)-oxy]-benzaldehyd-N-methyl-3- thiosemicarbazone, o-[(4,6-dimethoxy-2-pyrimidinyl)-oxy]-benzaldehyd-3-thiosemic arbazone.

Compounds of the formula I in which R^R⁴, Z, Y and B are as defined above and W is NR⁴ can be prepared by reacting an aldehyde of the formula II

in which

R¹, R², R³, Z, Y and B are as defined under formula I, with an amine, hydrazine, hvdrazide, carbazate, semicarbazide or thiosemicarbazide or oxime of the formula III in which R⁴ is as defined under formula I, if desired in the presence of a water-binding agent and an inert diluent.

II

Compounds of the formula I can also be prepared by reacting a pyrimidine of the formula IV in which R¹, R² and Z are as defined under formula I and L is a leaving group such as fluorine, chlorine, bromine, C^alkylsulfonyl (for example methylsulfonyl or ethylsulfonyl), benzylsulfonyl, S-C_j^alkylsulfonyl-lH-l^^-triazol-l-yl (for example 3-methylsulfonyl-lH-l,2,4-triazol-l-yl), with an imine, hydrazone, hydrazide, carbazate, semicarbazide, thiosemicarbazide or oxime compound of the general formula V in which R³, R⁴, B and Y are as defined under formula I, in the presence of an acid-binding agent, for example n-butyllithium, sodium hydride, potassium carbonate or triethylamine, and in the presence of an inert solvent, for example tetrahydrofuran, dimethoxyethane, acetone, methyl ethyl ketone, acetonitrile, propionitrile, dimethylformamide, N-methylpyrrolidone or dimethyl sulfoxide.

IV V

The process is advantageously carried out at 0°C to the boiling point of the solvent used, preferably between room temperature and about 100°C.

Furthermore, compounds of the formula I in which R¹, R², R³, B, Y and Z are as defined under formula I and in which R⁶ in the definition NR⁵R⁶ is C^alkylcarbonyl, trifluoromethylcarbonyl, C₃.₆cycloalkylcarbonyl, benzylcarbonyl, 2-, 3- or 4-pyridinyl, 2- or 3-furyl or thiophenylcarbonyl, or benzoyl which is monosubstituted to disubstituted by fluorine, chlorine, bromine, methyl, trifluoromethyl, methoxy or nitro; or C_j.₄alkoxycarbonyl, benzoyloxycarbonyl, aminocarbonyl, aminothiocarbonyl, or aminocarbonyl or aminothiocarbonyl each of which is monosubstituted to disubstituted by phenyl or C-^alkyl, it being possible for the phenyl group to be substituted by fluorine, chlorine, methyl or methoxy, can be prepared by reacting a compound of the formula II in which R¹, R², R³, Z, Y and B are as defined above, with hydrazine or hydrazine hydrate, and the hydrazide of the formula I' in which R¹, R², R³, B, Y and Z are as defined above and W is NNH₂ is then reacted with the corresponding acid chloride, chloroformic ester, carbamoyl chloride or thiocarbamoyl chloride of the formula VI in which U is oxygen or sulfur, or with the corresponding isocyanate or isothiocyanate of the formula VI' in which U is oxygen or sulfur.

r VΓ

The particular reaction conditions are known to those skilled in the art.

Furthermore, compounds of the formula I in which R¹, R², R³, B, Y and Z are as defined above and in which R⁷ in the definition W = NOR⁷ is

C₃.₆alkenyl which can be substituted by halogen or phenyl, or is C^alkoxy- or alkylthiocarbonyl-C_j^alk^ I, can be prepared by reacting an oxime of the formula I' ' in which R^R³, B, Y and Z are as defined above and in which W is NOH, with an alkyl-, alkenyl- or C-^alkoxy- or alkylthiocarbonyl-C-^-alkyl halide of the formula VII in the presence of an inert diluent, for example toluene, tetrahydrofuran, acetone, 2-butanone, acetonitrile or dimethylformamide, and in the presence of an acid-binding agent, for example potassium carbonate, sodium hydride or triethylamine.

I"

Compounds of the formula II are either known or can be prepared by known processes. For example, aldehydes of the formula II (R³ = H) have been disclosed in European Patent Applications EP-A-0223 406 (B=C-H), EP-A-0249708 (B=C-C1), EP-A-0 287 079 (B=OCHF₂, OCH₂CH=CH_2ι OCH₂C=CH, OCH₂phenyl, OCH₂OCH₃) and EP-A-0336 494 (Z=N, B=C-H).

Compounds of the formula I" in which R¹ and R² are methoxy, Y is oxygen and B is methine, are known from European Patent Application EP-A-0 374 839.

Compounds of the formula IV are also either known (cf. for example, the above references) and/or can be prepared by the processes cited therein.

Compounds of the formula V are also either known or can be prepared by the processes known to those skilled in the art.

For example., compounds of the formula V can be prepared by oxidising a compound of the formula VIII (cf. for example, Tetr. 3, 49-55 (1958) and J. Amer. Chem. Soc. 76, 648-652 (1954)) in which Y is as defined under formula I, by known methods using a suitable oxidising agent [ox], for example manganese dioxide.

viπ '

Compounds of the formula VI, VI' and VTI are furthermore known from the literature.

The compounds of the formula I (hereinafter also named "active substances") have herbicidal properties and are suitable for controlling weeds, including grass weeds, for example, inter alia, Agropyron repens, Alopecurus myosuroides, Avena fatua, Bromus inermis, Echinochloa crus-galli, Poa annua, Sorghum halepense, Abutilon theophrasti, Amaranthus retroflexus, Cassia obtusifolia, Chenopodium album, Galium aparine, Matricaria chamomilla, Sinapis arvensis and Stellaria media in a range of crops of useful plants, for example, inter alia, rice crops, in particular paddy rice, wheat, maize, soya, oilseed rape, sunflowers and cotton. Moreover, the compounds are both pre-emergence and post-emergence herbicides. In some compounds of the formula I, a good selectivity was noticed, for example in the control of weeds in wheat, soya crops and cotton crops.

Moreover, the compounds of the formula I have plant-growth-regulating properties and are suitable as active substances for positively influencing the growth of useful plants. This effect can lead to a desired growth inhibition in crop plants and also inhibit the germination of weeds sufficiently to eliminate them as competitors of the crop plants. From an ecological point of view, this is advantageous and hence extremely desirable. Aspects which should be mentioned in particular are the protection of the soil surface from drying out and/or erosion and the reduction of the bulk of weed seeds in the soil (combined with prevention of flowering and further seed production). This effect may therefore be preferred to the complete prevention of weed formation, which may, however, be limited to a particular period.

In practice, a concentration of 1 g to 3 kg of the compound of the formula I per ha, preferably 10 g to 1 kg/ha, is usually sufficient for achieving the desired herbicidal effect. To achieve the desired herbicidal effect in combination with optimum tolerance by the useful plants, the range from 10 to 100 g/ha is particularly favourable when carrying out a pre-e ergence treatment, and the range from 100 to 1000 g/ha is particularly favourable when carrying out a post-emergence treatment.

The weedkillers and plant-growth regulators according to the invention comprise an effective amount of at least one compound of the formula I and, as a rule, also formulation auxiliaries. Advantageously, they each comprise at least one formulation auxiliary from each of the following groups:

- solid carriers;

- solvents or dispersants;

- surfactants (wetting agents and emulsifϊers);

- dispersants (without surfactant action); and

- stabilisers.

The pesticidal formulations comprise, as a rule, besides the active substances of the formula 1 1 to 99 % of a formulation auxiliary from the group comprising

- solid carriers;

- solvents or dispersants;

- dispersants (without surfactant action); and

- stabilisers; and 0 to 25 %, in particular 0.1 to 25 %, of a surfactant (wetting agents and emulsifiers).

Using these and other auxiliaries, the compounds of the formula I, i.e. the herbicidal active substances, can be converted into the customary formulations such as dusts, powders, granules, solutions, emulsions, suspensions, emulsifiable concentrates, pastes and the like.

The compounds of the formula I are generally water-insoluble and can be formulated by methods customary in the case of water-insoluble compounds, using the known formulation auxiliaries. The compositions can be prepared in a manner known per se, for example by mixing the particular active substance with solid carriers, by dissolving or suspending in suitable solvents or dispersants, with or without the use of surfactants as wetting agents or emulsifiers and/or dispersants, or by diluting prefabricated emulsifiable concentrates with solvents or dispersants.

The following are mainly suitable as solid carriers:

- natural minerals, such as chalk, dolomite, limestone, clays and silica and its salts, for example kieselguhr, kaolin, bentonite, talc, attapulgite or montmorillonite; - synthetic minerals, such as highly-disperse silica, alumina or silicates;

- organic substances, such as cellulose, starch, urea or artificial resins; and

- fertilisers, such as phosphates or nitrates.

Such carriers can be, for example, in the form of powders or granules.

The following are mainly suitable as solvents or dispersants:

- aromatic substances, such as benzene, toluene, xylene and alkylnaphthalenes;

- chlorinated aromatic substances and chlorinated aliphatic hydrocarbons, such as chlorobenzene, chloroethylenes or methylene chloride;

- aliphatic hydrocarbons, such as cyclohexane or paraffins, for example mineral oil fractions;

- alcohols, such as butanol or glycol, and their ethers and esters;

- ketones, such as acetone, methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone; and

- strongly polar solvents or dispersants, such as dimethylformarnide, N-methylpyrrolidone or dimethyl sulfoxide (such solvents preferably having flash points of at least 30°C and boiling points of at least 50°C), or water.

Other suitable solvents or dispersants are also so-called liquefied gaseous, extenders or carriers, which are products which are gaseous at room temperature and under atmospheric pressure. Examples of such products are, in particular, aerosol propellants, such as halohydrocarbons, for example dichlorodifluoromethane.

If the weedkiller according to the invention is in the form of a pressurised gas pack, it is advantageous to employ a solvent in addition to the propellant.

The surfactants (wetting agents and emulsifiers) can be non-ionic compounds, such as:

- condensation products of fatty acids, fatty alcohols or fat-substituted phenols with ethylene oxide;

- fatty acid esters and fatty acid ethers of sugars or polyhydric alcohols;

- the products which are obtained from sugars or polyhydric alcohols by condensation with ethylene oxide;

- block polymers of ethylene oxide and propylene oxide; or

- alkyldimethylamine oxides. The surfactants can also be anionic compounds, such as:

- soaps;

- fatty sulfate esters, for example dodecyl sodium sulfate, octadecyl sodium sulfate or cetyl sodium sulfate;

- alkylsulfonates, arylsulfonates or fatty-aromatic sulfonates, such as alkylbenzenesulfonates, for example calcium dodecylbenzenesulfonate or butylnaphthalenesulfonates; or

- more complex fatty sulfonates, for example the amide condensation products of Isure and N-methyltaurine, or the sodium sulfonate of dioctyl succinate.

Finally, the surfactants can be cationic compounds, such as alkyldimethylbenzylammonium chlorides, dialkyldimethylammonium chlorides, alkylmethylammonium chlorides or ethoxylated ammonium chlorides.

The following are mainly suitable as dispersants (without surfactant action): lignin, sodium salts and ammonium salts of ligninsulfonic acids, sodium salts of maleic anhydride/diisobutylene copolymers, sodium salts and ammonium salts of sulfonated polycondensation products of naphthalene and formaldehyde, or sulfite waste liquors.

Dispersants which are particularly suitable as thickeners or anti-settling agents which cm be employed are, for example, methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, polyvinyl alcohol, alginates, caseinates or blood albumin.

Examples of suitable stabilisers are:

- acid-binding agents, for example epichlorohydrin, phenyl glycidyl ether or soya epoxides;

- antioxidants, for example gallic esters or butylatedhydroxy toluene;

- UV absorbers, for example substituted benzophenones, diphenyl-β-cyano acrylic acid esters or cinnamic esters; or

- deactivators, for example salts of ethylenediaminotetraacetic acid, or polyglycols.

In addition to the compounds of the formula I, the weedkillers and plant-growth regulators according to the invention can also contain other active substances, for example insecticides, acaricides, nematicides, molluscicides, bactericides, fungicides, herbicides, plant-growth-regulating substances, fertilisers and trace-element sources. Such combined compositions are suitable for widening the spectrum of action. In general, the weedkillers according to the invention comprise between 0.001 and 95 %, preferably between 0.5 and 75 %, by weight of one or more of the compounds of the formula I as active substance. For example, they can be in a form which is suitable for storage and transport. In such formulations, for example emulsifiable concentrates, the active substance concentration is usually in a higher range, preferably between 1 and 50 % by weight, in particular between 5 and 30 % by weight. These formulations can then be diluted, for example with identical or different inert substances, down to the active substance concentration which is suitable for use in practice, viz. preferably about 0.001 to 10 % by weight, in particular about 0.005 to 5 % by weight. However, the active substance concentrations can also be lower or higher.

As mentioned, the weedkiller according to the invention can be prepared in a manner known per se.

For preparing preparations in the form of powders, the active substance, i.e. at least one compound of the formula I, can be mixed with a solid carrier, for example by simultaneous grinding. Alternatively, the solid carrier can be impregnated with a solution or suspension of the active substance, and the solvent or dispersant can then be removed by evaporation, heating or filtering off under reduced pressure. By adding surfactants or dispersants, it is possible to render such agents, which are in the form of powders, readily wettable with water, so that they can be converted into aqueous suspensions which are suitable, for example, as sprays.

Alternatively, the active substance can be mixed with the surfactant and a solid carrier to give a wettable powder which is dispersible in water, or it can be mixed with a solid, pregranulated carrier to give a product in the form of granules.

If desired, the active substance can be dissolved in a solvent which is not miscible with water, for example a high-boiling hydrocarbon. This solvent expediently contains a dissolved emulsifier, so that the solution is self-emulsifying when added to water. On the other hand, the active substance can be mixed with an emulsifier, and the mixture can then be diluted with water to the desired concentration. Moreover, the active substance can be dissolved in a solvent, and the solution can then be mixed with an emulsifier. Such a mixture can also be diluted with water to the desired concentration. In this manner, emulsifiable concentrates or ready-for-use emulsions are obtained. The weedkillers described can be used according to the invention in customary application methods, such as spraying, atomising, dusting, pouring or scattering.

The examples which follow are intended to further illustrate the invention.

Preparation examples:

Example 1: 3-[(4,6-Dimethoxy-2-pyrimidinyl)oxy]-pyridine-2-carboxaldehyde can be prepared as follows:

15 g of 3-hydroxy-2-hydroxymethylpyridine are suspended in 1000 ml of chloroform, and the suspension is heated to boiling point. 80-100 ml of ethanol are subsequently added slowly until a clear solution has formed. 40 g of activated manganese oxide are then carefully introduced at reflux temperature. The mixture is heated for a further 3 hours and then filtered under hot conditions. The solvents are stripped off under reduced pressure. The resinous product in 10 ml of ethyl acetate is transferred to a "dry column flash chromatography" silica gel column and eluted using ethyl acetate hexane 1:3. 3-Hydroxypyridine-2-carboxaldehyde is obtained as yellowish crystals; melting point: 75-77°C.

8.6 g of the above 3-hydroxypyridine-2-carboxaldehyde are dissolved in a mixture of 125 ml of tetrahydrofuran and 100 ml of dimethylforma ide. 2.7 g of a 60 % suspension of sodium hydride in oil is washed with dry tetrahydrofuran and then added carefully to the above reaction mixture. When the evolution of hydrogen has ceased, 15 g of 4,6-dimethoxy-2-pyrimidinyl methyl sulfone are added, and the mixture is heated for 20 hours at reflux temperature, under a nitrogen atmosphere. When the mixture has cooled, the solvents are removed under reduced pressure and the product is then taken up in 500 ml of dichloromethane. The dark suspension is treated with active charcoal under hot conditions and filtered. Ti. solvent is removed under reduced pressure, and the residue which remains is recrystallised from ethyl acetate/hexane 7:8. 3-[(4,6-Dimethoxy-2-pyrimidinyl)oxy]pyridine-2-carboxaldehyde, of melting point 102 to 104°C, is obtained as an almost white solid.

Example 2: 4,6-Dimethoxy-2-[[α-[(E and/or Z)-phenylimino]-o-tolyl]oxy]pyrimidine (Compound No. 1.007) can be prepared as follows: 2.60 g of 2-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde and 1.05 g of aniline in 25 ml of ethanol and in the presence of 3 drops of acetic acid are maintained at reflux temperature for 45 minutes. The reaction mixture is cooled to -5°C, and the product which has precipitated is filtered off and washed with ice-cold ethanol. Pure 4,6-dimethoxy-2-[[α-[(E and/or Z)-phenylimino]-o-tolyl]oxy]pyrimidine (Compound No. 1.007), of melting point 74-75°C, are obtained by recrystallisation from hot ethanol.

Example 3: 4,6-Dimethoxy-2-[[α-[(E and/or Z)-phenylimino]-o-tolyl]oxy]pyrimidine (Compound No. 1.007) can also be prepared as follows:

2.0 g of N-phenyl-2-hydroxybenzimine and 2.2 g of 4,6-dimethoxy-2-pyrimidinyl methyl sulfone are heated at reflux temperature for 24 hours in the presence of 10 g of potassium carbonate in 150 ml of ethyl acetate. When cold, the reaction mixture is diluted with

150 ml of dichloromethane and filtered. The solvents are stripped off, and the residue is purified by means of dry flash chromatography. 4,6-Dimethoxy-2-[[α-[(E and/or Z)-phenylimino]-o-tolyl]oxy]pyrimidine (Compound No. 1.007) is obtained; 1H . NMR(CDC1₃): 3.80, s, 2xOCH₃; 5.79, s, CH; 7.1 - 7.5 8H, 8.26, m, IH; 8.67, s, CH=N.

Example 4:2-fTα-r(E and/or Z)-tert-butylimino]-o-tolynoxy]-4,6-dimethoxypvrimidine (Compound No. 1.008) can be prepared as follows:

4.2 g of 2-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde and 10 g of tert-butylamine are initially introduced into 100 ml of dry tetrahydrofuran. The sealed reaction vessel is allowed to stand for one week in the presence of 5 g of 4A molecular sieve. The mixture is subsequently evaporated to dryness, and 4.9 g of 2-[[α-[(E and/or Z)- tert-butyIimino]-o-tolyl]oxy]-4,6-dimethoxypyrimidine (Compound No. 1.008) are obtained as an oil; HNMR(CDC1₃): 1.19, s, C(CH₃)₃; 3.80, s, 2x OCH₃; 5.77, s, CH; 7.1 -

8.1 4H; 8.40, s, CH=N.

Example 5: o-[(4,6-Dimethoxy-2-pyrimidinyl)oxy]benzaldehyde (E and/or Z)-phenylhydrazone (Compound No. 1.054) can be prepared as follows:

2.6 g of 2-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde are introduced into a warm solution of 1.2 g of phenylhydrazine in 30 ml of ethanol, 3 drops of acetic acid are added, and the mixture is kept at boiling point for a further 5 minutes. The mixture is cooled and the product which has precipitated is filtered off and purified by recrystallisation from hot ethanol. o-[(4,6-Dimethoxy-2-pyrimidinyl)oxy]benzaldehyde (E and/or Z)-phenylhydrazone (Compound No. 1.054) are obtained, melting point: 107-108°C.

Example 6: N'-(E and/or Z)-o-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzylidene]- propionohydrazide (Compound No. 1.055) can be prepared as follows:

4 g of 2-[(4,6-dimethoxy-2-pyrimidinyl)oxy] benzaldehyde are introduced into a solution of 15 g of hydrazine hydrate in 100 ml of methanol, during which process the temperature is allowed to rise to +50°C. After the mixture has been cooled to room temperature, 150 ml of dichloromethane are added, the mixture is washed four times with water, and the organic phase is dried over sodium sulfate, 4 g of triethylamine are then added and the reaction mixture is treated dropwise with 1.7 g of propionyl chloride. Stirring is continued for 10 minutes, and the mixture is then washed twice with 200 ml of water, separated, dried and evaporated to dryness under reduced pressure. The crude product is recrystallised from ethyl acetate/hexane 2:1. N'-[(E and/or

Z)-o-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzylidene]propionohydrazide (Compound No. 1.055) is obtained, melting point: 144-146°C.

Example 7: 2-[(4,6-Dimethoxy-2-pyrimidinyl)oxy] benzaldehyde o-ethoxycarbonylmethyl oxime (Compound No. 4.003) can be prepared as follows:

2.0 g of 2-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldoxime, 0.94 ml of ethyl chloroacetate and 2.1 g of potassium carbonate are heated at reflux temperature for 2 hours in the presence of a spatula tip each of sodium iodide and 18-crown-6 in 20 ml of acetonitrile. The mixture is then extracted with ethyl acetate using water and sodium chloride solution as the aqueous phase, and, after evaporation to dryness, the crude product is purified on a silica gel column using 20 % acetic acid in hexane. 2-[(4,6-Dimethoxy-2-pyrimidinyl)oxy]benzaldoxime ethoxycarbonyl methyl ether (Compound No. 4.003) is obtained as a yellow oil; 1H NMR (CDC1₃): 1.29, t, J=7.5 Hz, OCH₂CH₃; 3.80, s, 2xOCH₃; 4.24, q, J=7.5 Hz, OCH₂CH₃; 5.78, s, CH, 4.68, s, NOCH₂; 7.19, txd, J=7.5xl.5 Hz, CH; 7.41, txd, J=7.5xl.5 Hz, CH; 7.86, dxd, J=7.5xl.5 Hz, CH; 8.38, s, CH=N.

Example 8: 3-[(4,6-Dimethoxy-2-pyrimidinyl)oxy)pyridine-2-carboxaldehyde oxime (Compound No. 4.004) can be prepared as follows: A methanolic solution of 1.0 g of sodium acetate and 0.7 g of hydroxylamine hydrochloride is briefly heated to reflux temperature. 1.8 g of 3-[(4,6-dimethoxy-2-pyrimidinyl)oxy]pyridine-2-carboxaldehyde (Example 1) are introduced after 1 minute. The reaction mixture is kept at reflux temperature for a further 5 minutes, and such an amount of water is then added until a clear solution is obtained. On cooling, 3-[(4,6-dimethoxy-2-pyrimidinyl)oxy]-pyridine-2-carboxaldehyde oxime (Compound No.4.004) precipitates as white crystals; melting point 169-171°C.

The compounds listed in the tables below can be prepared analogously to Examples 2 to 8. In those cases where no melting point or H NMR spectrum is indicated, the R_f values (refractive index) were determined in ethyl acetate/hexane.

Table 1 : Compounds of the formula la:

Table 2: Compounds of the formula lb:

Table 2, continuation:

Table 2. continuation:

Table 2. continuation:

Tabelle 1:

Tabelle 1:

Table 3: Compounds of the formula Ic:

Table 4: Compounds of the formula Id:

Table 5: Compounds of the formula le:

Table 6: Compounds of the formula If:

C. Formulation examples

Example Fl: To prepare a 25 % wettable powder, the components listed below are mixed with ea other:

Per cent by weight Compound of the formula I according to tables 1-6 25

Hydrated silica (carrier, grinding auxiliary) 20

Sodium lauryl sulfate (wetting agent) 2

Sodium lignosulfate (dispersant) 4

Kaolin (carrier) 49

100

First, the liquid or molten active substance is applied to the silica which has been introduced into grinding apparatus. The other components are subsequently admixed. The mixture is ground finel using a pin mill or a comparable grinding apparatus.

When stirred into water, the resulting wettable powder gives a fine suspension which is suitable a a ready-for-use spray mixture.

Active substances which are particularly suitable for this formulation are compounds of the formula I which are liquid or which have a low melting point, i.e. up to about +100°C.

Example F2: Compounds of the formula I which have a high melting point, i.e. above about +100°C, can preferably be used as active substances in concentrated wettable powders, for exampl as follows:

Per cent by weight Compound of the formula I according to tables 1-6 75

Hydrated silica (carrier, grinding auxiliary) 1

Alkylnaphthalenesulfonate and alkyl- carboxylate-sulfate as sodium salts 2

Sulfonated naphthalene/formaldehyde conden¬ sate as the sodium salt (dispersant) 10 Polyvinylpyrrolidone (binder) 1 Kaolin (carrier) J,

100

The components are mixed with each other and ground finely using a pin mill or a comparable grinding device, in particular a jet mill.

When stirred into water, the resulting wettable powder gives a fine suspension of any desired concentration which is suitable as a ready-for-use spray mixture.

Example F3: A wettable powder based on the composition of Example F3 can also be converted into dispersible granules. For this purpose, the ground powder is sprayed with an aqueous solution of the binder in a suitable granulation apparatus (for example granulation plate, mixing drum, high-speed stirrer or fluidised-bed granulator) until agglomerations have formed. After this, the water which has been added is removed again in a drying process. The granules of the desired size are collected by sieving.

Compared with the wettable powder, the resulting granules have a series of advantages (no dust formation on application, easier metering because of better flow properties). They are applied in just the same fashion as in the case of the wettable powder, after the preparation has been stirred into water and the granules have disintegrated completely into the primary particles. Example F4: The compounds of the formula I have limited solubility in the customary organic solvents. Accordingly, emulsifiable concentrates of relatively low concentration are possible; fo example:

Compound of the formula I according to tables 1-6 125 g/1

Emulsifier 300 g/1

N-Methyl-2-pyrrolidone (solvent) to 1000 ml

The active substance and the emulsifier are introduced into the solvent, with stirring. The mixtur is stirred until a homogeneous solution has formed.

The resulting emulsifiable concentrate can be emulsified in water, which gives a ready-for-use spray mixture of the desired concentration.

Example F5: Compounds of the formula I having a melting point higher than about +60°C can a be formulated as so-called suspension concentrates ("flowables"); for example:

Compound of the formula I according to tables 1-6 250 g/1

Ethylene glycol (antifreeze agent) 80 g/1

Silica (anti-settling agent) 5 g/1

Xanthan gum (thickener) 2 g/1

Silicone defoamer 5 g/1

Nonylphenol polyethoxylate (wetting agent) 20 g/1 Sulfonated naphthalene/formaldehyde condensate as the sodium salt (dispersant) 40 g/1

Water to 1000 ml

The formulation auxiliaries are dissolved in water. The pre-ground active substance is dispersed the solution, with stirring. The resulting coarse suspension is now subjected to wet grinding (for example in a colloid mill or a stirred ball mill). If desired, small amounts of further additives are now possible, such as antifoam agents, anti-settling agents and biocides.

For use, the resulting "flowable" can be diluted with water as desired, giving a ready-for-use spr mixture of the desired concentration. Biological examples

Example Bl: Pre-emergence herbicidal action

Immediately after the test plants (a number of weeds, both monocotyledon and dicotyledon) have been sown in seed dishes in a greenhouse, the soil surface is treated with an aqueous spray mixtur corresponding to a rate of application of 3 kg of active substance/hectare.

The test substances are preferably formulated as emulsifiable concentrate (EC) and diluted with water to the desired concentration immediately before application. Insoluble substances are formulated as a wettable powder (WP), using kaolin as the inert carrier. This wettable powder is suspended in water immediately before application.

The dosage rates in g of active ingredient ha relate to the soil surface in the containers, unless otherwise indicated. The spray volume is 5001 ha.

The seeds of the plants are sown in plastic plant pots of various sizes containing heat-sterilised (steamed) soil (terrestial soil 2.6 % peat, 20 % clay, 30 % silt, 47 % sand). The plants are kept in the greenhouse at an average temperature (17 - 25°C in winter, 18 - 35°C in summer) (atmospheric humidity 30 - 90 ). The length of the photoperiod is 13 to 16 hours/day; if necessary, artificial light is added (15000 to 18000 lux). Artificial illumination is also activated automatically when the daylight intensity is insufficient.

After 3 weeks, the herbicidal action is rated in comparison with an untreated control group, using a three-step, linear key (2 = 80-100 % damage, 1 = 30-79 % damage, 0 = 0-29 % damage).

In this test, the compounds of the formula I described in the examples have a powerful herbicidal action.

Examples of the good herbicidal action of the compounds of the formula I which are described in the tables of the present application are listed in Table B 1 : Table Bl: Pre-emergence herbicidal action:

CompoundNo. S E A A C S A D M C O C V L H T B A A A R H E O E E U T T S G I N P N L T U R S

Example B2: Post-emergence herbicidal action (contact herbicide) After emergence (in the 4- to 6-Ieaf stage), a number of weeds, both monocotyledon and dicotyledon, were treated with an aqueous dispersion of active substance at a dosage rate of 3 kg of active ingredient per hectare.

The test substances are preferably formulated as an emulsifiable concentrate (EC), and diluted with water to the desired concentration immediately before application. Insoluble substances are formulated as a wettable powder (WP), using kaolin as the inert carrier. This wettable powder is suspended in water immediately before application.

Unless otherwise indicated, dosage rates in g of active ingredient/ha are based on the soil surface in the containers. The spray volume is 5001/ha.

The seeds of the plants are sown in plastic plant pots of various sizes containing heat-sterilised (steamed) soil ("Optima" soil 80 % peat, 20 % loess). The plants are kept in the greenhouse at an average temperature (17 - 25°C in winter, 18 - 35°C in summer) (atmospheric humidity 30 - 90 %). The length of the photoperiod is 13 to 16 hours/day; if necessary, artificial light is added (15000 to 18000 lux). Artificial illumination is also activated automatically when the daylight intensity is insufficient.

In this test, the compounds described in the examples also have a powerful herbicidal action.

Examples of the good herbicidal action of the compounds of the formula I which are described in the tables of the present application are listed in Table B2: Table B2: Post-emergence herbicidal action:

Compound No. S E A A C S A

0 C V L H T B

R H E 0 E E U

G I N P N L T

In the table

SORG denotes Sorghum halepense Johnsongrass ECHI denotes Echinochloa crus-galli Barnyard grass AVEN denotes Avena fatua Wild oat ALOP denotes Alopecurus myosuroides Blackgrass CHEN denotes Chenopodium album Lambs quarters STEL denotes Stellaria media Chickweed ABUT denotes Abutilon theophrasti Velvetleaf

Example B3: Herbicidal action for paddy rice

The seeds of the plants are sown in plastic beakers or boxes of various sizes, sealed at the bottom end and containing fertilised soil. The soil is heat-sterilised (steamed) and contains about 80 % (w/v) loam and 20 % peat and 0.05 % Nutricote (16/10/10) and 0.05 % "Plantamaag" as fertiliser. The plants are kept in a special greenhouse cabin at a high temperature (20-35°C) and high atmospheric humidity (60-80 %), the latter being kept constant by means of a sprinkler system. The length of the photoperiod is 13 to 16 hours/day; if necessary, artificial light (15000 to 18000 lux) is added. Artificial illumination is also activated automatically when the daylight intensity is insufficient. The test substances are preferably formulated as emulsifiable concentrates (EC) and diluted to the desired concentration with water immediately before application. Insoluble substances are formulated as a wettable powder (WP), using kaolin as the inert carrier. This wettable powder is suspended in water immediately before application.

The dosage rates in g of active ingredient/ha are relative to the soil surface in the containers, unless otherwise indicated. The spray volume is 5001 ha.

The tests are rated after 3 or 4 weeks (post-emergence or pre-emergence treatment) in comparison with an untreated control group, using a ten-step, linear key (10 = complete damage, 0 = no action). Here, too, the compounds of the formula I have a selective herbicidal action against the weeds.

Claims

WHAT IS CLAIMED IS:

1. A pyrimidinyl- and triazinylsalicyl- and -picolinylaldehyde derivative of the formula I

in which

W is oxygen or NR⁴;

B is nitrogen, methine, or methine which is substituted by fluorine, chlorine, methyl, methoxy, 2-propenyloxy, 2-propynyloxy, difluoromethoxy or benzyloxy; Y is oxygen or sulfur; Z is methine or nitrogen; R¹ is chlorine, methyl, methoxy, ethoxy, difluoromethoxy, methylamino, ethylamino or dimethylamino; R² is methyl, methoxy or difluoromethoxy; R³ is hydrogen, fluorine, chlorine, methyl or methoxy; R⁴ is Cj.galkyl, or

which is substituted by up to 3 fluorine atoms, 1 chlorine atom, 1 C^alkoxy group, 1 ^alkoxycarbonyl group, 1 dimethylcarbamoyl group,

1 carbamoyl group, 1 cyano group, 1 vinyl group, 1 ethynyl group or 1 phenyl group which is unsubstituted or substituted by fluorine, chlorine, bromine, methyl, trifluoromethyl or methoxy, or is phenyl or phenyl which is up to trisubstituted by fluorine, chlorine, bromine, methyl, trifluoromethyl, methoxy or nitro, or NR⁵R⁶, or OR⁷; R⁵ is hydrogen or C_j . alkyl; R⁶ is hydrogen, Cj.galkyl, phenyl, pyridyl, 1,3-thiazinyl, pyridazinyl, pyrazinyl, pyrimidinyl, or phenyl which is monosubstituted to trisubstituted or pyridyl which is monosubstituted to disubstituted by C^alkyl, fluorine, chlorine, bromine, trifluoromethyl, methoxy or nitro; or pyridazinyl or pyrazinyl each of which is monosubstituted by methyl, fluorine, chlorine, trifluoromethyl or methoxy; or pyrimidinyl which is monosubstituted to disubstituted by methyl, trifluoromethyl or methoxy; or benzylcarbonyl, pyridylcarbonyl, furylcarbonyl, thiophenylcarbonyl or benzoyl each of which is monosubstituted to disubstituted by fluorine, chlorine, bromine, methyl, trifluoromethyl, methoxy or nitro; or is C_j^alkylcarbonyl, trifluoromethylcarbonyl, C3_₆Cycloalkylcarbonyl, benzylcarbonyl, 2-, 3- or 4-pyridylcarbonyl, 2- or 3-furyl- or thiophenylcarbonyl, benzoyl, or benzoyl which is monosubstituted to disubstituted by fluorine, chlorine, bromine, methyl, trifluoromethyl, methoxy or nitro; or C^alkoxycarbonyl, benzoyloxycarbonyl, aminocarbonyl, aminothiocarbonyl, or aminocarbonyl or aminothiocarbonyl each of which is monosubstituted to disubstituted by phenyl, C-^alkyl, C .₆-alkenyl or C₂_g-alkynyl it being possible for the phenyl group to be substituted by fluorine, chlorine, bromine, methyl, trifluoromethyl, methoxy; or is .g-alkylsulfonyl, phenylsulfonyl or phenylsulfonyl which is monosubstituted to disubstituted by fluorine, chlorine, bromine, methyl, trifluoromethyl, methoxy, cyano or nitro; R⁷ is hydrogen, C-^alkyl or C^alkenyl, or C₂.₆alkenyl which is substituted by halogen or phenyl, or C_j^alkoxycarbonyl-C^alkyl or C_j^alkylthiocarbonyl-C_j^alkyl; with the proviso that W is not oxygen when B is unsubstituted or substituted methine; that W is not NOR⁷ when, simultaneously, Z is methine, B is unsubstituted methine and R⁷ is hydrogen, C^alkyl or C₂.₆alkenyl which can be substituted by halogen or phenyl.

2. A compound of the formula I according to claim 1, in which R⁶ is hydrogen, C-^alkyl, phenyl, pyridyl, or phenyl which is monosubstituted to trisubstituted or pyridyl which is monosubstituted to disubstituted by C^alkyl, fluorine, chlorine, bromine, trifluoromethyl, methoxy or nitro; or is Cι_₆alkylcarbonyl, trifluoromethylcarbonyl, C₃_₆cycloalkylcarbonyl, benzylcarbonyl, 2-, 3- or 4-pyridylcarbonyl, 2- or 3-furyl- or thiophenylcarbonyl, benzoyl, or benzoyl which is monosubstituted to disubstituted by fluorine, chlorine, bromine, methyl, trifluoromethyl, methoxy or nitro; or ^alkoxycarbonyl, benzoyloxycarbonyl, aminocarbonyl, aminothiocarbonyl, or aminocarbonyl or aminothiocarbonyl each of which is monosubstituted to disubstituted by phenyl or C_j^alkyl, it being possible for the phenyl group to be substituted by fluorine, chlorine, methyl or methoxy;

3. A compound of the formula I according to claim 1, in which W is NR⁴.

4. A compound of the formula I according to claim 1, in which R¹ and R² are methoxy.

5. A compound of the formula I according to claim 1, in which Y is oxygen.

6. A compound of the formula I according to claim 1, in which Z is methine.

7. A compound of the formula I according to claim 1, in which B is nitrogen or methine which is unsubstituted and R³ is hydrogen.

8. A compound of the formula I according to claim 7, in which B is methine which is unsubstituted.

9. A compound of the formula I according to claim 1, in which R³ is hydrogen.

10. A compound of the formula I according to claim 1, in which W is NR⁴ and R⁴ being tert-butyl, phenyl, or phenyl which is substituted by halogen, methyl, trifluoromethyl or methoxy.

11. A compound of the formula I according to claim 1, in which R⁴ is an NR⁵R⁶ group in which R⁵ is hydrogen or methyl and R⁶ is

phenyl, or phenyl which is monosubstituted to disubstituted by halogen,

trifluoromethyl, nitro or methoxy or R⁶ is 2-pyridyl or 2-pyridyl which is monosubstituted by fluorine, chlorine, bromine, methyl or trifluoromethyl.

12. A compound of the formula I according to claim 1, in which R⁴ is an NR⁵R⁶ group in which R⁵ is hydrogen and R⁶ is C alkyl-, cyclopropyl-, benzyl-, 2-,3- or 4-pyridyl-, 2-furyl- or phenylcarbonyl or phenylcarbonyl which is monosubstituted or disubstituted by halogen, methyl, trifluoromethyl, methoxy or nitro.

13. A compound of the formula I according to claim 1, in which R⁴ is an NR⁵R⁶ group in which R⁵ is hydrogen and R⁶ is C_j ^alkoxycarbonyl.

14. A compound of the formula I according to claim 1, in which R⁴ is an NR⁵R⁶ group in which R⁵ is hydrogen or methyl and R⁶ is Cj ^alkylamino-, 2-propenylamino- or phenylaminocarbonyl or -aminothiocarbonyl, or phenylaminocarbonyl which is substituted by halogen, methyl, trifluoromethyl or methoxy.

15. A compound of the formula I according to claim 14, in which R⁵ is hydrogen and R⁶ is C_j^alkylamino- or phenylaminocarbonyl or phenylaminocarbonyl which is substituted by halogen, methyl or methoxy.

16. A compound of the formula I according to claim 1, in which R¹ and R² are methoxy;

R³ is hydrogen; Y is oxygen; Z is methine;

B is methine; andR⁴ is C(CH₃)₂CH₂CH₃, C(CH₃)₂C≡CH, C(CH₃)₂C≡N, CCH₃(i-Pr)C≡N, C(CH₃)₂CON(CH₃)₂, CH₂COOCH₃, CH(CH₃)COOCH₃, CH(i-Pr)COOCH₃, benzyl, 2-chIorobenzyl, 2-Cl-6-F-benzyl, 4-fluorophenyl, 2-chlorophenyl, 4-bromophenyl, 4-trifluoromethylphenyl, 2-methoxyphenyl, 4-methoxyphenyl, 3-nitrophenyl, 4-nitrophenyl, o-tolyl, m-tolyl, p-tolyl, 4-tert-butylphenyl, 2,4-dichlorophenyl, 3-CF₃-4-Cl-phenyl, NHCH₂CH=CH₂, NH-2-bromophenyl, NH-3-bromophenyl, NH-4-bromophenyl, NH-2-fluorophenyl, NH-4-fluorophenyl, NH-o-tolyl, NH-m-tolyl, NH-p-tolyl, NH-p-(i-Pr)phenyl, NH-2-trifluoromethylphenyl, NH-4-trifluoromethylphenyl, NH-2-methoxyphenyl, NH-2-nitrophenyl, NH-4-nitrophenyl, NH-o-(3-Cl)tolyl, NH-(3-Cl)p-tolyl, NH-o-(4-Cl)tolyl, NH-m-(4-Cl)tolyl, NH-2,4-xylyl, NH-2,4-(3-CI)xylyl, NH-2,4-difluorophenyl, NH-2,5-difluorophenyI, NH-2,4-dichlorophenyl, NH-3,5-dichlorophenyl, NH-3,4-dichlorophenyl, NH-(2-Cl-4-CF₃)phenyl, NH-(4-Cl-3-CF₃)phenyl, NH-2-pyridyl, NH-2-(3-CF₃)pyridyl, NH-2-(3-CI-5-CF₃)pyridyl, NH-2-(3-F-5-Cl)pyridyl, N(CH₃)phenyl, NHCOCF₃, NHCO-m-tolyl, NHCO-p-tolyl, NHCO-4-fluorophenyl, NHCO-4-bromophenyl, NHCO-4-methoxyphenyl, NHCO-3-furyl, NHCOOCH(CH₃)₂, NHCOO-benzyl, NHCONH₂ or NHCSNH₂.

17. A compound of the formula I according to claim 1, in which R¹ and R² are methoxy; R³ is hydrogen;

Y is sulfur; Z is methine;

B is methine and

R⁴ is tert-butyl, phenyl, 4-chlorophenyl, 3-methoxyphenyl, 3-trifluoromethylphenyl, N(CH₃)₂, NHC(CH₃)₃, NH-3-chlorophenyl, NH-4-chlorophenyl, NH-4-methoxyphenyl, NH-3-nitrophenyl, NH-2,3-xylyl, NH-2-(3-CF₃)pyridyl, NHCOCH₃, NHCOCH₂CH₃, NHCO-cyclopropyl, NHCO-benzyl, NHCO-3-chlorophenyl, NHCO-4-chlorophenyl, NHCO-2,3-dichlorophenyl, NHCO-2-pyridyl, NHCO-3-pyridyl, NHCO-4-pyridyl, NHCO-2-furyl, NHCOOCH₂CH₃, NHCONHCH₂CH₃, NHCSNHCH₃, NHCSNHCH₂CH₃, NHCSNHCH₂CH=CH₂, NHCSNH-phenyl or NHCSNH-2-chlorophenyl.

18. A compound of the formula I according to claim 1, in which R¹ and R² are methoxy;

R³ is hydrogen; Z is methine;

Y is oxygen;

B is nitrogen, or methine which is substituted by chlorine, methyl or methoxy, and R⁴ is tert-butyl, phenyl, 4-chlorophenyl, 3-methoxyphenyl, 3-trifluoromethylphenyl, N(CH₃)₂, NHC(CH₃)₃, NH-3-chlorophenyl, NH-4-chlorophenyl, NH-4-methoxyphenyl, NH-3-nitrophenyl, NH-2,3-xylyl, NH-2-(3-F-5-Cl)pyridyl, NH-2-(3-CF₃)pyridyl, NHCOCH₂CH₃, NHCO-cyclopropyl, NHCO-benzyl, NHCO-3-chlorophenyl, NHCO-4-chlorophenyl, NHCO-2,3-dichlorophenyl, NHCO-2-pyridyl, NHCO-3-pyridyl, NHCO-4-pyridyl, NHCO-2-furyl, NHCOOCH₂CH₃, NHCONHCH₂CH₃, NHCSNHCH₃, NHCSNHCH₂CH₃, NHCSNHCH₂CH=CH₂, NHCSNH-phenyl or NHCSNH-2-chlorophenyl.

19. A compound of the formula I according to claim 1, selected from amongst 3-[(4,6-dimethoxy-2-pyrimidinyl)oxy]pyridine-2-carboxaldehyde, 4,6-dimethoxy-2-[(α-phenylimino-o-tolyl)oxy]pyrimidine, 4,6-dimethoxy-2-[(α-(α,α,α-trifluoro-m-tolyl)imino-o-tolyl)oxy]pyrimidine, 4,6-dimethoxy-2-[(α-(m-methoxyphenyl)imino-o-tolyl)oxy]pyrimidine, 2-[(α-(p-chlorophenyl)imino)-o-tolyl)oxy]-4,6-dimethoxypyrimidine, 2-[(α-(tert-butyl)imino-o-tolyl)oxy]-4,6-dimethoxypyrimidine, o-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde phenylhydrazone, o-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde (p-chlorophenyI)hydrazone, o-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde dimethylhydrazone, o-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde tert-butylhydrazone,

3-[(4,6-dimethoxy-2-pyrimidinyl)oxy]pyridine-2-carboxaldehyde phenylhydrazone,

3-[(4,6-dimethoxy-2-pyrimidinyl)oxy]pyridine-2-carboxaldehyde

[(3-trifluoromethyl)-2-pyridyl]hydrazone, o-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde (p-methoxyphenyl)hydrazone, o-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde (m-nitrophenyl)hydrazone, o-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde (2,3-dimethylphenyl)hydrazone, p-chloro-N^,-[o-((4,6-dimethoxy-2-pyrimidinyl)oxy)]benzylidene]benzohydrazide,

N^,-[o-((4,6-dimethoxy-2-pyrimidinyl)oxy)]benzylidene]benzohydrazide,

N^,-[o-((4,6-dimethoxy-2-pyrimidinyl)oxy)]benzylidene]-o-methoxybenzohydrazide,

N^,-[o-((4,6-dimethoxy-2-pyrimidinyl)oxy)]benzylidene]nicotinohydrazide,

N^,-[o-((4,6-ώmethoxy-2-pyrimidinyl)oxy)]benzylidene]propionohydrazide,

N'-[o-((4,6-dimethoxy-2-pyrimidinyI)oxy)]benzylidene]-o-nitrobenzohydrazide,

N^,-[o-((4,6-dimethoxy-2-pyrimidinyl)oxy)]benzylidene]-2-pyridinecarboxyhydrazide,

N'-[o-((4,6-dimethoxy-2-pyrimidinyl)oxy)]benzylidene]-m-chlorobenzohydrazide,

N^,-[o-((4,6-dimethoxy-2-pyrimidinyI)oxy)]benzyIidene]acetohydrazide,

N-[o-((4,6-dimethoxy-2-pyrimidinyl)oxy)]beπzyIideπe]-2-phenylacetohydrazide,

N^,-[o-((4,6-dimethoxy-2-pyτimidinyl)oxy)]benzyIidene]-2-furanecarboxyhydrazide,

N'-[o-((4,6-dimethoxy-2-pyrimidinyl)oxy)]benzylidene]-2-thienyIcarboxyhydrazide,

N'-[o-((4,6-dimethoxy-2-pyrimidinyl)oxy)]benzylidene]-(2,3-dichloro)benzohydrazide,

Ethyl 3-[o-((4,6-dimethoxy-2-pyrimidinyI)oxy)]benzylidene]carbazate, o-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde 4-methyl-3-thiosemicarbazone, o-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde 4-ethylsemicarbazone, o-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde

4-(o-chlorophenyl)-3-thiosemicarbazone, o- [(4,6-dimethqxy-2-pyrimidinyl)oxy] benzaldehyde

4-(p-chlorophenyl)-3-thiosemicarbazone, o-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde 4-phenyl-3-thiosemicarbazone, o-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde 4-ethyI-3-thiosemicarbazone, o-[(4,6-dimethoxy-2-pyrimidinyl)oxy]benzaldehyde 4-allyl-3-thiosemicarbazone and 3-[(4,6-dimethoxy-2-pyrimidinyl)oxy]pyridine-2-carboxaldehyde oxime.

20. A compound of the formula I according to claim 1, selected from amongst o-[(4,6-dimethoxy-2-pyrimidinyl)-oxy]-benzaldehyde-(o-chlorphenyl)-hydrazone, o-[(4,6-dimethoxy-2-pyrimidinyl)-oxy]-benzaldehyde-(p-tert-butyl-phenyl)-hydrazone, o-[(4,6-dimethoxy-2-pyrimidinyl)-oxy]-benzaldehyde-(m-trifluo rmethylphenyl)-hydrazone, o-[(4,6-dimethoxy-2-pyrimidinyl)-oxy]-benzaldehyde-(2,3-dichl orphenyl)-hydrazone, o- [(4,6-dimethoxy-2-pyrimidinyl)-oxy] -benzaldehyde- [(3-chloro -5-trifluormethyl)-2-pyridyl]-hydrazone, o-[(4,6-dimethoxy-2-pyrimidinyl)-oxy]-benzaldehyde-N-methyl-p henylhydrazone, 3-[(4,6-dimethoxy-2-pyrimidinyl)-oxy]-pyridin-2-carboxyaldehy

^• de-(o-chlorphenyl)-hydrazone, N'-[o-((4,6-dimethoxy-2-pyrimidinyl)-oxy)-benzylidene]-o-meth ylbenzohydrazide, N'-[o-((4,6-dimethoxy-2-pyrimidinyl)-oxy)-benzylidene]-4-pyri dincarboxyhydrazide, N ' - [o- ((4,6-dimethoxy-2-pyrimidinyl)-oxy)-benzylidene] -o-meth ylbenzohydrazide, N'-[3-(o-((4,6-dimethoxy-2-pyrimidinyl)-oxy)-pyridyl)-methyli dene]-2-phenylacetohydrazide, o-[(4,6-dimethoxy-2-pyrimidinyl)-oxy]-benzaldehyd-N-methyl-3- thiosemicarbazone, o-[(4,6-dimethoxy-2-pyrimidinyl)-oxy]-benzaldehyd-3-thiosemic arbazone.

21. A process for preparing the compounds of the formula I according to claim 1, which comprises, a) in the case of compounds of the formula I in which W is NR⁴, reacting an aldehyde of the formula II

in which

R¹, R², R³, Z, Y and B are as defined under formula I in claim 1, with an amine, hydrazine, hydrazide, carbazate, semicarbazide or thiosemicarbazide or oxime of the formula III in which R⁴ is as defined under formula I in claim 1, if desired in the presence of a water-binding agent and an inert diluent, or

b) reacting a pyrimidine of the formula IV in which R¹, R² and Z are as defined under formula I in claim 1 and L is a leaving group,

II

IV V

with an imine, hydrazone, hydrazide, carbazate, semicarbazide, thiosemicarbazide or oxime compound of the general formula V in which R³, R⁴, B and Y are as defined under formula I in claim 1, in the presence of an acid-binding agent and in the presence of an inert solvent, or

c) in the case of compounds of the formula I in which R¹, R², R³, B, Y and Z are as defined under formula I in claim 1, and in which R⁶ in the definition NR⁵R⁶ is

C_j^alkylcarbonyl, trifluoromethylcarbonyl, C₃_₆cycloalkylcarbonyl, benzylcarbonyl, 2-,

3- or 4-pyridinyl-, 2- or 3-furyl- or thiophenylcarbonyl, or benzoyl which is monosubstituted to disubstituted by fluorine, chlorine, bromine, methyl, trifluoromethyl, methoxy or nitro; or Cwalkoxycarbonyl, benzoyloxycarbonyl, aminocarbonyl, aminothiocarbonyl, or aminocarbonyl or aminothiocarbonyl each of which is monosubstituted to disubstituted by phenyl or C_j.₄a.kyl, it being possible for the phenyl group to be substituted by fluorine, chlorine, methyl or methoxy, reacting a compound of the formula π in which R¹, R², R³, Z, Y and B are as defined above,

F VI'

with hydrazine or hydrazine hydrate, and then reacting the hydrazide of the formula I' in which R¹, R², R³, B, Y and Z are as defined above and W is NNH₂, with the corresponding acid chloride, chloroformic ester, carbamoyl chloride or thiocarbamoyl chloride of the formula VI in which U is oxygen or sulfur, or with the corresponding isocyanate or isothiocyanate of the formula VI' in which U is oxygen or sulfur, or

d) in the case of compounds of the formula I in which R¹, R², R³, B, Y and Z are as defined under formula I in claim 1 and in which R⁷ in the definition W = NOR⁷ is Cj.₆alkyl, C₃.₆alkenyl which can be substituted by halogen or phenyl, or is C^alkoxy- or alkylthiocarbonyl-Cj .₄ alkyl,

r

reacting an oxime of the formula I" in which R^R³, B, Y and Z are as defined under formula I in claim 1, and in which W is NOH, with an alkyl, alkenyl or C^alkoxy- or

halide of the formula VII in the presence of an inert diluent and in the presence of an acid-binding agent.

22. A herbicidal and plant-growth-inhibiting composition, which comprises one or more pyrimidinyl- and triazinylsalicyl- and -picolinylaldehyde derivatives of the formula I according to claim 1.

23. A composition according to claim 22, which comprises between 0.001 % and 95 % by weight of active substance of the formula I according to claim 1.

24. A method of controlling undesired plant growth, in which an effective amount of an active substance of the formula I according to claim 1, or a composition comprising this active substance, is applied to the plants or their environment.

25. A method according to claim 24, in which an amount of active substance between 0.001 and 3 kg is applied per hectare.

26. A method of regulating plant growth, in which an effective amount of an active substance of the formula I according to claim 1, or a composition comprising this active substance, is applied to the plants or their environment.

27. A method according to claim 24 for the selective pre- or post-emergence control of weeds in crops of useful plants.

28. The use of a compound of the formula I according to claim 1 as an active substance in weedkillers.