WO1994004509A1

WO1994004509A1 - Benzimidazole derivatives as microbicides

Info

Publication number: WO1994004509A1
Application number: PCT/EP1993/002174
Authority: WO
Inventors: Adolf Hubele; Martin Zeller; Marius Sutter; Urs Müller; Helmut Zondler
Original assignee: Ciba Geigy AG
Current assignee: Novartis AG
Priority date: 1992-08-25
Filing date: 1993-08-16
Publication date: 1994-03-03
Anticipated expiration: 1995-02-25
Also published as: IL106784A0; EP0656891A1; AU4948093A; JPH08500352A; MX9305135A; CN1083808A

Abstract

Compounds of formula (I) in which R1 is an acyl, oxime, ketal or hydrazone, R2 is halogen, nitro, or halogenated or unhalogenated alkyl or alkoxy, n being 0, 1 or 2, R3 is cyano, or a substituted or unsubstituted thioamide group and R4 is alkyl, cycloalkyl or a substituted amino group, are effective microbicides. They can be used in crop protection in suitably formulated compositions for controlling and preventing plant diseases.

Description

BENZIMIDAZOLE DERIVATIVES AS MICROBICIDES

The present invention relates to novel benzimidazolesulfonic acid derivatives of the formula I below. It furthermore relates to the preparation of these substances and to agrochemical compositions comprising at least one of these compounds as active ingredient. The invention also relates to the preparation of the abovementioned compositions and to the use of the active ingredients or of the compositions for controlling or preventing infestation of plants by phytopathogenic microorganisms, preferably fungi.

The compounds according to the invention are those of the general formula I

in which the R₄-SO₂-group is in the 1- or 3-position in the benzimidazole moiety and forms pure or mixed positional isomers relative to the substituents R₁ and R₂, the substituents being defined as follows: R₁ is R₅-CO- or a group a) to d):

in which R₅ is defined as follows:

- hydrogen;

- C₁-C₁₂alkyl;

- C₁-C₈alkyl, which is substituted by halogen, C₁-C₃alkoxy, C₂-C₄alkoxyalkoxy, C₁-C₃alkylthio, C₃-C₄alkenyloxy, C₃-C₄alkynyloxy, or else by phenoxy or phenylthio whose phenyl rings can be unsubstituted or substituted by halogen, C₁-C₄alkyl, C₁-C₄alkoxy, C₁-C₄haloalkyl or

C₁-C₄haloalkoxy; - C₂-C₈alkenyl;

- C₂-C₈alkynyl; C₃-C₄alkynyl which is substituted by halogen;

- C₃-C₇cycloalkyl; C₃-C₇cycloalkyl which is substituted by halogen or C₁-C₄alkyl;

- C₃-C₇cycloalkyl-C₁-C₄alkyl;

- phenyl which can be unsubstituted or monosubstituted to trisubstituted by identical or different substituents from the series consisting of halogen, C₁-C₃alkyl, C₁-C₃alkoxy, C₁-C₃haloalkyl, C₁-C₃haloalkoxy, cyano or nitro and which can also be bonded via a C₁-C₄alkylene bridge,

and in which

R₆ is defined as follows:

hydrogen, C₁-C₈alkyl; C₂-C₈alkenyl; C₂-C₈alkynyl; benzyl or phenyl, whose aromatic ring is unsubstituted or substituted by one or more of the substituents halogen, C₁-C₄alkyl,

C₁-C₄alkoxy, C₁-C₄haloalkyl and C₁-C₄haloalkoxy;

in which R₅ is as defined under a) and

R₇ and R₈ independently of one another can be hydrogen; C₁-C₈alkyl;

C₂-C₈alkenyl; C₂-C₈alkynyl; or benzyl or phenyl, whose aromatic ring is unsubstituted or substituted by one or more of the substituents C₁-C₄haloalkoxy, C₁-C₄haloalkyl, halogen, C₁-C₄alkyl and C₁-C₄alkoxy; and in which one of the two substituents R₇ and R₈ can be an aliphatic, araliphatic or aromatic acyl radical having not more than 8 carbon atoms; or R₇ and R₈ together are

where m is 3, 4 or 5;

in which R₅ is as defined under a) and

R₉ is C₁-C₈alkyl;

C₂-C₈alkenyl;

C₂-C₈alkynyl;

C₁-C₄alkoxy-C₁-C₆alkyl or

C₁-C₈haloalkyl;

in which R₅ is as defined under a) and

R₁₀ and R₁₁ independently of one another are

hydrogen, C₁-C₆alkyl; or C₁-C₄alkyl which is substituted by halogen, hydroxyl or C₁-C₃alkoxy, and p is the number 2 or 3; while the remaining substitutents in the formula I are as defined as follows:

R₂ radicals are identical or different and are

halogen;

C₁-C₄alkyl;

C₁-C₄alkoxy;

C₁-C₄haloalkyl;

C₁-C₄haloalkoxy;

nitro;

R₃ is cyano, -C(=S)NH₂ or -C(=NH)-S-R₁₂, in which R₁₂ is C₁-C₄alkyl,

C₁-C₄haloalkyl or benzyl which is unsubstituted or substituted in the aromatic ring by halogen, C₁-C₄alkyl or C₁-C₄haloalkyl;

R₄ is C₁-C₆alkyl;

C₃-C₇cycloalkyl; , in which R₁₃ and R₁₄ are identical or different C₁-C₄alkyl

radicals or R₁₃ and R₁₄ together form a chain

, in which q is the number 4 or 5; and n is 0, 1 or 2;

with the exception of the compound 1(3)-dimethylsulfamoyl-2-cyano-5-benzoyl-benzimidazole.

The term alkyl itself or as a component of a different substituent, such as haloalkyl, alkoxy or haloalkoxy, is to be understood as meaning, for example, the following straight-chain or branched groups, depending on the number of the carbon atoms indicated: methyl, ethyl, propyl, butyl and their isomers, isopropyl, isobutyl, sec-butyl and tert-butyl. Halogen and halo are fluorine, chlorine, bromine or iodine. Haloalkoxy therefore is a monohalogenated to perhalogenated alkoxy radical, such as, inter alia, OCH₂F, OCHF₂, OCHFCH₃, OCH₂CH₂Br and OCF₂CHFCl.

Since the group -SO₂R₄ can be in the 1- or 3-position, the compounds of the formula I are either regioisomer mixtures AB or pure regioisomers A or B.

In the case of the ketals d), the presence of one or more asymmetric carbon atoms must be expected in the compounds of the formula I. In this case, either pure optical antipodes or racemic mixtures are present.

If an aliphatic double bond or a C=N double bond exists, such as in the case of a) oximes or b) hydrazones, then geometric isomers occur.

The present invention relates to the isomers mentioned and to their mixtures with each other.

The compounds of the formula I are solids or oils which are stable at room temperature and which are distinguished by valuable microbicidal properties. They can be used preventively and curatively in the agricultural sector or related fields for controlling plant-injurious microorganisms. When used at low rates of concentration, the active ingredients of the formula I according to the invention are distinguished not only by an outstanding microbicidal, in particular fungicidal, activity, but also by the fact that they are particularly well tolerated by plants.

A main sub-group within the scope of the formula I are compounds in which R₁ is a group a) to d) and in which R₅ is hydrogen; C₁-C₁₂alkyl; C₁-C₆alkyl which is substituted by halogen, C₁-C₃alkoxy, C₂-C₄alkoxyalkoxy, C₁-C₃alkylthio, C₃-C₄alkenyloxy or C₃-C₄alkynyloxy, or else by phenoxy or phenylthio, whose phenyl rings can be

unsubstituted or substituted by halogen, C₁-C₄alkyl, C₁-C₄alkoxy, C₁-C₄haloalkyl or C₁-C₄haloalkoxy; C₂-C₈alkenyl; C₂-C₈alkynyl; C₃-C₄alkynyl which is substituted by halogen; C₃-C₇cycloalkyl; C₃-C₇cycloalkyl which is substituted by halogen or C₁-C₄alkyl; C₃-C₇cycloalkyl-C₁-C₄alkyl; phenyl which can be unsubstituted or monosubstituted to trisubstituted by identical or different substituents from the series consisting of halogen, C₁-C₃alkyl, C₁-C₃alkoxy, C₁-C₃haloalkyl, C₁-C₃haloalkoxy, cyano or nitro and which can also be bonded via a C₁-C₄alkylene bridge, while R₂ to R₁₁ are as defined above

(compound group IH1).

The following important sub-groups are to be mentioned within the scope of the formula I:

Compounds in which R₅ is a group a) to d) and is in the 4- or 5-position,

and

R₅ is hydrogen; or

C₁-C₈alkyl which is unsubstituted or substituted by halogen, C₁-C₃alkoxy, C₁-C₃alkylthio,

C₃-C₄alkenyloxy or by phenoxy whose phenyl moiety can be unsubstituted or substituted by halogen, C₁-C₄alkyl, C₁-C₄alkoxy, OCF₃ or CF₃; or

C₂-C₆alkenyl; C₂-C₄alkynyl; or else

C₃-C₆cycloalkyl which is unsubstituted or substituted by halogen or C₁-C₄alkyl and which can be bonded via C₁-C₂alkyl; or is

phenyl which is unsubstituted or monosubstituted to trisubstituted by identical or different substituents from the series consisting of halogen, C₁-C₃alkyl, C₁-C₃alkoxy,

C₁-C₃haloalkyl and C₁-C₃haloalkoxy and which can also be bonded via a C₁-C₄alkylene bridge;

R₂ is in the 6- or 7-position and is halogen, C₁-C₃alkyl, C₁-C₃alkoxy, C₁-C₄haloalkyl or

C₁-C₄haloalkoxy;

R₃ is cyano, -CS-NH₂ or -C(=NH)-SR₁₂, in which R₁₂ is C₁-C₄alkyl or benzyl which is unsubstituted or monosubstituted to trisubstituted by identical or different substituents from the series consisting of halogen, C₁-C₃alkyl or CF₃;

R₄ is C₁-C₄alkyl, cyclopropyl or -N(R₁₃)R₁₄) in which R₎₃ and R₁₄ are identical or different C₁-C₄alkyl radicals; and

n is 0, 1 or 2, while R₆, R₇, R₈, R₉, R₁₀ and R₁₁ have the abovementioned meaning.

(compound group IA).

Preferred compounds from amongst those of group IA are those in which R₁ is in the 5-position, and

R₅ is hydrogen; or C₁-C₈alkyl which is unsubstituted or substituted by halogen or C₁-C₃alkoxy; or C₂-C₄alkenyl, C₂-C₄alkynyl or C₃-C₆cycloalkyl, which is unsubstituted or substituted by halogen or C₁-C₄alkyl and which can be bonded via C₁-C₂alkyl; or is phenyl which is unsubstituted or monosubstituted to trisubstituted by identical or different substituents from the series consisting of halogen, C₁-C₃alkyl, C₁-C₃alkoxy,

C₁-C₃haloalkyl and C₁-C₃haloalkoxy and which can also be bonded via a C₁-C₄alkyl bridge;

R₂ radicals are identical or different and are halogen, C₁-C₄alkyl, C₁-C₄alkoxy or C₁-C₄haloalkoxy;

n is 0, 1 or 2;

R₃ is cyano or -CS-NH₂;

R₄ is N(R₁₃)(R₁₄), in which R₁₃ and R₁₄ are as defined under group IA, and

R₆ is hydrogen, C₁-C₈alkyl or C₂-C₈alkenyl (compound group IB1).

Important oximes within group IB 1 which must be mentioned are those compounds in which

R₁ is a group a) which is in the 5-position; and

R₅ is C₁-C₈alkyl which can be unsubstituted or substituted by halogen or C₁-C₃alkoxy; or phenyl which can be unsubstituted or substituted by halogen;

R₂ radicals are identical or different and are halogen, C₁-C₄alkyl, C₁-C₂alkoxy or C₁-C₂haloalkoxy;

n is 0 or 1;

R₃ is cyano or -CSNH₂;

R₄ is N(R₁₃)(R₁₄), in which R₁₃ and R₁₄ are C₁-C₄alkyl; and

R₆ is hydrogen, C₁-C₈alkyl or C₂-C₈alkenyl (compound group IC1).

Preferred oxime derivatives within the last-mentioned group IC1 are those in which R₅ is C₁-C₈alkyl which can be unsubstituted or substituted by halogen or C₁-C₃alkoxy; or is phenyl which can be unsubstituted or substituted by halogen; and

R₆ is C₁-C₄alkyl; while

R₁, n, R₃ and R₄ have the abovementioned meanings (compound group ID1).

One of the preferred sub-groups within ID1 are those in which

R₅ is C₁-C₈alkyl; and

R₂ is halogen: R₄ is dimethylamino; and

R₆ is methyl (compound group Id).

The following must be mentioned amongst the preferred individual compounds:

[6-chloro-2-cyano-3-dimethylsulfamoylbenzimidazolyl(5)]acetoxime O-methyl ester and l6-chloro-2-cyano-l-dimethylsulfamoylbenzimidazolyl(5)]acetoxime O-methyl ester.

Other preferred compounds of group IH1 are those in which

R₁ is in the 5-position, and

R₅ is hydrogen; or

C₁-C₅alkyl which is unsubstituted or substituted by halogen or C₁-C₃alkoxy; or is

C₂-C₄alkenyl, C₂-C₄alkynyl or C₃-C₆cycl_oalkyl; or is phenyl or benzyl, whose aromatic rings can be not more than disubstituted by identical or different substituents from the series consisting of halogen, C₁-C₃alkyl, CF₃ and CF₃O;

R₃ is cyano or -CS-NH₂ (thioamide); and

n is O or 1; while

R₂, R₄ and R₆ to R _{1 1} are as defined for group IH1 (compound group IB2).

Important oximes within the last-mentioned group 1B2 are those compounds in which

R₆ is hydrogen; C₁-C₈alkyl; C₂-C₈alkenyl; C₃-C₈alkynyl; or phenyl or benzyl, whose aromatic rings are unsubstituted or monosubstituted to trisubstituted by identical or different substituents from the series consisting of halogen, C₁-C₃alkyl, C₁-C₃alkoxy C₁-C₃haloalkyl or C₁-C₃haloalkoxy; while

R₅ is hydrogen; or C₁-C₅alkyl which is unsubstituted or substituted by halogen or methoxy; or is C₂-C₄alkenyl, C₂-C₄alkynyl, C₃-C₅Cycloalkyl or phenyl or benzyl, whose aromatic rings can be up to disubstituted by identical or different substituents from the series consisting of chlorine, bromine, methyl, CF₃ and CF₃O;

R₂ is in the 6- or 7-position and is hydrogen, halogen, methyl, methoxy, CF₃, CF₃O or

CHF₂O;

R₃ is cyano or -CS-NH₂; and

R₄ is C₁-C₄alkyl, cyclopropyl or -N(R₁₃)(R₁₄), in which R₁₃ and R₁₄ are identical or different C₁-C₄alkyl radicals and have a total of not more than 6 C atoms (compound group IC).

Preferred oxime derivatives within the last-mentioned group IC are those in which

R₆ is hydrogen; C₁-C₆alkyl; allyl; propargyl; or else phenyl or benzyl, each of which is up to trisubstituted in the ring by identical or different substituents from the series consisting of chlorine, bromine, methyl, methoxy, CF₃, CF₃O and CHF₂O;

R₅ is hydrogen; or C₁-C₅alkyl which is unsubstituted or substituted by halogen or methoxy; or C₂-C₄alkenyl, C₂-C₄alkynyl, C₃-C₅cycioalkyl or phenyl or benzyl, whose aromatic rings can be up to disubstituted by identical or different substituents from the series consisting of chlorine, bromine, methyl, CF3 and CF₃O;

R₂ is in the 7-position and is hydrogen, halogen, CF₃ or CHF₂O;

R₃ is cyano or -CS-NH₂; and

R₄ is methyl, ethyl, dimethylamino, methylethylamino or diethylamino (compound group

ID).

The following must be mentioned amongst the prefeσed individual compounds:

[7-bromo-2-cyano-3-dimethylsulfamoylbenzimidazolyl(5)]acetoxime O-methyl ether (compound no. 2.25)

Another main sub-group within the scope of the formula I are compounds where R₁ is R₅-CO-, in which R₅ is hydrogen; C₁-C₁₂alkyl; C₁-C₆alkyl which is substituted by halogen, C₁-C₃alkoxy, C₂-C₄alkoxyalkoxy, C₁-C₃alkylthio, C₃-C₄alkenyloxy or

C₃-C₄alkynyloxy, or else by phenoxy or phenylthio, whose phenyl rings can be

unsubstituted or substituted by halogen, C₁-C₄alkyl, C₁-C₄alkoxy, C₁-C₄haloalkyl or C₁-C₄haloalkoxy; C₂-C₈alkenyl; C₂-C₈alkynyl; C₃-C₄alkynyl which is substituted by halogen; C₃-C₇cycloalkyl; C₃-C₇cycloalkyl which is substituted by halogen, alkyl;

C₃-C₇cycloalkyl-C₁-C₄alkyl; phenyl which can be unsubstituted or monosubstituted to trisubstituted by identical or different substituents from the series consisting of halogen, C₁-C₃alkyl, C₁-C₃alkoxy, C₁-C₃haloalkyl, C₁-C₃haloalkoxy, cyano and nitro and which can also be bonded via a C₁-C₄alkylene bridge, while R₂ to R₄ are as defined above (compound group IH2).

An important sub-group of the formula I are compounds in which R₁ is R₅-CO- and is in the 4- or 5-position, and in which R₅ is hydrogen; C₁-C₈alkyl which is unsubstituted or substituted by halogen, C₁-C₃alkoxy, C₁-C₃alkylthio, C₃-C₄alkenyloxy or phenoxy whose phenyl moiety can be unsubstituted or substituted by halogen, C₁-C₄alkyl, C₁-C₄alkoxy, OCF₃ or CF₃; C₂-C₆alkenyl; C₂-C₄alkynyl; C₃-C₆cycloalkyl which is unsubstituted or substituted by halogen or C₁-C₄alkyl and which can be bonded via C₁-C₂alkyl; or is phenyl which is unsubstituted or monosubstituted to trisubstituted by identical or different substituents from the series consisting of halogen, C₁-C₃alkyl, C₁-C₃aIkoxy,

C₁-C₃haloalkyl and C₁-C₃haloalkoxy and which can also be bonded via a C₁-C₄alkyl bridge; and R₂ to R₄ are as defined above (compound group IK).

An important sub-group of IK are compounds in which

R₁ is in the 5-position; and

R₅ is C₁-C₈alkyl which can be unsubstituted or substituted by halogen or C₁-C₃alkoxy;

C₂-C₆alkenyl; C₂-C₄alkynyl; C₃-C₆cycloalkyl which is unsubstituted or substituted by halogen or C₁-C₄alkyl and which can be bonded via C₁-C₂alkyl; or is phenyl which is unsubstituted or monosubstituted to trisubstituted by identical or different substituents from the series consisting of halogen, C₁-C₃alkyl, C₁-C₃alkoxy, C₁-C₃haloalkyl and C₁-C₃haloalkoxy and which can also be bonded via a C₁-C₄alkyl bridge;

R₂ radicals are identical or different and are halogen, C₁-C₄alkyl, C₁-C₄alkoxy or

C₁-C₄haloalkoxy;

n is 0, 1 or 2;

R₃ is cyano or -CSNH₂; and

R₄ is N(R₁₃)(R₁₄), in which R₁₃ and R₁₄ are as defined above (compound group IKa).

A particularly preferred sub-group of IKa are compounds in which

R₂ radicals are identical or different and are halogen, C₁-C₄alkyl, C₁-C₂alkoxy or

C₁-C₂haloalkoxy;

n is 0 or 1; and

R₄ is N(R₁₃)(R₁₄) in which R₁₃ and R₁₄ are C₁-C₄alkyl (compound group IKc).

Preferred compounds within sub-group IKc are those in which

R₅ is C₁-C₈alkyl;

R₂ is halogen; and

R₄ is dimethylamino (compound group IKd).

Another important sub-group of IH2 are compounds in which R₁ is in the 4- or 5-position and

R₅ is hydrogen; C₁-C₆alkyl which is unsubstituted or substituted by halogen, C₁-C₃alkoxy, C₁-C₃alkylthio, C₃-C₄alkenyloxy or by phenoxy whose phenyl moiety can be

unsubstituted or substituted by halogen, C₁-C₄alkyl, C₁-C₄alkoxy, OCF₃ or CF₃, or can be substituted by phenylthio or halophenylthio; C₂-C₆alkenyl; C₂-C₄alkynyl;

C₃-C₆cycloalkyl which is unsubstituted or substituted by halogen or C₁-C₄alkyl and which can be bonded via C₁-C₂alkyl; or is phenyl which is unsubstituted or monosubstituted to trisubstituted by identical or different substituents from the series consisting of halogen, C₁-C₃alkyl, C₁-C₃alkoxy, C₁-C₃haloalkyl and C₁-C₃haloalkoxy and which can be bonded via a C₁-C₄alkyl bridge;

R₂ is in the 6- or 7-position and is halogen, C₁-C₃alkyl, C₁-C₃alkoxy, C₁-C₄haloalkyl or C₁-C₄haloalkoxy;

R₃ is cyano, -CS-NH₂ or -C(=NH)SR₁₂, in which R₁₂ is C₁-C₄alkyl or benzyl, which is unsubstituted or monosubstituted to trisubstituted by identical or different substituents from the series consisting of halogen, C₁-C₃alkyl or CF₃;

R₄ is C₁-C₄alkyl, cyclopropyl or N(R₁₃)(R₁₄), in which R₁₃ and R₁₄ are identical or different C₁-C₄alkyl radicals; and

n is 0, 1 or 2 (compound group 1Kb).

A particularly important sub-group of 1Kb are compounds in which

R₁ is in the 5-position and

R₅ is hydrogen; or

C₂-C₄alkenyl, C₂-C₄alkynyl or C₃-C₆cycloalkyl: or is phenyl or benzyl, whose aromatic rings can be not more than disubstituted by identical or different substituents from the series consisting of halogen, C₁-C₃alkyl, CF₃ and CF₃O;

R₃ is cyano or -CS-NH₂ (thioamide); and

n is O or 1; while

R₂ and R₄ are as defined for group 1Kb (compound group IKe).

The following must be mentioned as preferred individual compounds:

7-bromo-5-butyroyl-2-cyano-3-dimethylsulfamoylbenzimidazole;

7-bromo-2-cyano-3-dimethylsulfamoyl-5-valeroylbenzimidazole;

5-benzoyl-6-chloro-2-cyano-3-dimethylsulfamoylbenzimidazole and

5-benzoyl-6-chloro-2-cyano- 1-dimethylsulfamoylbenzimidazole.

One of the important sub-groups within formula I and group IH2 are those compounds in which R₃ is -CSNH₂ (compound group IKg). One of the important sub-groups within the formula I and group 1Kb are those compounds in which R₃ is -CSNH₂ (thioamide) (compound group IKf).

Another important sub-group within formula I and group IB2 are those compounds in which

R₃ is -C(=NH)-SR₁₂, in which R₁₂ is C₁-C₄alkyl or benzyl, which is unsubstituted or up to trisubstituted by identical or different halogen or methyl substituents (compound group

IBd).

Important ketals within compound group IB2 which must be mentioned are those compounds in which

R₉ is C₂-C₆alkenyl; C₂-C₆alkynyl or C₁-C₆alkyl, which is unsubstituted or substituted by C₁-C₄alkoxy or halogen; or in which

p is 2 or 3 and C(R₁₀)(R_{1 1}) together with the two oxygen atoms forms a dioxolane or dioxane ring in which

R₁₀ and R₁₁ are the substituents of these rings and independently of one another are hydrogen or C₁-C₄alkyl which is unsubstituted or substituted by halogen, hydroxyl, C₁-C₃alkoxy; while

R₅ is hydrogen; or is C₁-C₅alkyl which is unsubstituted or substituted by halogen or methoxy; or is C₂-C₄alkenyl, C₂-C₄alkynyl, C₃-C₅cycloalkyl or phenyl or benzyl, whose aromatic rings can be up to disubstituted by identical or different substituents from the series consisting of chlorine, bromine, methyl, CF₃ and CF₃O;

CHF₂O;

R₃ is cyano or -CS-NH₂; and

R₄ is C₁-C₄alkyl, cyclopropyl or -N(R₁₃)(R₁₄), in which R₁₃ and R₁₄ are identical or different C₁-C₄alkyl and together have not more than 6 C atoms (compound group IE).

Preferred amongst the last-mentioned compounds IE are those in which

R₂ is in the 7 -position and is hydrogen, halogen, CF₃ or CHF₂O;

R₃ is cyano or -CS-NH₂; and

R₄ is methyl, ethyl, dimethylamino, methylethylamino or diethylamino (compound group IF).

Important hydrazones within compound group IB2 which must be mentioned are those compounds in which

R₇ and Rg independently of one another are hydrogen, C₁-C₆alkyl, C₂-C₆alkenyl,

C₃-C₆alkynyl or phenyl, it being possible for the phenyl ring to be up to disubstituted by halogen, C₁-C₄alkyl, C₁-C₄alkoxy, CF₃, CF₃O, CHF₂O; and in which one of R₇ and R₈ can be an aliphatic, araliphatic or aromatu acyl radical having not more than 8 carbon atoms; while

R₅ is hydrogen; or C₁-C₅alkyl which is unsubstituted or substituted by halogen or methoxy; or is C₂-C₄alkenyl, C₂-C₄alkynyl, C₃-C₅cycloalkyl or phenyl or benzyl, whose aromatic rings can be up to disubstituted by identical or different substituents from the series consisting of chlorine, bromine, methyl, CF₃, CF₃O;

R₂ is in the 7 -position and is hydrogen, halogen, CF₃ or CHF₂O;

R₃ is cyano or -CS-NH₂; and

R₄ is methyl, ethyl, dimethylamino, methylethylamino or diethylamino. (compound group

IG)

The compounds of the formula I can be prepared by reacting a compound of the formula II

with a compound of the formula III

Q-SO₂-R₄ (III) in which R₁, R₂, R₃ and n are as defined in formula I and M is hydrogen or an alkali metal, preferably lithium, sodium or potassium, and Q is a leaving group, for example a halogen atom, preferably chlorine, bromine or the radical R₄-SO₂-O-, in an inert solvent, if desired in the presence of a base, at temperatures from -30° to +180°C, preferably -10° to 80°C, under atmospheric pressure, reduced pressure or elevated pressure, preferably at atmospheric pressure. Examples of suitable inert solvents are: aliphatic, cycloaliphatic or aromatic hydrocarbons, for example hexane, cyclohexane, toluene, xylene, petroleum ether or ligroin; chlorinated hydrocarbons, for example methylene chloride, chloroform, carbon tetrachloride or chlorobenzene; ethers, for example diethyl ether, diisopropyl ether, furan, tetrahydrofuran or dioxane; ketones, for example acetone, or methyl ethyl ketone; alcohols, for example methanol, ethanol or isopropanol; esters, for example ethyl acetate or butyl acetate;

nitriles, for example acetonitrile or propionitrile; acid amides, for example

dimethylformamide; sulfoxides, for example dimethyl sulfoxide or sulfolane. The benzimidazole derivative II' in which M is hydrogen is advantageously reacted in the presence of a base.

Suitable examples of bases or acid-binding agents are hydroxides, carbonates, hydrogen carbonates or alcoholates of the alkali metals and alkaline earth metals; furthermore alkali metal hydrides, for example sodium hydride, and tertiary amines, for example

triethylamine, triisopropylamine, pyridin or 4-N,N-dimethylaminopyridine.

The reactivity of the thioamide group [R₃ = -CSNH₂] or of the substituted isothioamide group [R₃ = -C(-SR')=NH] recommends a procedure in which these groups are introduced in the last reaction step after the sulfonylation. In this case, the sulfonylated

2-cyanobenzimidazole of the formula I'

will be reacted later either with H₂S or with HS-R', R' being as defined in formula I. The reaction leading to the thioamide [ R₃ = -CSNH₂] is carried out in polar solvents (for example alcohols, such as ethanol), but preferably in acid amides, for example dimethylformamide (DMF), in the presence of an approximately equimolar amount of dialkylamine (for example diethylamine) or in pyridine using a tert-amine, such as trialkylamine. H₂S is passed in at -20° to +80°C, in particular -10° to +40°C.

To prepare the substituted isothioamide group, it can be advantageous to use a procedure in which the sulfonylated 2-cyanobenzimidazole of the formula I' is treated with the thiol HS-R' in a polar aprotic solvent (such as acetonitrile) in the presence of weak bases (such as alkali metal carbonate) at -20° to +100°C, preferably -10° to +40°C.

The starting compounds of the formula II' (M = hydrogen; R₃ = cyano) are prepared by

A) reacting o-phenylenediamine derivatives or salts thereof of the formula IV

[HY is an acid, preferably a hydrohalic acid, or sulfuric acid] first with trihaloimidate of the formula V

in an organic solvent, such as ethers, for example diethyl ether, dioxane or

1,2-dimethoxyethane; esters, for example ethyl acetate, alcohols, for example methanol or ethanol, or preferably in glacial acetic acid, at temperatures between -20°C and +100°C, to give 2-trihalomethylbenzimidazoles of the formula VI

which can be isolated. In a second step, the product is reacted with aqueous ammonia solution to give the compounds of the formula II' (in which M is hydrogen and R₃ is cyano) (USP 3 576 818); B) reacting a compound of the formula VII

with formaldehyde and potassium cyanide with an addition of zinc chloride (or a different Lewis acid) as catalyst to give compounds of the formula VIII

[K. Dimroth et al. Chem. Ber. 98, 3902 (I965)] and subsequently reacting the product with potassium carbonate to give compounds of the formula IX

[B. Serafinowa et al. Rocz. Chem. 51, 1783 (1977), which is finally reacted with phosphorus trichloride to give compounds of the formula II' (M = hydrogen, R₃ = cyano);

C) reacting a compound of the formula II"

in which R₂, R₅ and n are as defined above, with a hydroxyl amine of the formula X

H₂N-O-R₆ (X) in an organic solvent, for example in a lower alcohol, preferably methanol, ethanol or isopropanol, if desired in a mixture with water, at temperatures between 0°C and the boiling point of the reaction mixture. The hydroxylamine reagent of the formula X can be used in the form of the free base or in the form of an acid addition salt, for example in the form of the hydrochloride or the hydrogensulfate salt. The oximation proceeds spontaneously or base-catalysed by adding an organic base, for example pyridine, triethylamine or 4-dimethylaminopyridine, or by adding an alkali metal carbonate or hydrogen carbonate or an alkaline earth metal carbonate or hydrogen carbonate, for example sodium carbonate or potassium carbonate. Salts of carboxylic acids, for example sodium acetate, can also be used as base;

D) reacting a compound of the formula II"

in which R₂, R₅ and n are as defined above, with a hydrazine of the formula XI

in an organic solvent, as described for the oximation in process variant E). The hydrazine of the formula XI can be used in the form of the free base or the acid addition salt, for example the hydrochloride or hydrogensulfate. The formation of hydrazone proceeds spontaneously or base-catalysed by adding an organic base, for example pyridine, triethylamine or 4-dimethylaminopyridine, or of an alkali metal carbonate or hydrogen carbonate or an alkaline earth metal carbonate or hydrogen carbonate, for example sodium carbonate, potassium carbonate or potassium hydrogen carbonate. Salts of carboxylic acids, for example sodium acetate, can also be used as base.

E) reacting the compounds of the formula II"

in which R₂, R₅ and n are as defined above, with an alcohol of the formula XII or XIII HO-R₉ (XII)

in an inert organic solvent, for example in an aromatic hydrocarbon, preferably benzene, toluene or xylene, or in a halogenated hydrocarbon, preferably chloroform, at temperatures between -30°C and the boiling point of the reaction mixture, with the addition of a carboxylic acid or organic sulfonic acid, for example p-toluenesulfonic acid, or a mineral acid, for example hydrochloric acid or sulfuric acid. The water of reaction which forms in this process can be removed from the reaction mixture for example by azeotropic distillation or by absorption using an alkali metal/alkaline earth metal aluminium silicate (molecular sieve).

It is also possible initially to react the compounds of the formula II'

with a compound of the formula III

QSO₂-R₄ (lH) as described above, to give a compound of the formula lo

This compound can then be reacted as described under processes C), D) and E) to give the compounds of the formula I' :

The compounds of the formulae IV and Vll

are known per se (for example A.H.K. Raeymaekers, J.L.H. Van Gelder, L.F.C. Roevens, P.AJ. Janssen; Arzneim.-Forsch. 28, 586 (1978)) or can be prepared by the processes described above.

GB-A-2 114567 discloses the compound

1(3)-dimethylsulfamoyl-2-cyano-5-benzoylbenzimidazole as fungicide 12A(B). As will be demonstrated further below, its activity is insufficient in comparison with acyl compounds of the present invention. There was therefore no reason for a person skilled in the art to synthesize precisely these acyl compounds of the formula I above, or to derivatize their carbonyl group.

Surprisingly, it has now been found that compounds of the formula I have a biocidal spectrum which is highly favourable for practical requirements for controlling

phytopathogenic microorganisms, in particular fungi. They have highly advantageous curative and preventive properties and are used for the protection of a large number of crop plants. The active ingredients of the formula I allow pests which can be found on plants or parts of plants (fruit, flowers, foliage, stalks, tubers, roots) of various crops of useful plants to be contained or destroyed, the protection against, for example,

phytopathogenic fungi extending even to parts of plants which are formed at a later point in time.

The novel active ingredients of the formula I prove to be effective against specific genera from the fungal class Fungi imperfecti (for example Cercospora), Basidiomycetes (for example Puccinia) and Ascomycetes (for example Erysiphe and Venturia) and, in particular, against Oomycetes (for example Plasmopara, Peronospora, Pythium and Phytophthora). In crop protection, they are therefore valuable complements of the compositions for controlling phytopathogenic fungi. For this use in practice, they advantageously have curative as well as preventative properties and can be used for the protection of a large number of crop plants. The pests which can be found on plants or parts of plants (fruits, flowers, foliage, stalks, tubers, roots) of a range of crops of useful plants are contained or destroyed by these active ingredients, the protection against, for example, phytopathogenic fungi even extending to parts of plants which are formed at a later point in time. The compounds of the formula I can furthermore be used as seed-dressing agents for the treatment of seed (fruits, tubers, kernels) and plant cuttings as a protection against fungal infections and against soil-borne phytopathogenic fungi. The invention also relates to the compositions which comprise, as active ingredient, compounds of the formula I, in particular crop protection products, and to their use in the agricultural sector or in related fields.

Moreover, the present invention also provides a process for the preparation of these compositions, which comprises intimately mixing the active ingredient with one or more substances or substance groups described herein. The invention furthermore provides a method of treating plants, which comprises applying the novel compounds of the formula I, or the novel compositions.

Target crops within the scope of this invention for the crop-protecting purpose disclosed herein are, for example, the following plant species: cereals (wheat, barley, rye, oats, rice, maize, sorghum and related species); beet (sugar beet and fodder beet); pome fruit, stone fruit and soft fruit (apples, pears, plums, peaches, almonds, cherries, strawberries, raspberries and blackberries); leguminous plants (beans, lentils, peas, soya beans); oil crops (oil seed rape, mustard, poppies, olives, sunflowers, coconut, castor, cocoa or groundnuts); cucurbits (pumpkins, cucumbers, melons); fibre plants (cotton, flax, hemp, jute); citrus fruits (oranges, lemons, grapefruit, tangerines); vegetables (spinach, lettuce, asparagus, cabbages, carrots, onions, tomatoes, potatoes, bell peppers); Lauraceae (avocado, cinnamon, camphor), or plants such as tobacco, nuts, coffee, sugarcane, tea, pepper, vines, hops, Musaceae, latex plants and ornamentals.

Active ingredients of the formula I are conventionally used in the form of compositions and can be applied to the area or plant to be treated together with other active ingredients, either simultaneously or in succession. These other active ingredients can be fertilizers, trace element mediators or other preparations which affect the growth of the plants.

Selective herbicides and insecticides, fungicides, bactericides, nematicides, molluscicides or mixtures of a plurality of these preparations, with or without other carriers or surfactants conventionally used in the art of formulation or other application-enhancing additives can also be used.

Suitable carriers and additives can be solid or liquid and are substances advantageously used in the an of formulation, for example natural or regenerated mineral substances, solvents, dispersants, wetting agents, adhesives, thickeners, binders or fertilizers. A preferred method of applying an active ingredient of the formula I, or an agrochemical composition comprising at least one of these active ingredients, is application to the foliage (foliar application). Frequency and rate of application will depend on the danger of infestation with the pathogen in question. The compounds of the formula I can also be applied to seed kernels (coating), either by soaking the kernels in a liquid preparation of the active ingredient or by coating them with a solid preparation.

The compounds of the formula I are employed in an unchanged form or, preferably, together with the auxiliaries conventionally used in the art of formulation. To this end, they are advantageously processed in the known manner to give, for example, emulsion concentrates, spreadable pastes, ready-to-spray or ready-to-dilute solutions, dilute emulsions, wettable powders, soluble powders, dusts, granules or encapsulations, for example in polymeric substances. The methods of application, such as spraying, atomizing, dusting, scattering, brushing on or pouring, as well as the nature of the compositions, will be selected to suit the intended aims and the prevailing circumstances.

Favourable application rates are, as a rule, 5 g to 2 kg of active ingredient (a.i.) per hectare (ha), preferably 10 g to 1 kg of a.i./ha, in particular 20 g to 600 g of a.i./ha.

The formulations, i.e. the compositions, preparations or combinations comprising the active ingredient of the formula 1 with or without a solid or liquid additive, are prepared in a known manner, for example by intimately mixing and/or grinding the active ingredient with extenders, such as solvents, solid carriers and, if desired, surface-active compounds (surfactants).

The following are examples of suitable solvents: aromatic hydrocarbons, preferably the fractions C₈ to C₁₂, such as xylene mixtures or substituted naphthalenes, phthalic esters, such as dibutyl phthalate or dioctyl phthalate, aliphatic hydrocarbons, such as cyclohexane or paraffins, alcohols and glycols as well as their ethers and esters, such as ethanol, ethylene glycol, ethylene glycol monomethyl ether or ethylene glycol monoethyl ether, ketones, such as cyclohexanone, strongly polar solvents, such as N-methyl-2-pyrrolidone, dimethyl sulfoxide or dimethyl formamide, epoxidized or unepoxidized vegetable oils, such as epoxidized coconut oil or soya oil, and water.

Solid carriers which are used, for example, for dusts and dispersible powders, are, as a rule, ground natural minerals, such as calcite, tale, kaolin, montmorillonite or attapulgite. To improve the physical properties, it is also possible to add highly-disperse silica or highly-disperse absorptive polymers. Possible paniculate, adsorptive carriers for granules are either porous types, such as pumice, brick grit, sepiolite or bentonite, or non-sorptive carrier materials, for example calcite or sand. Moreover, a large number of pregranulated materials of inorganic or organic nature can be used, in particular dolomite or comminuted plant residues.

Suitable surface-active compounds are, depending on the nature of the active ingredient of the formula I to be formulated, non-ionic, cationic and/or anionic surfactants which have good emulsifying, dispersing and wetting properties. Surfactants are also to be understood as meaning surfactant mixtures.

Suitable anionic surfactants can be either so-called water-soluble soaps or water-soluble synthetic surface-active compounds.

Examples of non-ionic surfactants which may be mentioned are

nonylphenolpolyethoxyethanols, castor oil polyglycol ethers, polypropylene/polyethylene oxide adducts, tributylphenoxypolyethylene-ethanol, polyethylene glycol and

octylphenoxypolyethoxyethanol.

Other suitable substances are fatty acid esters of polyoxyethylene sorbitan, such as polyoxyethylene sorbitan trioleate.

The cationic surfactants are mainly quaternary ammonium salts which have, as N substituents, at least one alkyl radical having 8 to 22 C atoms and, as funher substituents, lower, halogenated or unhalogenated alkyl, benzyl or lower hydroxyalkyl radicals.

Other surfactants conventionally used in the art of formulation are known to those skilled in the art or can be found in the relevant specialist literature.

As a rule, the agrochemical preparations comprise 0.1 to 99 per cent by weight, in particular 0.1 to 95 per cent by weight, of active ingredient of the formula I, 99.9 to 1 per cent by weight, in particular 99.8 to 5 per cent by weight, of a solid or liquid additive and 0 to 25 per cent by weight, in particular 0.1 to 25 per cent by weight, of a surfactant.

While concentrated compositions are more preferred as commercially available goods, the end consumer will, as a rule, use dilute compositions.

The compositions can also comprise other additives, such as stabilizers, antifoams, viscosity regulators, binders or adhesives, and also fertilizers and other active ingredients for achieving specific effects.

The examples which follow illustrate the invention described above without imposing any limitation to the scope thereof. Temperatures are given in degrees centigrade.

Preparation examples for intermediates

Z-1 : 2-Cyano-5-butyroylbenzimidazole (Comp. 7.3)

4.4 g of 3,4-diaminobutyrophenone are suspended in 40 ml of acetic acid, and 4.95 g of methyl trichloroacidimidate are slowly added dropwise with cooling at 20-25°C, whereupon dissolution occurs. After the mixture has been left to stand overnight, a solid product precipitates. The contents of the flask are poured into water and stirred, and the solid product is filtered off with suction, washed with water to neutrality and dried at 80°C in vacuo: 6.1 g (97.4 % of theory) of 2-trichloromethyl-5-butyroylbenzimidazole;

m.p. 206-207°C. Recrystallized from ethyl acetate: m.p. 209-210°C.

6.0 g of the crude product are dissolved in 50 ml of tetrahydrofuran at approximately 30°C, and the solution is added dropwise at 25-30°C to 40 ml of 25 per cent aqueous ammonia. After 30 minutes, the mixture is concentrated, the residue is treated with water, and the pH is brought to 4-5 using concentrated HCl. The end product crystallizes during this process. It is filtered off with suction, washed and dried, giving 3.9 g of crude 2-cyano-5-butyroylbenzimidazole (3 % of theory). After recrystallization from ethyl acetate, the m.p. is 163- 164°C (decomp.).

More examples of this type of intermediate in accordance with Z- 1 can be found in Table 7.

Z-2: 2-Cyano-5-butyroylbenzimidazole O-methyl oxime (Comp. 8.1 1)

6.5 g of 2-cyano-5-butyroylbenzimidazole and 3.0 g of O-methylhydroxylamine hydrochloride are boiled for 2 hours in 50 ml of methanol. The mixture is then

concentrated, the residue is treated with water and the mixture is extracted using ethyl acetate. Removal of the solvent on a rotary evaporator gives 6.9 g of crude product which is purified by column chromatography on silica gel (eluent mixture of 35 parts ethyl acetate and 65 parts hexane). This gives 5.9 g of 2-cyano-5-butyroylbenzimidazole O-methyl oxime which, after recrystallization from ethyl acetate, melts at 185°C with decomposition.

More examples of this compound type obtained in Example Z-2 are listed in Table 8.

Preparation example for compounds of the formula I

H-1 : 1-DiethylsuIfamoyl-2-cyano-5-butyroylbenzimidazole O-methyl oxime and

3-diethylsulfamoyl-2-cyano-5-butyroylbenzimidazole O-methyl oxime (Comp. 2.54)

and

0.9 g of 2-cyano-5-butyroylbenzimidazole O-methyl oxime in 10 ml of acetone is stirred for 4 hours at 30-40°C with 0.25 g of pulverulent potassium hydroxide and 0.8 g of diethylsulfamoyl chloride. The mixture is then poured into water and extracted using ethyl acetate. The solvent is removed, the crude product is chromatographed over silica gel (eluent 20 parts of ethyl acetate and 80 parts of hexane), giving 1J6 g of substance in the form of a resin. The mass spectrum shows the M⁺ peak at 377. The ¹H NMR spectrum in CDCl₃ shows two signals for the proton in position 4 at 8.02 and 8.15 ppm, and the large number of signals appear double in the ¹³C NMR spectrum (for example 157.6/157.4 ppm/ 142.1/141.9 ppm); accordingly, the substance is a mixture of the above isomers.

The compounds listed in Tables 2 (oxime ethers), 3 (open ketals), 4 (cyclic ketals) can be obtained in this manner or by one of the processes given further above.

H-2: 1-Dimethylsulfamoyl-2-cyano-5-butyroylbenzimidazole and

3-dimethylsulfamoyl-2-cyano-5-butyroylbenzimidazole (Comp. 1.21)

and

2.13 g of 2-cyano-5-butryoylimidazole are stirred in 15 ml of acetone together with 0.7 g of pulverulent potassium hydroxide and 0.5 ml of triethylamine, and the mixture is treated dropwise with 3.23 g of N,N-dimethylsulfamoyl chloride. After 3 hours, the reaction has ended. The mixture is subjected to filtration with suction and concentrated, and the crude product is chromatographed over silica gel (eluent mixture of 35 parts of ethyl acetate and 65 parts of hexane). This gives 2.5 g of product which is recrystallized from 10 ml of ethyl acetate and 10 ml of hexane. The yield is 2.17 g (68 % of theory); m.p. 110-111°C

(sintering). The ¹H NMR spectrum shows that the substance is composed of the above two isomers in the ratio of approximately 1 : 1 (H in position 4 at 8.45 and 8.55 ppm, measured in CDCl₃).

H-3: 1-Methylsulfonyl-2-cyano-5-butyroylbenzimidazole and

3-methylsulfonyl-2-cyano-5-butyroylbenzimidazole (Comp. 1.23) and

2.0 g of 2-cyano-5-butyroylimidazole, 0.56 g of pulverulent potassium hydroxide and 1.5 g of methanesulfonyl chloride are stirred in 15 ml of acetone at room temperature. After one hour the reaction has ended. The mixture is subjected to filtration with suction and concentrated, and the product is recrystallized from 15 ml of ethyl acetate and 10 ml of hexane. The yield is 1.95 g (71 % of theory); m.p. 156-158°C (sintering). The ¹H NMR spectrum in CDCl₃ shows two signals for the hydrogen in position 4 at 8.46 and 8.53 ppm in a ratio of 1 :2. The product is therefore composed of a 3:7 mixture of the two above isomers.

More examples of the type H-2 or H-3 can be found in Table 1.

The active ingredient is mixed intimately with the additives and ground thoroughly in a suitable mill. This gives wettable powders which can be diluted with water to give suspensions of any desired concentration.

F-2.2. Emulsion concentrate

Active ingredient of Tables 1 to 6 10 %

Octylphenol polyethylene glycol ether 3 %

(4-5 mol of ethylene oxide)

Calcium dodecylbenzenesulfonate 3 %

Castor oil polyglcol ether 4 %

(35 mol of ethylene oxide)

Cyclohexanone 34 %

Xylene mixture 50 %

Emulsions of any desired concentration can be prepared from this concentrate by dilution with water.

F-2.3. Dusts a) b)

Active ingredient of Tables 1 to 6 5 % 8 %

Talc 95 % -

Kaolin - 92 %

Ready-for-use dusts are obtained by mixing the active ingredient with the carrier and grinding the mixture on a suitable mill.

F-2.4. Extruder granules

Active ingredient of Tables 1 to 6 10 %

Sodium lignosulfonate 2 %

Carboxymethylcellulose 1 %

Kaolin 87 %

The active ingredient is mixed with the additives, and the mixture is ground and moistened with water. This mixture is extruded and subsequently dried in a stream of air.

F-2.5. Coated granules

Active ingredient of Tables 1 to 6 3 % Polyethylene glycol (MW 200) 3 %

Kaolin 94 %

(MW = molecular weight)

In a mixer, the finely ground active ingredient is applied uniformly to the kaolin which has been moistened with polyethylene glycol. Dust-free coated granules are obtained in this manner.

F-2.6. Suspension concentrate

Active ingredient of Tables 1 to 6 40 %

Ethylene glycol 10 %

Nonylphenol polyethylene glycol ether 6 %

(15 mol of ethylene oxide)

Sodium lignosulfonate 10 %

Carboxymethylcellulose 1 %

37 % aqueous formaldehyde solution 0.2 %

Silicone oil in the form of a 75 %

aqueous emulsion 0.8 %

Water 32 %

The finely ground active ingredient is intimately mixed with the additives. This gives a suspension concentrate from which suspensions of any desired concentration can be prepared by dilution with water.

3. Biological examples

B-3. 1: Activity against Plasmopara viticola on vines

a) Residual-protective activity

Vine seedlings in the 4-5-leaf stage are sprayed with a spray mixture (0.02 % of active ingredient) prepared with a wettable powder of the active ingredient. After 24 hours, the treated plants are infected with a sporangia suspension of the fungus. The fungus infestation is assessed after incubation for 6 days at 95-100 % relative atmospheric humidity and 20°C. b) Residual-curative activity

Vine seedlings in the 4-5-leaf stage are infected with a sporangia suspension of the fungus. After incubation for 24 hours in a humid chamber at 95-100 % relative atmospheric humidity and at 20°C, the infected plants are dried and sprayed with a spray mixture (0.02 % active ingredient) prepared with a wettable powder of the active ingredient. After the spray coating has dried on, the treated plants are returned to the humid chamber. The fungus infestation is assessed 6 days after the infection.

Compounds of Tables 1 to 6, in particular oxime ethers of Table 2, have a very good fungicidal activity against Plasmopara viticola on vines. Complete suppression of the fungus infestation (residual infestation 0 to 5 %) is obtained by, inter alia, the active ingredients No. 1.1, 1.5, 1.9, 1.17, 1.21, 1.22, 1.28, 1.45, 1.49, 1.59, 1.106, 2.25, 2.29, 2.31, 2.33, 2.37, 2.49, 2.53, 2.54, 2.57, 2.61, 2.62, 2.123, 2.131, 2.182, 4.1, 4.2, 4.3, 4.4, 4.6, 4.10, 4.12, 4.13, 4.16, 4J9, 4.29, 4.30, 4.31, 5.5 and 6.1. In contrast, the infestation with Plasmopara of untreated, but infected control plants is 100 %.

B-3.2: Activity against Phytophthora on tomato plants

a) Residual-protective activity

Tomato plants are grown for 3 weeks and then sprayed with a spray mixture (0.02 % of active ingredient) prepared with a wettable powder of the active ingredient. After 24 hours, the treated plants are infected with a sporangia suspension of the fungus. The fungus infestation is assessed after incubation of the infected plants for 5 days at 90-100 % relative atmospheric humidity and 20°C. b) Systemic activity

Tomato plants are grown for three weeks, and a spray mixture (0.002 % of active ingredient relative to the soil volume) prepared with a wettable powder of the active ingredient is added. Care is taken that the spray mixture does not come into contact with the aerial parts of the plants. After 48 hours, the treated plants are infected with a sporangia suspension of the fungus. The fungus infestation is assessed after incubation of the infected plants for 5 days at 90- 100 % relative atmospheric humidity and at 20°C.

Compounds of Tables 2 to 4 have a sustained effect (fungal infestation below 20 %). An infestation is prevented virtually completely (0 to 5 % infestation) by compounds No. 1.1, 1.5, 1.9, 1.17, 1.21, 1.22, 1.28, 1.45, 1.49, 1.59, 2.25, 2.29, 2.31, 2.33, 2.37, 2.49, 2.53, 2.54, 2.57, 2.61, 2.62, 2.131 , 4.1, 4.2, 4.3, 4.4, 4.6, 4.10, 4.12, 4.13, 4.16, 4.19, 4.29, 4.30 and 4.31. In contrast, the infestation with Phytophthora of untreated, but infected control plants is 100 %. B-3.3: Activity against Phytophthora on potato plants

a) Residual-protective activity

2-3-week old potato plants (cultivar Bintje) are grown for 3 weeks and then sprayed with a spray mixture (0.02 % active ingredient) prepared with a wettable powder of the active ingredient. After 24 hours, the treated plants are infected with a sporangia suspension of the fungus. The fungus infestation is assessed after incubation of the infected plants for 5 days at 90-100 % relative atmospheric humidity and 20°C. b) Systemic activity

2-3-week old potato plants (cultivar Bintje) are grown for three weeks, and a spray mixture (0.002 % of active ingredient relative to the soil volume) prepared with a wettable powder of the active ingredient is added. Care is taken that the spray mixture does not come into contact with the aerial parts of the plants. After 48 hours, the treated plants are infected with a sporangia suspension of the fungus. The fungus infestation is assessed after incubation of the infected plants for 5 days at 90-100 % relative atmospheric humidity and at 20°C.

Compounds of Tables 2 to 4 have a sustained effect (fungal infestation below 20 %). An infestation is prevented virtually completely (0 to 5 % infestation) by compounds No. 1.1, 1.5, 1.9, 1.17, 1.21 , 1.22, 1.28, 1.45, 1.49, 1.59, 2.25, 2.29, 2.31, 2.33, 2.37, 2.49, 2.53, 2.54, 2.57, 2.61, 2.62, 2.131 , 4.1, 4.2, 4.3, 4.4, 4.6, 4.10, 4.12, 4.13, 4.16, 4.19, 4.29, 4.30 and 4.31. In contrast, the infestation with Phytophthora of untreated, but infected control plants is 100 %.

Example B-3.4: Activity against Pythium debaryanum on sugar beet (Beta vulgaris) a) Activity after soil drench

The fungus is grown on sterile oat kernels and added to a mixture of soil and sand. The soil which has been infected in this way is filled into flower pots, and sugar beet seeds are sown. Immediately after sowing, the soil is drenched (20 ppm of active ingredient relative to the soil volume) of an aqueous suspension made with test preparations formulated as wettable powders. The pots are then placed in a greenhouse for 2-3 weeks at 20-24°C. The soil is constantly kept uniformly moist by spraying thinly with water. When the test is evaluated, the emergence of the sugar beet plants and the proportion of healthy and diseased plants is determined. b) Activity after application by seed-dressing

The fungus is grown on sterile oat kernels and added to a mixture of soil and sand. The soil which has been infected in this way is filled into flower pots, and sugar beet seeds are sown, which have been dressed with the test preparations formulated as a powder for dry seed treatment (1000 ppm of active ingredient relative to the weight of the seeds). The pots together with the seeds are placed in the greenhouse at 20-24°C for 2 to 3 weeks. The soil is constantly kept uniformly moist by spraying thinly with water. When the test is evaluated, the emergence of the sugar beet plants and the proportion of healthy and diseased plants is determined.

After treatment with the active ingredients of the formula I according to Tables 1 to 6, over 80 % of the plants emerge and have a vigorous appearance. Only few plants having a diseased appearance emerge in the control pots.

Example B-3.5: Comparison of the activities of selected acyl compounds of the formula I with the compound 1(3)-dimethylsulfamoyl-2-cyano-5-benzoylbenzimidazole (Comp. Z) of the prior art (GB-A-2 114 567).

The procedure of the abovementioned tests B-3.2 a) and B-3.3 a) is followed, using spray mixtures of various dilution steps starting with 200 ppm of a.i. (= 0.02 %), the tests being conducted in 3 replications. The following average results from in each case 3 tests are obtained.

Score figures: 10 = 100 % activity (no infestation)

9 = 90 - 99 % "

8 = 80 - 89 % "

.

1 = 10 - 19 % "

0 = no activity; plants (virtually) completely diseased B-3.2a) Phythophthora on tomatoes

Concn. Comp. Comp. Comp. Comp.

[ppm] No. 1.9 No. 1.25 No. 1.57 Z

200 9 9 9 9

60 9 9 9 9

20 8 9 8 2

6 7 7 5 0

2 0 1 0 0

B-3.3a) Phythophthora on potatoes

Concn. Comp. Comp. Comp. Comp.

[ppm] No. 1.9 No. 1.25 No. 1.57 Z

200 10 10 10 9

60 9 9 8 8

20 8 9 6 3

6 6 7 3 0

2 3 6 0 0

In addition, Compound No. 1.57 was tested in 3 dilution steps against

Plasmopara-infestation on vines (procedure as in Example B-3.1 a)).

In comparison with compound Z, the following average results from in each case 3 parallel applications were obtained.

B-3.1a) Plasmopara on vines

Concn. Comp. Comp.

[ppm] No. 1.57 Z

200 9 8

60 6 0

20 6 0 Summary: The above results demonstrate that the compound Z of the prior an, when used at low concentrations of 60 ppm and less, has no, or completely insufficient, activity against downy mildew species, while sustained activity is achieved by compounds of the present invention, even when diluted to 6 ppm or below.

Claims

WHAT IS CLAIMED IS:

1. A compound of the formula I

in which the R₄-SO₂-group is in the 1- or 3-position in the benzimidazole moiety and forms pure or mixed positional isomers relative to the substituents R₁ and R₂, the substituents being defined as follows:

R₁ is R₅-CO- or a group a) to d):

a) in which R₅ is defined as follows:

- hydrogen;

- C₁-C₁₂alkyl;

C₁-C₄haloalkoxy;

- C₂-C₈alkenyl;

- C₂-C₈alkynyl; C₃-C₄alkynyl which is substituted by halogen;

- C₃-C₇cycloalkyl-C₁-C₄alkyl;

- phenyl which can be unsubstituted or monosubstituted to trisubstituted by identical or different substituents from the series consisting of halogen, C₁-C₃alkyl, C₁-C₃alkoxy, C₁-C₃haloalkyl, C₁-C₃haloalkoxy, cyano or nitro and which can also be bonded via a C₁-C₄alkylene bridge, and in which

R₆ is defined as follows:

C₁-C₄alkoxy, C₁-C₄haloalkyl and C₁-C₄haloalkoxy;

b) in which R₅ is as defined under a) and

R₇ and R₈ independently of one another can be hydrogen; C₁-C₈alkyl;

where m is 3, 4 or 5;

c) in which R₅ is as defined under a) and

R₉ is C₁-C₈alkyl;

C₂-C₈alkenyl;

C₂-C₈alkynyl;

C₁-C₄alkoxy-C₁-C₆alkyl or

C₁-C₈haloalkyl;

d in which R₅ is as defined under a) and

R₁₀ and R₁ independently of one another are hydrogen, C₁-C₆alkyl; or C₁-C₄alkyl which is substituted by halogen, hydroxyl or C₁-C₃alkoxy, and p is the number 2 or 3; while the remaining substituents in the formula I are as defined as follows:

R₂ radicals are identical or different and are

halogen;

C₁-C₄alkyl;

C₁-C₄alkoxy;

C₁-C₄haloalkyl;

C₁-C₄haloalkoxy;

nitro;

R₄ is C₁-C₆alkyl;

radicals or R₁₃ and R₁₄ together form a chai

_, in which q is the number 4 or 5; and n is 0, 1 or 2;

with the exception of the compound 1(3)-dimethylsulfamoyl-2-cyano-5-benzoylbenzimidazole.

2. A compound of the formula I according to claim 1, in which R₁ is a group a) to d): a) in which R₅ is defined as follows:

- hydrogee; - C₁-C₁₂alkyl;

- C₁-C₆alkyl, which is substituted by halogen, C₁-C₃alkoxy, C₂-C₄alkoxyalkoxy, C₁-C₃alkylthio, C₃-C₄alkenyloxy, C₃-C₄alkynyloxy, or else by phenoxy or phenylthio whose phenyl rings can be unsubstituted or substituted by halogen, C₁-C₄ alkyl, C₁-C₄alkoxy, C₁-C₄haloalkyl or

C₁-C₄haloalkoxy;

- C₂-C₈alkenyl;

- C₂-C₈alkynyl; C₃-C₄alkynyl which is substituted by halogen;

- C₃-C₇cycloalkyl-C₁-C₄alkyl;

and in which

R₆ is defined as follows:

hydrogen, C₁-C₈alkyl; C₂-C₈alkenyl; C₂-C₈alkynyl; benzyl or phenyl, whose aromatic ring is unsubstituted or substituted by one of more of the substituents halogen, C₁-C₄ alkyl,

C₁-C₄alkoxy, C₁-C₄haloalkyl and C₁-C₄haloalkoxy;

in which R₅ is as defined under a) and

R₇ and R₈ independently of one another are hydrogen; C₁-C₈alkyl;

C₂-C₈alkenyl; C₂-C₈alkynyl; or benzyl or phenyl, whose aromatic ring is unsubstituted or substituted by one or more of the substituents C₁-C₄haloalkoxy, C₁-C₄haloalkyl, halogen, C₁-C₄alkyl and C₁-C₄ alkoxy; and in which one of the two substituents R₇ and R₈ can be an aliphatic, araliphatic or aromatic acyl radical having not more than 8 carbon atoms; or R₇ and R₈ together are

where m is 3, 4 or 5;

c) in which R₅ is as defined under a) and

R₉ is C₁-C₈alkyl;

C₂-C₈alkenyl;

C₂-C₈alkynyl;

C₁-C₄alkoxy-C₁-C₆alkyl or

C₁-C₈haloalkyl;

d) in which R₅ is as defined under a) and

R₁₀ and R₁₁ independently of one another are

hydrogen;

C₁-C₆alkyl; C₁-C₄alkyl which is substituted by halogen, hydroxyl, C₁-C₃alkoxy, and p is the number 2 or 3; while the remaining substituents in the formula 1 are as defined as follows:

R₂ radicals are identical or different and are

halogen;

C₁-C₄alkyl;

C₁-C₄alkoxy;

C₁-C₄haloalkyl;

C₁-C₄haloalkoxy;

nitro:

C₁-C₄haloalkyl or benzyl which is unsubstituted or substituted in the aromatic ring by halogen, C₁-C₄alkyl or C₁-C₄haloalkyl; R₄ is C₁-C₆alkyl;

C₃-C₇cycloalkyl; , in which R₁₃ and R₁₄ are identical or different and are

C₁-C₄alkyl, or R₁₃ and R₁₄ together form a chain ~(^"CH₂-^- , i_n which q is the number 4 or 5; and n is 0, 1 or 2.

3. A compound according to claim 1 , in which R₁ is a group a) to d) and is in the 4- or 5-position, and

R₅ is hydrogen; or

C₂-C₆alkenyl; C₂-C₄alkynyl; or

R₂ is in the 6- or 7-position and is halogen, C₁-C₃alkyl, C₁-C₃aIkoxy, C₁-C₄haloalkyl or C₁-C₄haloalkoxy;

R₄ is C₁-C₄alkyl, cyclopropyl or -N(R₁₃)R₁₄) in which R₁₃ and R₁₄ are identical or different C₁-C₄alkyl radicals; and

4. A compound according to claim 3, in which

R₁ is in the 5-position, and

R₅ is hydrogen; or C₁-C₈alkyl which is unsubstituted or substituted by halogen or C₁-C₃alkoxy; or C₂-C₄alkenyl, C₂-C₄alkynyl or C₃-C₆cycloalkyl, which is unsubstituted or substituted by halogen or C₁-C₄aIkyl and which can be bonded via C₁-C₂alkyl; or is phenyl which is unsubstituted or monosubstituted to trisubstituted by identical or different substituents from the series consisting of halogen, C₁-C₃alkyl, C₁-C₃alkoxy,

n is 0, 1 or 2;

R₃ is cyano or -CS-NH₂;

R₄ is N(R₁₃)(R₁₄), in which R₁₃ and R₁₄ are as defined in claim 3, and

R₆ is hydrogen, C₁-C₈alkyl or C₂-C₈alkenyl.

5. A compound according to claim 4, in which

R₁ is a group a) which is in the 5-position; and

n is 0 or 1;

R₃ is cyano or -CSNH₂;

R₆ is hydrogen, C₁-C₈alkyl or C₂-C₈alkenyl.

6. A compound according to claim 5, in which

R₅ is C₁-C₈alkyl which can be unsubstituted or substituted by halogen or C₁-C₃alkoxy; or is phenyl which can be unsubstituted or substituted by halogen; and

R₆ is C₁-C₄alkyl; while

R₁, n, R₃ and R₄ have the abovementioned meanings.

7. A compound according to claim 6, in which

R₅ is C₁-C₈alkyl; and

R₂ is halogen;

R₄ is dimethylamino; and

R₆ is methyl.

8. A compound according to claim 7, selected from amongst:

[6-chloro-2-cyano-3-dimethylsulfamoylbenzimidazolyl(5)]acetoxime O-methyl ester and [6-chloro-2-cyano-l-dimethylsulfamoylbenzimidazolyl(5)]acetoxime O-methyl ester.

9. A compound according to claim 2, in which

R₁ is in the 5-position, and

R₅ is hydrogen; or

C₂-C₄alkenyl, C₂-C₄alkynyl or C₃-C₆cycloalkyl; or is phenyl or benzyl, whose aromatic rings can be not more than disubstituted by identical or different substituents from the series consisting of halogen, C₁-C₃alkyl, CF₃ and CF₃O;

R₃ is cyano or -CS-NH₂ (thioamide); and

n is O or 1; while

R₂, R₄ and R₆ to R₁₁ are as defined in claim 2.

10. A compound according to claim 9, in which

R₆ is hydrogen; C₁-C₈alkyl; C₂-C₈alkenyl; C₃-C₈alkynyl; or phenyl or benzyl, whose aromatic rings are unsubstituted or monosubstituted to trisubstituted by identical or different substituents from the series consisting of halogen, C₁-C₃alkyl, C₁-C₃alkoxy, C₁-C₃haloalkyl or C₁-C₃haloalkoxy; while

CHF₂O;

R₃ is cyano or -CS-NH₂; and

R₄ is C₁-C₄alkyl, cyclopropyl or -N(R₁₃)(R₁₄), in which R₁₃ and R₁₄ are identical or different C₁-C₄alkyl radicals and have a total of not more than 6 C atoms.

11. A compound according to claim 10, in which

R₅ is hydrogen; or C₁-C₅alkyl which is unsubstituted or substituted by halogen or methoxy; or C₂-C₄alkenyl, C₂-C₄alkynyl, C₃-C₃cycloalkyl or phenyl or benzyl, whose aromatic rings can be up to disubstituted by identical or different substituents from the series consisting of chlorine, bromine, methyl, CF₃ and CF₃O;

R₂ is in the 7-position and is hydrogen, halogen, CF₃ or CHF₂O;

R₃ is cyano or -CS-NH₂; and

R₄ is methyl, ethyl, dimethylamino, methylethylamino or diethylamino.

12. The compound [7-bromo-2-cyano-3-dimethylsulfamoylbenzimidazolyl(5)]acetoxime O-methyl ether according to claim 11.

13. A compound of the formula I according to claim 1, in which

R₁ is R₅-CO- and

R₅ - hydrogen;

- C₁-C₁₂alkyl;

- C₁-C₆alkyl which is substituted by halogen, C₁-C₃alkoxy, C₂-C₄alkoxyalkoxy, C₁-C₃alkylthio, C₃-C₄alkenyloxy or C₃-C₄alkynyloxy, or else by phenoxy or phenylthio, whose phenyl rings can be unsubstituted or substituted by halogen, C₁-C₄alkyl, C₁-C₄alkoxy, C₁-C₄haloalkyl or C₁-C₄haloalkoxy;

- C₂-C₈alkenyl;

- C₂-C₈alkynyl; C₃-C₄alkynyl which is substituted by halogen;

- C₃-C₇cycloalkyl; C₃-C₇cycloalkyl which is substituted by halogen, alkyl;

- C₃-C₇cycloalkyl-C₁-C₄alkyl;

- phenyl which can be unsubstituted or monosubstituted to trisubstituted by identical or different substituents from the series consisting of halogen, C₁-C₃alkyl, C₁-C₃alkoxy, C₁-C₃haloalkyl, C₁-C₃haloalkoxy, cyano and nitro and which can also be bonded via a C₁-C₄alkylene bridge,

R₂ radicals are identical or different and are

halogen;

C₁-C₄alkyl; C₁-C₄alkoxy;

C₁-C₄haloalkyl; C₁-C₄haloalkoxy;

nitro; R₃ is cyano, -C(=S)NH₂ or -C(-NH)-S-R₁₂, in which R₁₂ is

C₁-C₄alkyl, C₁-C₄haloalkyl or benzyl, which is unsubstituted or substituted in the aromatic ring by halogen, C₁-C₄alkyl or C₁-C₄haloalkyl;

R₄ is C₁-C₆alkyl;

C₃-C₇cycloalkyl;

, in which R₁₃ and R₁₄ are identical or different

and are C₁-C₄alkyl, or R₁₃ and R₁₄ together form a chain

in which q is the number 4 or 5; and

n is 0, 1 or 2.

14. A compound according to claim 1, in which R₁ is R₅-CO- and is in the 4- or

5-position, and in which R₅ is hydrogen; C₁-C₈alkyl which is unsubstituted or substituted by halogen, C₁-C₃alkoxy, C^Csalkylthio, C₃-C₄alkenyloxy or phenoxy whose phenyl moiety can be unsubstituted or substituted by halogen, C₁-C₄alkyl, C₁-C₄alkoxy, OCF₃ or CF₃; C₂-C₆alkenyl; C₂-C₄alkynyl; C₃-C₆cycloalkyl which is unsubstituted or substituted by halogen or C₁-C₄alkyl and which can be bonded via C₁-C₂alkyl; or is phenyl which is unsubstituted or monosubstituted to trisubstituted by identical or different substituents from the series consisting of halogen, C₁-C₃alkyl, C₁-C₃alkoxy, C₁-C₃haloalkyl and C₁-C₃haloalkoxy and which can also be bonded via a C₁-C₄alkyl bridge; and R₂ to R₄ are as defined above.

15. A compound according to claim 14, in which

R₁ is in the 5-position; and

R₅ is C₁-C₈alkyl which can be unsubstituted or substituted by halogen or C₁-C₃alkoxy; C₂-C₆alkenyl; C₂-C₄alkynyl; C₃-C₆cycloalkyl which is unsubstituted or substituted by halogen or Ci^alkyl and which can be bonded via C₁-C₂alkyl; or is phenyl which is unsubstituted or monosubstituted to trisubstituted by identical or different substituents from the series consisting of halogen, C₁-C₃alkyl, C₁-C₃alkoxy, C₁-C₃haloalkyl and C₁-C₃haloalkoxy and which can also be bonded via a C₁-C₄alkyl bridge;

R₂ radicals are identical or different and are halogen, C₁-C₄alkyl, C₁-C₄alkoxy or C₁-C₄haloalkoxy; n is 0, 1 or 2;

R₃ is cyano or -CS-NH₂; and

R₄ is N(R₁₃)(R₁₄), in which R₁₃ and R₁₄ are as defined above in claim 14.

16. A compound according to claim 15, in which

C₁-C₂haloalkoxy;

n is 0 or 1; and

R₄ is N(R₁₃)(R₁₄) in which R₁₃ and R₁₄ are C₁-C₄alkyl.

17. A compound according to claim 16, in which

R₅ is C₁-C₈alkyl,

R₂ is halogen and

R₄ is dimethylamine.

18. A compound according to claim 13, in which R₁ is in the 4- or 5-position and R₅ is hydrogen; or

C₁-C₆alkyl which is unsubstituted or substituted by halogen, C₁-C₃alkoxy, C₁-C₃alkylthio, C₃-C₄alkenyloxy or by phenoxy whose phenyl moiety can be unsubstituted or substituted by halogen, C₁-C₄alkyl, C₁-C₄alkoxy, OCF₃ or CF₃, or can be substituted by phenylthio or halophenylthio; C₂-C₆alkenyl; C₂-C₄alkynyl; or C₃-C₆cycloalkyI which is unsubstituted or substituted by halogen or C₁-C₄alkyl and which can be bonded via C₁-Calkyl; or is phenyl which is unsubstituted or monosubstituted to trisubstituted by identical or different substituents from the series consisting of halogen, C₁-C₃aIkyl, C₁-C₃alkoxy, C₁-C₃haloalkyl and C₁-C₃haloaIkoxy and which can be bonded via a C₁-C₄alkyl bridge; R₂ is in the 6- or 7-position and is halogen, C₁-C₃alkyl, C₁-C₃alkoxy, C₁-C₄haloalkyl or C₁-C₄haloalkoxy;

R₄ is C₁-C₄alkyl, cyclopropyl or -N(R₁₃)(R₁₄), in which R₁₃ and R₁₄ are identical or different C₁-C₄alkyl radicals; and

n is 0, 1 or 2.

19. A compound according to claim 18, in which R₁ is in the 5-position, and

R₅ is hydrogen; or

R₃ is cyano or -CS-NH₂ (thioamide); and

n is O or 1; while

R₂ and R₄ are as defined in claim 18.

20. A compound according to claim 19, selected from amongst:

7-bromo-5-butyroyl-2-cyano-3-dimethylsulfamoylbenzimidazole;

7-bromo-2-cyano-3-dimethylsulfamoyl-5-valeroylbenzimidazole;

5-benzoyl-6-chloro-2-cyano-3-dimethylsulfamoylbenzimidazole and

5-benzoyl-6-chloro-2-cyano-1-dimethylsulfamoylbenzimidazole.

21. A compound according to claim 13, in which R₃ is -CS-NH₂.

22. A compound according to claim 18, in which R₃ is -CS-NH₂.

23. A process for the preparation of a compound of the formula I according to claim 1, by reacting a compound of the formula II

with a compound of the formula III

Q-SO₂-R₄ (III) in which R₁, R₂, R₃ and n are as defined under formula I and M is hydrogen or an alkali metal, preferably lithium, sodium or potassium, and Q is a leaving group, for example a halogen atom, preferably chlorine or bromine, or the radical R₄-SO₂-O-, in an inert solvent, if desired in the presence of a base, at temperatures from -30° to +180°C.

24. A composition for controlling and preventing microbial infestation of plants, which comprises, as active ingredient, a compound of the formula I together with a suitable carrier material.

25. A method of controlling and preventing microbial infestation of plants, which comprises applying, as active ingredient, a compound of the formula I to the plant, to the parts of the plant or to the plant substrate.

26. The use of a compound of the formula I as microbicide.