Note: Descriptions are shown in the official language in which they were submitted.
The invention relates to new 1-arylpyrazoles,
several processes to their preparation, and to their use as
herbicides.
It is already known that certain 1-arylpyrazoles,
such as, for example, 5-amino-1-(2,6-dichloro-4-trifluoro-
methylphenyl)-4-nitropyrazole, have herbicidal properties
(cf., for example, EP 154,115).
The herbicidal activity of these previously known
compounds against problem weeds and their tolerance by import-
ant crop plants are, however, not entirely satisfactory in all
fields of application.
According to one aspect of the present invention
there is provided a 1-arylpyrazole of the formula I
R~
N~
R3 \N R4 R2 C ~ 7
R5
CHF2
in which
R1 stands for hydrogen or nitro,
R2 stands for hydrogen or for a radical -C-R6,
0
R3 stands for hydrogen or halogen,
R4 stands for halogen, and
R5 stands for hydrogen or halogen, where
R6 stands for alkoxyalkyl or alkoxyalkoxyalkyl, each
straight-chain or branched and each having 1 to 6 carbon atoms
- 1 -
in the individual alkyl or alkoxy moieties, or for straight-
chain or branched haloalkyl having 1 to 6 carbon atoms and 1
to 9 identical or different halogen atoms.
Furthermore, it has been found that the new 1-aryl-
pyrazoles of the general formula (I)
R1
N~
R3 \N R4 R2 C ~ 7
R5
CHF2
in which
R1, R2, R3, R4, RS and R6 are as defined above are
obtained by one of the processes described below:
(a) 1-arylpyrazoles of the formula (Ia)
N~
R3 N9 2 ( I a]
R
~R5
CHF2
in which
R3, R4 and R5 have the abovementioned meaning, are
obtained when N-aryl-N'-cyanoethylhydrazines of the formula
(II)
- 2 _
134~~0
2a
R3
F3C ~ ~ NH-NH-CHp-CH2-CN ( I I]
R5 ~Rq
in which
R3, R4 and R5 have the abovementioned meaning,
_,
are cyclized using sodium hydroxide in the presence of a
d i l uent;
(b) 1-arylpyrazoles of the formula (Ib)
1 0
6
T1~N NH C R
Rg \ 4 (Ib)
~R
CHF2
5 in which
R1, R3, R4, RS and R6 have the abovementioned
meaning,
are obtained when the 1-arylpyrazoles of the formula (Iz)
1
TIN NH2
R3 4 (Iz)
av
RS
CHF2
in which
R1, R3, R4 and RS have the abovementioned meaning,
which can be obtained with the aid of process (a) or (c)
according to the invention, are reacted with acylating
agents of the formula (III)
R6- i-A ( I I I )
0
in which
R6 has the abovementioned meaning and
A stands for an electron-withdrawing leaving
group,
if appropriate in the presence of a diluent and if appro-
priate in the presence of an acid-binding agent;
Le A 25 438
- 3 -
134~~i~~1?
(c) 1-arylpyrazoles of the formula (Ic)
02
- 2
TIN NH R
R3 ' ~ 4 (Ic)
R5
CHF2
in which
R2, R3, R4 and R5 have the abovementioned
meaning,
are obtained when the 1-arylpyrazoles of the formula (Iy)
IJ~N NH-R2
R3 ~ 4 (Iy)
5
~R
CHF2
in which
R2, R3, R4 and R5 have the abovementioned
meaning,
which can be obtained with the aid of the process (a) or
(b) according to the invention, are reacted with a nitrat-
ing agent, if appropriate in the presence of a diluent and
if appropriate in the presence of a reaction auxiliary.
Finally, it has been found that the new 1-aryl-
pyrazoles of the general formula (I) have good herbicidal
properties, especially also selectively herbicidal pro-
perties.
Surprisingly, the 1-arylpyrazoles according to
the invention show a considerably improved selectivity
towards crop plants in comparison with the 1-arylpyra-
zoles known from the prior art, such as, for example,
5-amino-4-nitro-1-(2,6-dichloro-4-trifluoromethylphenyl>-
pyrazole, which are chemically similar and have a similar
Le A 25 438
- 4 -
1~~0~0~
action, while having a comparably good herbicidal action
against problem weeds.
Formula (I) provides a general definition of the 1-
arylpyrazoles according to the invention. Preferred compounds
of the formula (I) are those in which
R1 stands for hydrogen or nitro,
R2 stands for hydrogen or a radical -~-R6,
0
R3 stands for hydrogen, fluorine, chlorine or
bromine,
R4 stands for fluorine, chlorine or bromine, and
R5 stands for hydrogen, fluorine, chlorine or
bromine, where
R6, as mentioned above, stands for alkoxyalkyl or
alkoxyalkoxy-alkyl, each straight-chain or branched
and each having 1 to 6 carbon atoms in the
individual alkyl or alkoxy moieties, or for
straight-chain or branched haloalkyl having 1 to 6
carbon atoms and 1 to 9 identical or different
halogen atoms, especially fluorine, chlorine or
bromine. Particularly preferred compounds of the
formula (I) are those in which
R1 stands for hydrogen or nitro,
R2 stands for hydrogen or for a radical -C-R6,
0
R3 stands for hydrogen, fluorine or chlorine,
R4 stands for fluorine or chlorine, and
R5 stands for hydrogen, fluorine or chlorine,
'~1 ~% _ 5 _
13~~~~r~~~
where
R6 stands for methoxymethyl, ethoxymethyl, n- or i-
propoxymethyl, methoxyethyl, ethoxyethyl, n- or i-
propoxyethyl, methoxyethoxyethyl, ethoxy-
ethoxyethyl, n- or i-propoxyethoxy-ethyl, tri-
fluoromethyl, trichloromethyl, difluorochloro
methyl, difluorochloromethyl, chloromethyl, iodo-
methyl, bromomethyl, dichloromethyl, 1-chloroethyl,
2-chloroethyl, 2-bromoethyl, 3-chloro-propyl,
pentafluoroethyl or heptafluoropropyl.
Very particularly preferred compounds of the formula
(I) are those in which
R1 stands for nitro,
R2 stands for hydrogen or for a radical -C-R6,
R3 stands for hydrogen, fluorine or chlorine,
R4 stands for fluorine or chlorine, and
R5 stands for hydrogen, fluorine or chlorine,
where
R6 stands for methoxymethyl, ethoxymethyl,
methoxyethyl, ethoxyethyl, methoxyethoxymethyl,
ethoxyethoxyethyl, trifluoromethyl, chloromethyl,
dichloromethyl, 1-chloroethyl, 2-chloroethyl,
pentafluoroethyl or heptafluoropropyl.
If, for example, N-(2,6-dichloro-4-difluoro-
methylphenyl)-N'-(2-cyanoethyl-hydrazine is used as the
starting compound, the course of the reaction of process
- 6 -
.~
1340~0~
(a) according to the invention may be represented by the
following equation:
CI
F3C ~ ~ NH-NH-CH2-CHZ-CN
CI
NI
NaOH ~ ~N NHZ
CI CI
- HF
1o ~ i
CHF2
If, for example, 5-amino-1-(2,3,6-trichloro-4-
difluoromethylphenyl)-pyrazole and acetic anhydride are used
as the starting compounds, the course of the reac-
- 6a -
~~~o~o,
tion of process (b) according to the invention may be
represented by the following equation:
NON NH2 I) I)
C1 ~ C1 + CH3-C-0-C-CH3
1
CHF2
0
NON NH-C-CH3
-CH3COOH
C1 ~ C1
(Base)
1
CHF2
If, for example, S-acetamido-1-(2,6-dichloro-4-
difluoromethylphenyl)-pyrazole is used as the starting
compound, the course of the reaction of process (c)
according to the invention may be represented by the
following equation:
02
NON NH-C-CH t HNO -
N NH ~I-CH3
C1 ~ C1
-H20 C1 ~ ~ C1 0
CHF2 CHF2
Formula (II) provides a general definition of
the N-aryl-N'-cyanoethyl-hydrazines which are required as
starting compounds for carrying out process (a) according
to the invention. In this formula (II), R3, R4 and RS pre-
ferably or particularly preferably stand for those radicals
which have already been mentioned in connection with the
description of the substances of the formula (I) according
to the invention as being preferred or particularly
Le A 25 438
13~0~(~~
preferred respectively for these substituents.
The N-aryl-N'-cyanoethylhydrazines of the formula
(II) were hitherto unknown.
They are obtained when 1-arylhydrazines of the
formula (IV)
R3
F3C , H-NH2 (IV)
R R4
in which
R3, R4 and RS have the abovementioned meaning,
are reacted with acrylonitrile of the formula (V)
CH2=CH-CN (V)
if appropriate in the presence of a diluent, such as, for
example, ethanol, at temperatures between 50°C and 150°C.
The arylhydrazines of the formula (IV) are known
or can be obtained in analogy to known processes (cf.,
for example, DE-OS (German Published Specification)
3,226,513, DE-OS (German Published Specification)
3,226,496 or EP 224,831>.
Acrylonitrile of the formula (V) is a generally
known compound of organic chemistry.
Formula (Iz) provides a general definition of
the 1-arylpyrazoles which are required as starting com-
pounds for carrying out process (b) according to the
invention. In this formula (Iz>, R1, R3, R4 and R5 pre-
ferably stand for those radicals which have already been
mentioned in connection with the substances of the
formula (I) according to the invention as being preferred
for these substituents.
The 1-arylpyrazoles of the formula (Iz> are com-
pounds according to the invention and can be obtained with
the aid of process (a) or (c) according to the invention.
Le A 25 438
- g _
~~40~0~
Formula (III) provides a general definition of
the acylating agents which are also required as starting
compounds for carrying out process (b) according to the
invention. In this formula (III>, R6 preferably stands
for those radicals which have already been mentioned in
connection with the description of the substances of the
formula (I) according to the invention as being preferred
for this substituent.
A preferably stands for halogen, especially for
chlorine or bromine, or for a radical R6-C-0-,
II
0
where
R6 has the abovementioned meaning.
The acylating agents of the formula (III) are
generally known compounds of organic chemistry.
Formula (Iy) provides a general definition of the
1-arylpyrazoles which are required as starting compounds
for carrying out process (c) according to the invention.
In this formula (Iy>, R2, R3, R4 and R5 preferably stand
for those radicals which have already been mentioned in
connection with the description of the substances of the
formula (I) according to the invention as being preferred
for these substituents.
The 1-arylpyrazoles of the formula (Iy) are com-
pounds according to the invention and can be obtained with
the aid of process (a) or (b> according to the invention.
Suitable diluents for carrying out process (a)
according to the invention are customary organic solvents.
Alcohols, such as, for example, methanol, ethanol or pro-
panol, or mixtures thereof with water, are preferably
used.
When carrying out process (a) according to the
invention, the reaction temperatures may be varied within
a relatively wide range. In general, the reaction is car-
ried out at temperatures between 30°C and 150°C, preferably
at temperatures between 50°C and 120°C.
Le A 25 438
- 9 -
For carrying out process (a) according to the
invention, 1.0 to 5.0 mot, preferably 1.5 to 3.0 mot, of
sodium hydroxide are generally employed per mot of N-aryl-
N'-cyanoethylhydrazine of the formula (II). In a suitable
diluent, the reaction components are heated for several
hours at the reaction temperature necessary, and the
reaction is monitored by means of thin-layer chromato-
graphy. Working-up and isolation of the reaction pro-
ducts of the formula (Ia> is carried out by generally
customary methods.
Suitable diluents for carrying out process (b)
according to the invention are inert organic solvents.
These include, in particular, aliphatic, alicyclic or aro-
matic, optionally halogenated hydrocarbons, such as, for
example, benzine, benzene, toluene, xylene, chlorobenzene,
petroleum ether, hexane, cyclohexane, dichloromethane,
chloroform or carbon tetrachloride, ethers, such as di-
ethyl ether, dioxane, tetrahydrofuran, ethylene glycol
dimethyl ether or ethylene glycol diethyl ether, ketones,
such as acetone or butanone, nitrites, such as aceto-
nitrile or propionitrile, amides, such as dimethylform-
amide, dimethylacetamide, N-methylformanilide, N-methyl-
pyrrolidone or hexamethylphosphoric triamide, esters,
such as ethyl acetate, or sulphoxides, such as dimethyl
sulphoxide.
If appropriate, process (b) according to the
invention is carried out in the presence of a suitable
acid-binding agent. Suitable as such are all customary
inorganic or organic bases. These include, for example,
alkali metal hydroxides, such as sodium hydroxide or
potassium hydroxide, alkali metal carbonates, such as
sodium carbonate, potassium carbonate or sodium bicarbon-
ate, and also tertiary amines, such as triethylamine,
N,N-dimethylaniline, pyridine, N,N-dimethylaminopyridine,
diazabicyclooctane (DABCO), diazabicyclononene (DBN) or
diazabicycloundecene (DBU).
Le A 25 438
- 10 -
1~~~~0~
When carrying out process (b) according to the
invention, the reaction temperatures may be varied within
a relatively wide range. In general, the reaction is
carried out at temperatures between -20°C and 120°C,
preferably at temperatures between 0°C and 80°C.
For carrying out process (b) according to the
invention, 1.0 to 3.0 mol, preferably 1.0 to 1.5 mol, of
acylating agent of the formula (III) and, where appro-
priate, 1.0 to 3.0 mol, preferably 1.0 to 1.5 mol, of
acid-binding agent are generally employed per mol of
1-arylpyrazole of the formula (Iz). The reaction is
carried out and the reaction products are worked up and
isolated by generally customary methods.
Suitable nitrating agents for carrying out pro-
cess (c) according to the invention are all customary
nitrating agents. Concentrated nitric acid or nitrating
acid is preferably used.
Suitable diluents for carrying out process (c)
according to the invention are all solvents which can con-
ventionally be used for electrophilic substitutions of this
type. The acids or mixtures, such as, for example nitric
acid or nitrating acid, which are suitable reactants are
preferably used simultaneously as diluent. If approp-
riate, inert organic solvents, such as, for example,
glacial acetic acid or chlorinated hydrocarbons, such as
methylene chloride, chloroform or carbon tetrachloride,
are also suitable diluents.
Suitable catalysts or reaction auxiliaries for
carrying out process (c) according to the invention are
likewise catalysts which are customary for reactions of
this type; acid catalysts, such as, for example, sulphuric
acid, iron-III chloride or other Lewis acids, or acetic
anhydride, are preferably used.
When carrying out process (c) according to the
invention, the reaction temperatures may be varied within
a relatively wide range. In general, the reactions are
Le A 25 438
- 11 -
13~060~
carried out between -50°C and +200°C, preferably between
-20°C and +150°C.
For carrying out process (c) according to the
invention, 1.0 to 10.0 mol, preferably 1.0 to S.0 mol, of
nitrating agent and, where appropriate, 0.1 to 10 mol of
catalyst or reaction auxiliary are generally employed per
mol of 1-aryl-pyrazole of the formula (Iy). The reaction
is carried out and the reaction products of the formula
(Ic) are worked up and isolated in a generally customary
manner. Depending on the acid concentration, type of
diluent chosen, reaction temperature and duration of the
reaction, any acyl groups which may be present on the
amino substituent in the 5-position of the pyrazole ring
may either be retained or eliminated, in the course of the
nitration reaction (in this context, see also the pre-
paration examples).
The active compounds according to the invention
can be used as defoliants, desiccants, agents for des-
troying broad-leaved plants and, especially, as weed-
killers. By weeds, in the broadest sense, there are to
be understood all plants which grow in locations where
they are undesired. Whether the substances according to
the invention act as total or selective herbicides depends
essentially on the amount used.
The active compounds according to the invention
can be used, for example, in connection with the follow-
ing plants:
Dicotyledon weeds of the genera: Sinapis, Lepidium,
Galium, Stellaria, Matricaria, Anthemis, Galinsoga, Cheno-
podium, Urtica, Senecio, Amaranthus, Portulaca, Xanthium,
Convolvulus, Ipomoea, Polygonum, Sesbania, Ambrosia,
Cirsium, Carduus, Sonchus, Solanum, Rorippa, Rotala,
Lindernia, Lamium, Veronica, Abutilon, Emex, Datura,
Viola, Galeopsis, Papaver and Centaurea.
Dicotyledon cultures of the genera: Gossypium, Glycine,
Beta, Daucus, Phaseolus, Pisum, Solanum, Linum, Ipomoea,
Le A 25 438
- 12 -
~.3~(~~~~
Vicia, Nicotiana, Lycopersicon, Arachis, 8rassica, Lac-
tuca, Cucumis and Cucurbita.
Monocotyledon weeds of the genera: Echinochloa, Setaria,
Panicum, Digitaria, Phleum, Poa, Festuca, Eleusine, Bra-
chiaria, Lolium, Bromus, Avena, Cyperus, Sorghum, Agro-
pyron, Cynodon, Monochoria, Fimbristylis, Sagittaria,
Eleocharis, Scirpus, Paspalum, Ischaemum, Sphenoclea,
Dactyloctenium, Agrostis, Alopecurus and Apera.
Monocotyledon cultures of the genera: Oryza, Zea, Triti-
cum, Hordeum, Avena, Secale, Sorghum, Panicum, Saccharum,
Ananas, Asparagus and Allium.
However, the use of the active compounds accord-
ing to the invention is in no way restricted to these
genera, but also extends in the same manner to other
plants.
The compounds are suitable, depending on the con-
centration, for the total combating of weeds, for example
on industrial terrain and rail tracks, and on paths and
squares with or without tree plantings. Equally, the
compounds can be employed for combating weeds in peren-
nial cultures, for example afforestations, decorative
tree plantings, orchards, vineyards, citrus groves, nut
orchards, banana plantations, coffee plantations, tea
plantations, rubber plantations, oil palm plantations,
cocoa plantations, soft fruit plantings and hopfields,
and for the selective combating of weeds in annual
cultures.
The active compounds according to the invention
can be employed with particularly good success for the
selective combating of dicotyledon weeds in monocotyledon
and dicotyledon cultures, such as, for example, wheat,
maize, rice or soybean.
At suitable application rates, the active com-
pounds according to the invention furthermore have a
plant growth-regulating action, and can be employed, for
example, as defoliants.
Le A 25 438
- 13 -
The active compounds can be converted into the
customary formulations, such as solutions, emulsions,
wettable powders, suspensions, powders, dusting agents,
pastes, soluble powders, granules, suspension-emulsion
concentrates, natural and synthetic materials impregnated
with active compound, and very fine capsules in polymeric
substances.
These formulations are produced in known manner,
for example by mixing the active compounds with extenders,
that is liquid solvents and/or solid carriers, optionally
with the use of surface-active agents, that is emulsify-
ing agents and/or dispersing agents and/or foam-forming
agents.
In the case of the use of water as an extender,
organic solvents can, for example, also be used as auxi-
liary solvents. As liquid solvents, there are suitable
in the main: aromatics, such as xylene, toluene or alkyl-
naphthalenes, chlorinated aromatics and chlorinated ali-
phatic hydrocarbons, such as chlorobenzenes, chloroethyl-
enes or methylene chloride, aliphatic hydrocarbons, such
as cyclohexane or paraffins, for example petroleum frac-
tions, mineral and vegetable oils, alcohols, such as
butanol or glycol as well as their ethers and esters,
ketones, such as acetone, methyl ethyl ketone, methyl
isobutyl ketone or cyclohexanone, strongly polar solvents,
such as dimethylformamide and dimethyl sulphoxide, as well
as water.
As solid carriers there are suitable: for example
ammonium salts and ground natural minerals, such as kao-
fins, clays, talc, chalk, quartz, attapulgite, montmoril-
lonite or diatomaceous earth, and ground synthetic miner-
als, such as highly disperse silicic acid, alumina and
silicates, as solid carriers for granules there are suit-
able: for example crushed and fractionated natural rocks
such as calcite, marble, pumice, sepiolite and dolomite,
as well as synthetic granules of inorganic and organic
Le A 25 438
- 14 -
~3~:0~~~
meals, and granules of organic material such as sawdust,
coconut shells, maize cobs and tobacco stalks; as emulsi-
fying and/or foam-forming agents there are suitable: for
example non-ionic and anionic emulsifiers, such as poly-
oxyethylene-fatty acid esters, polyoxyethylene-fatty
alcohol ethers, for example alkylaryl polyglycol ethers,
alkylsulphonates, alkylsulphates, arylsulphonates as well
as albumin hydrolysation products; as dispersing agents
there are suitable: for example lignin-sulphite waste
liquors and methylcellulose.
Adhesives such as carboxymethylcellulose and
natural and synthetic polymers in the form of powders,
granules or latices, such as gum arabic, polyvinyl alco-
hol and polyvinyl acetate, as well as natural phospho-
lipids, such as cephalins and lecithins, and synthetic
phospholipids, can be used in the formulations. Further
additives can be mineral and vegetable oils.
It is possible to use colorants such as inorganic
pigments, for example iron oxide, titanium oxide and
Prussian Blue, and organic dyestuffs, such as alizarin
dyestuffs, azo dyestuffs and metal phthalocyanine dye-
stuffs, and trace nutrients such as salts of iron, man-
ganese, boron, copper, cobalt, molybdenum and zinc.
The formulations in general contain between 0.1
and 95 per cent by weight of active compound, preferably
between 0.5 and 90%.
The active compounds according to the invention,
as such or in the form of their formulations, can also
be used, for combating weeds, as mixtures with known
herbicides, finished formulations or tank mixes being
possible.
Suitable components for the mixtures are known
herbicides, such as, for example, 1-amino-6-ethylthio-
3-(2,2-di-methylpropyl)-1,3,5-triazine-2,4(1H,3H>-dione
or N-(2-benzthiazolyl)-N, N'-dimethylurea for combating
weeds in cereals; 4-amino-3-methyl-6-phenyl-1,2,4
Le A 25 438
- 15 -
13~060~
triazin-5(4H)-one for combating weeds in sugar beet, and
4-amino-6-(1,1-dimethylethyl)-3-methylthio-1,2,4-triazin-
5(4H)-one for combating weeds in soybeans. Where appro-
priate, mixtures with 2,4-dichlorophenoxyacetic acid;
2,4-dichlorophenoxypropionic acid; 4-(2,4-dichlorophenoxy)-
butyric acid; (2-methyl-4-chlorophenoxy>-acetic acid; (4-
chloro-2-methylphenoxy)-propionic acid; 3,5,6-trichloro-2-
pyridyloxyacetic acid; 2-C4-(2,4-dichlorophenoxy)-phen-
oxyJ-propionic acid, its methyl ester or its ethyl ester;
2-{4-C(6-chloro-2-benzoxazolyl)-oxyJ-phenoxy~-propanoic
acid, its methyl ester or its ethyl ester; butyl 2-C4-(5-
trifluoromethyl-2-pyridinyloxy)-phenoxyJ-propanoate;
trimethylsilylmethyl 2-C4-(3,5-dichloropyrid-2-yloxy>-
phenoxyJ-propionate; 2-~-4-C(3-chloro-5-(trifluoromethyl)-
2-pyridinyl>-oxyJ-phenoxy?-propanoic acid, or ethyl 2-~-4-
C(3-chloro-5-(trifluoromethyl)-2-pyridinyl>-oxyJ-phenoxy~-
propanoate; 3,6-dichloro-2-pyridinecarboxylic acid; 2,6-
diethyl-N-(methoxymethyl)chloroacetanilide; N-(butoxy-
methyl)-2-chloro-N-(2,6-diethylphenyl)-acetamide; 2-
chloro-N-(2,6-dimethylphenyl)-N-C(1H)-pyrazol-1-yl-
methylJ-acetamide; 2-ethyl-6-methyl-N-(1-methyl-2-meth-
oxyethyl)-chloroacetanilide; a-chloro-2',6'-diethyl-N-C2-
propoxyethyl>-acetanilide; 2-chloro-N-isopropylacet-
anilide; 4-(di-n-propylamino>-3,5-dinotrobenzenesulphon-
amide; N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitroaniline;
2,6-dinitro-4-trifluoromethyl-N,N-dipropylaniline; 5-(2-
chloro-4-trifluoromethyl-phenoxy)-2-nitro-benzoic acid;
methyl 5-(2,4-dichlorophenoxy)-2-nitrobenzoate; 5-(2-
chloro-4-trifluoromethyl-phenoxy)-N-methylsulphonyl-2-
nitrobenzamide; 2-ethoxy-1-methyl-2-oxo-ethyl 5-C2-
chloro-4-(trifluoromethyl)-phenoxy7-2-nitrobenzoate;
N,N-dimethyl-N'-(3-chloro-4-methylphenyl)-urea; N,N-
dimethyl-N'-(4-isopropylphenyl)-urea; 2-C1-(ethoximino)-
butylJ-3-hydroxy-5-Ctetrahydro-(2H)-thiopyran-3-ylJ-2-
cyclohexen-1-one; 2-C1-Cethoxamino)-butylideneJ-5-(2-
ethylthiopropyl)-1,3-cyclohexadione; 2-C4,5-dihydro-4-
Le A 25 438
- 16 -
13400?
methyl-4-isopropyl-5-oxo-(1H)-imidazol-2-ylJ-5-ethyl-
pyridine-3-carboxylic acid; methyl 2-C4,5-dihydro-4-
methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-ylJ-4(5>-
methylbenzoate; 2-C5-methyl-5-(1-methylethyl>-4-oxo-2-
imidazolin-2-yll-3-quinolinecarboxylic acid; 3,5-dibromo-
4-hydroxy-benzonitrile; 3,5-diiodo-4-hydroxybenzonitrile;
N-methyl-2-(1,3-benzothiazol-2-yloxy)-acetanilide;
methyl 2-CCCCC(4,6-dimethoxypyrimidin-2-yl)-aminoJ-
carbonylJ-aminoJ-sulphonylJ-methylJ-benzoate; ethyl 2-
~C(4-chloro-6-methoxy-2-pyrimidinyl)-aminocarbonylJ-
aminosulphonyl?-benzoate; 2-chloro-N-~C(4-methoxy-6-
methyl-1,3,5-triazin-2-yl)-aminoJ-carbony l-benzene-
sulphonamide; 2-ACC((4-methoxy-6-methyl-1,3,5-triazin-
2-yl)-amino)-carbonylJ-amino7-sulphonyl?-benzoic acid or
its methyl ester; methyl 2-~C(4,6-dimethyl-2-pyrimidinyl)-
aminocarbonylJ-aminosulphonyl?-benzoate; methyl 3-CCCC(4-
methoxy-6-methyl-1,3,5-triazin-2-yl)-aminoJ-carbonylJ-
aminoJ-sulphonylJ-thiophene-2-carboxylate; S-ethyl N,N-
di-n-propyl-thiocarbamate; S-ethyl N,N-hexamethylene-
thiolcarbamate; S-C(4-chlorophenyl>-methyl) N,N-diethyl-
thiocarbamate; S-(2,3,3-trichloroallyl) N,N-diisoproyl-
thiolcarbamate; 2-chloro-4-ethylamino-6-isopropylamino-
1,3,5-triazine; 2-chloro-4-ethylamino-6-(3-cyanopropyl-
amino)-1,3,5-triazine; 2,4-bis-CN-ethyl-amino)-6-methyl-
thio-1,3,5-triazine; 4-ethylamino-2-t-butylamino-6-
methylthio-s-triazine; 4-amino-6-t-butyl-3-ethylthio-
1,2,4-triazin-5(4H)-one; 3-isopropyl-2,1,3-benzothia-
diazin-4-one 2,2-dioxide; exo-1-methyl-4-(1-methylethyl)-
2-(2-methylphenyl-methoxy)-7-oxabicyclo-(2,2,1)-heptane
and 0-(6-chloro-3-phenyl-pyridazin-4-yl) S-octyl thio-
carbonate are advantageous.
Some mixtures surprisingly also exhibit a syner-
gistic effect.
Mixtures with other known active compounds, such
as fungicides, insecticides, acaricides, nematicides, bird
repellents, plant nutrients and agents which improve soil
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~.3~~~J
structure, are also possible.
The active compounds can be used as such, in the
form of their formulations or in the use forms prepared
therefrom by further dilution, such as ready-to-use solu-
tions, suspensions, emulsions, powders, pastes and gran-
ules. They are used in the customary manner, for example
by watering, spraying, atomizing or scattering.
The active compounds according to the invention can
be applied either before or after emergence of the plants.
They can also be incorporated into the soil before sowing.
The amount of active compound used can vary within
a substantial range. It depends essentially on the nature
of the desired effect. In general, the amounts used are
between 0.01 and 10 kg of active compound per hectare of
soil surface, preferably between 0.05 and 5 kg per ha.
The preparation and use of the active compounds
according to the invention are evident from the examples
which follow.
Preparation Examples
Example 1
NON NH2
C1 ~ C1
i
CHF2
(Process a)
29.8 g (0.1 mol) of N-(2,6-dichloro-4-trifluoro-
methylphenyl)-N'-(2-cyanoethyl)-hydrazine in 200 ml of
ethanol are heated at the reflux temperature for 2 hours
together with 18 g (0.2 mol) of 45% strength technical
grade sodium hydroxide solution. After the reaction has
ended (monitor by thin-layer chromatography; dichloro-
methane/methanol 19 . 1), the mixture is evaporated in
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~~~ooo~
vacuo, the residue is taken up in dichloromethane/water,
the organic phase is separated off, washed with water and
dried over sodium sulphate, and the solvent is removed in
vacuo. After recrystallization from 500 ml of toluene,
16 g (58% of theory) of 5-amino-1-(2,6-dichloro-4-di-
fluoromethylphenyl)-pyrazole of melting point 110°C -
111°C are obtained.
19F-NMR (CDCl3) . a= 34.3 (d, 2F) ppm.
Example 2
NON ~NH-C-CH3
C1 I ~ C1
CHF2
(Process b)
2 ml (0.021 mol) of acetic anhydride are added
dropwise to 5.56 g (0.02 mol) of S-amino-1-(2,6-dichloro-
4-difluoromethylphenyl)-pyrazole in 40 ml of toluene at
20°C with stirring, the mixture is stirred for a further
16 hours at room temperature after the addition has
ended, the precipitate formed is filtered off with
suction, and the residue is dried.
5.4 g (84% of theory) of 5-acetamido-1-(2,6
dichloro-4-difluoromethylphenyl)-pyrazole of melting
point 209°C - 211°C are obtained.
Example 3
02
T1~N NH2
C1 ~ C1
i
CHF2
(Process c)
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134~b02
1.07 ml of 98% strength nitric acid are added drop-
wise with stirring to 4.8 g (0.015 mol) of 5-acetamido-1-(2,6-
dichloro-4-difluoromethylphenyl)-pyrazole in 40 ml of concent-
rated sulphuric acid at -20°C, the mixture is stirred for 4
hours at 20°C after the addition has ended, the reaction mix-
ture is poured onto ice, the precipitated solid is filtered
off with suction and dissolved in dichloromethane, and the
solution is washed once each with water and with aqueous
sodium bicarbonate solution and dried over sodium sulphate,
and the solvent is removed in vacuo.
4.0 g (83% of theory) of S-amino-1-(2,6-dichloro-
4-difluoromethylphenyl)-4-vitro-pyrazole of melting point
165°C - 168°C are obtained.
The following 1-arylpyrazoles of the general
formula (I)
CHF2
_R2
(I)
are obtained in a corresponding manner and according to
the general data for the preparation:
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1~~Q60
Table 1
Example R1 R2 R3 R4 R5 Melting
No. point
4 H H C1 C1 C1 1H-NMR*):
5.2; 5.4;
7.25; 7.35;
7.9
O
5 H -C-CHC12 C1 C1 H 91-92
0
6 N02 -C-CHC12 C1 Cl N 104-106
Ci
7 N02 -CO-CH-CH3 C1 C1 H 107-113
8 N02 -CO-CH3 C1 C1 H 1H-NMR*):
8.35
C1
9 N02 -CO-CH-C2H5 C1 C1 H 79-87
*) The 1H-NMR spectrum was recorded hexa deutero-
in
dimethyl sulphoxide MSO-d6) ng tramethyl-
(D usi te
silane (T MS) as the ternal standard.The chemical
in
shift is given as the a-value ppm.
in
Preparation the starting compounds
of
Example II-1
C1
F3C / NH-NH-CH2-CH2-CN
Cl
24.5 g (0.1 mol) of 2,6-dichloro-4~r~fluoro
methyl-phenylhydrazine and 6 g (0.11 mol> of acrylo-
nitrile are heated at the reflux temperature for 4 days
in 100 ml of ethanol. After the volatile constituents
have been removed in vacuo, 30 g (99% of theory) of N-
(2,6-c~ichloro-4-trifluoromethylphenyl)-rT-(2-cvanoethyl)-
hydrazine are obtained as an oil.
1H-NMR (CDCl3/TMS): a = 2.55; 3.1; 4.55; 6.0; 7.55 ppm.
In a corresponding manner,
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1340~0~
Example II-2:
C1
F3C ~ NH-NH-CH2-CH2-CN
C1 C1
melting point 47°C - 49°C
is obtained.
Use Examples
In the following use examples, the compound
shown below was used as the comparison substance:
C2
N\N NH2
C1 ~ C1 (A)
CF3
5-amino-1-(2,6-dichloro-4-trifluoromethylphenyl)-4
nitropyrazole (known from EP 154,115/ Example No. 50).
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i~~ooo~
Example A
Pre-emergence test
Solvent: 5 parts by weight
Emulsifier: 1 part by weight of alkylaryl polyglycol ether
To produce a suitable preparation of active com-
pound, 1 part by weight of active compound is mixed with
the stated amount of solvent, the stated amount of emul-
sifier is added and the concentrate is diluted with water
to the desired concentration.
Seeds of the test plants are sown in normal soil
and, after 24 hours, watered with the preparation of the
active compound. It is expedient to keep constant the
amount of water per unit area. The concentration of the
active compound in the preparation is of no importance,
only the amount of active compound applied per unit area
being decisive. After three weeks, the degree of damage
to the plants is rated in X damage in comparison to the
development of the untreated control. The figures
denote:
0% = no action (like untreated control)
100% - total destruction
In this test, a significant superiority in the
crop plant selectivity over comparison substance (A) with
comparable herbicidal activity is shown in this test by,
for example, the compounds of the following Preparation
Examples:3, 6 and 7.
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. 134000
Example B
Post emergence test
Solvent: S parts by weight of acetone
Emulsifier: 1 part by weight of alkylaryl polyglycol ether
To produce a suitable preparation of active com-
pound, 1 part by weight of active compound is mixed with
the stated amount of solvent, the stated amount of emulsi-
fier is added and the concentrate is diluted with water to
the desired concentration.
Test plants which have a height of S - 15 cm are
sprayed with the preparation of the active compound in such
a way as to apply the particular amounts of active compound
desired per unit area. The concentration of the spray
liquor is so chosen that the particular amounts of active
compound desired are applied in 2,000 l of water/ha. After
three weeks, the degree of damage to the plants is rated in
% damage in comparison to the development of the untreated
control. The figures denote:
0% - no action (like untreated control)
100% - total destruction
In this test, a significant superiority in the
crop plant selectivity over comparison substance (A) with
comparable herbicidal activity is shown in this test by,
for example, the compounds of the following Preparation
Examples: 3 and 6.
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