Note: Descriptions are shown in the official language in which they were submitted.
1 338985
_ o.z. 0050/39798 Cyclohexenone compounds, their preparation and their
use for controlling undesirable plant growth
The present invention relates to cyclohexenone
compounds of the formula I
OH ~OR 1
\
O R2
where R1 is C3- or C~-alkenyl, C3- or C4-alkynyl, C2-C4-
haloalkyl, C2-C~-haloalkenyl, C2-C4-alkoxyalkyl or CH2-R3,
R3 is a 5-membered heterocyclic ring which has 1 to 3
nitrogen atoms and/or 1 or 2 oxygen atoms and/or a sulfur
atom as heteroatoms and not more than 2 double bonds and
may carry one or two of the substituents Cl-C4-alkyl, C1-
C4-alkoxy, C1-C~-alkylthio, halogen, trifluoromethyl, C1-
C~-alkoxymethyl, Cl-C~-alkylthiomethyl and/or vinyl or a
phenyl radical which may carry one to three of the groups
C1-C~-alkyl, C1-C4-alkoxy, C1-C~-alkylthio, halogen, tri-
fluoromethyl, nitro and/or C1-C~-dialkylamino, and R2 is
C1-C4-alkyl, and their agriculturally acceptable salts.
The present invention furthermore relates to a
proce~s for the preparation of these compounds and
method~ for controlling undesirable plant growth using
agents which contain the compound~ I.
The compounds I may occur in a plurality of taut-
omeric and stereoisomeric ( E and Z isomerism) forms, all
of which are embraced by the claim.
The literature describes 3-hydroxy-2-cyclohexen-
l-ones which carry a substituted phenyl radical in the 5-
position and are suitable for controlling undesirable
gras~es in broad-leaved crops (DE-A 24 39 104). Phenyl-
substituted cyclohexenone compounds, which are used for
controlling gras~ weeds in crops such as corn, wheat,
barley and rice are also disclosed ( DE-A 32 48 554, DE-A
33 29 017 and DE-A 30 47 924).
It is an ob~ect of the present invention to pro-
vide compound~ which have high selectivity at a low
application rate, ie. control undesirable plants without
1 338985
- 2 - o.z. 0050/39798
damaging the crops.
We have found that this ob~ect is achieved by the
cyclohexenone compounds defined at the outset.
The cyclohexenones of the formula I can be ob-
tAine~ in a known manner from known raw materials; forexample, the corresponding cyclohexenone of the formula
II
OH ,9
~R2 II
can be reacted with a hydroxylamine RlONH2.
Advantageously, the reaction is carried out in
the heterogeneous phase in a solvent at not more than
80C in the presence of a base, and the hydroxylamine
source used is the ammonium compound of the said hydroxy-
lamine.
Examples of suitable bases are carbonates, bi-
carbonates, acetates, alcoholates or oxides of alkali
metals or alkaline earth metals, in particular sodium
hydroxide, potassium hydroxide, magnesium oxide or cal-
cium oxide. Organic bases, ~uch as pyridine or tertiary
amines, can also be used. The base is added, for exam-
ple, in an amount of from 0.5 to 2 moles, based on the
ammonium compound (DE-A-34 33 767).
Examples of suitable solvents are dimethyl sul-
foxide, alcohols, such as methanol, ethanol and iso-
propanol, aromatic hydrocarbons, such as benzene and tol-
uene, chlorohydrocarbons, such as chloroform and di-
chloroethane, aliphatic hydrocarbons, such as hexane and
cyclohex~ne, esters, such as ethyl acetate, and ethers,
such as dioxane and tetrahydrofuran.
The reaction is complete after a few hours, and
the end product can be isolated by evaporating down the
mixture, distributing the residue in methylene chloride/
water and distilling off the solvent under reduced
1 338985
- 3 - o.z. 0050/39798
pressure.
It is also possible to use the free hydroxylamine
base directly, for example in the form of an aqueous
solution; dep~n~ing on the solvent used for the other
5reactant, a one-phase or two-phase reaction mixture is
obtA i n~
Examples of suitable solvents for this reaction
are alcohols, such as methanol, ethanol, isopropanol and
cycloh~YAnol, aliphatic and aromatic hydrocarbons and
10chlorohydrocarbons, such as heYAne~ cycloheYAn~, meth-
ylene chloride, toluene and dichloroethane, esters, such
as ethyl acetate, nitriles, such as acetonitrile, and
cyclic ethers, such as tetrahydrofuran.
Alkali metal salts of the compounds I can be ob-
15tA i n~ by treating the 3-hydroxy compounds with sodium
hydroxide, potassium hydroxide, a sodium alcoholate or a
potassium alcoholate in aqueous solution or in an organic
solvent, such as methanol, ethanol, acetone or toluene.
Other metal salts, for example the manganese,
20copper, zinc, iron, calcium, magnesium and barium salts,
can be prepared from sodium salts in a conventional man-
ner, as can ammonium, phosphonium, sulfonium and sulfox-
onium salts by using ammonia or phosphonium, sulfonium or
sulfoxonium hydroxides.
25The compounds of type II can be prepared, for
example, from the corresponding cycloheYAne-1,3-diones of
the formula III
OH
III
Y O
where Y is hydrogen or methoxycarbonyl, by known methods
30[Tetrahedron Lett. (1975), 2491].
It is also possible to prepare the compounds of
the formula II via the enolester intermediates, which are
obtAineA in the reaction of compounds of the formula III
with acyl chlorides in the presence of a base and are
1 33898S
- 4 - o.z. 0050/39798
then sub~ected to a rearrangement reaction with certain
imidazole or pyridine derivatives (JApAne~e Preliminary
Published Application 79/063052).
OH O--C--R 2 OH
A~--(R2COCI A ~< ll A ~ O
R 2
r o Y o Y o
III II
Compounds of the formula I are obtained using
known, commercial compounds are starting materials and by
a number of known process steps, as shown in the scheme
below and illustrated by a practical example.
~0 ~ceton~ ~J~ CH2Y (C02CH3) _~OH
NaOH NaOCH3
I I I
OH O 3 ~ OH 1`~--OR I
R2COCI ,~_</ R10--NH3Y ,~</
O R2 R2
II I
Because of the biological activity, preferred
cyclohexenone compounds I are those in which the radicals
have the following meanings:
Rl is alkenyl, such as allyl, buten-2-yl, buten-3-yl and
2-methylbuten-2-yl, in particular allyl and buten-2-yl,
alkynyl, such as prop-2-ynyl, but-2-ynyl, but-3-ynyl and
l-methylprop-2-ynyl, in particular prop-2-ynyl and but-
2-ynyl; haloalkyl, such as l-fluoroethyl, 2-fluoroethyl,
2,2-difluoroethyl, 2,2,2-trifluoroethyl, 2-chloro-2,2-
difluoroethyl, 2,2-dichloro-2-fluoroethyl, 2,2,2-tri-
chloroethyl and pentafluoroethyl, in particular 2-chloro-
ethyl, 2-fluoroethyl, 2,2,2-trifluoroethyl and penta-
fluoroethyl; haloalkenyl, such as 2-chloroprop-2-enyl, 3-
chloroprop-2-enyl or 3,3,2-trichloroprop-2-enyl, in par-
icular 3-chloroprop-2-enyl; alkoxyalkyl, such as methoxy-
methyl, ethoxymethyl, methoxyethyl and ethoxyethyl, in
1 338985
- 5 - o.z. 0050/39798
particular methoxyethyl and ethoxyethyl; phenyl which may
carry one to three of the following substituents: nitro,
trifluoromethyl, halogen, such as fluorine, chlorine,
bromine or iodine, in particular fluorine or chlorine,
alkyl, such as methyl, ethyl, propyl, l-methyl-ethyl,
butyl, l-methylpropyl, 2-methylpropyl or 1,1-di-methyl-
ethyl, in particular methyl or ethyl, alkoxy, such as
methoxy, ethoxy, propoxy, l-methylethoxy, butoxy, 1-
methylpropoxy, 2-methylpropoxy or 1,1-dimethylethoxy, in
particular methoxy or l-methylethoxy, alkylthio, such as
methylthio, ethylthio, propylthio, l-methylethylthio,
butylthio, l-methylpropylthio, 2-methylpropylthio or 1,1-
dimethylethylthio, in particular methylthio or ethylthio
and/or dialkylamino, such as dimethylamino, ethylmethyl-
amino or dimethylamino, in particular dimethylamino, or
a radical -CH2-R3, where R3 is tetrahydrofuranyl, tetra-
hydrothiophenyl, dioxolanyl, dithiolanyl, oxathiolanyl,
dihydrofuranyl, dihydrothienyl, pyrrolinyl, pyrazolinyl,
imidazolinyl, isoxazolinyl, oxazolinyl, isothiazolinyl,
thiazolinyl, furanyl, thienyl, pyrrolyl, pyrazolyl,
isoxazolyl, oxazolyl, isothiazolyl, thiazolyl, oxadiazol-
yl, thiA~iAzolyl~ imidazolyl, oYA~iAzolyl, thiodiazolyl
or triazolyl, in particular thiophenyl or isoxazolyl, and
this heterocyclic structure may carry one or two of the
following substituents: C1-C4-alkyl as stated above, in
particular methyl, ethyl or isopropyl, Cl-C4-alkoxy as
stated above, in particular methoxy, ethoxy or isoprop-
oxy, C1-C~-alkylthio as stated above, in particular
methylthio or ethylthio, halogen as stated above, in
particular fluorine or chlorine, alkoxymethyl, such as
methoxymethyl, ethoxymethyl, propoxymethyl, isopropoxy-
methyl, butoxymethyl, l-methylpropoxymethyl, 2-methyl-
propoxyethyl or l,l-dimethylethoxymethyl, in particular
methoxyethyl or ethoxymethyl, alkylthiomethyl, such as
methylthiomethyl, ethylthiomethyl, propylthiomethyl,
isopropylthiomethyl,butylthiomethyl,l-methylpropylthio-
methyl, 2-methylpropylthiomethyl or l,l-dimethylethyl-
1 338985
.
6 O.Z. 0050/39798
thiomethyl, in particular methylthiomethyl or ethylthiomethyl, trifluoro-
methyl and/or vinyl, and R2 is C1-C4-alkyl, such as methyl, ethyl, propyl,
l-methylethyl, butyl, l-methylpropyl, 2-methylpropyl or l,l-dimethylethyl,
in particular ethyl or propyl.
Suitable salts of the compounds of the formula I are agriculturally
acceptable salts, for example alkali metal salts, in particular potassium
salts or sodium salts, alkaline earth metal salts, in particular calcium
salts, and also manganese salts, copper salts, zinc salts, iron salts and
10 ammonium, tetraalkylammonium, benzyltrialkylammonium, trialkylsulfoxonium
and trialkylsulfonium salts.
The cyclohexenones, or the herbicidal agents containing them, may be
applied for instance in the form of directly sprayable solutions, powders,
15 suspensions (including high-percentage aqueous, oily or other suspen-
sions), dispersions, emulsions, oil dispersions, pastes, dusts, broadcast-
ing agents, or granules by spraying, atomizing, dusting, broadcasting or
watering. The forms of application depend entirely on the purpose for
which the agents are being used, but they must ensure as fine a distribu-
20 tion of the active ingredients according to the invention as possible.
For the preparation of solutions, emulsions, pastes and oil dispersions tobe sprayed direct, mineral oil fractions of medium to high boiling point,
such as kerosene or diesel oil, further coal-tar oils, and oils of vege-
25 table or animal origin, aliphatic, cyclic and aromatic hydrocarbons suchas benzene, toluene, xylene, paraffin, tetrahydronaphthalene, alkylated
naphthalenes and their derivatives such as methanol, ethanol, propanol,
butanol, chloroform, carbon tetrachloride, cyclohexanol, cyclohexanone,
chlorobenzene, isophorone, etc., and strongly polar solvents such as
30 dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, water, etc.
are suitable.
Aqueous formulations may be prepared from emulsion concentrates, pastes,
dispersions, wettable powders or water-dispersible granules by adding
35 water. To prepare emulsions, pastes and oil dispersions the ingredients as
such or dissolved in an oil or solvent may be homogenized in water by
means of wetting or dispersing agents, adherents or emulsifiers. Concen-
trates which are suitable for dilution with water may be prepared from
active ingredient, wetting agent, adherent, emulsifying or dispersing
40 agent and possibly solvent or oil.
Examples of surfactants are: alkali metal, alkaline earth metal and
ammonium salts of ligninsulfonic acid, naphthalenesulfonic acids,
phenolsulfonic acids, alkylaryl sulfonates, alkyl sulfates, and alkyl
1 338985
7 O.z. 0050/39798
sulfonates, alkali metal and alkaline earth metal salts of dibutyl-
naphthalenesulfonic acid, lauryl ether sulfate, fatty alcohol sulfates,
alkali metal and alkaline earth metal salts of fatty acids, salts of
sulfated hexadecanols, heptadecanols, and octadecanols, salts of sulfated
5 fatty alcohol glycol ethers, condensation products of sulfonated
naphthalene and naphthalene derivatives with formaldehyde, condensation
products of naphthalene or naphthalenesulfonic acids with phenol and
formaldehyde, polyoxyethylene octylphenol ethers, ethoxylated isooctyl-
phenol, ethoxylated octylphenol and ethoxylated nonylphenol, alkylphenol
10 polyglycol ethers, tributylphenyl polyglycol ethers, alkylaryl polyether
alcohols, isotridecyl alcohol, fatty alcohol ethylene oxide condensates,
ethoxylated castor oil, polyoxyethylene alkyl ethers, ethoxylated poly-
oxypropylene, lauryl alcohol polyglycol ether acetal, sorbitol esters,
lignin, sulfite waste liquors and methyl cellulose.
Powders, dusts and broadcasting agents may be prepared by mixing or
grinding the active ingredients with a solid carrier.
Granules, e.g., coated, impregnated or homogeneous granules, may be
20 prepared by bonding the active ingredients to solid carriers. Examples of
solid carriers are mineral earths such as silicic acid, silica gels,
silicates, talc, kaolin, attapulgus clay, limestone, lime, chalk, bole,
loess, clay, dolomite, diatomaceous earth, calcium sulfate, magnesium
sulfate, magnesium oxide, ground plastics, fertilizers such as ammonium
25 sulfate, ammonium phosphate, ammonium nitrate, and ureas, and vegetable
products such as grain flours, bark meal, wood meal, and nutshell meal,
cellulosic powders, etc.
The formulations contain from 0.1 to 95, and preferably 0.5 to 90, % by30 weight of active ingredient.
The cyclohexenone compounds may be formulated for instance as follows:
I. 90 parts by weight of compound no. 1 is mixed with 10 parts by weight
35 of N-methyl-alpha-pyrrolidone. A mixture is obtained which is suitable for
application in the form of very fine drops.
II. 20 parts by weight of compound no. 1 is dissolved in a mixture con-
sisting of 80 parts by weight of xylene, 10 parts by weight of the adduct
40 of 8 to 10 moles of ethylene oxide and 1 mole of oleic acid-N-monoethanol-
amide, 5 parts by weight of the calcium salt of dodecylbenzenesulfonic
acid, and 5 parts by weight of the adduct of 40 moles of ethylene oxide
and I mole of castor oil. By pouring the solution into 100,000 parts by
weight of water and uniformly distributing it therein, an aqueous disper-
sion is obtained containing 0.02% by weight of the active ingredient.
1 338985
8 O.Z. 0050/39798
III. 20 parts by weight of compound no. 2 is dissolved in a mixture con-
sisting of 40 parts by weight of cyclohexanone, 30 parts by weight of iso-
butanol, 20 parts by weight of the adduct of 7 moles of ethylene oxide and
1 mole of isooctylphenol, and 10 parts by weight of the adduct of 40 moles
5 of ethylene oxide and 1 mole of castor oil. By pouring the solution into
100,000 parts by weight of water and finely distributing it therein, an
aqueous dispersion is obtained containing 0.02% by weight of the active
ingredient.
10 IV. 20 parts by weight of compound no. 8 is dissolved in a mixture con-
sisting of 25 parts by weight of cyclohexanone, 65 parts by weight of a
mineral oil fraction having a boiling point between 210 and 280C, and
10 parts by weight of the adduct of 40 moles of ethylene oxide and 1 mole
of castor oil. By pouring the solution into 100,000 parts by weight of
15 water and uniformly distributing it therein, an aqueous dispersion is
obtained containing 0.02% by weight of the active ingredient.
V. 20 parts by weight of compound no. 3 is well mixed with 3 parts by
weight of the sodium salt of diisobutylnaphthalene-alpha-sulfonic acid,
20 17 parts by weight of the sodium salt of a lignin-sulfonic acid obtained
from a sulfite waste liquor, and 60 parts by weight of powdered silica
gel, and triturated in a hammer mill. By uniformly distributing the
mixture in 20,000 parts by weight of water, a spray liquor is obtained
containing 0.1% by weight of the active ingredient.
VI. 3 parts by weight of compound no. 9 is intimately mixed with 97 parts
by weight of particulate kaolin. A dust is obtained containing 3% by
weight of the active ingredient.
30 VII. 30 parts by weight of compound no. 13 is intimately mixed with a
mixture consisting of 92 parts by weight of powdered silica gel and
8 parts by weight of paraffin oil which has been sprayed onto the surface
of this silica gel. A formulation of the active ingredient is obtained
having good adherence.
VIII. 20 parts of compound no. 12 is intimately mixed with 2 parts of the
calcium salt of dodecylbenzenesulfonic acid, 8 parts of a fatty alcohol
polyglycol ether, 2 parts of the sodium salt of a phenolsulfonic acid-
urea-formaldehyde condensate and 68 parts of a paraffinic mineral oil. A
40 stable oily dispersion is obtained.
The active ingredients may be applied pre- or postemergence. If certain
crop plants tolerate the active ingredients less well, application tech-
1 338985
g O.Z. 0050/39798
niques may be used in which the herbicidal agents are sprayed fromsuitable equipment in such a manner that the leaves of sensitive crop
plants are if possible not touched, and the agents reach the soil or the
unwanted plants growing beneath the crop plants (post-directed, lay-by
5 treatment).
The application rates depend on the objective to be achieved, the time of
the year, the plants to be combated and their growth stage, and are from
0.01 to 3.0, preferably 0.05 to 1.0, kg of active ingredient per hectare.
In view of the number of application methods possible, the compounds
according to the invention, or agents containing them, may be used in a
further large number of crops for removing unwanted plants. The following
crops are given by way of example:
1 338985
O.Z. 0050/39798
Botanical name Common name
Allium cepa onions
Ananas comosus pineapples
Arachis hypogaea peanuts (groundnuts)
5 Asparagus officinalis asparagus
Avena sativa oats
Beta vulgaris spp. altissima sugarbeets
Beta vulgaris spp. rapa fodder beets
Beta vulgaris spp. esculenta table beets, red beets
10 Brassica napus var. napus rapeseed
Brassica napus var. napobrassica swedes
Brassica napus var. rapa turnips
Brassica rapa var. siIvestris
Camellia sinensis tea plants
15 Carthamus tinctorius safflower
Carya illinoinensis pecan trees
Citrus limon lemons
Citrus maxima grapefruits
Citrus reticulata mandarins
20 Citrus sinensis orange trees
Coffea arabica (Coffea canephora,
Coffea liberica) coffee plants
Cucumis melo melons
Cucumis sativus cucumbers
25 Cynodon dactylon Bermudagrass
Daucus carota carrots
Elais guineensis oil palms
Fragaria vesca strawberries
Glycine max soybeans
30 Gossypium hirsutum (Gossypium arboreum,
Gossypium herbaceum, Gossypium vitifolium) cotton
Helianthus annuus sunflowers
Helianthus tuberosus Jerusalem artichoke
Hevea brasiliensis rubber plants
35 Hordeum vulgare barley
Humulus lupulus hops
Ipomoea batatas sweet potatoes
Juglans regia walnut trees
Lactuca sativa lettuce
40 Lens culinaris lentils
Linum usitatissimum flax
Lycopersicon Iycopersicum tomatoes
1 338985
11 O.Z. 0050/39798
Botanical name Common name
Malus spp. apple trees
Manihot esculenta cassava
Medicago sativa alfalfa (lucerne)
5 Mentha piperita peppermint
Musa spp. banana plants
Nicotiana tabacum (N. rustica) tobacco
Olea europaea olive trees
Oryza sativa rice
10 Panicum miliaceum millet
Phaseolus lunatus limabeans
Phaseolus mungo mungbeans
Phaseolus vulgaris snapbeans, green beans,
dry beans
15 Pennisetum glaucum pearl millet
Petroselinum crispum spp. tuberosum parsley
Picea abies Norway spruce
Abies alba fir trees
Pinus spp. pine trees
20 Pisum sativum English peas
Prunus avium cherry trees
Prunus domestica plum trees
Prunus dulcis almond trees
Prunus persica peach trees
25 Pyrus communis pear trees
Ribes sylvestre redcurrants
Ribes uva-crispa gooseberries
Ricinus communis castor-oil plants
Saccharum officinarum sugar cane
30 Secale cereale rye
Sesamum indicum sesame
Solanum tuberosum Irish potatoes
Sorghum bicolor (s. vulgare) sorghum
Sorghum dochna sorgo
35 Spinacia oleracea spinach
Theobroma cacao cacao plants
Trifolium pratense red clover
Triticum aestivum wheat
Triticum durum durum wheat
40 Vaccinium corymbosum blueberries
Vaccinium vitis-idaea cranberries
Vicia faba tick beans
Vigna sinensis (V. unguiculata) cow peas
Vitis vinifera grapes
Zea mays Indian corn, sweet corn,
maize
1 338985
12 O.Z. 0050/39798
To increase the spectrum of action and to achieve synergistic effects, the
cyclohexenones of the formula I may be mixed and applied together with
numerous representatives of other herbicidal or growth-regulating active
ingredient groups. Examples of suitable components are diazines, 4H-3,1-
5 benzoxazine derivatives, benzothiadiazinones, 2,6-dinitroanilines, N-
phenylcarbamates, thiolcarbamates, halocarboxylic acids, triazines,
amides, ureas, diphenyl ethers, triazinones, uracils, benzofuran deriva-
tives, cyclohexane-1,3-dione derivatives, quinolinecarboxylic acids,
phenyloxy- or heteroaryloxy-phenylpropionic acids and salts, esters and
10 amides thereof, etc.
It may also be useful to apply the novel compounds of the formula I,
either alone or in combination with other herbicides, in admixture with
other crop protection agents, e.g., agents for combating pests or phyto-
15 pathogenic fungi or bacteria. The compounds may also be mixed withsolutions of mineral salts used to remedy nutritional or trace element
deficiencies. Non-phytotoxic oils and oil concentrates may also be added.
Manufacturing examples
The directions given in the synthesis examples below were employed, after
appropriate modifications to the starting materials, to obtain further
compounds of the formula I; the compounds obtained are listed in the
tables below with physical data. Those compounds for which no data are
25 given may be produced analogously from the appropriate materials. In view
of their close structural similarity with the compounds produced and
investigated, they are expected to have a similar action.
Example 1
a) 4-(4-Ethylphenyl)-3-buten-2-one
20 ml of 10% strength sodium hydroxide solution is added to a mixture
of 111.4 g (0.83 mol) of 4-ethylbenzaldehyde, 133 9 of acetone and
100 ml of water, and the mixture is stirred overnight at room tempera-
ture. It is then diluted with 300 ml of ice water and extracted five
times, each time with 100 ml of dichloromethane. The extracts are
dried over sodium sulfate and concentrated.
Yield: 144 g of a yellow oil, which is reacted as follows:
1 338985
13 O.Z. 0050/39798
b) 5-(4-Ethylphenyl)-3-hydroxy-2-cyclohexen-1-one
144 g (0.83 mol) of 4-(4-ethylphenyl)-3-buten-2-one dissolved in a
small amount of methanol is dripped into 109 g (0.83 mol) of dimethyl
malonate and 45 g (0.83 mol) of sodium methylate in 40 ml of methanol.
The mixture is stirred at reflux for 3 hours and for 10 hours at room
temperature. The methanol is distilled off, and the residue is taken
up in 2 liters of 10% strength potassium hydroxide solution and
stirred for 8 hours at room temperature. At 60C, the mixture is
acidified to pH 1 with concentrated hydrochloric acid. The mixture is
stirred for a further 2 hours and suction filtered, and the precipi-
tate is dried under reduced pressure.
Yield: 167 g of a yellow solid; m.p. 162 - 164C.
c) 2-Butyryl-5-(4-ethylphenyl)-3-hydroxy-2-cyclohexen-1-one
51 g (0.51 mol) of triethylamine and - with ice cooling - 54 g (0.51
mol) of butyryl chloride are dripped into a solution of 110 g (0.51
mol) of the 5-(4-ethylphenyl)-3-hydroxy-2-cyclohexen-1-one, obtained
in accordance with the foregoing instructions, in 500 ml of tetra-
hydrofuran. After 8 hours at room temperature, the mixture is filtered
and the precipitate is washed with tetrahydrofuran. The filtrate is
concentrated, the residue is taken up in 500 ml of ethyl acetate and
6.2 g of 4-N,N-dimethylaminopyridine is added. The homogeneous solu-
tion is kept for 40 hours at room temperature, is then concentrated
and the residue is taken up in 10% strength potassium hydroxide solu-
tion. The undissolved constituents are separated off, and the fiItrate
is acidified to pH 1. The product which precipitates out is filtered
off and dried under reduced pressure.
Yield: 100 g of a yellow solid; m.p. 60 - 62C.
d) 2-(E)-3-Chloro-2-propenyloxyiminobutyl-5-(4-ethylphenyl)-3-hydroxy-2- cyclohexen-1-one
16.6 g (0.12 mol) of (E)-3-chloro-2-propenyloxyamine hydrochloride and
9.7 g (0.12 mol) of sodium bicarbonate are added to 30 g (0.11 mol) of
the 2-butyryl-5-(4-ethylphenyl)-3-hydroxy-2-cyclohexen-1-one, obtained
in accordance with the foregoing instructions, in 300 ml of methanol,
and the solution is stirred overnight at room temperature. After con-
centration, the residue is taken up in 300 ml of dichloromethane and
washed twice with water, followed by drying over sodium sulfate and
concentration.
~ 338985
14 O.Z. 0050/39798
Yield: 22 9 of a yellow solid (active ingredient no. 11 in the table
below); m.p. 56 58C.
The compounds of the formula I given in the table below are characterized
5 by their melting point and/or 1H-NMR data. The 1H-NMR spectra were taken
in deuterochloroform or hexadeuterosulfoxide as solvent, with tetramethyl-
silane as internal standard. The chemical shifts were registered in ppm.
The multiplicities are given as follows: s = singlet, d = doublet, t =
triplet, q = quartet, m = multiplet.
1 338985
_ _
I I
_ _
a~ . . . . .
r) ____ ___ __ ___
I I I I I I I -- I II I I
o ~ v ~ f7 v~ ~ V ~ V ~
O -- -- -- -- _ _ _ ~ _ _ _ _ _
~ .... ... ~1~
O ~
____ ___ ____ ___
I I I II I II I I I I I I
V ~ V VV ~r ~n V ~ V v~ V V v~
____ ___ ____ ___
___ ________ ___
I I T II I I I I I I I I I I
- - - - - - - - - - - -
'O I I I I I I I I I ~: I I I I I
S ------_ ________ ___
O
~ ~ 0 0 0 0 0 0 0
~/ _
0~,~ ~0 o
E ~ cr~
I I --~ ~ I I ~
`J E C ~
S ~ S S ~ ~ C--
~L
O O
~ C~ Z
1 338985
16 O.Z. 0050/39798
Use examples
The action of the cyclohexenone derivatives of the formula I on plant
growth is demonstrated by the following greenhouse experiments:
The vessels employed were plastic flowerpots having a volume of 300 cm3
and filled with a sandy loam containing about 3.0% humus. The seeds of the
test plants were sown separately, according to species.
10 For the preemergence treatment, the active ingredients were applied to the
surface of the soil immediately after the seeds had been sown. The com-
pounds were emulsified or suspended in water as vehicle, and sprayed
through finely distributing nozzles. The application rate was 0.5 kg of
active ingredient per hectare. After the agents had been applied, the
15 vessels were lightly sprinkler-irrigated to induce germination and growth.
Transparent plastic covers were then placed on the vessels until the
plants had taken root. The cover ensured uniform germination of the
plants, insofar as this was not impaired by the active ingredients.
20 For the postemergence treatment, the plants were grown, depending on
growth form, to a height of 3 to 15 cm before being treated. In this
treatment method, either plants which had been sown in the pots and grown
there were selected, or they were cultivated separately as seedlings and
transplanted to the pots a few days before being treated. The application
25 rate for postemergence treatment was 0.125 kg/ha. No covers were placed on
the vessels in this method.
The pots were set up in the greenhouse, species from warmer climates in
warmer areas (20 to 35C) and species from moderate climates at 10 to
30 25C. The experiments were run for from 2 to 4 weeks. During this time the
plants were tended and their reactions to the various treatments assessed.
The assessment scale was 0 to 100, 100 denoting nonemergence or complete
destruction of at least the visible plant parts, and 0 denoting no damage
or normal growth.
The plants used in the greenhouse experiments were Avena fatua, Alopecurus
myosuroides, Digitaria sanguinalis, Echinochloa crus-galli, Lolium multi-
florum, Medicago sativa, Triticum aestivum and Zea mays.
40 Active ingredients 3 and 11, on preemergence application of 0.5 kg/ha,
have a strong herbicidal action on grassy plants; mustard, as an example
of a broadleaved species, remains undamaged.
1 338985
17 O.Z. 0050/39798
For combating grassy vegetation, examples nos. 2 and 3 are suitable at a
postemergence application rate of 0.125 kg/ha. Broadleaved crops, such as
alfalfa, are not damaged. The novel active ingredients have a selective
herbicidal action.
Active ingredients 3 and 11 may be used postemergence for combating
unwanted grassy species in wheat. The crop plants only suffer minor
damage, if any at all.
