Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
Cyclohexane~1,3-dione derivatives and their use for controlling
_ _undesirable_plant_~rowth _ _ _
The present invention relates to cyclohexane~l,3-
dione derivatives, herbicides containing these compounds as
active ingredients, and processes for controlling undesirable
plant growth using these compounds.
It has been disclosed that 5-arylcyclohexane-1,3-
dione derivatives may be used for the selective control of
undesirable grasses in broad-leaved crops (German Published
Application DAS 2,439,104). Furthermore, it has been disclosed
that the active ingredient is tolerated by the gramineous crop
wheat particularly when the phenyl ring is p-substituted
(Proc. 4th International Congress of Pesticide Chemistry
(IUPAC), 1978, page 235), the best results being achieved with
the p-methyl radical, as in 2-(1-ethoxyaminopropylidene)-5-(4-
methylphenyl)-cyclohexane-1,3-dione. Particularly noteworthy
in the above publication is the finding that when the alkoxy-
aminoalkylidene radical is alkoxyaminobutylidene instead of
alkoxyaminopropylidene, the herbicidal ac~ivity and the
toleration by crops are reduced. In the experiments with wheat
as the crop, the active ingredients described are exclusively
ethoxyaminopropylidene-containing 5-arylcyclohexane-1,3-dione
derivatives, which do little damage to wheat.
We have found that cyclohexane-1,3-dione derivatives
of the formula
.., /.
1 ~ NH-oR4
R O-A ~ ~ C (I)
~ ~ R3
R O
where R is alkylene of 3 or 4 carbon atoms, or phenyl, benzyl,
2 phenylethyl or phenylpropyl, each of which is unsubstituted
or substituted by halogen, alkyl, alkoxy, nitro, cyano or
sulfonyl, ~ is alkylene or alkenylene, each of which is of not
more than 3 carbon atoms and may b~ substituted by 1 or 2 alkyl
radicals of 1 to 5 carbon atoms, cyclohexyl, alkenyl of 2 or 3
carbon atoms, ethynyl or phenyl, R is hydrogen, or alkoxycarbonyl
where alkoxy is of 1 or 2 carbon atoms, R is alkyl of 1 to 4
carbon atoms~ and ~ is alkyl of 1 to 3 carbon atoms, alkenyl
of 3 or 4 carbon atoms, propargyl, or haloalkenyl of 3 or 4
carbon atoms and 1 to 3 halogen atoms, and agriculturally
acceptable salts of these compounds have a good herbicidal action
against undesirable grasses, and are very well tolerated by
cereals, especially wheat, and other crops.
Thus, in accordance with another aspect, the
present invention provides a process for combating unwanted
plant growth, wherein the plants and/or their location are
treated with a herbicidally effective amount of a compound
of the formula I as defined above or an agriculturally
acceptable salt thereof.
The compounds of the formula I can occur
in several tautomeric forms, all of which are claimed:
NH-OR~ ~ N-oR4
RlO A ~ ~ ~
R2 0 R2 0
~ N-oR4 1 ~ N~OR
~ ~ \ 3 R O-A - ~ R3
Rl may, for example, be allyl, benzyl, fluorobenzyl, chloro-
benzyl, bromobenzyl, dichlorobenzyl, trichlorobenzyl, nitro-
benzyl, cyanobenzyl, methoxybenzyl, methylbenzyl, ethylben~yl,
tert.-butylbenzyl, dimethylbenzyl, phenyl, chlorophenyl,
i-propylphenyl/ dichlorophenyl, methylphenyl, dimethylphenyl,
methoxyphenyl, 2-phenylethyl or.2-phenyl-n-propyl.
A may be methylene, methylmethylene, ethylmethylene,
propylmethylene, cyclohexylmethylene, methylethylmethylene,
methylvinylmethylene, methylpropinylmethylene, propylmethylene,
4-methylbutylmethylene, phenylmethylene, ethylene, propylene,
methylpropylene or l-methylpropen-l-yl-ene.
R2 may be hydrogen, methoxycarbonyl or ethoxycarbonyl.
R3 may be methyl, ethyl, n-propyl, i propyl, n-butyl,
sec.-butyl, i-butyl or tert.-butyl.
R may, for example, be methyl, ethyl, n-propyl,
i-propyl, n-butyl, sec.-butyl, i-butyl, tert.-butyl, allyl,
propar~yl/ l-chloroprop-l-en-3-yl, 2-chlcroprop-1-en-3-yl r
1,2 dichloroprop-1-en-3-yl or 1,1,2 trichloroprop-l~en-3-yl.
For the purposes of the invention, salts of the
compounds of the formula I are understood as meaning, for
~ . ~
'~ . ,.
~ 4 ~ O.Z. 0050/35289
example the alkali metal salts in particular the potass;um
salts and sodium salts and manganese salts copper salts
zinc salts ;ron salts and barium salts.
The compounds can be obta;ned by reacting a com-
pound of the formula
o
// O
R10-A~C (IT)
\ \ R3
R 0
with a hydroxylamine derivative of the formula R40NH4Y where
R1 A R2 R3 and R4 have the above meanings and Y is an
an;on~
The react;on is advantageously carr;ed out in -the
' heterogeneous phase ;n an inert solvent at from û to 80C
or at the boiling point of the m;xture in the presence of
a base. Examples of su;table bases are carbonates bicar-
bonates acetates alcoholates hydroxides and oxides of
alkal; metals and alkaline earth metals in particular of
sodium potass;um magnes;um and calcium. It ;s also
poss;ble to employ an organic base such as pyridine or a
tertiary amine.
A well-defined pH range particularly suitable for
the reaction is from 2 to 7 in part;cular from 4.5 to 5.5
and tnis ;s advantageously obtained by the addition of an
acetate for exanple an alkal; metal açetate ;n part;cular
sodium acetate or potassium acetate or their m;xtures.
The alkali metal acetate is employed for examp~e in an
arnount of from 0~5 to 2 moles based on the ammonium
-- 5 --
compound.
Examples oE suitable solvents are methanol, ethanol,
isopropanol, benzene, tetrahydrofuran, chloroform, aceto-
nitrile, dichloroethane, ethyl acetate, dioxane and dimethyl-
sulfoxide~
The reaction is complete after a few hours, and the
product may be isolated by concentrating the mixture, adding
water, extracting the mixture with a non-polar solvent, and
distilling off the solvent under reduced pressure.
In addition, the compounds of the formllla I may be
obtained by reacting the compound of the formula II with a
hydroxylamine of the formula R4-o-NH2, where R4 has the above
meanings, in an inert solvent, at from 0C to the boiling
point of the mixture, e.g. from 0C to 80C, preferably from
15 to 70C.
Examples of suitable solvents are methanol, ethanol,
isopropanol, cyclohexanol, methylene chloride, toluene, tetra-
hydrofuran, acetonitrile, dichloroethane and ethyl acetate.
If appxopriate r the obtained compounds of formula
(I) as defined above may be converted into agriculturally
acceptable salts thereof. The sodium salts or potassium salts
of the cyclohexane-1,3-dione derivatives may, for example, be
obtained by treating these compounds with sodium hydroxide or
potassium hydroxide in aqueous solution ox in an organic
solvent, e.g. methanol, etharol or acetone D A sodium alco-
holate or potassium alcoholate may also be used as the ba~eO
Other metal salts, for example the manganese salts,
copper salts, zinc salts, iron salts and barium salts, may be
prepared by reacting the sodium salt with the appropriate
metal chloride in aqueous solution.
Compounds of the formula II may be prepared rom
cyclohexane 1,3-diones of the formula III by conventional
- -- 6 --
f'~
methods (Tetrahedron Lett., ~9, 2491~i the compounds of the
formula II~ can also occur in the tautomeric forms IIIa and
IIIb:
RlO~ ~~ ~ R O-A
III IIIa IIIb
It is also possible to prepare compounds of the
formula II via the enol ester intermediate, which is obtained,
possibly as an isomer mixture, in the conversion of a compound
of the formule III, and rearranged in the presence of an
imidazole or pyridine derivative (Japanese Patent 54/063,052).
The compounds of the formula III are obtained by
conventional processes, as can be seen from the equation
helow:
. ;~
7 ~ O. Z . 0050/35289
R -O-A- CHO
O / ~ ~
CH 3- C- CH 3/ \ CH2 ( COOH ) 2
base / \~yridine
O '
R10-A-CH=CH-C-CH3 Rl-O-A-CH=CH-C-OH
- 'I ' .'
CH2 ( COOCH3 ) 2 ¦ CH 3-OH
CH3-ONa
R -O-A- CH = CH- COOCH3
~3-C-C~l2-cOOOc~3/c}13_oNa
,~
.. .
., //
R~-O-A--Q
COOCH 3 0
1 ) ~OH
2) HCl
~ ' O
R1-O-A~
~\0
- 8 - O.Z. 0050/35289
The Exampies ~hicl1 follo~ ;llustrate the prepara-
t;on of the cyclohexane-1,3-dione der;vatives. In the
Examples, parts by ~e;ght bear tne same relat;on to parts
by volume as that of the k;logram to the liter.
EXAMPLE 1
10.5 parts ~y weight of 2-butyryl-5~(4'-chloro-
benzyloxyethylidene)-cyclohexane-1,3-dione, 3.1 parts by
we;ght of ethoxyammonium chloride and 2.7 parts by ~eight
of anhydrous sod;~Jm acetate in 100 parts by volume of
ethanol were st;rred for 12 hours at roo~n temperature.
The solvent waS distilled off under reduced pressure,
the residue l~zs st;rred with 120 parts of water and 100
parts of methylene chloride, the organ;c phase was separated
off, the a~ueous phase was extracted u;th 50 parts of
methylene chlor;de~ and the combined organ;c phases were
washed with ~ater, dried over sod;um sulfate and concen-
trated under reduced pressure. The product obtained was
2-ethoxyaminobutyl;dene-5 (4'-chlorobenzyloxyethylidene)
cyclohexane-1,3-d;one with the follow;ng formula:
O
CH3 ~ ~ NH-OC2H5
2 ~ \0 ~ n-C3H7 1ngred~ent No.1
n24: 1.5424
C21H28ClN04 (3q4)
calculated: C 64.03 H 7.16 N 3.56 Cl 9.00
found: C 63.9 ~ 7.0 ~l 3~7 Cl 9.3
EXAMPLE 2
10.0 par-s by we;ght of 2-butyryl 5-(4'-me~hyl
benxyloxyethylidene)~cyclohexane-1,3-dione and 2.0 parts by
weight of ethoxyamine in 100 parts by volume of ethanol were
stirred for 12 hours at room temperature. The solvent was
distilled off under reduced pressure, the residue was stirred
with 120 parts of water and 100 parts of methylene chloride,
the organic phase was separated off, the aqueous phase was
extracted with 50 parts of methylene chloride, and the combined
organic phases were dried over sodium sulfate and concentrated
under reduced pressure. 2-Ethoxyaminobutylidene-(4'-methyl-
benzyloxyethylidene)-cyclohexane-1,3-dione was obtained as an
oil (active ingredient No. 2).
n 2: 1.5343
C22H31NO4 (373)
calculated: C 70.75 H.8.37 N 3.75
found: C 70.2 H 8.4 N 3.8
The compounds given below were obtained in a
corresponding manner:
~ / NH-oR4
RlO-A~= C\R3
`r~
~ 10 ~ 0~ Z ~ 0050~35289
C.) a~
O ~ ~ O Cl:lO ~D N ~-1 ~ n
nIn ,~
r~ n ~ n In o ~
L~ ~nIn n In ~ ~n ~In In
Q~ . . . . . . . . ~.
~jN ~ ~ ~--O a. ~ ~ Q ~ ~
L: ~a ~a ~a ~a ~a ~,a ~a ~ Na ~a
~1
:
=
~;
0
r~
~ ..~n
Y ~ Y
P;
~;~ ~ q X ~ ~ X
~C~ -
C~
2 0 N
N N O
h
~ a) o
R R
h
O
1:~ ~) ~ N
~3 C) (:~ : ~ ~1 _
~r
o
~n ~ r a: a~ o ~ ~`
Ei o
o.æ. 0050/35289
,_
O
~-1t~1`0a~ ~ ~
._ O ~Ll~~:r ~ r` t o r`
t~t~~'tl ~ ~ tY~ o~ t'l
, .. ,, , , ~ U7
~1
t~tO~ ~CD tO ~ r~ ~
~ ,,a ~at~ ~ t~a ~ ~a tr,a t~a ~a
~, ~~~, ~ ~ ~, ~, r~ I
~ ~~ ~ ~.
1~~ ~, ~ ~ ~ ~ S: ~,
r~~ r~ ~ ~ ~ ~ ~ ~
P~ 0 au 0 tV td 0 0 a) 0
1~ 1~
t~l tl~ a
C~ C~
t
1:~ ~: ~
t.'~
P; ~: ~ m ~ m
-u-
t.~
t,~ t~ I
~ q m~
I I ~) ^
m e v - , ~ ,
V
^ C.) I _
11 t~ t~ p:
o m cv ~ I
_, o
,~ ~
N N ~:
~ aJ
R R Q
O : O
h S
~-1 ~1 0 r1 0 ,~ ~1
N,C N ~ U S::
U
~ ~ ,4
o
Q~ ~ ~I~ a~ O ~ O 1-- oo
O O
12 - 0.Z. 0050/35289
._
o~ o ~ ~
o
o ~ ~ u u~ Ln ~r
~ ~ a ~ a ~ a ~ ~ ~ a ~a ~ a
~/ ~ ~ ~ ~1
~: s ~ ~ ~ ~ .c
~I ~ ~ ~ ~
~ - U~ : Y
r~ I
~:
O ,~r
~ ~ ~ ) y
~-
Q~
.
~; ,~ ~ ~ a
~i
~ ~ ~ I
o ~ ~ ~ ~ ~o ~ C~ ~ CO
o o
s~
- 13 O.Z. 0050/35289
,~ .
C~ ~ ~ O ~D ~ ~ Ln ~ ~r
Cl~ ~ OD ~ 0~ ~ ~D O Cl~ ~r
U~
. . . . .
~1
a
2~ F~ ~ a~ ~ ~ a
m
~, ~ o Y ~ ~ ~,
m~
~; ~
m'~ m
ir;
m ~ m m m m m m m
m~ Y
~o
~ ~ ~, ::~
~ ~ ~ o
R ~ ~ Q,
--' : X - ~ ~ = _ _
~r ~ R
~ ~ o ~ ~ ~ ~ u) ~ r~ c~
O O
V ~
0 - 14 O.Z. 0050/35289
1~-NMR spectroscopic data, based on tetramethylsilane as internal
standard, and given in ~values (ppm). Abbreviations for the
signal structures:
s = singlet, d = doublet, t = triplet, q = quartet, m = multiplet
(strongest signal).
OR ~ /
CH -CH ~ ~ C " " ~'
3 ¦ ~ \ ~ NH-O-CH -
4.30 (m) 4.15 (q)
41 4.1 (m) 4.05 (q)
42 4.23 (m) 4.51 (d)
43 4.18 (m) 4.48 (d)
44 4.08 (m) 4.04 (q)
4.1 (m~ 4.09 (q)
47 4.21 (m) 4.49 (d)
48 4.13 (m) 4.06 (q)
61 4.21 (m) 4.48 (d)
62 4.25 (m) 4.05 (q)
63 4.30 (m) 4.50 (d)
79 4.30 (m) 4.55 (d)
4.35 (~) 4.10 (q)
The following compounds of the formula I ma~ be obtained
analogously:
- 15 - O.Z. 0050~35289
.
~ ~ ~:
P~ ~
e w
c
~ l l l
~;
m m ~ m m m m m m m m w m
1~
I m
I
,) ~ O I
I - I I ~ u~
m m m
N ,_1
~/
Q) ~ N N
~ N Q N ~ ~ N
N
~ ~ ~ ~ ~ ~rq
,4 0 ~ ~ X ~C O
C: h: ~: ::~ : O O h
~1 ~1 I .C ~ 0 ~1
~) ~1 ~ ~ ~ ~ ~
~1 .~ N
~ 3 y
o
~ r-! N ~ ~ ~ Dr~ : ~ O u~
O O
V ~
- 16 - O.Z. 0050/35289
,~ Y ~ ~ ~ ~ ~
~;
~`
P~
~ ::~ m m m m m m m m m m m m m
I tq
o
~ C.~
C~ 11 1 1 : :
V mr~
m c) c,
~,
N N ~ ~ ~
a)
0: 0 0 ~1 ~ X -
h h ~ o
O O ~ O
P; ~ U C) ~
~ ~ ~ ~ ~ ~r
o o
C3 ~
- 1 7 - 0 . Z . 0050/3528~
i~O
~
~Y
_~ X
C.) I ~ - 3 3 ~
2 0 t~ ?t ~ ~ ~ ~
,1 ~ ,~ ~ ~ ,1 ,1 s s
~1 a~
o
: ~:
Q. RJ 3 r
o o ~ a
0 5~
~1 ~ IJ S l O
~ a) a~ aJ I ~ ~ I I I I
~ 0 0 ~r ~r Lt') ~
o ~ r Ln ~ o ~ ~ n ~o
E3 ' ~ ~ ~ Lf11~ Lt~ L~) Ln n L~ D LD ~D
O Q
- lg - O.Z. 0050/35289
,,
Lf
,,
m'` ~'` m~
C~ O X ~
I I ~ -
r~
U
O = 5
~I O
~; v m ~ m m m m m m m m m
I ~ ~.
~ c) ~
I
1~
I ~ O
~ ~: ~ I I ~ ô
,. ..
N N
~ ~ a) a)
,-~ ,J - O O
>1 ~ S~ h
O O ~1
~; ~ ~ ~ ~ ~ ~
~3 - C) y ~: _
~p r.
ra
o
Q~ c~ o ~ c~ o ~1 ~ 0 ~1 ~I
~ ~D 1~ r~ 1` Cl~ Cl~ COa~ co Cl:) : a~ o o o
O O
C~ ~
- 19 - O.Z. 0050/35289
~ pplication of the cyclohexane-1,3-dione derivatives of the
formula I as herbicides may be effected for instance in the form
of directly sprayable solutions, powders, suspensions, dlsper-
sions, emulsions, oil dispersions, pastes, dusts, broadcasting
agents, or granules by spraying, atomizing, dusting, broadcasting
or watering. The forms of application depend~entirely o~ the pur-
pose for which the agents are being used, but they must ensure as
fine a distriblltion of the active ingredient as possible.
For the preparation of solutions, emulsions, pastes and oil
dispersions to be ~prayed direct, mineral oil fractions of medium
to high boiling point, such as kerosene or diesel oil, further
coal-tar oils, and oils of vegetable or animal origin, aliphatic,
cyclic and aromatic hydrocarbons such as benzene, toluene, xylene,
paraffin, tetrahydronaphthalene, alkylated naphthalenes and their
derivatives such as methanol, ethanol, propanol, butanol, chloro-
form, carbon tetrachloride, cyclohexanol, cyclohexanone, chloro-
benzene, isophorone, etc., and strongly polar solvents such as
dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, water,
etc. are suitable.
Aqueous formulations may be prepared from emulsion concen
trates, pastes, oil dispersions or wettable powders by adding
waterO To prepare emulsions, pastes and oil disperslons the ingre-
dients as such or dissolved in an oil or solvent may be homoge-
nized in water by means of wetting or dispersing agents, adherents
or emulsifiers. Concentrates which are suitable for dilution with
water may be prepared from active ingredient, wetting agent, ad-
herent, emulsifying or dispersing agent and possibly 501vent or
oil.
- 20 - O.Z. 0050/35289
The herbicides contain, in addition to inert additives, ~rom
5 to 95, and especially from 10 to 80, wt~ of cyclohexane-
-1,3-dione as active ingredient.
Examples of surfactants are: alkali metal, alkaline earth
metal and ammonium salts of ligninsulfonic acid, naphthalenesul-
fonic acids, phenolsulfonic acids, alkylaryl sulfonates, alkyl
sulfates, and alkyl sulfonates, alkali metal and alkaline earth
metal salts of dibutylnaphthalenesulfonic acid, lauryl ether sul-
fate, fatty alcohol sulfates, alkali metal and alkaline earth
metal salts oE fatty acids, salts of sulfated hexadecanols, hepta-
decanols, and octadecanols, salts of sulfated fatty alcohol glycol
ethers, condensation products of sulfonated naphthalene and
naphthalene derivatives with formaldehyde, condensation prod~lcts
of naphthalene or naphthalenesulfonic acids wlth phenol and form-
aldehyde, polyoxyethylene octylphenol ethers, ethoxylated isooctyl-
phenol, ethoxylated octylphenol and ethoxylated nonylphenol, alkyl-
phenol polyglycol ethers, tributylphenyl polyglycol ethers, alkyl-
aryl polyether alcohols, isotridecyl alcohol, fatty alcohol
ethylene oxide condensates, ethoxylated castor oil, polyoxy-
ethylene alkyl ethers, ethoxylated polyoxypropylene, laurylalcohol polyglycol ether acetal, sorbitol esters, lignin, sulfite
waste liquors and methyl cellulose.
Powders, dusts and broadcasting agents may be prepared b~
mixing or grinding the active ingredients with a solid carrier.
Granules, e.g., coated, impregnated or homogeneous granules,
may be prepared by bonding the active ingredients to solid car-
riers. Examples of solid carriers are mineral earths such as
silicic acid, silica gels, silicates, talc, kaolin, Attaclay,
- 21 - O.Z. 0050/35289
limestone, lime, chalk, bole, loess, clay, dolomite, diatomaceous
earth, calcium sulfate, magnesium sulfate, magnesium oxide, ground
plastics, fertilizers such as ammonium sulfate, ammonium
phosphate, ammonium nitrate, and ureas, and vegetable products
such as grain flours~ bark meal, wood meal, and nutshell meal,
cellulosic powders, etc.
EXAMPLE a
90 parts by weight of compound 1 is mixed with 10 parts by
weight of N-methyl~alpha-pyrrolidone. A mixture is obtained which
is suitable for application in the form of very fine drops.
EXAMPLE b
10 parts by weight of compound 1 is dissolved in a mixture
consisting of 90 parts by weight of xylene, 6 parts by we ght of
the adduct of 8 to 10 moles of ethylene oxide and 1 mole of oleic
acid~N-monoethanolamide, 2 parts by weight of the calcium salt of
dodecylbenzenesulfonic acid, and 2 parts by weight of the adduct
of 40 moles of ethylene oxide and 1 mole of castor oil.
EXAMPhE c
20 parts by weight of compound 44 is dissolved in a mixture
consisting of 60 parts by weight of cyclohexanone, 30 parts by
weight of isobutanol, 5 parts by weight of the adduct of 7 moles
of ethylene oxide and 1 mole of isooctylphenol, and 5 parts by
weight of the adduct of 40 moles of ethylene oxide and 1 mole of
castor oil.
EXA~PLE d
20 parts by weight of compound 1 is dissolved ln a mixture
consisting of 2S parts by weight of cyclohexanol, 65 parts by
weight of a mineral oil fraction having a boiling point between
- 22 - O.Z. 0050/35289
210 and 280C, and 10 parts by weight of the adduct of 40 moles
of ethylene oxide and 1 mole of castor oil.
EXAMPLE e
820 parts by weight of compound 1 is well mixed with 3 parts
by weight of the sodium salt of diisobutylnaphthalene-alpha 5ul-
fonic acid, 10 parts by weight of the sodium salt of a lignin-sul-
fonic acid obtained from a sulfite waste liquor, and 7 parts by
weight of powdered silica gel~ and triturated in a hammer mill.
EXAMPLE f
5 parts by weight of compound 44 is intimately mixed with
95 paxts by weight of particulate kaolin. A dust is obtained con-
taining 5% by weight of the active ingredient.
~XAMPLE g
30 parts by weight of compound 1 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 ingre-
dient is obtained having good adherence.
EXAMPLE h
40 parts by weight of compound 44 is intimately mixed with
10 parts of the sodium salt of phenolsulfonic acid-urea-form-
aldehyde condensater 2 parts of silica gel and 48 parts of water
to give a stable aqueous dispersionO Dilution in 100,000 parts by
weight of water gives an aqueous dispersion containing 0.0~ wt% of
active ingredient.
EXAMPLE i
20 parts of compound 1 i3 intimately mixed with 12 parts of
the calcium salt of dodecylbenzenesulfonic acid, 8 parts of a
,, .
- 23 - O.Z. 0050/35289
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 stable oily dispersion is obtained.
The agents may be appliPd pre- or postemergence; the latter
method is preferred.
The amount of active ingredient which is applied depends on
the objective to be attained, the growth stage and type of plant,
and on the weather conditions, and varies from 0.1 to 15 kg/ha and
more, but is preferably from 0.25 to 1.5 kg/ha.
The influence of the cyclohexane-1,3-dione derivatives of the
formula I on the growth of unwanted and crop plants was demonstrated
in greenhouse experiments.
The vessels employed were plastic flow0rpots having a volume
of 300 cm3 and containing, as substrate, a sandy loam with about
1.5~ humus. The seeds of the test plants were sown shallow, and
separately, according to species. For the postemergence treatment
described here, the plants were first grown to a height of 5 to
15 cm, depending on growth form. The application rates varied from
active ingredient to active ingredient, and were either 0.25, 0.5
at 1.0 kg/ha.
The active ingredients were sprayed as an aqueous suspension
or emulsion by means of finely distributing nozzles.
The prior art compound
0 H
-C ~ -0-C2~5 (A)
- 24 - O.Z. 0050/35289
disclosed as having a particularly selective and good herbicidal
action in German Published Application DAS 2,439,104 was used for
comparison purposes.
The experiments were run for from 2 to 4 weeks. During this
period, the plants were tended and their reactions to the various
treatments assessed. The scale used for assessment was O to lOO, O
denoting no damage or normal emergence, and 100 denoting nonemer-
gence or complete destruction of at least the visible plant parts.
The test plants were Alopecurus myosuroides, Avena fatua,
Beta vulgaris, Lolium multiflorum, Triticum aestivum, Glycine
max., Echinochloa crus-galli, Setaria italica, Sorghum bicolor,
Rottboellia exaltata, and ~ordeum vulgare.
The results revealed that compound no. 44, applied post-
emergence at a rate of 0.25 kg/ha, had an action on the unwanted
grasses Alopecurus myosuroides and Avena fatua which was somewhat
weaker than that of comparative compound A. At a rate of
loO kg/ha, the herbicidal action of both compounds on both weeds
is identical. ~owever, the tolerance of compound no. 44 by wheat
is clearly better than the tolerance of comparative compound A.
The experiments also showed that compound no. l, on post-
emergence application of 0.25 kg/ha, is superior to comparative
compound A (applied at the same rate) in combating the grass
species Alopecurus myosuroides and Lolium multiflorum. This com-
pound too is much better tolerated by wheat than comparative
compound A.
On postemergence application of l.O kg of compounds nos. 2,
8, 45, 72 and 73, these compound~ had an excellent action on
unwanted grass species. Soybeans, as an example of a broadleaved
crop plant, were not damaged.
- 25 - O.Z. 0050/35289
Compounds nos. 27, 28 and 50, applied postemergence at
0.5 kg/ha, selectively controlled unwanted grasses in cereals,
such as barley and wheat, and in soybeans.
The compounds of the formula I have a selective herbicidal
action not only in cereal species (preferably wheat), but also in
broadleaved crops, such as sugarbeets, soybeans, cotton, rape, and
sunflowers, and in oiher crops not belonging to the Gramineae
family.
If certain crop plants tolerate the active ingxedients less
well, application techniques may be used in which the herbicidal
agents are sprayed from suitable 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 treatment).
To increase the spectrum of action and to achieve synergistic
effects, the cyclohexane 1,3-dione derivatives of the formula I
may be mixed and applied together with prior art cyclohexane-
-1,3-dione derivatives and with numerous representatives of other
herbicidal or growth-regulating active ingredient groups. Examples
of suitable mixture components are diazines, 4H-3,1-benzoxazine
derivatives, benzothiadiazinones, 2,6-dinitroanilines, N-phenyl
carbamates, thiolcarbamates, halocarboxylic acids, triazines,
amides, ureas, diphenyl ethers, triazinones, uracils, benzofuran
derivatives, etc.
It may also be useful to apply the novel compounds, either
alone or in combination with other herbicides, in admixture with
other crop protection agents, e.g., agents for combating pests or
phytopathogenic fungi or bacteria. The compounds may also be mixed
- 26 - O.Z. 0050/35289
with solutions of min~ral salts used to remedy nutritional or
trace element deficiencies. Wetting agents, spreader-stickers,
non-phytotoxic oils and oil concentrates may be also be added to
initiate the herbicidal action.
