Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
This invention relates ~o a he-rbicidally-active
composition comprising certain N-substituted alanine compounds.
~he her~icidal composition according to the invention
comprises a carrier and/or a surface-active agent and as
active ingredient at least one N-substituted alanine compound
having the general formula:
X _ ~ _ NH-CH-COR ~I)
CH2Z
Y
wherein X is a fluorine or chlorine atom; Y is a hydrogen,
fluorine or chlorine atom; Z i.s a hydrogen atom or an alkoxy
1~ group; and R is a group of formula -ORl J
in which Rl 1S hydrogen, a metal salt-forming or
an optionally alkyl substituted ammonium ion, an
optionally substituted alkyl, cycloalkyl, aryl,
alkenyl or alkaryl group; or
a group of formula -SR2 in which R2 is an optionally
substituted alkyl, cycloalkyl, aryl, alkenyl or
alkaryl group, with the proviso that if Z is hydrogen,
and both X and Y are chlorine, then Rl is other
. than hydrogen.
- 2 -
- 3 ~6~6~7
A preferred herbicidal composition according to the
invention is one in which the active in~,redient is an
N-substituted alanine compound with the general formula (II).
X ~/ ~ N~-~H-COOR (Il)
~ CH3
y
where X is fluorine or chlorine, Y is chlorine; ~ is a
5 hydrogen atom or an alkyl group of 1 to l~ carbon atoms
for example a methyl,ethyl or isopropyl group.
It will be appreeiated that the N-substituted
eompounds aeeording to the invention can exhibit optical
isomerism. The indiv:Ldual isomers together with mixtures
thereof are included within the scope of the inventlon.
The Applieant has observed that in the majority of cases
one of the optically active isomers (the dextro-rotatcry
isomer) of the N-substituted alanine compounds is more
herbicidally active than the other isomer~ ~ccordingly
a particularly preferred herbicidal composition according
to the invention is one in which the N-substituted alanine
compound, as defined in formula (I), is present in the
dextro-rotatory form.
The eomposition according to the invention exhibits
good herbicidal activity against broad-leaved weeds
when applied as a foliar spray. In particular it gives
improved selective control of these weeds in cereal
crops, especiaIly in barley crops. The invention therefore
also relates to a method of eradicating or controllin~
broad-leaved weeds which comprises applying to the weeds
or their habitat a herbicidally effective amount of
the N-substituted alanine compound of general formula (I),
wherein X is a fluorinc or chlorine atom; Y is a hydrogen,
fluorine or chlorine atom; Z is a hydrogen atom or an alkoxy
group; and R is a group of formula -~Rl in which Rl is hydrogen,
a metal salt-forming or an optionally alkyl substituted ammonium
ion, an optionally substituted alkyl, cycloalkyl, aryl, alkenyl
or alkaryl group; or a group of formula -SR2 in which R2 is an
optionally substituted alkyl, cycloalkyl, aryl, alkenyl or
alkaryl group.
Preferably, a herbicidally effective amount of a compound
of general formula ~II) is used.
Some of the compounds of formula (I) are novel
compounds and they are believed to be the following: N-(3,4-
dichlorophenyl)alanine, isopropyl ester and methyl 2-(3-chloro-4-
fluorophenyl)amino-3-methoxy propionate. The N-substituted
alanine compounds may be prepared by conventional methods available
to the organic chemist~ e.g. by reaction of an aniline derivative
of formula:
X ~3 NH2
y
wherein X and Y are as defined above, with a propionic acid
derivative of formula:
CH2- ICH-C(:)OH
Z Cl
wherein Z is a hydrogen atom or methoxy group, in the presence of a
suitable base to absorb the hydrogen halide which is eliminated,
for example, sodium bicarbonate. The carboxylic acid product may
then be esterified to give the required ester.
-- 4 --
~,j
L6~
The Applicant has also found that the spectrum of
activity of the composition according to the invention
may be remarkably increased by including in the composition
a second active ingredient, namely a compound from the
group of wild oat herbicides having the N"N-disubstituted
alanine skructure. Surprisingly although the N-substituted
alanine compounds of formula (I) have no activity against
grass-like weeds ~including wild oats) the combination
gives rise to an increased activity with regard to
wild oat, whilst lea~ing the broad-leàved activity
unaffected.
Accordingly the present invention further provides
a composition for the control of broad-leaved weeds and
wild oats comprisine as active ingredients (a) an
N-substituted alanine compound having the general
formula (I), and (b) an N,N-disubstituted alanine
compound of the following general formula:
CQ ~
X ~ N (III)
~ \
~ CH-COR
Y CH3
wherein Y is hydrogen, ~luorine or chlorine; X is chlorine
or fluorine; Q is oxygen or sulphur; and R is
a group of formula -OR1, in which R1 is hydrogen,
a metal salt-forming or an optionally alkyl substituted
ammonium ion, an optionally substltuted alkyl, cyclo-
a~yl, aryl, alkenyl or alkaryl group;
a group of formula -SR2 in which R~2 ls an optionally
substituted alkyl3 cycloalkyl9 aryl,alkenyl or
alkaryl group; or
a group of formula -NR3R4-or -oN=CR3R4 in which
R3 and R each individually is hydrogen, hydroxy,
an optionally~substituted alkyl, alkenyl, aryl,
alkaryl, heterocyclyl, alkoxy, alkylthio or amino
groupg or R3 and R4 togekher represent a polymethylene
group optionally interrupted by one or more hetero
atoms.
Examples of these N,N-disubstltuted alanine compounds
and their methods of synthesis can be found in the following
German patent specifications:
OLS 1 643 527, OLS 2 109 910, OLS 2 302,029, 0LS 2 349 970,
OLS 2 504 3199 OLS 2 460 691.
Especially preferred N,N-disubstituted alanine compounds
are those having the following general formula:
` ~ ~ CQ ~
X ~ N / (IV3
Y \
y C~-COO~,
CH3
wherein X and Y each individually represent chlorine or `
fluorine and R is a hydrogen atom or an alkyl group
containing up to 6 carbon atoms, e.g. methyl, ethyl or
isopropyl. Of these compounds the wild oat herbicide
especially suitable ~or use in barley crops is the
compound having the formula(IV) above wherein:
X= fluorine, Y= chlorine; and ~= iso~ropyl.
The best compounds for use in wheat crops have the
formula (IV) above wherein: X = chlorine or fluorine;
Y = chlorine; and R - methyl or ethyl.
As in the case of the N-substituted alanine compounds~,
the N,N-disubstituted compounds can also exist in
optically active forms and, generally speaking, the
laevo-rotator~ isomer is the most active form. Thus,
where it is appropriate the N3N-disubstituted alanine
compound may be employed in its most active optically-
active form in the composition according to the invention.
A particularly preferred herbicidal composition
for the control of broad-leaved weeds and w1ld oat
is one in which the N-substituted alanine compound as
defined in formula (I) is present in the dextro-rotatory
form and the N,N-disubstituted alanine compound as
defined in formula (III) is present in the laevo-rotatory
form.
The invention also includes a method of eradicating
or controlling both broad-leaved and ~rass weeds infesting
cereal crops at a locus which compr1ses applying to the
locus a herbicidally effective amount of an N-substituted
alanine compound of formula (I) and an N,N-disubstituted
alanine compound of formula (III).
The optional substituents in the alanine derivatives
of general formulae(I) and (III) referred to above are
preferably one or two chlorine, fluorine, alkyl (1-4C)~
-- 8 ~
or alkoxy (1-4C) groups. The alkyl, alkenyl, alkoxy,
alkylthio groups referred to in the above general
formulae suitably contain up to ~ carbon atoms,
preferably up to 4 carbon atoms. l'he aryl, alkaryl,
cycloalkyl~ heterocyclyl and poIymethylene groups
suitably contain up to 10 carbon atoms, preferably
up to 7 carbon atoms. The hetero-atoms which may be
in the polymethylene group or in the heterocyclyl
groups can be oxygen, nitrogen or sulphur atoms but
are preferably one or two oxygen and/or nitrogen
atoms
For many years the broad-leaved weeds which
infest cereal crops have been successfully controlled
by ~iar application of plant gro.wth regulator herbicides
such as the phenoxy-alkanoic acid derivatives, known
as hormone weed-killers. In an attempt to eradicate
both broad-leaved and grass weeds by a single post-
emergence application to a cereal crop, it has been
observed that the presence of the hormone weedkiller
has an antagonistic effect on the activity of N,N-di-
substituted alanine wild oat herbicides and the latter's
effectiveness is reduced~ leading to a poorer control
of the wlld oats than is obtalned by applying to the
two types of herbicide separately. Thus the composition
according to the invention comprising both types of
alanine derivatives has a two-fold advantage over any
existing systems for dealing with weed-infested cereal
_ 9 ~
crops, namely the ability to control broad-leaved
weeds and wild oats in one application to cereal
crops and the synergistic effect of the mixture with
regard to the selective control of wild oats in
cereal crops.
The herbicidal composition according to the invention
may be formulated in such a way as to ~acilitate its
application to the area to be tested and, conveniently,
the composition includes a carrier or a surfactant and
usually a carrier and a surfactant.
The term "carrier~' as used herein means a material,
which may be inorganic or organic and of synthetic or
natural origin, with which the active compound or compounds
is mixed or formulated to facilitate its application to
the plant, seed, soil or other object to be treatec,
or its storage, transport or handling. The carrier may
be a solid or a fluid. AnD Of the material usually
applied in formulating pesticides may be used as a
carrier.
Examples of suitable solid carrier are silicates,
clays, for example, kaolinite clay~ synthetic hydrated
silicon oxides, synthetic calcium silicates, elements
such as for example, carbon and sulphur, natural and
synthetic resins such as for example, coumarone resins,
rosin, copal, shellac, dammar, polyvinyl chloride and
styrene polymers and copolymers, solid polychlorophenols,
- 1 o ~ 637
bitumen, asphaltite, ~axes such as for example~ beeswax,
paraffirl wax, montan wax and chlorinated mineral waxes,
and solid fertilisers, for example superphosphates.
Examples of suitable fluid carriers are water,
alcohols, such as for example, isopropanol, ketones
such as for example, acetone methyl ethy] keto~, methyl
isobutyl ketoreand'cyclohexanone, ethers, aromatic hydro-
carbons such as for example, benzene and toluene~
petroleum fractions such as for example, kerosine~ chlorinated
hydrocarbons, such as for example, carbon tetrachloride,
including liquefied normally vaporous gaseous compounds.
Mixtures of different liquids are often suitable.
The surface-active agent may be a wetting agent,
an emulsifying agent or a dispersing agent; it may be
non-ionic or ionic. Any of the surface-active agents
usually applied in formulating herbicides may be used.
Examples of suitable surface-active agents are the sodium
or calcium salts of polyacrylic acids, the condensation
products of fatty acids or aliphatic amines or amides
containing at least 12 carbon atoms in the molecule with
ethylene oxide and/~r propylene oxide; partial esters of
the above fatty acids with glycerol, sorbitan3 sucrose
or pentaerythritol; condensation products of alkyl
phenols, for example p-octylphenol or p-octylcresol,
with ethylene oxide and/or propylene oxide; sulphates
or sulphonates of these condensation products; and
alkali metal salts, preferably sodium salts, of sulphuric
6~7
acid esters or sulphinic acids containing at least
10 carbon atoms in the molecule, for example3 sodium
lauryl sulphate, sodium secondary alkyl sulphates,
sodium salts of sul~honated castor oil~ and sodium
alkylaryl sulphonates such as sodium dodecylbenzene
sulphonate.
The compositions of the invention may be formulated
as wettable powders5 dusts, granules, solutionsg emulsifiable
concentrates, emulsions and pastes. Wettable powders are
usually compounded to contain 25, 50 or 75% of toxicant
and usually contain, in addition to solid carrler, 3-10%
of a dispersing agent and, where necessary, 0-10% of
stabiliser(s) and/or other additives such as penetrants
or stickers. Dusts are usually formulated as a dust
concentrate having a similar composition to that of a
wettable powder but without a dispersant, and are dilute
in the field with further solid carrier to give a
composition usually containing 0.5-10% of toxicant.
Granules are usually prepared to have a size between
10 and 100 BS mesh~ and may be manufactured by agglomeration
or impregnation techniques. Generally, granules will contain
0.5-25% toxicant and 0-25% of additives such as stabilisers,
slow release modifiers, binding agents etc. ~mulsifiable
concentrates usually contain, in addition to the solvent
and, when necessary, co-solvent, 10-50~ w/v toxicant~
2-20% w/v emulsifiers and 0-20% of appropriate additives
such as stabilisers, penetrants and corrosion inhibitors.
- 12 ~
Pastes are compounded so as to obtain a stable, flowable
product and usually contain 10-60% toxicant, 2 20% of
appropriate additives and, as carrier, water or an organic
liquid in which the toxicant is substantially insoluble.
The compositions of the invention may contain other
ingredients 3 for example protective colloids such as
gelatin, glue, casein, gums and polyvinyl alcohol;
sodium polyphosphates; cellulose ethers~ stabilisers
such as ethylene diamine tetra-acetic acid; other
herbicides or pesticides; and stickers, for example,
non-volatile oils.
A~ueous dispersions and emulsions, compositions
obtained by d~uting a wettable powder or an emulsifiable
concentrate according to the invention with water,
also lie within the scope of the present invention. The
said emulsions may be of the water-in-oil or of the
oil-in-water type, and may have a thick "mayonnaise"-like
consistency.
The invention is further illustrated by reference to the
following Examples:
Exam~e 1 Demons'tra'tion of herbicidal activity of N-sub-
~1~ .
To demonstrate their herbicidal activity against broad-
leaved weeds the compositions according to the invention
Z5 were tested as foliar sprays on seedling plants of the
following species: linseed, Linum us`i't'at'issi'mum (L);
mustardj ~ alba (M); sugar beet, Beta vulgaris (SB);
; and soya bean,' ~ max (S).
The for~ulations used in the test were prepared by
diluting with water solutlons of the compounds in acetone
containing 0.4% by weight o~ an alkylphenyl/ethylene oxide
condensate available under the trade name Triton X-155.
The acetone solutions were diluted with an equal volume
of water and the resulting rormulations applied at four
dosage levels correspondlng to 0.1, 0.~, 1.0 or 3.0 kilograms
of active material per hectare. There were ~ replicates
of each treatment. Phytotoxicity was assessed visually
12 to 14 days after spraying the roliage, on the standard
0-9 scale. These phytotoxicity scores were submittecl ~or
probit analysis to calculate the growth inhibition dosages
in kg/ha required to give a 50% reduction (G I D50).
14~ 57
1~ ~1 IS~ 3 ~J 1
U~ ~ ~ ~1 ~1 ~ ~O
H . . . . ~ .
~ O
LOr~
m ~ t~ O
H ~-- ~ ~ ~. . .
O O O O
:
O
O O ~O
t~
~: ~ O O O O O ~\I
C~
L
~ ~ CO ~ CO ~1
~S O 0 0 0 0 ~1
H ~ .
~ a ~
~ ~ 3 ~ ~
~d .
E~ ~ ~ ~, ~, o
.
a
X ~ ~ d ~ 0
X ~ ~ ~ s
, 5 ~ o
Q, a) ~ ~ S-~ Q~ 1
::; o-~l o ~ o ~
O S~o ~ I O
Q O /1) 0 ~ O O O ~
: ~ ~-rl S ~ S ~ a
o ~1 ~ ~ ~ C) a-r~ ~1 o
V ~ ~ C~ + o ~ o
I ~ I ~ O ~ o--~ ~ C) O
o a~ o ~ o
~ ~ ~ ,
O ~ O rR ~ ~ rl J~ O `
a~
I ~
=~ ~ I
I ~ I ~ rl ~ O
~s~S ~ ~~ ~ ~ ~ ~
rl
~ I a~I a) I ~ I ~ I ~ a
:~ ~; ~z ~ z a~
:
'~ -
`:
6~7
- 15
These ~igures also demonstrate that for a given
compound the dextro-rotatory ~orm is mor~ herbicidally
active than the racemic mixture.
Example 2 Demonstration of herbicidal activity of
N substituted alanine compounds
~ . . ~ _
A second series of compounds were applied as foliar
- sprays to soya bean at the cotyledon stage using the
procedure described in example I and applying four
dosage levels corresponding to 0.3, o.6, 1.2 or 2.4
10 kilograms of active material per hectare. Phytotoxicity
was assessed 16 days after spraying and ~he G I D50
calculated.
Table 2 -
Compound S
I D50
N-(3,4-dichlorophenyl)alanine isopropyl ester 0.12
(dextro-rotatory isomer)
N-(3,4-dichlorophenyl)alanine ethyl ester0.07
(dextro-rotatory isomer)
N-(3-chloro~4-fluorophenyl)alanine isopropylester 0.60
(dextro-rotatory isomer)
N-3-chloro-4-fluorophenyl)alanine methyl ester o.80
(dextro-rotatory isomer)
Example 3
of N-substituted' alani'ne c'ompounds
.
TG demonstrate their selective herbicidal action (in
~ controlling the growth of broad-leaved weeds in barley
; crops) the compositions according to the invention were
~ lfi -
tested as foliar sprays on seedling plants of th~
following species: mustard, ~ alba (M); soya
bean, Glycine max (S); convolvulus, Ipo~ea
(I) and barley, Hordeum vulg re (B).
The formulations used in the test were prepared
as in Example I. Two tests were carried out.
Test I The compounds were applied post-emergence to
soya bean, mustard and barley at 4 dosages: Barley
from 3 to 24 kg/ha; soya bean and mustard from 0.2
1~ to 1.6 kg/ha. There were 4 replicates of each treatment.
Phytotoxicity was assessed visually on the standard
0-9 scale, 8 days after spraying. This data was analysed
by computer to calculate the growth inhibition dosages
required to give a 50% reduction for barley, soya bean
and mustard. The results are given in Table 3.
Table 3
Compound G I D50 G I D50 G I D50
N-(3-chloro-4-fluorophenyl) ~20 2.89 o.69
alanirie
N-~3-chloro-4-fluorophenyl) 16.3 0.93 o.65
alanine methyl ester (racemic
~ mixture)
; Test 2 The compounds were applied to soya bean,
convolvulus and barley at 4 dosages: Barley from ll
to 32 kg/ha and soya bean and convolvulus from 0.3
to 2.4 kg/ha. ~here were 3 replicates of each treatment.
17~ 6~7
Phytotoxicity was assessed visually on the standard 0-9
scale 14 days (for barley) and 22 days (for soya bean
and convolvulus) after spraying. The G I D50's obtained
from this data are shown in Table 4.
Table 4
~
Compound G I D50 G I D50 G I D50
N-(3-chloro-4-fluorophenyl)alanine 11~7 1.28 1.60
isopropyl ester (racemic mixture3
N-(3-chloro-4-fluorophenyl)alanine 11.2 0.92 o.g8
isopropyl ester (+ isomer)
Example 4 Demons'trat'ion o.f synergi'stic' h_rb'i'c'i'dal acti'vity
''o'f mixt'ures''o'f N-s~ub's~ti~t~ut'ed'and' N,N-d'is'ubst'ituted
_ _ _ _
alenines
; The miYtures under test in this example were as follows:
Mixtur'e I N-Benzoyl-N-(3,4-dichlorophenyl)alanine ethyl
ester (A) and N-(3,4-dichlorophenyl)alanine ethyl ester
(B)
Mixture 2 N-Benzoyl-N-(3-chloro-4-fluorophenyl)alanine
methyl ester (C) and N-(3-chloro-4-fluorophenyl)alanine
methyl ester (D).
Mixture 3 N-BenzoyI-N-(3-chloro-4-fluorophenyl)alanine
methyl ester (C) and N-(3-chloro-4-fluorophenyljalanine (E)~
ixture'4 N-Benzoyl-N-(3-chloro-4-fluorophenyl)alanine
methyl ester (-isomer) (F) and N-(3-chloro-4-fluorophenyl)
alanine methyl ester (+ isomer) (G).
~ , .
6S7
Mixture 5 N-Benzoyl-N-(3-chloro-4-fluoro~henyl)alanine
methyl ester (-isomer) (F) and N-(3~4-dichlorophenyl)
alanine ethyl ester (+ isomer) (H).
All compounds were formulated as 15-20% emulsifiable
concentrates. The dosages used for com~ound (A) were
0,04, o.o8, 0.16 or 0.32 kg/ha and for compounds (C)
and (F) 0.02, 0.04, o.o8 or 0.16 kg/ha. Sufficient amounts
of the five compounds of the invention were added to
produce mixtures with the required ratios. These five
compounds (i.e. B, D, E, G, and H) were also applied
alone at high dosages and were found ko be inactive against
cultivated oats at the dosages given in the test.
A number of 7 ~m pots o~ John Innes No. 1 Compost
were sown with 25-30 seeds of cultivated oats (Avena
sativa). When the plants had reached the l-lz leaf
stage mixtures of different ratios of the compounds
were sprayed using a lo~arithmic sprayer. Assessments
were made 10 to 15 days after spraying according to
the mixture. Phytotoxicity was assessed visually on
a percentage scale (where 0 = no effect and 100 = no
growth after spraying). The data was analysed to
calculate the growth inhibition dosages in kg/ha
required to give a 90% reduction for oat (G I Dgo).
Results of these mixture tests are given in Table 5.
- 19~ 5~
_ _ .
O ~
o o o o
~ ~ 6, o o o o
~ td ~
IA ~ _
o o ~ o o ~ ~ =r
~-rl
.X o ~ .. .. .. .. .. .. ..
o
o -
~D ~ Lt~ Lr~ ~
o o o
H O O O O O
~ ~ :
_ . ~
O O CS O ~ 1
P.~rl
X ~ ...... .. .. .. .. .. ..
~r~ O ~
O S~ ¢~ t\l rl ~1 ~1 0
O
u~ ~ c~ o
H ~ ~1 ~1 0 ~1
~ ' . . . . I
C~ O O O O O
1~ - ~
a~ ~:
~ ~ 0~ O O ~ ~ ~ .'
~ Q~ri
~ o3~ ..........
~ O ~ ~ ~1 ~1 ~1 ~1 0
a~ .- .
r~ cO
P ~ ~ ~ Lr~
~d H ~ O O O O O
E~ ~d .
C~ O O O O O O
,, _ _ _
:~ ~0 0 ~ O ~ ~ ~ CO
p,-rl ,
X ~ .. .. .. .. .. .. ..
~1 O td
C~ ~ V ~1 ~1 ~1 ~1 ~1 o
-~ --.
n :
u~ ~ ~ ~ ~r
H ~ ~J ~1 ~1 ~1
(~
O o o o o o
~_
.
~:
o om o ~ ~1 ~ ~ ~ :
L~-rl
X ~ .. .. .. .. .. .. ..
~1 o ~
~ . = ~_
- 20 -
Example 5
The mixture under test in this example was as follows
N-Thiobenzoyl N-(3~chloro-4-fluorophenyl)alanine isopropyl
ester (.A) and N-(3-chloro-4-fluorophenyl)alanine isopropyl
ester (B).
The test procedure was the same as that given in Example 4.
The dosages used for compou~d (A) were 0.24, o.48, or o.g6
kg/ha with sufficient amounts of the compound of the
invention added to give mixtures with the required ratios.
Visual assessments were made 19 day.s after spraying and
G I Dgo calculated as for prevlous tests.
Results o~ the test are given in Table 6,
Table 6
.
_ . _ .
Compound ratio oGat Dgo
- -- - ~
, 1: 0 0.99
1: 1 0.91
1 : 2 0.73
1 : 4 o.60
0 : I . _ .
.~
.'
,
.