Note: Descriptions are shown in the official language in which they were submitted.
10~8()89
This invention relates to N,N-disubstituted alanine derivatives,
to herbicidal compositions containing them and to a method of combating
undesired plant growth. Of special interest is the ability of these alanine
derivatives to exhibit selective herbicidal properties.
The present invention provides N,N-disubstituted alanine deriva-
tives of the general formula:
COY
(X) ~ ! (I)
\
CHCOON=CRl R2
wherein each X individually represents a hydrogen, fluorine, chlorine,
bromine or iodine atom and n is an integer of from 1 to 5;
Y represents an aryl group;
Z represents an alkyl group;
Rl represents an acyl, carboxyl, alkoxycarbonyl, aminocarbonyl, mono- or
di-alkylaminocarbonyl or mono or di-arylaminocarbonyl group in which the
aryl groups may be unsubstituted or substituted
R2 represents an alkyl, alkenyl, aryl, alkaryl, alkoxy, alkylthio or acyl
group.
0~9
The preferred class of compounds have the general formula I
wherein X represents a chlorine or fluorine atom; n is 1 or 2; Y represents
a phenyl and Z represents a methyl group~
Of these compounds, those of most interest are the 3,4-dichloro-,
the 3-chloro-4 fluoro~, the 4-chloro- or the 4-fluoro-derivatives.
A further preferred class of compounds have the general formula I
~herein X represents a chlorine or fluorine atom; n is 1 or 2; Y represents
a phenyl and Z a methyl group and Rl represents an acyl or alkoxycarbonyl
group of 1 to 6 carbon atoms, an aminocarbonyl group, a mono- or dialkyl
substituted aminocarbonyl group where each alkyl group contains 1 to 4 carbon
atoms, a mono-arylaminocarbonyl group or a dihalophenyl aminocarbonyl group
and R2 represents an alkyl group of 1 to 4 carbon atoms, an acyl group of
1 to 6 carbon atoms, a phenyl group, a benzyl group, or an alkoxy or
alkylthio group of 1 to 4 carbon atoms.
It will be appreciated that many of the compounds according to
the invention will exhibit geometrical and/or optical isomerism and that,
therefore the individual isomers of these compounds together with isomeric
mixtures thereof are included within the scope of the present invention.
-~ ~ _3_
10W089
The invention also lncludes a process for the
preparation of the compounds of formula I which com-
prises reacting a compound of formula:
(X~ ~COY
~ N (II)
\~
CHCOOH
with a compound of formula:
HON=C (III)
wherein X, Y, Z, n, Rl and R2 are as defined above. Since
reaction is a condensat~on process involving the elimina-
tion of water, it is preferably carried out in the
presence of a dehydrative agent to absorb this by-product,
an example of a suitable agent being dicyclohexylcarbodiimide.
The reaction takes place at room temperature and is
preferably carried out in an inert liquid reaction medium
10l~8089
in which reactants and dehydrative agent are soluble.
A preferred solvent is methylene chloride. During the
reaction dicyclohexylcarbodiimide is converted to
dicyclohexylurea and removed by filtration; the remaining
mixture may be worked up by conventional means.
The compounds according to the invention may be
used in a manner known for herbicides, that is to say
they may be used alone or together with a suitable
carrier and/or surface-active agent. The invention
therefore includes herbicidal compositions comprising
a compound according to the invention and a carrier
or a surface-active agent, or both a carrier and a
surface-active agent.
The Applicant has found that the compounds are
of particular interest in selectively attacking wild
oats in cereal crops, particularly wheat and barley,
and accordingly the invention further includes a
method of combating wild oat in cereal crops by applying
to the infested area a compound or composition according
to the invention.
The term ~carrier~ as used herein means a solid
or fluid material, which may be inorganic or organic
and of synthetic or natural origin, with which the
lO~W~9
6 -
active compound is mixed or formulated to facilitate
its application to the plant, seed, soil or other object
to be treated, or its storage, transport or handling. The
carrier may be a solid or a fluid. Any of the materials
usually applied in f~rmulating pesticides may be used as
the carrier.
Suitable solid carriers are natural and synthetic
clays and silicates, for example natural silicas
such as diatomaceous earths; magnesium silicates, for
example, talcs; magnesium aluminium silicates, for
example, attapulgites and vermiculites; aluminium
silicates, for example, kaolinites, montmorillinites and
micas; calcium carbonates; calcium sulphate; synthetic
hydrated silicon oxides and synthetic calcium or
aluminium silicates; elements such as for example,
carbon and sulphur; natural and synthetic resins such
as, for example coumarone resins, polyvinyl chloride
and styrene polymers and copolymers; solid polychlor-
phenols; bitumen; waxes such as for example, beeswax,
paraffin wax, and chlorinated mineral waxes; and solid
fertilizers, for example superphosphates.
Examples of suitable fluid carriers are water,alcohols,
such as for example, ispropanol~ glycols; ketones such as for
example, acetone, methyl ethyl ketone, methyl isobutyl
ketone and cyclohexanone; ethers; aromatic hydrocarbons
108~0~9
such as for example, benzene, toluene and xylene; petroleum
fractions such as for eXample, kerosine, light mineral
oils; chlorinated hydro~arbons, such as for example,
carbon tetrachloride, perchloroethylene, trichloroethane,
including liquefied normally vaporous gaseous compounds.
Mixtures of different liquids are often suitable.
The surface-active agent may be an emulsifying agent
or a dispersing agent or a wetting agent; it may be
nonionic or ionic. Any of the surface-active agents
usually applied in formulating herbicides or insecticides
may be used. Examples of suitable surfac-active agents
are the sodium or calciumsalts of polyacrylic acids and
lignin sulphonicacids; the condensation products of
fatty acids or aliphatic amines or amides containing at
least 12 carbon atoms in the molecule with ethylene
oxide and/or propylene oxide; fatty acid esters of
glycerol, sorbitan, sucrose or pentaerythritol; conden-
sates of these with ethylene oxide and/or propylene
oxide; condensation products of fatty alcohols or
alkyl phenols for example _-octylphenol or _-octylcresol,
with ethylene oxide and/or propylene oxide; sulphates or
sulphonates of these condensation products;
alkali or alkaline earth metal salts, preferably sodium
salts, of sulphuric or sulphonic acid esters containing
at least 10 carbon atoms in the molecule, for example~
io~ s
- ~ -
sodium lauryl sulphate, sodium secondary alkyl sulphates,
sodium salts of sulphonated castor oil, and sodium al-
kylarylsulphonates such as sodium dodecylbenzene sulphonate;
and polymers of ethylene oxide and copolymers of ethylene
oxide and propylene oxide.
The compositions of the invention may be formulated
as wettable powders, dusts, granules, solutions,
emulsifiable concentrates, emulsions, suspension
concentrates and aerosols and will generally contain 0.5
to 95%w, preferably 0.5 to 75%w, of toxicant. Wettable
powders are usually compounded to contain 25, 50 or 75%w
of toxicant and usually contain, in addition to solid
carrier, 3-10%w of a dispersing agent and, where
necessary, 0-10%w 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 diluted in the field with
further solid carrier to give a composition usually con-
taining 0.5-10%w 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%w toxicant and
0-lO~w of additives such as stabilisers, slow-release
modifiers and binding agents. Emulsifiable concentrates
10~80~9
g
usually contain, in addition to the solvent and, when
necessary, co-solvent, 10-50% W~V toxicant, 2-20% w/v emul-
sifiers and 0-20% w~v of appropriate additives such
as stabilisers, penetrants~nd corrosion inhibitors. Sus-
pension concentrates are compounded so as to obtain
a stable, non-sedimenting, flowable product and usually
contain 10-75%w toxicant, 0.5-15%w of dispersing agents,
0.1-10%w of suspending agents such as protective colloids
and thixotropic agents, 0-10%w of appropriate additives
such as defoamers, corrosion inhibitors, stabilisers,
penetrants and stickers, and as carrier, water or an
organic liquid in which the toxicant is substantially
insolublei certain organic salts may be dissolved in
the carrier to assist in preventing sedimentation or as
antifreeze agents for water.
Aqueous dispersions and emulsions, for example,
compositions obtained by diluting a wettable powder or
a concentrate according to the invention with water,
also lie within the scope of the present invention.
The said emulsions ma~ be of the water-in-oil or of the
oil-in-water type, and may have a thick 'mayonnaise'
-like consistency.
3089
-- 10 --
The invention i9 illustrated in the following
Examples.
EXAMPLE 1 Preparation of N-benzoyl-N-(3-chloro,
4-fluoropheny) alanine, propionyloxime
ester
N-benzoyl-N-(3-chloro,4-fluorophenyl)alanine
(6.4 g, 0.02 mole) was dissolved in methylene chloride
(60 ml) containing 2,3-pentanedione-2-monoxime
(2.3 g, 0.02 mole). The reaction mixture was stirred
during the addition of 4.4 g dicyclohexylcarbodiimide in
methylene chloride (40 ml). The progress of the reaction
was followed by thin-layer chromatography (silicon plates),
the eluent beingmethylene chloride.
The reaction was completed in 8 hours. The N,N'-dicyclo-
hexylurea was filtered off. After evaporation,the residue
was crystallized from ethyl acetate/petroleum ether
60-80C to give the required product. m.p. 159-161C.
Yield 21%.
Analysis alculated for C21H20N204FCl: C 60.2; H 4.8;
N 6.7%
Found : C 59.9; H 5.0;
N 6.7%
EXAMPLES 2-6
A series of related compounds were prepared using
the method employedin Example 1. The structure of
these compounds and their physical properties are given
in Table I.
108W89
11
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~D N O
o~ o~ ~ o~
Z; Z,' ~ Z Z Z
~ ~ ~ ~ ~ r~
~ 3 3 3 ~t
~ ~C, X ~: :~ ~
a~ ~. ~ L
c~ j ~ ~ ~ ~
o~ U~ U~ L~ ~ ~D
rl C~ C~ ~ {~ V
.... .... ....
c~ c~
1 ~
a~ z a~ z a~ Z
J~ U~ ~ ~ J~ U~
\ / ~ OL~ ~ Oo ~d 0~
C~ ~ X3 ~ ~ X(~ ~
ll ~ ~l O t~l ~`J O ~ ~I O
Z C~ ~ 4 VC,) ~
O
~a
c~ c~ a~ ~ ~I c~
~ J` -- ~Z ~ U~
0~ l E~
~ 3 ~D J
-.~
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.,` ~ ~ ~ 0~~ X_~
: O~ ~ 0_~ O-C~
a) ,'`
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Z C) C~
O - ~ O - ~ O -
~ ~ V C~
X
X Q,
G (~1 1.~ 3
V ~
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1~ ~ 3 ~I
t- ~ a~ o~
Z Z Z Z
~ O
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.~ .~ .~ .
O ~ ~ O~
U~
C~
.... ....
h ~ h
O ~ O
~ C~
Z ~ :2
r~ J~
O ~ O
o~ ,1 ~
td ~ O ~ ~ O
C~ C~ C~ ¢ .;
~ Cr~
. _ _ ,.
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., _
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:~ ~C X
~ Z~ ~>
O=c~ O-~
V ~
C~ ~ ~D
iO~801
- 13 -
EXAMPLE 7 Tests on herb;cidal activity
To evaluate their herbicidal activity, the compounds
of the invention were tested using as a representative
range of plants: maize, Zea mays (Mz); oat, Avena sativa (0);
rye grass, Lolium perenre (R); barnyard grass, Echinochloa
crusgalli (BG); pea, Pisum sativum (P); linseed, Linum
usitatissimum (L); mustard, Sinapis a _ (M); sugar beet,
B _ vulgaris (SB); and tomato, Solanum lycopersicum (T).
The tests fall into two catgories, pre-emergence
and post-emergence. The pre-emergence tests involved
spraying a liquid formulation of the compound onto the
soil in which the seeds of the plant species mentioned
above had recently been sown. The post-emergence
tests involved two types of test, viz., soil drench and
foliar spray tests.
In the soil drench tests the soil is which seedling plants
of the above species were growing, was drenched with
a liquid formulation containing a compound of the
invention, and in the foliar spray tests the seedling
plants were sprayed with such a formulation.
The soil used in the tests was a steam-sterilized,
modified John Innes Compost mixture in which half the
peat, by loose bulk, had been replaced by vermiculite.
10~ 9
The formulations used in the tests were prepared
by diluting with water solutions of the compounds in
acetone containing 0.4% by weight of an alkylphenol/
ethylene oxide condensate available under the trade
mark Triton X-155. In the soil spray and foliar spray
tests the acetone solutions were diluted with an equal
volume of water and the resulting formulations applied
at two dosage levels corresponding to 5and 1 kilogrammes
of active material per hectare respectively in ~ volume
equivalent to 400 litres per hectare. In the soil drench
tests one volume of the acetone solution was diluted
to 155 volumes with water and the resulting formulation
applied at one dosage level equivalent to 10 kilogrammes
of active material per hectare in a volume equivalent to
approximately ~,000 litres per hectare.
The herbicidal effects of the compounds were assessed
visually seven days after spraying the foliage and drenching
the soil and eleven days after spraying the soil, and
were recorded on a 0-9 sci~le. A rating 0 indicates no
effect on the treated plants, a rating 2 indicates a
reduction in fresh weight of stem and leaf of the plants
of approximately 25%, a rating 5 indicates a reduction of
approximately 55%, a rating 9 indicates a reduction cf
95%, etc.
The results of the tests are set out in Table II.
- l r) _ 10~089
_ __ . _ ~ o __ _ _ ___ ~ ~ C ~ N O
a~ ~ t- 1~ 3 1~ ~ OC) 3 ~D ~1 t- 1
N ~ ~ ~ ~ t~ 3 ~ ~ IS-
h ~ ~ N ~ O ~ O ~ ~1 N O N O
u, ~ m o ~D ~ u~ o N O N O N O
a~ ~ t-- ,~ ~ 3 t-- N ~ N ~ N ~ O
P~ N ~ ~1 3 0 \~ D ~ O N O IS~ N
~ O ~ C) N O ~ O O O
_ .
m N ~1 ~1 0 ~t N N ~1 ~ O ~ O
U~ O O Ir~ O N O N O O
~ ~ ~ N 1~ N 15~ N 3 ~1 ~ ~1 IS~ 3
a~ ~ L-- ~O 3 N ~ 11'\ ~D O ~D ~
_~ ~d ~ ~ ~ ~1 ~1 ~ ~ 3 N 3 ~J ~ I_
H m o o ~ N ~D O 3 0 ~D O N O
~d O ~ ~D ~ t- ~O ~ ~ ~ ~ ~ ~
_, 1~ N I_ 1~ ~ ~D ~D ~D ~ ~D N
~1) ~i 3 0 ~1 ~1 ~ O ~C) N l~ O lr~ O
H ¦ ~
~ ~1 ~ m o o 3 1~ ~1 O
J~ V:l N O ~ O O O
`: P.. ~C ~ ~ O Lr\ ~ 3 1
~ 1~ ~ O ~D ~D ~ ~C)
H m ~ N O 3 N N
'O 1~ Ir~ ~O ~ Ir~ ~ O
V:~ O =r ~D IS~ ~D 3 O
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