STABLE HERBICIDAL COMPOSITIONS CONTAINING METAL CHELATES OF HERBICIDAL DIONE COMPOUNDS

COMPOSITIONS HERBICIDES STABLES CONTENANT DES CHELATES DE METAL DE COMPOSES HERBICIDES DIONES

English Abstract

Metal chelates of herbicidal dione compounds of formula (I)
are chemically stable for long periods of time under normal as
well as extreme temperature conditions. Chemically stable liquid
herbicidal formulations containing metal chelates of the herbicidal
compounds of formula (I) and water, an organic solvent or a
liquid co-herbicide and processes for producing chemically stable
herbicidal compositions containing such metal chelates are also
described.

French Abstract

Chélates de métal de composés herbicides diones représenté par la formule (I). Ces chélates sont chimiquement stables pendant des durées prolongées dans des conditions de température normales ou extrêmes. L'invention concerne également des formulations herbicides liquides chimiquement stables contenant des chélates de métal des composés herbicides représentés par la formule (I), de l'eau, un solvant organique ou un herbicide liquide associé, ainsi que des procédés servant à préparer des compositions herbicides chimiquement stables contenant ces chélates de métal.

Claims

WHAT IS CLAIMED IS:
1. A chemically stable herbicidal composition comprising, in a liquid medium,
a di- or
trivalent transition metal chelate of an herbicidal dione of the formula (I):
<IMG>
wherein
R1 represents a straight- or branched-chain alkyl, alkenyl or alkynyl group
containing
up to six carbon atoms which is optionally substituted by one or more halogen
atoms; a
cycloalkyl group containing from three to six carbon atoms optionally
substituted by one or
more R3 groups or one or more groups selected from halogen, -CO2R4; -SR5 and -
OR5; a
cycloalkenyl group containing five or six carbon atoms optionally substituted
by one or more
R3 groups or one or more halogen atoms or a group -CO2R4 or a group of the
formula
-(CH2)p-phenyl-(R6)q;
R2 represents cyano; -COR7; -CO2R7; or -S(O)m R8; or
R1 and R2 together with the carbon atoms to which they are attached form a
five- or
six-membered 1,3-cycloalkanedione group, which 1,3-cycloalkanedione group is
optionally
substituted with from one to six substituents independently selected from
halogen, (C1-
C6)alkyl, (C1-C6)alkoxy, (C1-C6)haloalkyl, (C3-C6)cycloalkyl, cyano, nitro,
(C1-C6) halo-
alkoxy, -CO2R9, -S(O)m R10, -NR11R12, -C(O)R13, -SO2NR11R12, phenyl and phenyl
substituted with one or more halo or C1-C4 alkyl groups, wherein two
substituents on the
same carbon atom of the 1,3-cycloalkanedione group taken together can form an
alkylene
group having 2 to 6 carbon atoms;
26

R3 represents a straight-or branched chain alkyl, alkenyl or alkynyl group
containing
up to six carbon atoms optionally substituted by one or more halogen atoms; or
a cycloalkyl
group containing from three to six carbon atoms.
R4 represents a straight- or branched-chain alkyl group containing up to six
carbon
atoms optionally substituted by one or more halogen atoms; or a cycloalkyl
group containing
from three to six carbon atoms;
R5 represents a straight- or branched-chain alkyl group containing up to three
carbon
atoms.
R6 represents a halogen atom or a group selected from -R4, nitro, cyano, -
CO2R4,
-NR61R62 and -OR4;
R61 represents hydrogen; a straight- or branched-chain alkyl group containing
up to six
carbon atoms optionally substituted by one or more halogen atoms, or a
cycloalkyl group
containing from three to six carbon atoms;
R62 represents a straight- or branched-chain alkyl group containing up to six
carbon
atoms optionally substituted by one or more halogen atoms, a cycloalkyl group
containing
from three to six carbon atoms, or a group selected from -COR4, -CO2R4, and -
CONR4R61;
wherein R4 and R61 are part of a group -CONR4R61 they may, together with the
nitrogen to
which they are attached, form a five- or six-membered ring optionally having
one additional
heteroatom in the ring which is oxygen or nitrogen,
wherein the ring is optionally substituted by one or more alkyl
groups containing up to three carbon atoms; and when R61 and R62 are part of a
group
-NR61R61 they may, together with the nitrogen to which they are attached, form
a five- or six-
membered ring optionally having one additional heteroatom in the ring which is
oxygen or
nitrogen
wherein the ring
is optionally substituted by one or more alkyl groups containing up to three
carbon atoms;
R7 represents hydrogen or straight- or branched-chain alkyl group containing
up to six
carbon atoms;
27

R8 represents (C1-C6)alkyl, (C1-C6)haloalkyl; (C1-C6)cyanoalkyl (C3-
C8)cycloalkyl
optionally substituted with halogen, cyano or (C1-C4)alkyl; or phenyl
optionally substituted
with one to three of the same or different halogen, nitro, cyano, (C1-
C4)haloalkyl, (C1-C4
alkyl, (C1-C4)alkoxy or -S(O)m R8:
R9 represents (C1-C4)alkyl;
R10 represents (C1-C4)alkyl, (C1-C4)alkyl substituted with halogen or cyano,
phenyl or
benzyl;
R11 and R12 independently represents hydrogen or (C1-C4)alkoxy;
R13 represents (C1-C4)alkyl or (C1-C4)alkoxy;
X represents a halogen atom; a straight- or branched-chain alkyl or alkoxy
group
containing up to six carbon atoms which is optionally substituted by one or
more groups
-OR15 or one or more halogen atoms; or a group selected from nitro, cyano, -
CO2R16,
-S(O)m R15, -O(CH2)r OR15, -COR16, -OSO2R18 , -NR16R17, -SO2NR16R17, -
CONR16R17 and
-CSNR16R17;
R15 represents a straight- or branched-chain alkyl group containing up to six
carbon
atoms which is optionally substituted by one or more halogen atoms;
R16 and R17 each independently represents a hydrogen atom; or a straight- or
blanched-chain alkyl group containing up to six carbon atoms which is
optionally substituted
by one or more halogen atoms;
R18 represents a straight- or branched-chain alkyl, alkenyl or alkynyl group
containing
up to six carbon atoms optionally substituted by one or more halogen atoms; or
a cycloalkyl
group containing from three to six carbon atoms;
each Z independently represents halo, nitro, cyano, sulfonylmethyl, S(O)m R2,
OS(O)m R2, (C1-
C6)alkyl, (C1-C6)alkoxy, (C1-C6)haloalkyl, (C1-C6)haloalkoxy, carboxy, (C1-
C6)alkylcarbonyloxy, (C1-C6)alkoxycarbonyl, (C1-C6)alkylcarbonyl, amino, (C1-
C6)alkylamino, (C1-C6)dialkylamino having independently the stated number of
carbon
atoms in each alkyl group, (C1-C6)alkylcarbonylamino, (C1-
C6)alkoxycarbonylamino, (C1-
28

C6)alkylaminocarbonylamino, (C1-C6)dialkylaminocarbonylamino having
independently the
stated number of carbon atoms in each alkyl group, (C1-C6)alkoxycarbonyloxy,
(C1-
C6)alkylaminocarbonyloxy, (C1-C6)dialkylaminocarbonyloxy, phenylcarbonyl,
substituted
phenylcarbonyl, phenylcarbonyloxy, substituted phenylcarbonyloxy,
phenylcarbonylamino,
substituted phenylcarbonylamino, phenoxy or substituted phenoxy;
m is zero, one or two;
n is zero or an integer from one to four;
p is zero or one;
q is zero or an integer from one to five; and
r is one, two or three.
2. A chemically stable herbicidal composition according to claim 1, wherein
said liquid
medium is a member selected from the group consisting of water, organic
solvents and liquid
herbicides.
3. A chemically stable herbicidal composition according to claim 1, wherein
the transition
metal is selected from the group consisting of Cu+2, Co+2, Zn+2 and Ni+2.
4. A chemically stable herbicidal composition according to claim 1 having a pH
of between
about 2 and about 7.
5. A chemically stable herbicidal composition according to claim 1, wherein
the molar ratio
of the compound of formula (I) to the transition metal is between about 2:1
and 2:5.
6. A chemically stable herbicidal composition according to claim 1, further
comprising at
least one co-herbicide.
7. A chemically stable herbicidal composition according to claim 6, wherein
said co-
herbicide is selected from the group consisting of acetanilides, tralkoxydim,
bromoxynil and
its esters, thiafluamide, MCPA and its esters, 2,4-D and its esters, and
fluroxypyr meptyl.
29

8. A chemically stable herbicidal composition according to claim 6, wherein
said liquid
medium is a co-herbicide.
9. A chemically stable herbicidal composition according to claim 6, wherein
said liquid
medium is water.
10. A chemically stable herbicidal composition according to claim 6, wherein
said liquid
medium comprises a microencapsulated co-herbicide dispersed in water.
11. A chemically stable herbicidal composition according to claim 1, wherein
the herbicidal
dione is of the formula:
<IMG>
wherein X, Z and n have the same meanings as in claim 1; each Q independently
represents
C1-C4 alkyl or -CO2R8 wherein R a is C1-C4 alkyl; and z is 0 or an integer
from 1 to 6.
12. A chemically stable herbicidal composition according to claim 11, wherein
z is zero; X is
chloro, bromo, nitro, cyano, C1-C4 alkyl, -CF3, -S(O)m R15 or -OR15; and n is
one or two; and
each Z is independently chloro, bromo, nitro, cyano, C1-C4 alkyl, -CF3, -OR15,
-OS(O)m R2 or
-S(O)m R2.
13. A chemically stable herbicidal composition according to claim 11, wherein
the herbicidal
dione is a member selected from the group consisting of 2-(2'-nitro-4'-
methylsulfonyl-
benzoyl)-1,3-cyclohexanedione, 2-(2'-nitro-4'- methylsulfonyloxybenzoyl)-1,3-
cyclohexanedione and 2-(2'-chloro-4'-methylsulfonylbenzoyl)-1,3-
cyclohexanedione.

14. A chemically stable herbicidal composition according to claim 1, wherein
the herbicidal
dione is of the formula:
<IMG>
wherein:
R50 is a straight- or branched-chain alkyl group containing up to six carbon
atoms
which is optionally substituted by one or more halogen atoms which may be the
same or
different; or a cycloalkyl group containing from three to six carbon atoms
which is optionally
substituted by one or more groups selected from R55 and one or more halogen
atoms which
may be the same or different;
one of R51 and R53 is -S(O)t R56 and the other of R51 and R53 is a halogen
atom; a
straight- or branched-chain alkyl group containing up to six carbon atoms
which is substituted
by -OR55; -R55; nitro; cyano; -SR55; -OR55; -O(CH2)s OR55; or -CO2R55; and
when R51 is
-S(O)t R56, R53 may be hydrogen;
R52 and R54, which may be the same or different, each is a halogen atom; a
hydrogen
atom; a straight- or branched-chain alkyl group containing up to six carbon
atoms which is
substituted by -OR55; -R55; nitro; cyano; -OR55; -O(CH2)SOR55; or -CO2R55;
R55 and R56, which may be the same or different, each is a straight- or
branched-chain
alkyl group containing up to six carbon atoms which is optionally substituted
by one or more
halogen atoms which may be the same or different;
s is an integer from 1 to 3; and
t is zero, 1 or 2.
31

15. A chemically stable herbicidal composition according to claim 14, wherein
R50 is a
cycloalkyl group.
16. A chemically stable herbicidal composition according to claim 14, wherein
the herbicidal
dione is a member selected from the group consisting of 2-cyano-1-[2-chloro-3-
ethoxy-4-
(ethylsulfonyl)phenyl]-3-cyclopropylpropan-1,3-dione; 2-cyano-1-[4-chloro-2-
(methyl-
sulfonyl)phenyl]-3-cyclopropylpropan-1,3-dione; 2-cyano-1-[2-methylsulfonyl-4-
(trifluoromethyl)phenyl]-3-cyclopropylpropan-1,3-dione; and 2-cyano-1-[4-bromo-
2-(methyl-
sulfonyl)phenyl]-3-cyclopropylpropan-1,3-dione.
17. A dry, chemically stable herbicidal composition comprising a di- or
trivalent transition
metal chelate of an herbicidal dione of the formula (I):
<IMG>
wherein
R1 represents a straight- or branched-chain alkyl, alkenyl or alkynyl group
containing
up to six carbon atoms which is optionally substituted by one or more halogen
atoms; a
cycloalkyl group containing from three to six carbon atoms optionally
substituted by one or
more R3 groups or one or more groups selected from halogen, -CO2R4; -SR5 and -
OR5; a
cycloalkenyl group containing five or six carbon atoms optionally substituted
by one or more
R3 groups or one or more halogen atoms or a group -CO2R4 or a group of the
formula
-(CH2)p-phenyl-(R6)q;
R2 represents cyano; -COR7; -CO2R7; or -S(O)m R8; or
R1 and R2 together with the carbon atoms to which they are attached form a
five- or
six-membered 1,3-cycloalkanedione group, which 1,3-cycloalkanedione group is
optionally
32

substituted with from one to six substituents independently selected from
halogen, (C1-
C6)alkyl, (C1-C6)alkoxy, (C1-C6)haloalkyl, (C3-C6)cycloalkyl, cyano, nitro,
(C1-C6) halo-
alkoxy, -CO2R9, -S(O)m R10, -NR11R12, -C(O)R13, -SO2NR11R12, phenyl and phenyl
substituted with one or more halo or C1-C4 alkyl groups, wherein two
substituents on the
same carbon atom of the 1,3-cycloalkanedione group taken together can form an
alkylene
group having 2 to 6 carbon atoms;
R3 represents a straight-or branched chain alkyl, alkenyl or alkynyl group
containing
up to six carbon atoms optionally substituted by one or more halogen atoms; or
a cycloalkyl
group containing from three to six carbon atoms.
R4 represents a straight- or branched-chain alkyl group containing up to six
carbon
atoms optionally substituted by one or more halogen atoms; or a cycloalkyl
group containing
from three to six carbon atoms;
R5 represents a straight- or branched-chain alkyl group containing up to three
carbon
atoms.
R6 represents a halogen atom or a group selected from -R4, nitro, cyano, -
CO2R4,
-NR61R62 and -OR4;
R61 represents hydrogen, a straight- or branched-chain alkyl group containing
up to six
carbon atoms optionally substituted by one or more halogen atoms, or a
cycloalkyl group
containing from three to six carbon atoms;
R62 represents a straight- or branched-chain alkyl group containing up to six
carbon
atoms optionally substituted by one or more halogen atoms, a cycloalkyl group
containing
from three to six carbon atoms, or a group selected from -COR4, -CO2R4 and -
CONR4R61;
wherein R4 and R61 are part of a group -CONR4R61 they may, together with the
nitrogen to
which they are attached, form a five- or six-membered ring optionally having
one additional
heteroatom in the ring which is oxygen or nitrogen
, wherein the ring is optionally substituted by one or more alkyl
groups containing up to three carbon atoms; and when R61 and R62 are part of a
group
33

-NR61R62 they may, together with the nitrogen to which they are attached, form
a five- or six-
membered ring optionally having one additional heteroatom in the ring which is
oxygen or
nitrogen, wherein the ring
is optionally substituted by one or more alkyl groups containing up to three
carbon atoms;
R7 represents hydrogen or straight- or branched-chain alkyl group containing
up to six
carbon atoms;
R8 represents (C1-C6)alkyl, (C1-C6)haloalkyl, (C1-C6)cyanoalkyl (C3-
C8)cycloalkyl
optionally substituted with halogen, cyano or (C1-C4)alkyl; or phenyl
optionally substituted
with one to three of the same or different halogen, nitro, cyano, (C1-
C4)haloalkyl, (C1-C4
alkyl, (C1-C4)alkoxy or -S(O)m R8;
R9 represents (C1-C4)alkyl;
R10 represents (C1-C4)alkyl, (C1-C4)alkyl substituted with halogen or cyano,
phenyl or
benzyl;
R11 and R12 independently represents hydrogen or (C1-C4)alkoxy;
R13 represents (C1-C4)alkyl or (C1-C4)alkoxy;
X represents a halogen atom; a straight- or branched-chain alkyl or alkoxy
group
containing up to six carbon atoms which is optionally substituted by one or
more groups
-OR15 or one or more halogen atoms; or a group selected from nitro, cyano, -
CO2R16,
-S(O)m R15, -O(CH2)r OR15, -COR16, -OSO2R18, -NR16R17, -SO2NR16R17, -CONR16R17
and
-CSNR16R17;
R15 represents a straight- or branched-chain alkyl group containing up to six
carbon
atoms which is optionally substituted by one or more halogen atoms;
R16 and R17 each independently represents a hydrogen atom; or a straight- or
branched chain alkyl group containing up to six carbon atoms which is
optionally substituted
by one or more halogen atoms;
34

R18 represents a straight- or branched-chain alkyl, alkenyl or alkynyl group
containing
up to six carbon atoms optionally substituted by one or more halogen atoms; or
a cycloalkyl
group containing from three to six carbon atoms;
each Z independently represents halo, nitro, cyano, S(O)m R2, OS(O)m R2, (C1-
C6)alkyl, (C1-C6)alkoxy, (C1-C6)haloalkyl, (C1-C6)haloalkoxy, carboxy, (C1-
C6)alkylcarbonyloxy, (C1-C6)alkoxycarbonyl, (C1-C6)alkylcarbonyl, amino, (C1-
C6)alkylamino, (C1-C6)dialkylamino having independently the stated number of
carbon
atoms in each alkyl group, (C1-C6)alkylcarbonylamino, (C1-
C6)alkoxycarbonylamino, (C1-
C6)alkylaminocarbonylamino, (C1-C6)dialkylaminocarbonylamino having
independently the
stated number of carbon atoms in each alkyl group, (C1-C6)alkoxycarbonyloxy,
(C1-
C6)alkylaminocarbonyloxy, (C1-C6)dialkylaminocarbonyloxy, phenylcarbonyl,
substituted
phenylcarbonyl, phenylcarbonyloxy, substituted phenylcarbonyloxy,
phenylcarbonylamino,
substituted phenylcarbonylamino, phenoxy or substituted phenoxy;
m is zero, one or two;
n is zero or an integer from one to four;
p is zero or one;
q is zero or an integer from one to five; and
r is one, two or three.
18. A dry, chemically stable herbicidal composition according to claim 17,
further
comprising at least one co-herbicide.
19. A dry, chemically stable herbicidal composition according to claim 18,
wherein said co-
herbicide is selected from the group consisting of acetanilides, tralkoxydim,
bromoxynil and
its esters, thiafluamide, MCPA and its esters, 2,4-D and its esters, and
fluroxypyr meptyl.
20. A process for producing a chemically stable composition of claim 1,
comprising the steps
of:
adding an herbicidal dione of formula (I) to a liquid medium to produce a
first
mixture;
35

adding an aqueous solution of a di- or trivalent transition metal salt to said
first
mixture, said metal salt solution being added in an amount sufficient to
provide a stoichiometric excess of said metal relative to said herbicidal
dione;
allowing said metal salt and said herbicidal dione to react for a period of
time
sufficient to convert all of said herbicidal dione to its corresponding metal
chelate; and then
adjusting the pH of the resulting composition to between about 2 and 7.
21. A process according to claim 20, wherein said liquid medium is water.
22. A process according to claim 21, wherein said liquid medium comprises a
microencapsulated herbicide dispersed in water.
23. A process according to claim 20, wherein said herbicidal dione is solid
and said process
comprises the steps of:
milling said herbicidal dione;
adding an herbicidal dione of formula (I) to a liquid medium to produce a
first
mixture;
adding an aqueous solution of a di- or trivalent transition metal salt to said
first
mixture, said metal salt solution being added in an amount sufficient to
provide a stoichiometric excess of said metal relative to said herbicidal
dione;
allowing said metal salt and said herbicidal dione to react for a period of
time
sufficient to convert all of said herbicidal dione to its corresponding metal
chelate; and then
adjusting the pH of the resulting composition to between about 2 and 7.
36

24. A process according to claim 20, wherein said process comprises the steps
of:
adding an herbicidal dione of formula (I) to a liquid medium to produce a
first
mixture;
adjusting the pH of said first mixture to about 10; and then
adding an aqueous solution of a di- or trivalent transition metal salt to said
first
mixture, said metal salt solution being added in an amount sufficient to
provide a stoichiometric excess of said metal relative to said herbicidal
dione;
allowing said metal salt and said herbicidal dione to react for a period of
time
sufficient to convert all of said herbicidal dione to its corresponding metal
chelate; and then
adjusting the pH of the resulting composition to between about 2 and 7.
25. A chemically stable herbicidal composition comprising in a liquid medium,
a di- or trivalent transition metal chelate of 2-(2'-nitro-4'-
methylsulfonylbenzoyl)
-1,3-cyclohexanedione.
26. A chemically stable herbicidal composition according to claim 1 or 17,
wherein
-NR61R62 is a pyrrolidine, morpholine, pyrrole, piperidine or piperazine.
37

Description

CA 02245537 1998-07-30
WO 97/27748 PCT/GB97/00302
STABLE HERBICIDAL COMPOSITIONS CONTAINING
METAL CHELATES OF HERBICIDAL DIONE COMPOUNDS
FIELD OF THE INVENTION
The present invention relates to chemically stable metal chelates of
herbicidal dione
compounds. According to one aspect of the invention, these chemically stable
metal chelates
of herbicidal dione compounds can be used in liquid formulations or with a
liquid carrier,
optionally with another agriculturally active chemical.
BACKGROUND OF THE INVENTION
Herbicidally active compounds are used to control or modify the growth of
plants.
Herbicidal compositions containing one or more active herbicidal compounds can
be
formulated and applied in a variety of ways. The object of a particular
formulation is to apply
the herbicidal compound{s) to an area where plant growth control is desired in
a convenient,
safe and effective way.
The choice of formulation and mode of application for any given herbicidal
compound
may affect its activity, and selection must be made accordingly. Herbicidal
compositions may
thus be formulated as granules, as wettable powders, as emulsifiable
concentrates, as powders
or dusts. as flowables, as solutions, as suspensions or emulsions, or as
controlled release
forms such as microcapsules.
Wettable powders are in the form of finely divided particles which disperse
readily in
water or other liquid carriers. The particles contain the active ingredient
retained in a solid
matrix or the active ingredient can be commingled with the solid matrix
particles. Typical
solid matrices include fuller's earth, kaolin clays, silicas and other readily
wet organic or
inorganic solids. Wettable powders normally contain about 5% to about 95% of
the active
ingredient plus a small amount of wetting, dispersing, or emulsifying agent.
Emulsifiable concentrates are homogeneous liquid compositions dispersible in
water
or other liquid. and may consist entirely of the active compound with a liquid
or solid
emulsifying agent, or may also contain a liquid carrier, such as xylene, heavy
aromatic

CA 02245537 1998-07-30
. . WO 97/27748 PCT/GB97/00302
naphthas, isophorone and other non-volatile organic solvents. In use, these
concentrates are
dispersed in water or other liquid and normally axe applied as a spray to the
area to be treated.
The amount of active ingredient may range from about 0.5°!o to about
95°10 of the
concentrate.
Granular formulations include both extrudates and relatively coarse panicles,
and are
usually applied without dilution to the area in which suppression of
vegetation is desired.
Typical carriers for granular formulations include sand, fuller's earth,
attapulgite clay,
bentonite clays, montmorillonite clay, vermiculite, perlite and other organic
or inorganic
materials which absorb or which can be coated with the active compound.
Granular
formulations normally contain about 5% to about 25°!o active
ingredients which rnay include
surface-active agents such as heavy aromatic naphthas, kerosene and other
petroleum
fractions, or vegetable oils; and/or stickers such as dextrins, glue or
synthetic resins.
Dusts are free-flowing admixtures of the active ingredient with finely divided
solids
such as talc, clays, flours and other organic and inorganic solids which act
as dispersants and
carriers.
Micrvcapsules and encapsulated granules are typical controlled release
formulations.
Microcapsules are typically droplets of the active material enclosed in an
inert porous shell
which allows escape of the enclosed material to the surroundings at controlled
rates.
Encapsulated droplets are typically about I to 50 microns in diameter. The
enclosed liquid
typically constitutes about 50 to 95% of the weight of the capsule, and may
include solvent in
addition to the active compound. Encapsulated granules are generally porous
granules with
porous membranes sealing the granule pore openings, retaining the active
species in liquid
form inside the granule pores. Granules typically range from I millimeter to I
centimeter,
preferably 1 to 2 millimeters in diameter. Granules are formed by extrusion,
agglomeration
or prilling, or are naturally occurring. Examples of such materials are
vermiculite, sintered
clay, kaolin, attapulgite clay, sawdust and granular carbon. Shell or membrane
materials
include natural and synthetic rubbers, cellulosic materials, styrene-butadiene
copoljrmers,
polyacrylonitriies, polyacrylates, polyesters, polyamides, polyureas,
polyurethanes and starch
xanthates.
2

CA 02245537 1998-07-30
WO 97/27748 PCT/GB97/00302
Other useful formulations for herbicidal applications include simple solutions
of the
active ingredient in a solvent in which it is completely soluble at the
desired concentration,
such as acetone, aIkylated naphthalenes, xylene and other organic solvents.
Pressurized
sprayers, wherein the active ingredient is dispersed in f nely-divided form as
a result of
atomization and vaporization of a low boiling dispersant solvent carrier, may
also be used.
Although dusts and granular formulations are used for the application of some
herbicidal compounds, drift due to wind is a problem with such dry
formulations and,
consequently, liquid formulations are preferred. Liquid formulations are also
advantageous in
that they permit the "tank mixing" of two or more agriculturally active
formulations at the
grower site.
The discovery of herbicidal dione compounds having the general formula (I):
X
R'
R2
~Zjn
(I)
wherein R1, R2, X and Z have the meanings set forth hereinafter, has resulted
in considerable
field testing of these compounds alone and in combination with other
agriculturally active
compounds for various uses worldwide.
These herbicidal dione compounds have the disadvantage chat in water and other
solvents (in which there is appreciable solubility) they can undergo
decomposition. This
decomposition occurs at such a rate that the use of these herbicidal dione
compounds in
aqueous herbicidal formulations or formulations containing an organic solvent
or liquid co-
herbicide is impractical, unless the formulation is prepared immediately or
within a short
period of time prior to use.
It is, therefore, an object of this invention to provide metal chelates of the
herbicidal
dione compounds of formula (I) which are chemically stable for long periods of
time under
3

CA 02245537 1998-07-30
. . WO 97/27748 PCT/GB97/00302
normal as well as extreme temperature conditions. Another object of the
present invention is
to provide liquid herbicidal formulations based on the herbicidal dione
compounds of formula.
(I) and water, an organic solvent or a liquid co-herbicide, which formulations
are chemically '
stable.
SUMMARY OF THE INVENTION
The present invention relates to chemically stable metal chelates of
herbicidal dione
compounds of the formula (I):
X
R'
R2
tZ~n
wherein
R' represents a straight- or branched-chain alkyl, aIkenyl or alkynyi group
containing
up to six carbon atoms which is optionally substituted by one or more halogen
atoms; a
cycloalkyl group containing from three to six carbon atoms optionally
substituted by one or
more R3 groups or one or more groups selected from halogen, -COZR4; -SRS and -
ORS; a ,
cycloalkenyl group containing five or six carbon atoms optionally substituted
by one or more
R3 groups or one or more halogen atoms or a group -COzR4 or a group of the
formula
-(CHa)p phenyl-(R6)q;
R2 represents cyano; -COR'; -C02R'; or -S(O)mRg; or
R' and R2 together with the carbon atoms to which they are attached form a
five- or
six-membered 1,3-cycloalkanedione group, which I,3-cycloalkanedione group is
optionally
substituted with from one to six substituents independently selected from
halogen, (C1-
C6)alkyl, (CI-C6)alkoxy, (C,-C6)haloalkyl, (C3-C6)cycloalkyl, cyano, nitro,
(C,-C6) halo-
4

CA 02245537 1998-07-30
WO 97/27748 PCT/GB97/003Ui2
alkoxy, -C02R9, -S(O)mR'°, -NR"R'2, -C(O)R'3~ -SOZNR"R12, phenyl and
phenyl
substituted with one or more halo or CI-C4 alkyl groups, wherein two
substituents on the
same carbon atom of the 1,3-cycloaIkanedione group taken together can form an
alkylene
group having 2 to 6 carbon atoms;
R3 represents a straight-or branched chain alkyl, alkenyl or aikynyl group
containing
up to six carbon atoms optionally substituted by one or more halogen atoms; or
a cycloalkyl
group containing from three to six carbon atoms.
R4 represents a straight- or branched-chain alkyl group containing up to six
carbon
atoms optionally substituted by .one or more halogen atoms; or a cycloalkyI
group containing
from three to six carbon atoms;
R5 represents a straight- or branched-chain alkyl group containing up to three
carbon
atoms.
Rb represents a halogen atom or a group selected from -R4, vitro, cyano, -
COZR4,
_NR6iRsz ~d _OR4;
R~' represents hydrogen, a straight- or branched-chain alkyl group containing
up to six
carbon atoms optionally substituted by one or more halogen atoms, or a
cycloalkyl group
containing from three to six carbon atoms;
R62 represents a straight- or branched-chain alkyl group containing up to six
carbon
atoms optionally substituted by one or more halogen atoms, a cycloaIkyI group
containing
from three to six carbon atoms, or a group selected from -COR4, -C02R°
and -CONR4R6';
wherein R4 and R6' are part of a group -CONR4R6' they may, together with the
nitrogen to
which they are attached, form a five- or six-membered ring optionally having
one additional
heteroatom in the ring which is oxygen or nitrogen (e.g., pyrrolidine,
morpholine, pyrrole,
piperidine and piperazine), wherein the ring is optionally substituted by one
or more alkyl
groups containing up to three carbon atoms; and when R6' and R62 are part of a
group
-NR6'R62 they may, together with the nitrogen to which they are attached, form
a five- or six-
membered ring optionally having one additional heteroatom in the ring which is
oxygen or

CA 02245537 1998-07-30
. . WO 97/27748 PCT/GB9?/00302
nitrogen (e.g., pyrrolidine, morpholine, pyrrole, piperidine and piperazine),
wherein the ring
is optionally substituted by one or more alkyl groups containing up to three
carbon atoms;
R' represents hydrogen or straight- or branched-chain alkyl group containing
up to six
carbon atoms;
R8 represents (C,-C6)aikyl, (CI-C6)haloalkyl, (Cl-C6)cyanoalkyl (C3-
C8)cycloalkyi
optionally substituted with halogen, cyano or {C,-C4)alkyl; or phenyl
optionally substituted
with one to three of the same or different halogen, nitro, cyano, {C,-
C4)haloalkyl, (C,-C4
alkyl, (C~-C4)alkoxy or -S(O)mR8;
R9 represents (C,-C4)alkyl;
R'° represents (C,-C4)alkyl, (C,-C4)alkyl substituted with halogen or
cyano, phenyl or
benzyl;
R" and R'2 independently represents hydrogen or (C,-C4)alkoxy;
R'3 represents (C~-C4)alkyl or (C,-C4)aikoxy;
X represents a halogen atom; a straight- or branched-chain alkyl or alkoxy
group
containing up to six carbon atoms which is optionally substituted by one or
more groups
-OR'S or one or more halogen atoms; or a group selected from nitro, cyano, -
COZR'6,
-S(O)",R'S, -O{Cl-iz),.OR'$, -COR'6, -OSOZR'$ , -NR'6R'~, -S02NR'6R'7,
_CONR'6Ro and
-CSNR'6R";
R'S represents a straight- or branched-chain alkyl group containing up to six
carbon
atoms which is optionally substituted by one or more halogen atoms;
R'6 and R" each independently represents a hydrogen atom; or a straight- or
branched-chain alkyl group containing up to six carbon atoms which is
optionally substituted
by one or more halogen atoms;
R'8 represents a straight- or branched-chain alkyl, alkenyl or alkynyl group
containing
up to six carbon atoms optionally substituted by one or more halogen atoms; or
a cycloalkyl
group containing from three to six carbon atoms;
6

CA 02245537 2002-02-18
l~Vt19~r~'>'~a$ rc~r~r>t;s~mo3oz
nna~arQrt~~tnmmn
_ ,
each Z independently represents halo, vitro, cyano, sulfonylmethyl, S(O),"RZ,
OS(O)",Rz, (C,-
C6)s~lkyl, (Ci-C6)alkoxy, (C,-C6)haloalkyl, (C,-C6)haloalkoxy, carbvxy; (C,-
C~)~llkyicgtbonyloxy, (Ct-C6)alkoxycarbonyl, (Ct-C6)alkylcarbonyl, amino; (Ct-
C~jtllkylatttino, (Ct-C6)dialkylamino having independently the stated number
of curbott
~tttitris in egch alkyl group, (Ct-C6)alkylc~rbonylamino, (C,-
C6)alkoxycarbonylamino, (Ct-
C6)glkylaminocarbonylamino, (Ct-C6)dialkylaminocarbvnylamino having
independently the
strittd number of carbon atoms in tech alkyl group, (Ct-C6)alkoxycarbonyioxy,
(Ct-
C6)tltlkylaminocarbonyioxy, (C,-C6)dialkylantinocarbonyloxy, phenylcarbonyl,
substituted
ptinnylcarbvnyl, phenylcarbonyloxy, substituted phenylcarbvnyloxy,
phenylcarbonylgminv,
Substituted phenylcarbonylamino, phenoxy or substituted phenoxy;
m is zero, one or two;
n is zero or an integer from one to four;
p is zero yr vne;
q is zero or an integer from one to five; and
r Is one, two or three.
As used herein, the terms "halogen" and "halo" include fluorine, chlorine,
bromine
and iodine atoms. In pvlyhalogenated groups, the halogens may be the same or
different. The
term "substituted" in the terms "substituted phenylcarbonyl," "substituted
phenylcarbonyloxy; ' "substituted phenylcarbonylamino" and "substituted
phenoxy" means
having vne to five substituents, which may be the same or different, selected
from the
following: halo, vitro, cyano, S(~),"Rt, (Ct-C6)alkyl, (Ct-C6)alkoxy, (C,-
C6)haloalkyl, (Ci-
C6)haloalkoxy, carboxy, (Ct-C6)alkylcarbonyloxy, (Ct-Cs)alkylcarbanyl, (Ci-
Cs)~lkoxycarbonyl, (C,-C6)alkylcarbonylamino, amine, (Ct-Cs)alkylamino and (Ct-
C6)dislkylamino having independently the stated number of carbon atoms in each
group.
7

CA 02245537 1998-07-30
. . WO 97/27748 PCT/GB97/00302
DETAILED DESGR1PTION OF THE INVENTION
Many herbicidal dione compounds of formula (I) nave been described in a number
of
U.S. and foreign patent publications in recent years. Two known groups of
compounds within
the scope of formula (I) are particularly useful in the present invention.
These two groups of
compounds are:
(A) 2-(substituted benzoyl)-1,3-cyclohexanedione compounds of the formula:
~Z~n
(B)
wherein X, Z and n have the meanings given above; each Q independently
represents C,-C4
alkyl or -COZRa wherein R° is C!-C4 alkyl; and z is 0 or an integer
from 1 to 6; and
(B) 2-cyano-1,3-dione compounds of the formula:
Rs2
R~°
Rs3
Rs~ (IB)
wherein:
RS° is a straight- or branched-chain alkyl group containing up to six
carbon atoms
which is optionally substituted by one or more halogen atoms which may be the
same or
different; or a cycloalkyl group containing from three to six carbon atoms
which is optionally
substituted by one or more groups selected from R55 and one or more halogen
atoms which
may be the same or different;
8

CA 02245537 2004-05-05
PCTIGB9710030Z
one of Rs~ and Rs3 is -S(O)tRs6 and the other of Rst and R53 is a halogen
atom; a
straight- or branched-chain alkyl group containing up to six carbon atoms
which is substituted
by -ORSS; -Rss~ ~~.o; cyano; -SRss; -ORss; -O(CH2)SORss; yr -COZRss; and when
Rs~ is
-S(O),Rs6, Rs3 may be hydrogen;
Rs2 and Rs°, which may be the same or different, each is a halogen
atom; a hydrogen
atom; a straight- or branched-chain alkyl group containing up tv six carbon
atoms wtuch is
substituted by -ORss; -RsS; vitro: cyano; -ORss; -O(Cfl2)SORss; or -COzRss;
Rss and R56, which may be the same or different, each is a straight- yr
branched-chain
alkyl group containing up to six carbon atoms which is optionally substituted
by one or more
halogen atoms which may be the same or different;
s is an integer from I to 3; and
t is zero, I or 2.
2-(substituted benzoyl)-1,3-cyclohexanedione compounds of formula 1I are
described,
inter cilia, in U.S. Patent Nos. 4,780,127, 4,938,796, 5,006,158 and
5,089,046.
Herbicidal 2-(substituted benzoyl)-1,3-
cyclohexanedione compounds for use in this invention may be prepared by the
methods
described in the aforementioned patent publications, or by the application and
adaptation of
known methods used yr described in the chemical literature.
Especially preferred 2-(substituted benzoyl)-1,3-cyclol~exanedione compounds
useful
in the present invention include those in which z is zero; X is chloro, bromo,
vitro, cyano, Ct-
-C4 t3lkyl, -CF3, -S(O)mRts or -ORts; n is vn~e or two; >~nd each Z is
independently chloro,
bromo, vitro, cyano, C,-C4 alkyl, -CF3, -OR'S, sulfonylmethyl, -OS(O)",Rz or-
S(O)",R2. Examples of
preferred cyclvhexanedione compounds are 2-(2'-vitro-4'-
mettaylsulfonylbenzoyl)-1,3-
cyclohexane- dione, 2-(2'-vitro-4'- methylsulfonyloxybenzoyl)-1,3-
cyclvhexanedione and 2-
(2'-chloro-4'-methylsulfonylbenzoyl)-I ,3-cycloltexanedione.
Compounds of formula (1T) may exist in enolic tautomeric forms that may give
rise to
geometric isomers. Furthermore, in certain cases, the various substituents may
contribute to
9

CA 02245537 2004-05-05
VVO 97/27748 PCT/GB97l00302
optical isomerism and/or stereoisomerism. Ali such forms are embraced within
compounds
useful in the present invention.
2-Cyano-1,3-dione herbicide compounds useful in the present invention are
described
in European Patent Publication Nos. 0 496 630 and 0 496 631.
Herbicidal 2-cyano-1,3-dione compounds for use in
this invention may be prepared by the methods described in the aforementioned
patent
publications, or by the application and adaptation of known methods used or
described in the
chemical literature. Preferred 2-cyano-1,3-diones of formula (IiI) for use in
the present
invention are those in which RS° is a cycloalkyl group, most preferably
a cyclopropyl group.
Examples of preferred compounds of formula (III) are: 2-cyano-1-[2-chloro-3-
ethoxy-4-
(ethylsulfonyl)phenyl)-3-cyclopropylpropan-1,3-dione; 2-cyano-1-[4-chloro-2-
(methyl-
sulfonyl)phenyl]-3-cyclopropylpropan-1,3-dione; 2-cyano-1-[2-methylsulfonyl-4-
(trifluoromethyl)phenyl]-3-cyclopropylpropan-1,3-dione; and 2-cyano-1-[4-bromo-
2-(methyl-
sulfonyl)phenyl)-3-cyclopropylpropan-1,3-dione.
Compounds of formula (III) may exist in enolic tautomeric forms that may give
rise to
geometric isomers around the enolic double bond. Furthermore, in certain
cases, the
substituents RS~, RS~, R52, Rs3, Rsa~ Rss and Rs6 may contribute to optical
isomerism and/or
stereoisomerism. All such forms are embraced within 2-cyano-1,3-dione
compounds useful in
the present invention.
The herbicidal dione compounds useful in the present invention have been
described
above. The metal chelates of the herbicidal compounds of formula (I) can be
formed by
adding the desired metal ion to the dione compound in the presence of water or
an organic
solvent or carrier. Conveniently, an aqueous solution of an appropriate metal
salt is added to
a liquid medium, such as water or an organic solvent, having the herbicide!
dione compound
dispersed or dissolved therein, and then the metal salt and the dione compound
are allowed to
react at room temperature for a period of time sufficient to convert all of
the dione compound
to its corresponding metal chelate compound. Following conversion of the dione
to its
corresponding metal chelate, the pH of the mixture is adjusted to be between
about 2 and
about 7, using an acid such as hydrochloric acid, nitric acid, sulfuric acid
or the like.

CA 02245537 1998-07-30
WO 97/27748 PCT/GB97/00302
The formation of the metal chelate compound can be accomplished in an aqueous
phase of a composition containing another agriculturally active compound, such
as a
herbicide. According to one process, the dione compound is milled and then
added to the
aqueous phase of an herbicidal composition having a microencapsulated
agriculturally active
ingredient suspended in the aqueous phase. An aqueous solution of an
appropriate metal salt
is then added to the mixture of the herbicidal composition and the dione
compound, and
allowed to react at room temperature for a period of time sufficient to
convert ail of the dione
compound to its corresponding metal chelate. Again, the pH of the resulting
mixture is
adjusted to be between about 2 and about 7, using an appropriate acid.
According to another process of the present invention, the dione compound need
not
be milled prior to formation of the metal chelate. In this process, the dione
compound is
added to the aqueous phase of an herbicidal composition having a
microencapsulated
agriculturally active ingredient suspended therein. The pH of the resultant
mixture is then
adjusted to about 10, using sodium hydroxide or another base. An aqueous
solution of an
appropriate metal salt is then added to the mixture with stirring and crystals
of the metal
chelate of the dione compound form instantly. The reaction is allowed to
proceed until all of
the dione compound is converted to its corresponding metal chelate. Finally,
the pH of the
mixture is adjusted to between about 2 and about 7 using an acid, such as
hydrochloric acid.
According to another aspect of the invention, stable solid herbicidal
compositions
containing metal chelates of dione compounds can ,also be produced. These
solid
compositions are formed by preparing an aqueous formulation of a metal chelate
of a dione
compound alone or in the presence of a another herbicide, as described above,
and then spray
drying the resultant metal chelate composition to produce a stable, dry
particulate formulation
which can be added to water or another carrier for application to an area for
control of
undesired vegetation.
Metal ions which may be useful in forming the metal chelate compounds of the
present invention include di- and trivalent transition metal ions such as
Cu'"z, Zn+a, Co+2, Fe+z
Ni+2, and Fe+3. The selection of a particular metal ion to form the metal
chelate compound
will depend upon the dione compound to be chelated. Certain metal ions may be
more
11

CA 02245537 1998-07-30
WO 97/27748 PCT/GB97/00302
effective in imparting physical and/or chemical stability to a specific dione
compound within
the scope of formula (I) than others. Those skilled in the art will be able to
readily determine
the appropriate metal ion for use with a specific dione compound, without
undue
experimentation. The preferred metal ions are divalent transition metal ions,
particularly
Cu*z, Zn*2 and Co*2, with Cu*2 being especially preferred.
Any appropriate salt which would be a source of a di- or trivalent metal ion
may be
used to form the metal chelate of the dione compound in accordance with this
invention.
Particularly suitable salts include: chlorides, sulfates, nitrates,
carbonates, phosphates and
acetates.
It has been found that the stability of the herbicidal metal chelate
compositions of the
present invention is pH dependent. The pH of the metal chelate compositions
should be
between about 2 and about 7, with an acidic pH of less than about 6 being
preferred for most
metals. Generally, it is believed that for Cu*2 chelate compositions the pH
should be between
about 4 and 6; for Co*z between about 3 and 5; and for Ni*2 and Zn*2 about 5.
The optimum
pH for a particular metal chelate composition can be determined using routine
experimental
techniques.
It has also been found that an excess of metal ion in the final formulation
can increase
the chemical stability of the dione compound. For divalent metals, the
stoichiometric molar
ratio of dione compound to metal ion is 2:1. Thus, the minimum amount of metal
ion to be
added to the dione compound to produce the metal chelate is an amount
sufficient to provide
a molar ratio of dione to metal ion of 2:1. However, amounts in excess of the
stoichiometric
amount may enhance the chemical stability of the dione compound, and a molar
ratio of dione
to metal ion of between 2: I and 2:5 is preferred, with a molar ratio of
between about 2: l and
2:2 being especially preferred.
The metal chelates of the dione compounds are chemically stable in solid or
dry form
by themselves, but it is their chemical stability in the presence of water or
another liquid
medium or a co-herbicide which makes these chelates particularly useful in
herbicidal
formulations. As compared to the unchelated dione compounds, the metal
chelates exhibit
enhanced chemical stability in any liquid medium in which the parent dune
compound is at
12

CA 02245537 1998-07-30
. . WO 97/27748 PCT/GB97/00302
least partially soluble. The metal cheiates of the dione compounds of formula
(I) are
chemically stable in water, in other polar solvents such as dibutyl phthalate,
in commonly
used agriculturally acceptable solvents and carriers such as SOLVESSO 200, and
in liquid
agriculturally active ingredients such as acetochlor and other acetanilides,
thiafluamide,
butroxydim, esters of bromoxynil, MCPA, and 2,4-D, and the like.
Liquid formulations containing the chemically stable metal chelates of the
herbicidal
dione compounds of formula (I) can be applied directly to an area where
control of undesired
vegetation is located, using known techniques for applying liquid or flowable
herbicide
formulations. The stable, liquid formulations containing an herbicidal metal
chelate according
to the invention can also be diluted to a desired concentration of active
ingredients) prior to
application, or can be tank-mixed with one or more additional herbicidal or
other agricultural
compositions. Specific examples of other herbicides which may be incorporated
in an
herbicidal formulation with the metal chelates according the invention include
acetanilides,
tralkoxydim, bromoxynil and its esters, thiafluamide, MCPA and its esters, 2,4-
D and its
esters, and fluroxypyr meptyl.
The following examples are for illustrative purposes only and are not intended
as
necessarily representative of the overall testing performed and are not
intended to limit the
invention in any way.
I3

CA 02245537 1998-07-30
WO 97/27748 PCTlGB97/00302
EXAMPLE '1
This is an example of one process for producing an herbicidal composition
containing
a copper chelate of a 2-(substituted benzoyl)-1,3-cyclohexanedione herbicide.
Particulate, air milled technical grade 2-{2'-nitro-4.'-methylsulfonylbenzoyl)-
I,3-cyclohexanedione ("NMSBC") was blended with an herbicidal formulation
containing
microencapsulated acetochIor suspended in a continuous aqueous phase at an
acetochlor to
NMSBC weight ratio of 10:1. An aqueous solution of cupric chloride was then
added to the
formulation in a molar ratio of NMSCB to copper to 2: I . The resultant
mixture was allowed
to react overnight at room temperature to produce the copper chelate of NMSBC
in the
aqueous phase of the formulation. The pH of the final formulation was then
adjusted to 3
using hydrochloric acid.
The same process was then employed to produce a formulation in which the molar
ratio of NMSBC to copper was 2:5.
The process described above was then employed to produce two formulations in
which the molar ratio of NMSBC to copper was 1:2 and 2:5, respectively, and
the pH of the
final formulations was adjusted to 5.0 using hydrochloric acid.
Samples of each of these formulations were stored at 50° C for four
weeks to
determine their chemical stability. After storage, samples were extracted and
analyzed by high
pressure liquid chromatography (HPLC). The procedure for extracting NMSBC from
the
copper chelate for analysis was as follows. To convert the copper chelate of
NMSBC to its
parent compound, the formulation was treated with concentrated hydrochloric
acid.
Concentrated hydrochloric acid {5 grams) was added to a I gram sample of the
formulation.
The mixture was sonicated for 5 minutes. Then, 10 grams of chloroform was
added to extract
NMSBC. After centrifuging to get phase separation, 5 grams of the chloroform
phase was
withdrawn. The chloroform was allowed to evaporate and the remaining NMSBC was
analyzed by HPLC. The results of these storage stability tests are shown in
Table 1 below.
The results of the same chemical stability testing conducted on control sample
formulations in
14

CA 02245537 1998-07-30
WO 97/27748 PCT/GB97/00302
which NMSBC was suspended in the aqueous phase of a microencapsulated
acetochlor
formulation without chelating the NMSBC are also shown in Table 1.
Table 1
' Molar ratio o f pH Storage Weight % of NMSBC
NMSBC: Cu Temperature remaining after 4
week;
storage
2:1 3.0 - 50 C 97%
2:5 3.0 50 C 97%
2:1 5.0 50 C 97.5%
2:5 5.0 50C 100%
No Cu+Z 3.0 SOC 65%
No Cu+2 5.0 50C 30%
The above results clearly demonstrate the superior chemical stability of the
copper chelate of
NMSBC as compared to non-chelated NMSBC under the same conditions.
EXAMPLE 2
The chemical stability of various metal chelates dispersed in water was
studied
Using appropriate metal salt solutions, the following metal chelates of NMSBC
were
prepared: Cu+2, Ca+2, Zn+2, Mg+2, AI+3, Co+2, Fe+3~ Fe+2 ~d Ni+2. In each
instance, NMSBC
was dispersed in water and then the appropriate aqueous solution of a metal
salt was added in
an amount suffcient to provide a molar excess of metal ion with respect to
NMSBC. The
resultant mixture was allowed to react overnight at room temperature to permit
an aqueous
dispersion of the respective metal chelate to form. The pH of each metal
chelate suspension
was adjusted to about 7 or less using hydrochloric acid. Samples were stored
at 50°C for f~ur
weeks and then extracted and analyzed as described in Example 1. Table 2 below
shows the
results obtained from this four week storage test. Table 2 also shows the
results of the same
chemical stability testing conducted on a control sample in which NMSBC was
not chelated.

CA 02245537 1998-07-30
. . WO 97/27748 PCT/GB97/00302
TABLE 2
Metal Storage Weight % of NMSBC
(on pH remaining after 4 week
store a at SOC
~+3
3.0 69%
~+3
5.4 70%
Ca+2 5.0 66%
Ca+2 7.6 24%
Co+2 3.0 97%
Co+2 5.0 85%
Cu+2 5.0 100%
Cu+a
7.0 99%
Fe+Z 2.0 84%
Fe+3
2.0 73 k
Fe+3 7.0 38%
Mg+i 3.2 80%
Mg+2 5.4 76%
Ni+2
5.0 93 %
Ni+2 7.0 61 %
~+2 5.0 100%
None 5.0 81 %
The results shown in Table 2 demonstrate that the divalent transition metal
chelates of
NMSBC, particularly the Zn+2, Co+Z and Ni+2 chelates, and most especially the
Cu+Z chelate,
exhibit superior chemical stability in water as compared to non-chelated
NMSBC.
16

CA 02245537 1998-07-30
. . WO 97/27748 PCTlGB97/00302
EXAMPLE 3
The chemical stability of various metal chelates of NMSBC in the aqueous phase
of a
microencapsulated acetochlor formulation was studied. The procedure of Example
I was
followed, using the appropriate metal salt solutions, to prepare the following
metal chelates of
NMSBC: Cu+z, Ca+2, Zn+z, Mg+z, ~+s, Co+z, Fe+3, Fe+z and Ni+2. In each
instance, the
NMSBC was compIexed with the metal ions in the aqueous phase outside the
acetochlor
microcapsules. The amount of metal ion added to the aqueous phase was an
amount
sufficient to provide a molar ratio of NMSBC to metal ion of 2:5. Samples were
stored at 50°
C for four weeks and then extracted and analyzed as described in Example 1.
Table 3 below
shows the results obtained from this four week storage test. These results
indicate that the
chemical stability of NMSBC varies depending upon the metal ion used to form
the chelate
and varies depending upon the storage pH. Table 3 also shows the result of the
same chemical
stability testing conducted on a control sample formulation in which NMSBC was
suspended
in the aqueous phase of a microencapsulated acetochlor formulation without
chelating the
NMSBC.
TABLE 3
Metal Storage Weight % of NMSBC
lon pH remaining after
storage
at 50C
2 weeks 4 weeks
~+3 3.0 38.5!0
'~+3 4.5 34.8%
Ca+z 5.0 6.9% 2.2%
Ca+Z 7.4 43.5% 38.3%
Co+z 3.0 83.8% 77.3%
Co+2 5.0 95.7% 91.8%
Cu+z 3.0 99.1 % 102.9%
Cu+z 5.0 100.2% 98.9%
Fe+z 2.0 49.9%
Fe+3 1.0 64.3%
17

CA 02245537 1998-07-30
. . WO 97/27748 PCT/GB97/00302
TABLE 3
Meta! Storage Weight % of NMSBC
PH remaining after storage
at 5~C
2 weeks 4 weeks
Fe+ 2.0 54.1 %
Mg+2 5.0 19.9%
Ni+z 5.0 30.4%
~+2
5.0 92.8% 93. I %
None 3.0 75.2% 64.9%
None 5:0 38.2%
30.0%
The results shown in Table 3 demonstrate the improved chemical stability of
the Cu+2,
Co+2 and Zn+Z chelates of NMSBC in an aqueous formulation of acetochlor
microcapsules as
compared to a non-chelated NMSBC.
EXAMPLE 4
Storage tests at 50° C, as described above, were conducted to determine
the effect of
storage pH on the chemical stability of several different metal chelates of
NMSBC. Chemical
stability determinations were made after 2 weeks and 4 weeks of storage.
Formulations of
metal cheiates of NMSBC in the aqueous phase of a suspension of
microencapsulated
acetochlor were made according to the processes described in Examples 1 and 3,
except that
the molar ratio of metal ion to NMSBC used in each formulation was 1.1:2.
Table 4 below
shows the chemical stability of NMSBC complexed with Cu+2, Zn+2 and Co+2 in
the aqueous
phase of a formulation of microencapsulated acetoehlor at various pH levels of
the final
formulation. These results indicate that the chemical stability of the metal
chelates of
NMSBC is dependent on the storage pH of the formulation.
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Table 4
Metal Storage Weight % of NMSBC
lon pH remaining after storage
at 50C
2 weeks 4 weeks
Cu+2 5.0 97.0% 97.5%
?.0 97.7% 98.8%
9.0 86.2% 80.8%
I0.0 69.6%
~+2 5.0 59.5%
7.0 65.1 %
9.0 23.1 %
10.0 I0.5%
Co+2 5.0 68.0%
7.0 37.3%
9.0 10.7%
10.0 4.6%
EXAMPLE ~
This example shows the preemergence herbicidal activity of formulations
prepared
according to Examples 1 and 3, which contain metal chelates of NMSBC together
with
microencapsulated acetochlor in the aqueous phase the formulation. A control
formulation
containing NMSBC suspended in the aqueous phase of a microencapsulated
acetochlor
formulation was also tested, for comparison purposes. The herbicidal testing
was conducted
as follows.
On the day preceding treatment, seeds of several different weed species were
planted
' in sandy loam soil containing only trace organic matter. Propagules were
sown in individual
rows using one species per row across the width of an aluminum flat. Seeding
depths ranged
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from I.0 to I.S cm and plant densities ranged from 3 to 25 plants per row
depending on
individual plant species.
For the screening tests results shown in Table 5, the grass weeds planted were
barnyardgrass (Echinochloa crus-galli); large crabgrass (Digitaria
sanguinalis); rigid ryegrass
(Lolium rigidum); wild proso millet (Panicum miliaceum); and shattercane
(Sorghum
vulgare). The average control achieved against these grass species ("AVG") is
indicated in
Table 5. The broadleaf weeds planted were velvetleaf (Abutilon theophrasti);
common
sunflower (Helianthus annuus); ivyleaf morningglory (Ipomoea hederacea);
common
purslane (Portulaca oleracea); and common cockleburs (Xanthium strumarium).
The average
control achieved against these broadleaf species ("AVB") is indicated in Table
5.
The soil surface was sprayed inside an enclosed linear spray table with the
nozzle set
above the soil line. The spray table was calibrated to deliver the appropriate
amount to
provide the desired application rates, as indicated. After treatment, the
flats were placed into a
greenhouse and watered as needed. The greenhouse environmental systems
provided the
plants with natural and artificial lighting to attain 14 hours of light per
day. Day and night
temperatures were maintained at 29° and 21 °C, respectively.
The degree of weed control was evaluated and recorded 17-21 days after
treatment as
a percentage of weed control as compared to the growth of the same species of
the same age
in an untreated control flat. Percent control is the total injury to the
plants due to all factors
including: inhibited emergence, stunting, malformation, chlorosis and other
types of plant
injury. The control ratings range from 0 to 100 percent, where 0 represents no
effect with
growth equal to the untreated control and where 100 represents complete kill.

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Table 5
Application Weed
Rate (ct/ha) Control
Formulation pH Acetochior NMSBC AVB AVG.
' Acetochlor/NMSBC-Cu+23 30 3 23 66
100 10 55 95
300 30 85 98
900 90 98 100
Acetochlor/NMSBC-Cu~25 30 3 6 55
100 10 32 76
300 30 89 100
900 90 97 I00
Acetochlor/NMSBC-Ca+27 30 3 2 58
100 10 28 92
300 30 81 I00
900 90 97 100
Acetochlor/NMSBC-Co+25 30 3 0 I9
100 10 18 45
300 30 79 87
900 90 97 98
Acetochlor/NMSBC-Zn+25 30 3 4 68
I00 10 34 95
3~ 30 81 99
900 90 97 100
Acetochlor/NMSBC-Fe+32 30 3 0 I9
I00 10 28 50
300 30 77 83
900 90 95 97
Acetochlor/NMSBC - 30 3 7 69
100 10 42 89
300 30 95 99
900 90 g9 Ipp
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The results shown in Table 5 demonstrate that chelation of NMSBC with
transition
metal ions does not reduce the herbicidal efficacy of a formulation containing
acetochlor and
the metal chelate as compared to a similar composition containing acetochlor
and non-
cheIated NMSBC.
EXAMPLE fi
This is an example of a process for preparing a chemically stable, dry form of
an
herbicidal formulation containing the copper chelate of NMSBC and acetochlor.
The copper chelate of NMSBC was formed in the aqueous phase of a formulation
of
microencapsulated acetochlor as described in Examples 1 and 3. After formation
of the
copper chelate, the formulation was spray-dried to remove the water and form a
dry
formulation. Dry samples were stored at 50° C and after 2 weeks and
then 4 weeks, samples
were extracted and analyzed by HPLC, as described previously, to determine the
amount of
NMSBC remaining. For comparison purposes, a formulation containing unchelated
NMSBC
in the aqueous phase was also prepared, spray-dried and tested for chemical
stability. The
results of these tests are shown in Table 6 below.
Table 6
Metal NMSBC/Metal Weight % of NMSBC
Ion Molar Ratio remaining after storage
at 50C
2 weeks 4 weeks
None N/A 20.6!0 0.0%
Cu+2 2/1
84.4% 65.2%
Cu+2 2/5 98.4% 101.4%
The results in Table 6 show that the Cu+2 chelate of NMSBC is stable in dry
form in
the presence of acetochlor microcapsules.
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EXAMPLE 7
This is an example of another process for preparing an herbicidal formulation
containing the copper chelate of NMSBC and microencapsulated acetochlor in the
aqueous
phase thereof. Technical grade NMSBC, which had not been milled, was dispersed
in the
aqueous phase of an herbicidal formulation containing microencapsulated
acetochlor. The pH
of the formulation was then adjusted to 10 by adding a sufficient amount of
sodium
hydroxide. An aqueous copper sulfate solution was then added to the
formulation while
stirring. Instantly, crystals of the copper-NMSBC chelate formed and began to
precipitate.
The chelation reaction was completed within about 10 minutes. This process was
repeated
several times to produce mixtures having the NMSBC:Cu+2 ratios and pHs shown
in Table 7.
Samples were stored at SO°C and extracted and analyzed as described in
Example l, after 4
weeks and 8 weeks storage. The results of this stability testing are shown in
Table 7.
Table 7
NMSBClCu'' Weight % of NMSBC
Molar Ratio pH remaining after storage
at 50°C
4 weeks 8 weeks
2/i.I S.0 97.6% 9S.S%
2/1.1 7.0 93.2% 91.1
2/l.S S.0 98.1 % n.d.
2/1.S 7.0 96.9% n.d.
n.d. - not determined
EXAMPLE 8
Copper chelates of 2-(2'-chloro-4.'-methylsulfonylbenzoyl}-1,3-
cyclohexanedione
("CMSBC"), 2-(2'-nitro-4'-trifluoromethylbenzoyl)-1,3-cyclohexanedione
("NTMBC") and
- 2-(2'-methyl-4'-methylsulfonylbenzoyl)-4,4,6-trimethyl-1,3-cyclohexanedione
("MMSBTC")
were prepared as follows. An aqueous suspension of each cyclohexanedione
compound was
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prepared. An aqueous cupric sulfate solution was added to the cyclohexanedione
suspension
and the chelation reaction was allowed to proceed to completion. Each copper-
chelated
cyclohexanedione suspension was then blended with an aqueous formulation of
microencapsulated acetochlor which had a pH of about 10. The weight ratio of
cyclohexanedione (based on the unchelated cyclohexanedione) to acetochlor in
each
formulation was 1:10. The pH of the fnal formulation was adjusted to 5.0 by
adding
hydrochloric acid.
To test the chemical stability of these cyclohexanedione compounds in an
aqueous
acetochlor rnicrocapsule formulation, samples of the three formulations
prepared above were
stored at SO° C for four weeks. 'Corresponding samples of the same
cyclohexanediones
without cheIation were also prepared and tested for chemical stability during
storage. After
storage, samples of both the chelated and unchelated formulations were
extracted and
analyzed by HPLC, as previously described, to determine the amounts of
cyclohexanedione
remaining in the formulation. Table 8 shows the results of these storage
tests.
Table 8
Compound Metal lon Weight % of Compound
remaining after 4 week
CMSBC Cu+2 100.0%
CMSBC None g~.$ofo
Cu+2 84.5%
NTMBC None 71.2%
MMSBTC Cut2 100.0%
MMSBTC None 86.2%
The results shown in Table 8 demonstrate the improved chemical stability ,
exhibited by the Cu+2 chelates of a variety of dione compounds as compared to
the respective
non-chelated compounds.
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EXAMPLE 9
This example demonstrates the chemical stability of a copper chelate of NMSBC
in an
herbicidal formulation of liquid, non-encapsulated acetochlor. An aqueous
dispersion of the
copper chelate of NMSBC was produced and then this copper chelate was air
dried. The
dried copper chelate of NMSBC was added to a liquid acetochlor composition
which
contained dichlormid, a safener for the acetochlor, at an
acetochlor:dichlormid ratio of 6:11.
The chemical stability of the NMSBC copper chelate in the acetochlor
formulation after two
weeks storage at 50°C was determined, using the procedures described in
Example I. The
results are shown in Table 9 below, together with the results of a control
sample in which the
NMSBC was not chelated.
Table 9
Metal Weight % of NMSBC
Ion remaining after 2
week storage
Cu+2 96.3%
None 34.7%
These results demonstrate the chemical stability of the Cu+2 chelate of NMSBC
in a
non-aqueous liquid herbicidal formulation containing a safener and various
formulation
additives, such as would be found in many typical commercial formulations of
liquid
herbicides.
Although the invention has been described with reference to preferred
embodiments
and examples thereof, the scope of the present invention is not limited only
to those
described embodiments. As will be apparent to persons skilled in the art,
modifications and
adaptations to the above-described invention can be made without departing
from the spirit
and scope of the invention, which is def ned and circumscribed by the appended
claims.

Representative Drawing