Note: Descriptions are shown in the official language in which they were submitted.
This invention provides novel substituted heterocyclic
phenoxyalkanoic acid derivatives of the formula I
(R) _ ~ ~ ~ C-X- ~O ~ O-C-Z (I)
in which
, 3, NO2, CN, NH2, (Cl - C4)alkyl, (Cl - C )alkoxy
(Cl - C4)alkylthio, or phenoxy which is optionally mono-, di- or
tri-substituted by halogen, CF3, (Cl - C4)alkyl or NO2,
n is zero or an integer from 1 to 4,
A is O, S, NH, or N-(Cl - C4)alkyl,
X is -CH2- or -CH2-CH2,
Rl is H or (Cl - C4)alkyl,
Z is a group of the formula
O O O O R6 R8 S
" 3 " 4 " 5 " ' ~ "
-C-OR , -C-S-R , -C-NH-R , -C-N-N ~ 7 ~ -C-NH2l CN,
o
-CH2OH, -CH2-0-C-R or -CH2-0-S02-R
R is H, (Cl - C12)alkyl optionally substituted by 1 to 6 halogen
atoms, preferably F, Cl, Br, and/or by OH, (Cl - C6)alkoxy,
(Cl - C4)alkylthio, (Cl - C6)alkoxy (C2 - C6)alkoxy, halo(Cl - C2)-
alkoxy, methoxyethoxyethoxy, (Cl - C4)alkylamino, di(Cl - C4)-
alkylamino, (Cl - C4)alkoxycarbonyl, phenyl and phenoxy which in
turn may be mono- or disubstituted by halogen or
(Cl - C4)alkyl,
(C5 - C6)cycloalkyl or halo(C2 - C6)alkyl;
(C3 - C6)alkenyl, halo(C3- C6)alkenyl or (C5 - C6)cycloalkenyl;
- 2 -
g~
(C3 - C4)alkinyl, optionally mono- or disubstituted by (Cl - C6)-
alkyl, phenyl, halogen, or (Cl - C2)alkoxy; phenyl optionally mono-,
di-, or trisubstituted by (Cl - C4)alkyl, (Cl - C4)alkoxy, halogen,
N02, or CF3i or an alkali metal or alkaline earth metal cation;
R4 is (Cl - C6)alkyl optionally substituted by (Cl - C4)alkoxy,
halogen or phenyl which in turn may be mono-, di- or trisubstituted
by (Cl - C4)alkyl and halogen;
(C3 - C6)alkenyl or phenyl which is optionally mono-, di- or tri-
substituted by (Cl - C4)alkyl and/or halogen;
R5 is H, ( C1 - C6 ) alkyl, hydroxy(Cl - C6)alkyl, or ( C5 - C6 ) cyclo-
alkyl;
R is H or CH3;
R is H, CH3 or C2H5;
R8 is H, CH3, C2H5, or phenyl;
R is (C1 - C6)alkyl, (C1 - C4)haloalkyl, C3-, C5-, or C6- cyclo-
alkyl, (C3 - C6) alkenyl, phenyl, (Cl - C4)alkylphenyl, (Cl - C4)-
alkoxyphenyl, halophenyl, trifluoromethylphenyl, or nitrophenyl; and
R is (C1 - C4)alkyl or phenyl which is optionally mono-, di-, or
trisubstituted by halogen, CF3, N02, or (Cl - C4)alkyl.
The compounds according to the invention are valuable
herbicides which exhibit a special effect against weed grasses.
GB-PS 1,157,558 discloses certain compounds of the
formula I in which Z denotes different carboamido and carbanilido
radicals (not claimed in this specification) having vasodilatory
properties. Nothing is said about any herbicidal effect. Experi-
ments have revealed, however, that they do have a certain herbicidal
activity.
Alkyl, alkenyl or alkinyl groups occurring in the radicals
-- 3 --
3Z
R1 to R5, R9 and R10 can be linear as well as branched.
Preferred compounds of the formula I are those in which
R is halogen or (Cl - C2)alkyl,
n is zero or 1 or 2,
A is 0, S or (N-(Cl - C4)alkyl,
X is -CH2- or -CH2-CH2-,
Rl is H or CH3,
Z is a group of the formula
O O S
-COR , -C-NH-R -CNH2 or -CN
R3 is H, (C1 - C8)alkyl optionally substituted by halogen or
(Cl - C6)alkoxy, or an alkali metal or alkaline earth metal cation,
R is H or (Cl ~ C4)alkyl.
Especially preferred compounds of the formula I are those
in which
R is chlorine or bromine, n is zero or 1, A is O or S, X is -CH2,
Rl is -CH3, Z is -CooR3, and R3 is Hl (Cl - C6)alkyl optionally
substituted by (Cl - C4)alkoxy, Cl or Br, or is an alkali metal
or alkaline earth metal cation.
The compounds of the formula I can be produced from start-
ing materials known per se or obtainable by known methods. Theprocesses of the invention are characterized in that
a) a compound of the formula II
(R)n ~ ~H2 (II)
is reacted with a compound of the formula III
" ~ Rl (III),
~9~9z
in which Q is hydroxy, alkoxy or halogen and Z' is lower alkoxy-
carbonyl;
b) a compound of the formula IV
n ~ J ~ ~ ~ (IV)
is reacted with a compound of the formula V
~ i Rl
W-CH-Z (V),
in which W is halogen, toluenesulfonyl Qr methanesulfonyl radical;
c) a compound of the formula I in which Z is -CooR3 is hydro-
genated and the alcohol obtained (Z = CH20H) is optionally converted
into the corresponding carboxylic acid ester (Z = CH2-0-,C,-R ) by
reaction with a carboxylic acid, carboxylic acid halide or carboxylic
anhydride, or is converted into the sulfonic acid ester
(Z= -CH2-0-S02-R10) by reaction with a sulfonic acid halide;
d) a compound of the formula I in which Z is an ester group is
converted in known manner into a salt (Z = CooR3) in which R3 is a
cation as defined above or the free acid (Z = COOH);
e) a compound of the formula I in which Z is -CooR3 is reacted
with ammonia, an amine or hydrazine to give the corresponding acid
amide (Z = CONHR ) or acid hydrazide
(Z = -CO-N(R )-N ~ 7
R
f) a compound of the formula I in which Z is -COOH is converted
into the corresponding acid halide which is then converted into the
acid amide, acid hydrazide or ester by reaction with an amine, a
ny~razine or an alcohol;
3~
g) a compound of the formula I in which Z is a low molecular
weight ester group is transesterified with an alcohol of the
formula R OH;
h) a compound of the formula I in which Z is -CO-NH2 is dehy-
drated and the nitrile obtained (Z - CN) is converted, if desired,
into the corresponding thioamide (Z = CS-NH2) by addition of H2S.
Item a): Preferably the free acids (Q = OH) or the acid
halides (Q = Cl) are used as starting compounds III. The reaction
may be carried out in the presence or absence of a solvent at a
temperature of from 100 to 200C. Preferred solvents are xylene,
chlorobenzene, dichlorobenzene. The water formed in the reaction is
distilled off.
Item b): The reaction is preferably carried out in inert
aprotic solvents such as aliphatic or aromatic hydrocarbons, for
example benzene, toluene, acetonitrile, acetone, dimethy] sulfoxide,
or dimethyl formamide at temperatures of from 50C to the boiling
point of the solvent used, in the presence of a base, for example an
alkali metal carbonate, alkali metal hydroxide or a tertiary organic
base. W denotes halogen or a sulfonic acid radical selected from
tosyl and mesyl radicals.
Item c): The reduction of acids or esters to give alcohols
is preferably carried out with a complex metal hydride such as
LiAlH4, in ethereal, anhydrous solvents. In general, the reaction
is exothermic and, therefore, heating from the outside is unnecessary.
The subsequent esterification with acid anhydrides or halides is
carried out in an inert solvent (as used in method a) at a temper-
ature between 0C and the boiling point of the solvent used with
;,
addition of an organic or inorganic base, for example Na2C03,
K2C03, pyridine or triethylamine. The esterification with
carboxylic acids is carried out either with the addition of a
water binding agent such as P205 or by extractive azeotropic
distillation of the acidified components.
- 6a -
- 7 - HOE 79/F 039
Item e): The reaction is preferably carried out in a
solvent as specified in b), the reaction temperature being
in the range of from 40C to reflux temperature.
Item f): The acids of the formula I are converted into
the acid halide in known manner. The same applies to the
subsequent reaction with ammonia, amines or hydrazines. To
bind the hydrogen halide set free an at least one molar
excess of the base used is necessary.
Item g): The reaction proceeds by means of acid or
basic catalysis. The alcohol used for transesterification
is preferably added in an excess and the lower boiling
alcohol set free is distilled off as it is formed.
It,em h): The dehydration of amides to give nitriles
is preferably carried out in an aromatic hydrocarbon at a
temperature between 50C and boiling temperature. The
subsequent addition of H2S is expediently performed in
an autoclave in the presence of catalytic amounts of a
base, preferably ethanol amine, at temperatures between 50
and 150C.
The heterocyclic phenols of formula IV used for the
manufacture of the compounds of formula I are preferably
prepared by condensation of aminophenols, aminothiophenols
and diaminobenzenes with 4-hydroxyphenylacetic acid or 3-
(4'-hydroxyphenyl)-propionic acid while distilling off
25 water at reaction temperatures of 120 to 200C.
The compounds of the formula I according to the in-
vention exhibit a very good herbicidal effect in pre-emer-
gence and post-emergence application against a broad spec-
trum of monocotyledonous weeds while, at the same time,
they are excellently tolerated by dicotyledonous crop
plants and some cereals.
The compounds can, therefore, be used, irter alia,
for the selective control of weed grasses in crop plants.
It is, therfore, another object of the present invention
to provide herbicidal compositions containing a carrier
and a herbicidally effective amount of a compound of the
formula I.
'3~
- 8 - HOE 79/F 039
The compositions of the invention generally contain
from 2 to 95 % by weight of the compounds of the formula I
as active substance. The compositions can be formulated as
wettable powders, emulsifiable concentrates, sprayable so-
lutions, dusts and granules, together with the usual addi-
tives.
Wettable powders are formulations which are uniformly
dispersible in water and which, in addition to the active
compound and a diluent or inert material, also contain
wetting agents, for example polyoxethylated alkylphenols,
polyoxethylated oleyl- or stearylamines, alkylsulfonates or
alkylphenylsulfonates, and dispersing agents, for example
sodium ligninsulfonate, sodium-2,2'-dinaphthylmethane-6,6'-
disulfonate or the sodium salt of oleoylmethyl taurine.
Emulsifiable concentrates are obtained by dissolving
the active compound in an organic solvent, for example bu-
tanol, cyclohexanone, dimethyl formamide, xylene or even
higher boiling aromatics, and adding a non ionic emul-
sifier, for example a polyoxethylated alkylphenol or a
polyoxethylated oleyl-or stearylamine.
Dusts are obtained by grinding the active compound
together with finely divided solid substances, for example
talc, natural clays such as kaolin, bentonite, pyrophillite
or diatomaceous earth.
Granules can be manufactured either by spraying the
active compound onto adsorbent, granular inert material or
by applying active compound concentrates by means of adhe-
sives, for example polyvinyl alcohol, sodium polyacrylate
or even mineral oils, onto the surfaces of carriers, such
as sand, kaolinites or granular inert material. Suitable
formulations can also be manufactured by the customary me-
thods of manufacture of fertilizer granules, if desired in
admixture with fertilizers.
In the herbicidal compositions the conentrations of
the active compounds in the commercial formulations may
vary. In wettable powders, the active compound concentra-
tion varies, for example, between about 10 and 95 %, the
- 9 - HOE 79/F 039
remainder consisting of the abovementioned formulation ad-
ditives. In the case of emulsifiable concentrates, the ac-
tive compound concentration is about 10 % to 80 %. Dust
formulations usually contain 5 - 20 % of active compound,
and sprayable solutions about 2 - 20 ~. In the case of
granules, the active compound content in part depends on
whether the active compound is in a liquid or solid form
and what granulation auxiliaries, fillers and the like are
used.
The commercial concentrates are diluted prior to appli-
cation in the usual manner, for example by means of water
in the case of wettable powders and emulsifiable concentra-
tes. Dusts, granules and sprayable solutions need not be
diluted with further inert material prior to use. The
amount of active ingredients necessary for obtaining the
desired result depends on external conditions such as tem-
perature, humidity and the like. It may vary within wide
limits, for example between 0.05 and 10.0 kg of active sub-
stance per hectare, preferably however, between 0.1 and
5 kgihectare.
The active compounds according to the invention can
be combined with other herbicides, insecticides and fun-
gicides.
The following examples illustrate the invention.
EXAMPLES OF MANUFACTURE
E x a m p l e
2-/ 4' (2"-Benzthiazolylmethyl)-phenoxy_7-propionic acid
eth l ester
y
24.1 g (0.1 mol) of 4-(2'-benzthiazolyolmethyl)-phe-
30 nol, 16.6 g (0.12 mol) of potassium carbonate and 19.9 g
(0.11 mol) of 2-bromopropionic acid ethyl ester in 100 cc
of acetonitrile are refluxed for 8 hours. Inorganic salts
are filtered off, acetonitrile is distilled off under re-
duced pressure and the residue is distilled in high vaccum.
35 30 g _ 88 ~ of theory of 2-/ 4'-(2"-benzthiazolylmethyl)-
phenoxy_7-propionic acid ethyl ester are obtained (boil-
ing point 205 - 208C, 0.07 mbar).
9 ~ Z
- 10 - HOE 7~/F 039
~ ~CH2-~)-OCHC02C2H5
E x a m p l e 2
2-/ 4'-t2"-Benzthiazolylmethyl)-phenoxy_7-propionic acid
_________________________________________________________
34.1 g (o.1 mol) of 2-/ 4'-(2"-benzthiazolylmethyl)-
phenoxy_7-propionic acid ethyl ester, 4,4 g (0.11 mol) of
sodium hydroxide, 200 cc of water and 50 cc of methanol
are stirred for 16 hours at room temperature. The reaction
mixture is acidified with 15 cc of concentrated hydrochlor-
ic acid, the precipitate formed is filtered off and dried.
30 g = 96 % of theory of 2-/ 4l-(2~'-benzthiazolylmethyl)-
phenoxy_7-propionic acid melting at 154 to 156C are ob-
tained.
~ ~CH2-~-OCHCOOH
The following compounds are prepared in analogous manner.
x. No. compound accord. b.p./m.p.
to Ex.
(process)
__________________________________________________________
N CH
3 ~ / 2 ~ 2 3 m.p. 63C
N CH
4 ~ ~ CH2- ~ CHc2c2H5 1 b.p.174-6C
0.013 mbar
3~Z
~ HOE 79/F 039
Ex. No. compound accord. b.p./m.p.
to Ex.
(process)
__________________________________________________________
~ ~ CH2- ~ -OCHCO2CH3 1 m.p. 70C
6 ~ N~ CH3 2 vitreous
S mass
Cl ~ ~ CH2- ~ -OCHCO2C2H5
8 ~ N~ CH3 1 b.p. 192C
Cl O 0.007 mbar
C ~ ~ CH2- ~ -OCHC02C2H5
Cl ~ N~ CH3 b.p. 181C
0 0.005 mbar
Cl ~ CH2 ~ CHc2cH2cH2cH3
N CH
12 C ~ ~ H2 ~ OCHCO2CH2CH2Cl
3~2
- 12 - HOE 79/F 039
Ex . No. compound accord. b.p./m.p.
to Ex.
( proc es s )
________________________________. ___________. _ ___________
3 ~ \~CH2~-OCH2CO2CH3 1 m.p 91 -
~CH2-~-OCHC02CH3 1 b.p. 226C
N O . 08 mbar
CH3
(~ ~CH2~-OcHc02c2H5 1 b.p.206C
N O . 07 mbar
CH3
16 ~ ~ CH2-CH2 ~ -OCHC02CH3 1 m p 65 -
7 ~ ~ CH2-CH2- ~ CHc2c2H5 1 b.p. 198C
S 0.01 mbar
18 ~ ~CH2-GH2~-ocHco2cH3 1 b.p. 190C
S O . 007 mbar
19 Cl ~ ~/ CH2~0CHc02cH2cH ( CH2 ) 2
3;~3~
- 13 - HOE 79/F 039
Ex. No. compound accord. b.p./m.p.
to Ex.
(process)
__________________________________________________________
20Cl ~ ~ CH2- ~ -OCHCH2OH c
Cl~ ~CH ~0 CH COS C 2H 5
22~ ~ CH2- ~ -o8HCoNHC2H5
23Cl ~ ~ CH ~ -OCH-CN h
24 Cl ~ N~ CH3
Cl ~ N~ CH3 5 h
O NH2
3~
- 14 - HOE 79/F 039
EXAMPLES OF FORMULATION
E x a m p l e A:
An emulsifiable concentrate is obtained from
15 parts by weight of active substance
75 parts by weight of cyclohexanone as solvent and
10 parts by weight of oxethylated nonyl phenol (10 EO) as
emulsifier.
E x a m p l e B:
A wettable powder which is easily dispersible in wa-
ter is obtained by mixing25 parts by weight of active substance
64 parts by weight of kaolin containing quartz as inert
material,
10 parts by weight of potassium lignosulfonate and5 1 part by weight of sodium oleoyl-methyl tauride as wet-
ting and dispersing agent, and grinding the
mixture in a pin mill.
E x a m p l e C:
A dust composition is obtained by mixing
10 parts by weight of active substance and
90 parts by weight of talc as inert material
and grinding the mixture in a hammer mill.
E x a m p l e D:
A granular formulation consists, for example, of about
2 to 15 parts by weight of active substance and
98 to 85 parts by weight of inert granular carrier material
such as attapulgite, granular pumice and quartz sand.
EXAMPLES OF APPLICATION:
E x a m p l e
Various economically important weed grasses and crop
plants were sown in pots and treated in pre-emergence
application ~ith compounds according to the invention. The
pots were then kept in the greenhouse under good growing
conditions. 4 Weeks after the treatment the herbicidal
effect against the weed grasses and the selectivity with
respect to the crop plants were evalated by visual inspec-
tion. The damage in percent in comparison with untreated
- 15 - HOE 79/F 039
plants is indicated in the following Table 1. The results
show that the compounds of the invention have a good her-
bicidal effect against many weed grasses and simultaneously
that they do no harm or little harm only to the crop
plants even in a high dosage of 2.4 kg of active substance
per hectare. Hence, they can be used for selectively com-
bating weeds in such cultivations.
E x a m p l e 2
In analogous manner the compounds of the invention
were sprayed in a post-emergence process on some important
types of weed grasses and various crop plants which had
been grown in the greenhouse to a height of 8 to 15 cm.
4 Weeks after the treatment in the greenhouse the plants
were inspected as to their damage in percent. The results
listed in Table 2 show that also in a post-emergence pro-
cess the compounds of the invention can be used for selec-
tively combating weed grasses in crops of numerous di-
cotyledonous and monocotyledonous plants, such as cotton
or'rice.
i
3~2
- 16 - HOE 79/F 039
Table 1
Herbicidal effect and selectivity of compounds of the in-
vention in a pre-emergence process
Effective- Selectivity in crop
ness against plants (damages in %)
Ex. No. kg AS/ha AL ECG SA GH GS BA
in % _ _
2.4 100 100 100 0 2 5
0.6 100 100 95 o o O
2 2.4 98 99 95 4 5 4
0.6 g5 98 90 0 0 0
3 2.4 85 90 90 o o o
4 2.4 85 90 75 0 0 0
1 2.4 99 99 95 0 O O
o.6 98 95 90 - - -
2.4 100 loO 95 o o o
0.6 98 95 92 - - -
Al = Alopecurus
ECG = Echinochloa
SA = Setaria
CH = Cotton
GS = Soybean
BA = Sugar beet
- 17 - HOE 79/F 039
Table 2
Herbicidal effect and selectivity in a post-emergence
process ~damages in ~)
Ex. No. kg AS/ha AL ECG SA GH GS BA HV OS
2.4 100 99100 0 2 1 7 4
0.6 96 9999 0 0 0 1 2
2.4 96 9595 0 2 0
0.6 92 90 - O O O - -
_
HV = Barley
OS - Rice
