CA1095735A

CA1095735A - Herbicidal compositions

Info

Publication number: CA1095735A
Application number: CA275,189A
Authority: CA
Inventors: Reinhard Handte; Helmut Kocher; Gerhard Horlein; Manfred Koch; Peter Langeluddeke
Original assignee: Hoechst AG
Current assignee: Hoechst AG
Priority date: 1976-03-31
Filing date: 1977-03-30
Publication date: 1981-02-17
Also published as: JPS6146444B2; AU505610B2; DE2613697A1; AT354801B; PT66361B; PT66361A; AU2376277A; BE853104A; NL7703250A; ATA213177A; FR2346329A1; IL51768A0; SU645518A3; IL51768A; BR7702022A; HU178245B; GR70777B; BG27722A3; PL197043A1; OA05622A

Abstract

HERBICIDAL COMPOSITIONS
Abstract of the disclosure:

Herbicidal compositions containing a compound of formula I

wherein Rn represents one or several halogen, CF3 or alkyl,

Description

i73~

The subject of the invention is herbicidal compounds and their use in preventing, eradicating or reducing the presence of grasses from a tract of land by applying to the tract of land or said grasses a herbicidally effective amount of a compound of the general formula X ~ ~ Y-C-Z

(R)n (Rl)n wherein R represents the same or different substituents from the group consisting of halogen, CF3, (Cl-C6)-alkYl, Rl represents halogen, CF3 R2 represents (Cl-C4)-alkyl;
n represents 1 or 2;
nl represents 0 or 1;
X and Y represent 0 or S and Z represents -CN, -CHO, R3~
~ \ R ~ wherein R3 represents hydrogen, (Cl-C6) S 4~' alkyl, methoxy, (C5-C6)cycloalkyl, benzyl, or phenyl, and R4 represents hydrogen, (Cl-C6)alkyl, (C5-C6)cycloalkyl or benzyl, or wherein R3 and R4 together represent pyrrolidine and morpholine ~t~ 73~

C ~ N IN-R6 C~5 N INI
\ N _ - N \ N - N

wherein R6 represents hydrogen or (Cl-C4) alkyl;
X-Rll wherein Rlo represents (Cl-C6)alkyl, -C-R (C3-C6) alkenyl, (C5-CG cycloalkyl, phenyl., X-R12 halophenyl, trifluoromethylphenyl or hydrogen Rll and R12 each represent ~Cl-C4) alkyl or together represent an alkylene chain having

2 - 3 carbon atoms;
OH
-CH-SO (~)cat ~+) wherein cat( )is the cation of an inorganic or organic base, -CH-N-W-Rlo/ wherein W represents a direct bond or an oxygen atom.
The alkyl or alkenyl groups mentioned may be straight-chained or branched.

t~

.

73~

Of the radicals mentioned, the ones that are preferred are those in which (R) represents up to 2 Cl, Br, CF3; in particular 4-Cl, 2,4-Cl, 2-Cl-4-Br, 4-CF3 and 2-Cl-4-CF3;
R2: CH3;
nl: 0 or ~Rl)nl=Cl in the 2 position to the radical Y
X, Y, : oxygen;
Z; CN, C(S)-NH2 ,~N-NH

-C/\ I
N=N

OH ~ NH ~ NH2- +

-f-H -C or -C A
SO3 cat NH2 NH2_ and cat : Na , K or NH4 and A : Cl , HSO4 , Br .

A further subject of the invention is the compounds of formula I provided that Z does not represent -C-NH2 , -C-NH2 or -CHO if S NH

(R)n stands for 4-CF3.

The compounds of formula I can be prepared, for example starting from parent substances of the formula X ~ Y -H II

n (Rl)nl ~9573~

according to numerous processes known for similar compounds.
Thus, compounds of formula II can be reacted in a manner known per se with those of the formula B-C-Z III
H

wherein B represents halogen, preferably chlorine, bromine or a sulfo ester group, for example with ~-Cl- or ~-Br-acetonitrile or -propionitrile, optionally in the presence of acid-binding agents, and they can then be converted into other compounds of formula I by reactions customary in organic chemistry.
Some processes suitable for the production of compounds of formula I are to be described in the following and in the examples.

::

l~g~73~

Process 1 _ Nitriles of formula I are obtained by reacting compounds of formula II with the corresponding halogen nitriles ~III, Z = CN) or, preparatively, by splitting off water from the corresponding acid amides of formula I (Z = C~0)-NH2), e.g.
by means of phosphorus pentachloride, phosphorus pentoxide or thionyl chloride.
Process 2 Unsubstituted thioamides of formula I ~Z = -C~S)-NH2) are obtained, e.g. by reacting the corresponding nitriles of formula I with hydrogen sulfide or also by reacting the corres-ponding acid amides with halogenating agents such as phosphorus halides and then reacting with hydrogen sulfide in the presence of acid binders. Substituted thioamides ~Z = -C~S)-NR3R4) with R3 and R4 = H result if the above reaction is effected in the presence of an amine of the formula HNR3R4 or if a reaction is subsequently effected with such an amine.

Process 3 /,N - ~-H
Tetrazole derivatives of formula I ~Z = -C I ) `~N - N
are obtained by reacting the corresponding nitriles of formula I
with alkali metal azides and/or ammonium azides.
Process 4 Amidines of formula I or derivatives thereof with 573~

H ~ R7 +
ZC~ 7 ~N-R A or ~N~ A

\N\R3 \ N~R3 _ \~ ~R3 are obtained, for example~ by reacting the corresponding acid amides of formula I (Z = -C~O) -NR3R4) with halogenating agents and then reacting with amines of the formula H2NR7 or 1~R7R8, optionally in the presence of acid bindersJ or by reacting the said acid amides with dimethyl sulfate and then reacting with the said amines, or by reacting the corresponding imino esters ~N-R7 (Z = -C
\0- (Cl-C6) alkyl with amines of the formula HNR3R4.
Process 5 Imino esters or imino-thioesters of formula I or the acid addition salts thereof ~1l i ~N - R3 ~Z = -C A
X - Rg l are obtained by reacting the corresponding acid amides (Z = -C(O)NHR3) with halogenating agents to form the imide halide and by further reaction with alcohols or mercaptans of the formula HXRg, optionally in the presence of acid binders.
Process 6 Ketals or acetals of formula I

73~
X-Rll (H = -C-Rlo are obtained by reacting compounds of formula II with corresponding compounds of formula III, or from compounds of formula I (Z = C~
Rlo by reaction with alcohols of the formula HORll or HOR12 or mercaptans of the formula HSRll or HSR12 under conditions used for the formation of thioacetals or thioketals, e.g. in the presence of acid or (where X = 0) in the presence of ortho-esters.
Process 7 a) Aldehydes of formula I (Z = -CH0) are obtained, e.g. in a manner known per se by gentle selective oxidation of the corresponding alcohols (Z = -CH20H) - cf. e.g. J. org. Chem. ~9, (1974), page 3304 - for example by oxidizing with dimethyl sulfoxide and dicyclohexylcarbodiimide in the presence of phosphoric acid as the acid catalyst, or by the reduction of the corresponding acid chlorides (Z = -C(O)Cl) under Rosenmund-reduction conditions in ~he presence of contaminated noble metal catalysts, or by the reduction of corresponding acid derivatives (esters) with metal hydrides, e.g. LiAlH4 or by the reduction of the corresponding imide-chlorides ~ NH
(Z = -C ) with inorganic reducing agents such as, for example, tin (II)chloride, or by the reduction of the nitriles according to the invention of formula I (Z - CN) in ether with tin(II)chloride in the presence of hydrogen chloride or by the acid cleavage of the acetals obtainable according to process 6.

b) Bisulfite adducts of formula I ~ Z = -C-OH cat( ) ) SO3(-) are obtained in a manner known ~ se by reacting aldehydes of formula ~ (Z = -CHO) with bisulfites (hydrogen sulfites~.
Process 8 H, Compounds of formula I, in which Z = -C=N-W-Rlo and which are to be understood as oximes or Schiff's bases of aldehydes of formula I (Z = -CHO), are obtained by reacting these aldehydes with amines or hydroxylamines of the formula H2N-W-Rlo (IV) under conditions known for the production of Schiff's bases and oximes. When W = oxygen, compounds of formula I with Z = -HC=N-OH can also be reacted with compounds of the formula B-Rlo (B = halogen, preferably chlorine or bromine) to form the desired compounds.
Processes known ~ se can be used for the production of the acid amides and acid chlorides that are in some cases used as starting substances.
The compounds according to the invention of the general formula I have herbicidal action against a wide range of harmful grasses, these compounds being at the same time very compatible with useful dicotyledons as well as, to an extent, with various types of cereal. Thus, the compounds of the general formula I are suitable for the selective combating of harmful grasses in crop plants.
The active substances according to the general 5~3~i formula I constitute 2-95% of the content of the active agents, according to the invention. These agents can be applied in the normal forms of preparation as emulsifiable concentrates, wettable powders, sprayable solutions, dusts or granulates.
Wettable powders are preparations that can be evenly dispersed in water and that contain, apart from a diluent or ~nert substance, also wetting agents in addition to the active substance, e.g. polyoxyethylated alkylphenols, polyoxyethylated oleylamines or stearylamines, alkyl sulfonates or alkyl-phenyl sulfonates and dispersing agents, e.g. sodium lignin-sulfonate sodium 212'-dinaphthylmethane-6,6'-disulfonate or also sodium oleylmethyl tauride.
Emulsifiable concentrates are obtained by dissolving the active substance in an organic solvent, e.g. butanol, cyclohexanone, dimethylformamide, xylene or also high-boiling aromatic substances.
Dusts are obtained by grinding the active substance with finely divided, solid substances, e.g. talcum, natural clays, such as kaolin, bentonite, pyrophillite or diatomaceous earth.
Sprayable solutions, as widely marketed in spray-cans, contain the active substance dissolved in an organic solvent and in addition, as a propellant, e.g. a mixture of fluorochloro-hydrocarbons.
Granulates may be produced either by spraying the active substance onto adsorptive, granulated inert material or by applying 1~''9573~

active substance concentrates, by means of adhesives, e.g.
polyvinyl alcohol, sodium polyacrylate or also mineral oils, i to the surface of carrier substances, such as sand, kaolinite, or of granulated inert material. Also suitable active substances can be produced in the manner usual for the production of granulated fertilizer materials - optionally in admixture with fertilizers.
In the case of herbicidal agents, the concentrations of the active substances in commercial formulations may vary.
In wettable powders the active substance concentration varies e.g. between approximately 10% and 95% and the rest consists of the formulation additives indicated above. In emulsifiable concentrates the active substance concentration is approximately 10% to 80%. Dust formulations in most cases consist of 5-20%
of active substance, and sprayable solutions of about 2-20%.
In the case of granulates, the active substance content depends partly upon whether the active compound is liquid or solid and upon what granulation auxiliaries, fillers etc. are used.
In order to apply them, the commercial concentrates are optionally diluted in the normal manner, e.g. by water in the case of wettable powders and emulsifiable concentrates.
Dusts and granulated preparations as well as sprayable solutions are not diluted with other inert substances before application.
The amount which must be applied varies with external conditions such as temperature, moisture int. al. It can vary within a wide range, e.g. between 0.1 kg/ha and 10 kg/ha of active substance, but is preferably between 0.3 and 3 kg/ha.

1~9573~

The active s~lbstances according to the invention may be combined with other herbicides and soil insecticides.

~ss~3~

Examples of formulation Example A
An emulsifiable concentrate is obtained from:
15 parts by weight of active substance " " " " cyclohexanone as the solvent " " " " oxyethylated nonylphenol (10 EO) as the emulsifier.
Example B
A wettable powder that is readily dispersable in water is obtained by mixing 25 parts by weight of active substance 64 " " " " kaoline-containing quartz as the inert substance " " " " potassium lignin sulfonate and 1 " " " " sodium oleylmethyl tauride as the wetting and dispersing agent and grinding the whole in a pin mill.
Example C
A dust is obtained by mixing 10 parts by weight of active substance go " " " " talcum as the inert substanc0 and pulverizing the whole in a cross beater mill.
Example D
A granulate consists, e.g. of approximately 2 - 15 parts by weight of active substance 98 - 85 " " " " inert granulate carrier materials such as~ for example, atapulgite, pumice and quartz sand.

~9~73~i Examples of preparation Example 1 2- [4'-(4"chlorophenoxy)-phenoxy] -propionitrile 125 g (0.429 mol) of 2- [4'-~4"chlorophenoxy)-phenoxy] -propionic acid amide are heated for 10 hours under reflux in 500 ml of dry toluene with 66.3 g (0.55 mol) of thionyl chloride.
Excess thionyl chloride and toluene are distilled off under reduced pressure.
The viscous residue remaining is distilled. After distillation 111 g (94.6%
of theory) of Z- ¦4'-(4"-chlorophenoxy)-phenoxy] -propionitrile with b.p.
0 05 : 173C are obtained. The distillate solidifies in the receiver and has a melting point of 79C. r~ CH3 Cl- ~ 0- ~ -0-C-C_N

Prepared in a similar manner were:
Example [
No. Compound of Formula I b.p. [ C] m.p. C
__ 2 F C- ~ 0- ~ 0-C-CN 0.05:160 58 - 69

3 F3C- CO ~ ~ ~ 0-C-CN 0.1 :175

4 Cl- ~ 0- ~ 0-C-CN 0.o5:l87 65 - 66 H C- ~ - ~ -0-C-CN 0.05:159 6 H3C- ~ ~ CH3 0.02:178 7 ~ ~ H 73 - 74 - 14 _ ~q~9S73~

Example 8 2- [4'-~4"-chlorophenoxy)-phenoxy] -propionic acid thioamide 150 g (0.55 mol) of the nitrile obtained in Example (1) are reacted in 150 ml of fluid hydro-gen sulfide with 6.7 g (0.091 mol) of diethylamine for 6 hours at 70C under its own pressure. The solid residue is recrystallized from ethanol. 150 g (88% of theory) of 2- ¦4'-(4"-chlorophenoxy~-phenoxy~ -propionic acid thio-amide with a melting point of 127 - 128C are obtained.

Cl- ~ -0- ~ o_CclH3 C-NH2 Prepared in a similar manner were: [o ]
Example No. Compound of Formula I m.p. _ C

9 ~ F C- ~ 0- ~ CH3 ~ S

IO l Cl- ~ -0- ~ 0-C- ¦155 - 156 (Ethanol) ~ r__~ CH3 11 Br- ~ -O- ~ O-C-C \

Cl CH3~5 12 F C- ~ 0- ~ o_¦_c 13 ~ ~ CH3 ~ 5 14 H C- ~ 0- ~ -0-C-C ~

5~3~i Example 15 2- [4'-(4"-trifluoromethylphenoxy)-phenox~ -thiopropionic acid N-butylamide.
17.1 g (0.05 mol) of the thioamide obtained in Example 8 are reacted for 3 hours at 80C with ll g (0.15 mol) of n-butylamine. After cooling, approxi-mately 50 ml of water are added. The precipitate formed is sucked off and washed neutral with water. Recrystallization from cyclohexane yields 18.2 g (91.3~ of theory) of 2- [4'-(4"-trifluoromethylphenoxy)-phenoxy] -thiopro-pionic acid N-butylamide with a melting point of 88C.

F C- ~ 0_ ~ CH3 ~ S

Prepared in a similar manner were:
Example No. Compound of Formula I m.p. [ C]

16 ~ ~ H ill-CH2- ~ 119 - 120 17 Cl- ~ -0- ~ 0-C-C-NH-(C4Hg)ll 72.5 (Hexane~

18 Cl- ~ 0- ~ -0-C-C-N ~ 0 19 Cl- ~ ~ -0- -N~C2H5)2 Cl- ~ -0- ~ 0-CH~lsl-N 107.5 Example No. Compound of Formula I m.p. [ C

21 F C- ~ O- ~ -O-C-C
H NH-Example 22 l- ~4'-(4"-trifluoromethylphenoxy)-phenoxy] -l-(tetrazol-5'-yl)-ethane 39.9 g (0.13 mol) of the nitrile obtained in Example 2 are added to a suspension of 9.3 g (0.143 mol) of sodium azide and 7.65 g (0,143 mol) of ammonium chlGride in 200 ml of dimethylformamide and heated, while stirring, ~o 105-110C.
The reaction is complete after 7 hours. Dimethylformamide is distilled off under reduced pressure. The residue remaining is taken up in 200 ml of tolu-ene and washed with water. Toluene is distilled off under reduced pressure.
After drying in vacuo 34.6 g (76% of theory) of l- [4'-(4"-trifluoromethyl-phenoxy)-phenoxy] -l-(tetrazol-5'-yl) ethane with a melting point of 122-123C are obtained.
~ ~ ~H3 N - N-H

Prepared in a similar manner were:

Example [o No. _Compound of Formula I m.p. C

23 Cl- ~ -O- ~ -O-C-C ~ ¦ 133.5-135 (EtOH/

24 ~ ~ Ul3 N - N H 115 ~ ~ H N - N

~9~3~

Example 26 2- [4'-(2",4"-dichlorophenoxy)-phenoxy~ -propionaldehyde as a bisulfite adduct a) 2- C4'-(2",4"-dichlorophenoxy)-phenoxy~ -propionaldehyde 103.6 g (0.3 mol) of 2- [4'-(2",4"-dichlorophenoxy)-phenoxy] -pro-pionic acid chloride are dissolved in 5 times this amount of absolute xylene, regulated with the addition of Pd/BaS04 catalyst, reduced with quinoline S

at 135C for 2-4 hours in a hydrogen atmosphere. The catalyst is filtered off Cl CH3 0 Cl-~_o_ ~O-C-C~

b) Bisulfite adduct of 2- ~4'-(2",4"-dichlorophenoxy)-phenoxy] -propio _ aldehyde.
The solution of the aldehyde in xylene obtained in Example 28a is reacted with 100 ml of saturated sodium bisulfite solution while stirring thoroughly until the precipitation of the bisulfite adduct is quantitative.
The precipitate is removed by suction and then washed with xylene and diethyl ether. 87.3 g (70% of theory~ of bisulfite adduct, calculated on the acid chloride used, are obtained. Cl 1 3/

Cl- ~ 0- ~ 0-C-C-II
S3 (~)Na(+) 20Analysis Calculated: C 43.4 H 3.15 S 7.7 found: C 42.1 H 3.5 S 7.3 prepared in a similar manner were:

lq~ 73S

Example No.Compound of Formula I m.p.[ C]

27 F3C- ~ o_ ~ -O-C-C-H with H SO ~ a~3 decomp-3 osition 28 ~ ~ CH3 OH 170 - 172 29 ~ 3 Example 30 2- [4'-(2",4"-dichlorophenoxy)-phenoxy] -propanal-diethylacetal 30 g ~0.072 mol) of the bisulfite adduct obtained in Example 28 are stirred at 60C in a mixture of 100 ml of ethyl acetate and 80 ml of 1 N sul~uric acid under nitrogen until the development of sulfur dioxide is completed. The organic phase is neutralized with bicarbona~e solution and dried. Most of the ethyl acetate is distilled off under reduced pressure. The aldehyde thus obtained is added, under nitrogen, to a solution of 30 ml of absolute ethanol, 0.6 g of ammonium nitrate and 30 g of triethyl orthoformate. The reaction mixture is left to stand until the end of the reaction (approximately 8-10 hours).
The salt is separated and the alkalinity of the remaining solution is adjust-ed with morpholine. The solvent is distilled off. The remaining oil is distilled. The distillation yields 22.5 g (81% of theory) of 2- ~4'-(2",4"-dichlorophenoxy)-phenoxy] -propanal-diethylacetal with b.p. o 06:185 C.

Cl- ~ -O ~ O 1 3/ 2 S

-- 19 -- ...

l~R~'73 Obtained in a similar manner are:
Example Compound of Formula I B.p.[ C]
No.

31 F3C~-O ~ C,-C-H

32 Cl-- ~ O ~~)-- 0-C-C-H 185 / 0.1 Torr 33 Br ~Cl 0-r-C-H

Cl H 0C2H5 34 Cl--~ 0 -~--0-C-C-H 180-181/0.07 Torr 35F3C-- ~ 0 -~- C-H 158 / O.O5 Torr 36Cl ~ 0 ~ 0-C-C-ÉI
l-l 0CE-13 37~ 3r --~ O--~>--0-C- -H
El OCE13 Example 38 2-[4'-(2",4"-dichlorophenoxy)-phenoxy]-propanal-N-propylamine 15 g (0.036 mol) of the bisulfite adduct obtained in Example 28 are stirred at 60C in a mixture of 100 ml of ethyl acetate and 50 ml of 1 N sulfuric acid under nitrogen until the development o:E sulfur dioxide is completed. The organic phase is neutralized with ~: :

573~

bicarbonate solution. The solution of the aldehyde in ethyl acetate thus obtained is added dropwise under nitrogen to a solution of 2.95 g (0.05 mol) of propylamine in 50 ml of ethyl acetate with external cooling. The reaction mixture is left to stand for 12 hours at room temperature. Ethyl acetate is distilled off under reduced pressure. The residue remaining is freed of adhering impurities by means of column chromatography. 9.6 g (76% of theory) of 2- [4'-(2",4"-dichlorophenoxy)-phenoxy~ -propanal-N-propylimine are obtained.

Cl- ~ -0- ~ 0-C-CH=N-C3H7 Analysis caluculated: C 61.3 H 5.45 Cl 20.1 N 3.95 found: C 60.4 H 5.4 Cl 20.2 N 4.3 ` ~

~g5735 Biological Examples Example I
Seeds of various grasses were sown in pots and the preparations according to the invention formulated as dusting powders are sprayed in dif-ferent quantities onto the surface of the soil. The pots were then placed in a greenhouse for 4 weeks. The result of treatment (also in the case of the following examples) was determined by assessment according to Bolle's scheme ~Nachrichtenblatt des Deutschen Pflanzenschutzdienstes 16, 1964, 92-94):

-~armful effect in %
_Number _ Weeds on Crop plants 2 97.5 to < 100 > O to 2.5 3 95 to ' 97.5 ' 2.5 to 5 4 90 to < 95 > 5 to 10 85 to < 90 ~10 to 15

6 75 to < 85 >15 to 25

7 65 to < 75 '25 to 35

8 32.5 t~ ' 65 ~ 35 to 67.5

9 0 to ~ 32.5 ~ 67.5 to 100 The procedure was the same with the herbicidal comparison agents used, Fluro-difen (4-nitrophenyl-~2'-nitro-4'-trifluoromethylphenyl)-ether) and Mecoprop (2-(4'-chloro-2'-methylphenoxy)-propionic acid. The results collated in Table I show that the claimed compounds are, on average, more effective against grasses than the two herbicides used for comparison. Further, the claimed com-pounds from Examples 1, 10, 23, 24, 26 and 27 had a similar effect against grasses.
Example II
Grass seeds were sown in pots and grown in a greenhouse.

3 weeks after sowing the preparations according to the invention formulated as dusting powders were sprayed in different quantities onto the plants and after 4 weeks' standing in the greenhouse the effect of the preparations was assessed. In this case, too, Flurodifen and Mecoprop were used as the herbicidal comparison agents. Although with this application process the claimed compounds were not quite as effective as in the preemergence process described in Example I they were more effective against grasses than the two comparison agents (Tab. II). Further, the claimed compounds from Examples 1, 109 23, 26 and 27 had a similar effect against grasses.
Example III
In another experiment substances according to the invention were applied to numerous crop plants before emergence. Evaluation showed (cf.
Table III) that all types of useful dicotyledon tested toerated treatment with 2.5 kg/ha 4, 2, 9 and 8. The same also applies to onions.
In addition, wheat and barley are not harmed either when the com-pounds according to Examples 4 and 9 are applied.

., 73~

Table I
Weed assessment figures in the case of pre-emergence treatment Example Quantity P l a n t t y p e s No. (kg/ha AS) L SA L0 EC
9 2.5 2 2 0.6 3 3 2 8 2.5 0.6 2 4 2.5 4 1 1 2 0.6 6 2 2 3 2 2.5 0.6 2 22 2.5 4 2 3 3 0.6 6 4 6 5 1 2.5 2 0.6 3 3 - 1 3 2.5 2 1 - 2 0.6 3 2 - 3 7 2.5 2 0.6 3 1 - 2 2.5 - 1 - 3 0.6 - 2 - 4 2.5 0.6 2 16 2.5 - 1 - 1 0.6 17 2.5 2 2 - 3 23 2.5 - ~ - 2 0.6 - 4 - 4 `

16'9573~

Example Quantity P 1 a n t t y p e s No. (kg/ha AS) AL ~A L0 EC
24 2.5 4 3 ~ 4 26 b) 2.5 2 1 - 1 0.6 3 27 2.5 0.6 28 2.5 2 2 0.6 4 2 - 2 2.5 - 2 - 3 32 2.5 4 3 - 3 34 2.5 3 1 - 1 0.6 5 3 - 2 2.5 0.6 38 2.5 4 2 - 2 ______________________.~_______ Fluorodifen 2.5 7 1 1 4 0.6 8 5 8 8 Mecoprop 2.5 4 3 5 3 0.6 7 6 8 7 ._, AL = Alopecurus myosuroides SA = Setaria lutesceus L0 = Lolium multiflorum EC = Echinochloa crus-galli i7~

~able II
Weed-assessment figures in the case of post-emergence application Example Quantity P 1 a n t t y p e s No. (kg/ha AS) AV AL SA L0 EC
9 2.5 9 2 1 6 0.6 9 6 8 8 2 8 2.5 0.6 3 4 1 2 4 2.5 9 g 3 3 0.6 9 9 7 7 5 2 2.5 0.6 8 5 2 2 24 2.5 9 2 4 8 0.6 9 7 9 9 3 22 2.5 2 3 2 5 0.6 9 6 7 7 5 1 2.5 - 2 5 - 1 0.6 - 7 7 3 2.5 - 1 4 0.6 - 4 7 - 4 7 2.5 - - - - 4 0.6 - - - - 8 2.5 - - - - 2 0.6 - - - - 7 23 2.5 - - 3 - 3 0.6 - - 8 - 7 26 b) 2.5 - 3 0.6 - 6 i'735 Example Quantity P 1 a n t t y p e s No. (k~!ha AS) _ AV AL SA L0 EC
27 2.5 - 1 1 - 1 0.6 34 2.5 0.6 - 6 6 - 2 2.5 0.6 - - - - 2 ___________________ ______________________________________________________ 10Fluorodifen 2.5 8 8 2 6 4 0.6 8 8 3 8 6 Mecoprop 2.5 8 8 7 8 8 0.6 9 9 8 9 9 AV = Avena fatua , :

Table III
Effect on crop plants~ pre-emergence process.
Quantity: 2.5 kg/ha Example No.
Plant types 4 2 9 8 Dwarf bean Sugar beet 1 2 Spinach Sunflower Rape Alfalfa Pea 1 2 Field bean Lettuce Cabbage Flax Onion 3 3 1 2 Tomato 2 2 Carrot Celery Cucumber 1 3 Soya bean Cotton 3 Tobacco Wheat 1 -- 1 -Barley 1 - 1 -

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

l. A method of preventing, eradicating or reducing the presence of grasses from a tract of land which comprises applying to the tract of land or said grasses a herbicidally effective amount of a compound of the general formula wherein R represents the same or different substituents from the group consisting of halogen, CF3, (C1-C6)-alkyl, R1 represents halogen, CF3 R2 represents (C1-C4)-alkyl;
n represents 1 or 2;
n1 represents 0 or 1;
X and Y represent O or S and Z represents -CN, -CHO, wherein R3 represents hydrogen, (C1-C6) alkyl, methoxy, (C5-C6)cycloalkyl, benzyl, or phenyl, and R4 represents hydrogen, (C1-C6)alkyl, (C5-C6)cycloalkyl or benzyl, or wherein R3 and R4 together represent pyrrolidine and morpholine or wherein R6 represents hydrogen or (C1-C4)alkyl;

wherein R10 represents (C1-C6) alkyl, (C3-C6) alkenyl, (C5-C6) cycloalkyl, phenyl, halophenyl, trifluoromethylphenyl, or hydrogen and R11 and R12 each represent (C1-C4) alkyl or together represent an alkylene chain having 2 - 3 carbon atoms;

wherein cat (+) is the cation of an inorganic or organic base, -CH-N-W-R10 wherein W represents a direct bond or an oxygen atom.
2. A method according to claim 1 wherein in said compound of formula I
R represents C1, Br, CF3;
n represents 1 or 2;
R2 represents CH3;
n1 represents O or (R1)n1 = C1 in the 2-position to Y
X, Y: oxygen;
Z represents CN, C(S)-NH2 , or and cat+: Na+, K+ or NH4 and A- : C1-, HSO4-, Br-.
3. A method according to claim 2 wherein R = 4-C1, 2,4-C1, 2-C1-4-Br, 4-CF3 and 2 C1-4-CF3, and n1 = O and n, R2, X, Y, Z, cat+ and A-have the meanings given in claim 2.
4. A method according to claim 1 in which said compounds of the formula I is
5. A method according to claim 1 in which said compound of the formula I is
6. A method according to claim 1 wherein in said compound of formula I, R, R1, R2, Z, n and n1 have the meanings indicated provided that Z does not represent or -CHO
if (R)n stands for 4-CF3, and X and Y each represent oxygen.