NO151586B - 2-HALOGEN ACETANILIDES AND HERBICID PREPARATION CONTAINING SAME - Google Patents

Description

This invention relates to 2-haloacetanilides and their use in agriculture, especially as herbicides. There is a large number of publications in this field that describe 2-haloacetanilides, which can be unsubstituted or substituted with a number of different substituents on the anilide nitrogen atom and in the anilide ring. Examples of substituents are alkyl, alkoxy, alkoxyalkyl and halogen radicals.

Seen against the background that the compounds according to the invention

are characterized by having an alkoxymethyl radical on the anilide nitrogen atom, an alkoxy radical in an ortho-position and a specific alkyl radical in the other ortho-position, are the closest representatives of the state of the art known to the inventor, US patent documents no. 3,442,945 and 3,547,620. The most relevant compounds in these two patents are the compound 2<1->tert-butyl-2-chloro-N-methoxymethyl-6'-methoxyacetanilide and its bromo-analog (examples 18 and 34 in US pat.

3,547,620, respective examples 18 and 38 in US pat. 3,442,945).

In US patent documents no. 4 070 389 and 4 152 137, a general formula is indicated which includes compounds of the type described in the above-mentioned US patent documents no. 3 4 42 94 5

and 3,547,620. However, the only specifically indicated compound with an alkyl radical in one ortho position and an alkoxy radical in the other ortho position is a compound with an alkoxyethyl radical on the anilide nitrogen atom. Connections of this type will be explained in more detail below.

Other, less relevant representatives of the technique

stand is Belgian Patent Document No. 810 753 and German Patent Application No. 2 402 983. The compounds described in these publica-

tions, include compounds of the type described in the above-mentioned US Patent Nos. 4,070,389 and 4,152,137, and they are characterized by an alkoxyalkyl radical with two or more carbon atoms between the anilide nitrogen atom and the oxygen atom in the alkoxy radical. The most relevant specific indications in the above-mentioned Belgian patent document and mentioned German patent application seem to be compounds with an ethoxyethyl radical on the anilide nitrogen atom, a methoxy or ethoxy radical in an ortho position and a methyl or ethyl radical in the other ortho position. Reference is made to compounds No. 7, 13 and 18 in the Belgian patent specification (810 763). Other less relevant homo-

loge of these compounds is also described, e.g. compounds 6, 9, 16 and 17, which have methoxyethyl or methoxypropyl radicals on the nitrogen atom and a methoxy or ethoxy radical in one ortho position and a methyl radical in the other ortho position.

The above-mentioned US patent document no. 3,442,945 contains certain data for the herbicidal effect of the above-mentioned compounds with the chemical structure that is closest to the structure of the compounds according to the invention, and some data is also given in the other patent documents for other homologous and analogous compounds which are less closely related in terms of chemical structure. This applies, for example, to for compounds no. 6 and 9 in Belgian patent document no. 810 763. Although the most relevant of the publications indicate herbicidal action on a number of different weed plants, they do not provide for any compounds data showing that they can be additionally and/or simultaneously used for control of the difficult-to-control perennial weeds such as quack and Cyperus esculentus, and annual weeds including equally difficult-to-control broad-leaved annual weeds such as Sida spinosa, hemp sesbania, Datura stramonium, etc., and annual weeds such as seedlings of sorghum, brachiaria, sedges, Oryza sativa, at the same time as they also have a herbicidal effect on other harmful perennial and annual weed plants, e.g. Polygonum, Chenopodium, purumelde, foxtail, Digitaria sanguinalis and hen's millet.

A very useful and desirable property of herbicides

is the ability to maintain the weed-killing effect for a longer period of time. For many previously known herbicides, weed control is effective for only 2-3 weeks, or, for some particularly beneficial herbicides, perhaps for up to 4-6 weeks, before the chemical loses its effective phytotoxic properties. A disadvantage of most previously known herbicides is thus their relatively short period of action in the soil.

Another disadvantage of some of the previously known herbicides, which has a certain connection with the time of action in the soil under normal weather conditions, is the lack of retention of the weed-killing effect under heavy rainfall, which inactivates many herbicides.

A further disadvantage of many known herbicides is their limited applicability in certain types of soil. Thus, while some herbicides are effective in soils containing small amounts of organic matter, they are ineffective in other types of soil with a high content of organic matter, or vice versa. It is therefore advantageous that a herbicide can be used in all types of soil, ranging from those containing little organic material to heavy clay and heavily fertilized soil.

Another disadvantage of many previously known herbicides

is the limitation of a given effective application method, e.g. application before germination takes place or incorporation into the soil. It is very desirable to be able to add the herbicide in any way, either by application to the surface or by incorporation into the soil.

Finally, some herbicides have the disadvantage that it is necessary to take special precautions during their treatment, because they are toxic. It is therefore a further wish that the herbicide can be handled without risk.

It is thus an aim of the present invention

to provide a group of herbicidal compounds which are not encumbered with the above-mentioned shortcomings and disadvantages and to provide a number of advantages which have not hitherto been achieved by means of a single group of herbicides.

It is an aim of the invention to provide herbicides that can be used for the control of difficult-to-eradicate perennial and annual weed species, such as quack, Cyperus esculentus, seedlings of sorghum, Sida spinosa, hemp sesbania, brachiaria, millet, Oryza sativa, in addition to a wide selection of other noxious weed species, such as Polygonum, Chenpodium, purumelde, Datura stramonium, foxtail, hen's millet and finger millet, and

which also provide better control of resistant weed species, such as ragweed, Abutilon theophrasti, knotweed and hookworm, while being able to maintain the health status of a range of crops, including soybeans, cotton plants, peanuts, canola and creeping beans.

It is a further aim of the invention to provide herbicides which are effective in the soil for periods of up to 18 weeks.

Furthermore, it is an aim of the invention to provide herbicides which are resistant to leaching and dilution as a result of high humidity, e.g. as a result of heavy rainfall.

Furthermore, it is an aim of the invention to provide herbicides which are effective in a large variety of soils, namely in soils which can vary from those with a low or medium content of organic material to soils consisting of heavy clay or highly fertilized soil. Another advantage of the herbicides according to the invention is the flexibility with which they can be applied. They can thus be applied both to the surface of the soil before germination and when incorporated into the soil.

Finally, it is an advantage of the herbicides according to the invention that they are safe and do not require special handling regulations.

The above-mentioned aims and purposes of the invention will

be better elucidated in the detailed description below.

The invention relates to compounds with herbicidal action

and herbicidal preparations containing these compounds as active ingredients.

It has now been shown that a more specific group of 2-haloacetanilides which are characterized by specific hydrocarbyl-oxymethyl radicals on the anilide nitrogen atom, specific alkoxy radicals in an ortho-position and hydrogen or a methyl-

or ethyl radical in the second ortho-position, has unexpectedly improved herbicidal properties compared to the previously known herbicides, therein included homologous compounds according to the most relevant representatives of the state of the art.

A main feature of the herbicidal preparations according to the invention is their ability to combat a wide variety of weed species, including weed species that can be controlled with the usual herbicides and, in addition to that, a number of weed species that individually and/or together have resisted control with a single class of known herbicides, while being capable of maintaining the health status of one or more of a variety of beneficial plants, including in particular soybeans, cotton plants, peanuts, canola and ornamental beans. Although the previously known herbicides can be used to control a number of weed species, including occasionally some resistant weed species, the particular herbicides according to the invention have been shown to be able to eradicate or strongly control a number of resistant perennial and annual weed species, such as the perennial weed species quack and Cyperus esculentus, annual broad-leaved plants, such as Sida spinosa, hemp sesbania, Datura stramonium, Polygonum, Chenopodium, purumelde, and annual grass species, such as brachiara, seedlings of sorghum, Texas-

millet, wild millet Oryza sativa, and other harmful weed species, such as spring millet, foxtail, hen's millet and finger millet. Improved control has also been achieved for weed species such as ragweed, Abutilon theophrasti, wormwood and hookworm.

The compounds according to the invention are characterized by the formula:

where R is ethyl, n-propyl, isopropyl, isobutyl, sec-butyl, cyclopropylmethyl, allyl or propargyl, R, is methyl, ethyl, n-propyl or isopropyl, and R2 is hydrogen, methyl or ethyl, with the proviso that:

when R_ is hydrogen, R^ is ethyl and R is allyl,

when R 2 is ethyl, R 2 is methyl and R is isopropyl,

when R-^ is methyl, R is ethyl, isopropyl, isobutyl, sec-butyl or cyclopropylmethyl,

when R^ is ethyl, R is sec-butyl, allyl or propargyl, when R^ is n-propyl, R is ethyl, and

when R-1 is isopropyl, R is ethyl or n-propyl.

The preferred compound 1 according to the invention is 2'-methoxy-6'methyl-N-(isopropoxymethyl)-2-chloroacetanilide (Ex. 1).

Other very advantageous compounds according to the invention are: 2'-methoxy-6<1->methyl-N-(ethoxymethyl)-2-chloroacetanilide (Ex. 2) and

2'-isopropoxy-6<1>methyl-N-(ethoxymethyl)-2-chloroacetanilide (Ex. 11).

The use and applicability of the compounds according to the invention as active ingredients in herbicidal preparations will be described below.

The compounds according to the invention can be prepared on

a number of different ways. For example, the compounds can be prepared via azomethine according to the methods described in the above-mentioned US patents no. 3 442 945 and 3 54 7 620. According to the azomethine process, the suitable primary aniline is reacted with formaldehyde to form the corresponding methyleneaniline (substituted phenylazomethine) , which is then reacted with a halogen-acetylating agent, such as chloroacetyl chloride or chloroacetyl anhydride. The reaction product is in turn reacted with the appropriate alcohol to form the corresponding N-Alkoxymethyl-2-chloroacetanilide which is the end product.

Another method, described in more detail below, involves transesterification of the appropriate N-methylene-ether-2-haloacetanilide with the desired alcohol to form the corresponding transesterified N-hydrocarbylmethyl-2-haloacetanilide.

Yet another method for preparing compounds according to the invention includes an N-alkylation of the anion in the suitable secondary 2-haloacetanilide with an alkylating agent under basic conditions. The N-alkylation process is described in more detail in the examples 1-14 below.

Example 1

This example describes the preparation of a preferred compound, namely 2'-methoxy-6<1->methyl-N-(isopropoxy-methyl)-2-chloroacetanilide.

0.025 mol 2'-methoxy-6'-methyl-N-(methoxymethyl)-2-chloroacetanilide in 100 - 150 ml isopropanol containing approx.

0.02 mole of methanesulfonic acid was refluxed under a Soxhlet extraction apparatus whose sleeve contained 25 g of activated "3A Molecular Sieves" to absorb the liberated methanol. The course of the reaction was followed by glass chromatography. When the reaction was complete, the excess was lost

alcohol removed in vacuo and the residue taken up in ether or chloroform. The solution was washed with 5% sodium carbonate solution, dried (ffc^SO^ and evaporated. The product was purified by Kugelrohr distillation. A bright, amber-colored solid with a melting point of 40 - 41°C was obtained. Yield 55%.

Analysis. Calculated for C14H20ClNO3(%): C 58.84; H 7.05

N 4.90; Cl 12.41

Found : C 58.55; H 7.08;

N 4.89; Cl 12.45 The product was identified as the compound indicated at the beginning of the example.

Examples 2-9

Using the same procedure, the same amounts of reactants and the same general conditions as in Example 1, but using the alcohol suitable in each case to achieve the transesterification to the final product, other N-hydrocarbyloxy-methyl-2-haloacetanilides were also according to the above formula prepared. These compounds are identified in Table I.

Production of starting materials

Below is described the production of the tertiary N-(methoxymethyl)-anilide starting materials used for the production of the final products according to examples 1 - 9.

The N-methylene ether substituted 2-chloroacetanilide starting materials used in Examples 1-9 were prepared by alkylating the appropriate secondary 2-haloacetanilide by the above N-alkylation process. This method will be illustrated in this example with regard to the production of the starting material used in example 1.

0.025 mol of 2<1->methoxy-6'-methyl-2-chloroacetanilide, 0.05 mol of bromomethyl methyl ether and 2 g of benzyltriethylammonium bromide were dissolved in 70 ml of methylene chloride. 40 ml of a 50% sodium hydroxide solution was then added portionwise with stirring and while maintaining the temperature between 20 and 25°C. After the addition was complete, the mixture was stirred for an additional 1.5 hours. 100 ml of water was then added while cooling, and the layers were separated. The methylene chloride layer was washed twice with 30 ml saturated sodium chloride solution, dried over Mg 2 SO 4 and evaporated. The residue was crystallized or distilled in vacuo, whereby a yellow liquid with a boiling point of 140°C at 1.2 ml of Hg was obtained.

Analysis Calculated for C12H16C1N03 (%): C 55.92; H 6.26;

N 5.44;

Found: C 56.15; H 6.33;

N 5.36

The product was identified as 2'-methoxy-6<1->methyl-N-(methoxy-methyl)-2-chloroacetanilide.

In a similar way, the N-methylene ether-substituted 2-chloro-acetanilides used as starting materials in examples 2-9 were prepared by alkylation of the corresponding secondary anilide with bromomethyl-methyl ether. The analogous chloromethyl methyl ethers and iodomethyl methyl ethers can also be used.

The secondary anilide which was used as starting material in this example for the preparation of the tertiary N-methoxy-methyl compound was prepared by chloroacetylation of the corresponding primary amine in the following manner: 0.03 mol of 2-methoxy-6-methylaniline in 30 ml of methylene chloride was vigorously stirred with 0.05 mol of sodium hydroxide in the form of a 10% solution, at the same time that a solution of 0.033 mol of chloroacetyl chloride in 20 ml of methylene chloride was added while maintaining the temperature between 15 and 25°C with external cooling. The reaction mixture was stirred for an additional 30 minutes after the addition was complete. The layers were separated and the methylene chloride layer was washed with water, dried and evaporated in vacuo. The product was crystallized from a suitable solvent and was obtained in the form of white needles with a melting point of 130 - 131°C.

Analysis Calculated for C10H12ClNO2(%): C 56.21; H 5.66;

N 6.56; Cl 16.59

Found: C 56.16; H 5.66

N 6.57; Cl 16.55. The product was identified as 2<1->methoxy-6'-methyl-2-chloro-acetanilide.

The secondary anilides that were used as starting materials in examples 2-9 were prepared in a similar way.

The primary amines used for the preparation of the above-mentioned secondary anilides can be prepared in a known manner, e.g. by catalytic reduction of the correspondingly substituted nitro:benzene in ethanol using a platinum oxide catalyst.

As mentioned above, the compounds according to the invention can also be prepared directly from the secondary anilide using the aforementioned N-alkylation process, without first preparing the N-hydrocarbyloxymethyl intermediate product (as described above), the transesterification to the final product being carried out as described in example 1. Examples 10 - 13 illustrate the preparation of compounds according to the invention following this N-alkylation process.

Example 10

4.35 g of 2<1->n-p:opoxy-6'-methyl-2-chloroacetanilide, 3.4 g of chloromethyl ethyl ether and 1.5 g of benzyltriethyl ammonium chloride were mixed in 250 ml of methylene chloride and cooled. To the mixture was added 50 ml of 50% NaOH at 15°C, and the mixture was stirred for 2 hours, after which 100 ml of water was added. The layers were separated, washed with water, dried over MgSO 4 and

evaporated. The product was purified by Kugelrohr distillation, whereby 4.8 g (89% yield) of a clear liquid with boiling point 130°C at 0.07 ml Hg was obtained.

Analysis Calculated for C15H22C1N03 (%) : C 60.10; H 7.40

Cl 11.83

Found: C 59.95; H 7.39

Cl 11.79

The product was identified as 2<1->n-propoxy-6<1->methyl-N-(ethoxy-methyl)-2-chloroacetanilide.

Example 1 i

5.55 g of 2<1->isopropoxy-6<1->methyl-2-chloroacetanilide 4.4 g of chloromethyl ethyl ether and 2.5 g of benzyltriethylammonium chloride were mixed together in 250 ml of methylene chloride and cooled to 0°C. To the mixture was added 50 ml of 50% NaOH in one portion, while the temperature was kept lower than 15°C. The mixture was stirred for 2 hours and cooled, after which 100 ml of water was added. The layers were separated, washed with water, dried over MgSO 4 and evaporated to give 4.7 g (69% yield) of the product as a yellow oil.

Analysis Bergnet for C15H22C1N03(%): C 60.10; H 7.40

N 4.67; Cl 11.83

Found: C 60.10; H 7.40

N 4.64; Cl 11.73. “The product was identified as 2'-isopropoxy-6'-methyl-N-(ethoxymethyl)-2-chloroacetanilide.

Oak sample 12

By proceeding mainly as described in examples 10 and 11, but by using chloromethyl-propyl ether as alkylating agent, 5.0 g (88% yield) of a yellow oil was obtained.

Analysis Bergenet for C16H24C1N03(%): C 61.24; H 7.71

N 4.46; Cl 11.30

Found: C 61.18: H 7.76

N 4.43; Cl 11.31.

The product was identified as 2<1->isopropoxy-6-methyl-N-(n-propoxymethyl)-2-chloroacetanilide.

Example 13

By following the procedure described in examples

10 - 12, but using the appropriate sec-anilide and halomethyl-allyl ether, a yellow oil with boiling point 134°C/

0.08 mm Hg (Kugelrohr)

Analysis Calculated for C14HlgClN03(%): C 59.26; H 6.39

N 6.94; Cl 12.49

Found: C 59.20; H 6.41

N 6.95; Cl 12.52. The product was identified as 2'-ethoxy-N-(allyloxy-methyl)-2-chloroacetanilide.

The herbicides according to the invention have been shown to have unexpectedly improved properties as herbicides for use before germination, and in particular for selective eradication of hard-to-eradicate perennial and annual weed species, including such perennial weed species as quack and Cyperus esculentus, annual broad-leaved weed species, such as Sida spinosa, hemp sesbania, Datura stramonium, Polygonum, Chenopodium, purumelde, and annual grasses, such as seedlings of sorghum, Brachiaria plantaginea, Texas millet, Oryxa sativa, reverumpe (e.g.

Setaria viridis and Setaria faberii), chick's millet and big finger millet. Improved reduction of the weed population compared to known acetanilides has also been achieved for other resistant species, such as ragweed, Abutilon theophrasti, wormwood and hookseed.

Selective control and increased suppression of the above-mentioned weed species by means of the herbicides according to the invention have been achieved in a number of different crops, such as in crops of soybeans, cotton plants, peanuts, rape and creeping beans. Selectivity has been demonstrated in certain experiments with sugar beet, maize, wheat, barley and sorghum. However, these useful plants are less resistant to the herbicides according to the invention than the useful plants mentioned above. A person skilled in the field will understand that not all of the above-mentioned weed species are selectively eradicated by means of all the compounds according to the invention under all conditions with respect to climate, soil type, humidity and/or method of herbicide application.

In order to show the unexpectedly improved properties of the compounds according to the invention both on an absolute basis and on a relative basis, comparison experiments were carried out in a greenhouse and in the open field with: (1) the compounds known in the art which in terms of chemical structure are most closely related to the compounds according to the invention, (2) other homologous compounds which are known in the art, and which have good herbicidal properties, and (3) commercial herbicidal compounds with a chemical structure which is generally related to the structure of the compounds according to the invention. All of the compounds that were used in the comparison experiments below are generally defined as substituted phenyl-N-alkoxyalkyl-2-haloacetanilides. The identification of the known comparative compounds used in the tables below is as follows: A. 2'methoxy-6<1->tert-butyl-N-(methoxymethyl)-2-chloro-acetanilide; (Example 18 in US Patents 3,442,945 and 3,547,620). B. 2'methoxy-6'-tert-butyl-N-(methoxymethyl)-2-bromoacetanilide; (Example 34 in US Patent 3,547,620 and Example 36 in US Patent 3,442,945). C. 2',6'-diethyl-N-(methoxymethyl)-2-chloroacetanilide; (Example 5 in US Patents 3,547,620 and 3,442,945; this compound has the trivial name "alachlor" and is the active ingredient in the commercial herbicide Las D. 2<1->methyl-6'-ethyl-N-(ethoxymethyl) -2-chloroacetanilide; (Example 53 in US Patent 3,547,620;

trivial name "acetochlor").

E. 2',6'-dimethyl-N-(isopropoxymethyl)-2-chloroacetanilide; (Example 31 in US Patent 3,547,620 and Example 33 in US Patent 3,442,945).

F. 21-methoxy-6'-methyl-N-(methoxyethyl)-2-chloroacetanilide; (compound no. 6 in Belgian patent document 810 763) .

G. 2'-methoxy-6'-methyl-N-(ethoxyethyl)-2-chloroacetanilide;

(compound no. 7 in Belgian patent specification 810 763).

H. 2<1->methoxy-6'-methyl-N-(1-methoxyprop-2-yl)-2-chloro-acetanilide; (compound no. 9 in Belgian patent specification 810 763) and

I. 2'-methyl-6'-ethyl-N-(1-methoxyprop-2-yl)-2-chloro-acetanilide (US Patent 3,937,730; common name "metolachlor". This compound is the active ingredient in the commercial herbicide Dual ^) .

When testing the herbicidal action before germination, the compounds according to the invention were compared with the known compounds A-I with regard to the control of various perennial and annual weed species, with particular emphasis on the difficult-to-eradicate species which are the most frequently occurring weed species in crops of important useful plants such as soybean plants , cotton plants, peanuts, canola and creeping beans. The test results are reproduced below.

In the discussion of data below, reference is made to herbicide application rates symbolized by "GR^" and "GRg^". GR^ indicates the maximum amount of herbicide required to achieve

15% damage to the crop, and GRg5 indicates the minimum amount required to achieve 85% control of the weed. GR^,. and GRgj. used as a measure of commercially acceptable performance. However, it should be noted that suitable commercial herbicides can of course cause greater or lesser plant damage within reasonable limits.

A further indication of the effectiveness of a chemical compound as a selective herbicide is the "selectivity factor" ("SF") of a herbicide for given crops and weed species. The selectivity factor is a measure of the safety of the crop and is expressed as the ratio GR^/GRg,-, i.e. the GR^,.-amount for the crop divided by the GRg^-amount for the weed, both amounts being expressed in kilograms per hectares (kg/ha). In the tables below, the selectivity factors, when listed, are given in parentheses according to the weed species. The symbol "IS" indicates "non-selectivity"..Marginal or indeterminate selectivity is indicated by a dash (-) after the weed species, and an empty field indicates that the plant species was not included in a given test, that the data were not obtained by a or - another reason or was less significant than other data obtained at the same time. For example, some observations made over shorter periods of time have been omitted in favor of data obtained on the basis of longer test periods, or data for longer test periods have been omitted, because data for shorter periods of time gave a definitive answer with regard to the activity of

a given herbicide.

As the resistance of the crop and the weed control have mutual effects on each other, a brief explanation of this relationship in the light of the selectivity factors is in order. Generally, it is desirable that the crop's resistance ability or tolerance values are high, as high herbicide concentrations are often desired for one reason or another. Conversely, it is desirable that the weed control quantities are small, i.e. that the herbicide has a high activity per quantity unit, this for economic reasons and possibly for ecological reasons. However, the application of one herbicide in small quantities may not be sufficient to control certain weed species, so that larger quantities must be used. Consequently, the best herbicides are those which eradicate the greatest possible number of weed species using the least possible amount of herbicide, and which provide the greatest degree of crop safety, i.e. have the highest crop tolerance value. Consequently, use is made of "selectivity factors" (as defined above) to quantify the relationship between the safety of the crop and the weed control. As far as the selectivity factors indicated in the tables are concerned, it should be noted that the higher the numerical value, the greater the selectivity of the herbicide for weed control in a given crop.

The experiments discussed here, which were carried out before germination, include both experiments carried out in greenhouses and experiments carried out in the open field. In the greenhouse experiments, the herbicide is applied either on the surface after the seeds or the vegetative propargules have been set down or by incorporation into a given amount of soil for application as a cover layer over the test seeds in pre-sown test containers. In the trials carried out in the open field, the herbicide is incorporated into the soil before sowing or planting (i.e. the herbicide is applied to the surface of the soil and then incorporated into it by means of a mixing device, after which sowing is carried out.

The method used for surface application in the greenhouse is. as follows: containers, e.g. aluminum tubs of dimensions 24.13 cm x 13.34 cm x 6.99 cm or plastic pots of dimensions 9.53 cm x 9.53 cm x 7.62 cm, which are provided with drainage holes in the bottom, are filled to the brim with Ray clayey soil, which is then compacted to a level 1.27 cm from the edge of the tubs or pots. The pots (vessels) are then filled with seeds of the plant species to be tested and then covered with a 1.27 mm thick layer of the test soil. The herbicide is then applied to the surface of the soil with a belt sprayer in a quantity of 187 litres/hectare with a pressure of 2.11 kg/cm. Also other spray devices, e.g. a DeVilbiss brand sprayer is occasionally used. Each pot is supplied with 0.64 cm of water from above, and then placed in a greenhouse bed for subsequent watering from below as needed. As an alternative method, the sprinkling can be omitted. Observations of the herbicidal effects are carried out approx.

3 weeks after treatment.

The herbicide treatment carried out by incorporation into the soil in experiments in a greenhouse is as follows: A top soil of good quality is placed in an aluminum tub and compacted to a depth of from 9.5 to 12.7 mm from the top edge of the tub. A number of seeds or vegetative propagules of various plant species are placed on the soil layer. The amount of soil required to fill the tubs to the brim after sowing or adding vegetative propagules is weighed out in a tub. The soil and a known quantity of the active ingredient, supplied in a solvent or as a suspension of a wettable powder, are thoroughly mixed and used to cover the prepared vessels. After the treatment, the tubs are first sprinkled with water, corresponding to a rainfall amount of 0.64 cm, after which watering is carried out from below as needed to ensure a suitable humidity for germination and growth. As an alternative method, the sprinkling can be omitted. Observations are made approx. 3 weeks after sowing and treatment.

For a first series of experiments, data for the herbicidal effect before germination are listed in Table II, the relative effectiveness of the compounds according to the invention being compared with relevant known compounds with regard to the control of Cyperus esculentus, and weevil in crops of soybeans, cotton plants and maize.

The data in Table II show that the compounds according to the invention in general and considered as a class are significantly more active against both Cyperus esculentus and quack and are more harmless to soybeans and cotton plants than the reference compounds.

In particular, as far as the control of Cyperus esculentus is concerned, it will be seen that each and every one of the tested compounds according to the invention was significantly more active against Cyperus esculentus than compounds A and B, which are structurally the most closely related of the reference compounds, and compound H, which , despite being less closely related than A and B, may be considered to be more closely related in certain respects to the compounds of the invention than compounds C, D, E and I. It will also be seen that the compound of Example 1, which has a GRg,. of 0.10 kg/ha, was approximately twice as active as the most active reference compound, compound E (GRg^= 0.17), while exhibiting a yield safety factor three times greater than that of compound E in soybean crops, and which exhibit an equivalent safety factor in crops of cotton plants. It is likewise to be noted that the new compounds according to examples 2 and 11 also exhibited a unit activity which was respectively equivalent to and greater than the unit activity of compound E against Cyperus esculentus. Although the reference compounds F and G

had rather high unit activity, moreover, none of these compounds were selective against Cyperus esculentus in soybean crops, nor was compound F selective in cotton crops. Although compound G gave selective control of Cyperus esculentus in crops of cotton plants, the degree of safety was lower than for all of the compounds according to the invention, except for the compound according to example 2, and markedly lower than the degree of safety for the compounds according to examples 5, 6 and 12. The selectivity factors for the compounds according to examples 9 and 13 against Cyperus esculentus in soybean crops were particularly noteworthy.

With respect to quack control, the compound of Example 2 was nearly three times as active as the most active of the reference compounds, compound D, while exhibiting equivalent crop safety in soybean crops. Also the new compound according to example 3 showed higher unit activity against quack and showed three times greater safety in soybean crops than compound D. Here too it is to be noted that each of the compounds according to the invention that were tested on quack had far better unit activity than compounds A and B, which are the most closely related of the compounds tested. Although the unit activity of compound H against quack was slightly higher than that of the compounds of Examples 9 and 13, the selectivity factors of the latter compounds against quack in soybean crops were about twice that of compound H, which is the second most closely related of the reference compounds. Moreover, the reference compounds A, B, F and G were non-selective towards quack in soybean crops.

Other things to note in Table II is that of all the compounds tested, the compounds according to examples 5, 6, 9 and 13 had by far the highest safety factors in soybean crops in relation to both Cyperus esculentus and quack. The compounds according to examples 5, 6 and 12 showed by far the highest safety factors in cotton crops in relation to Cyperus esculentus. It is further noted that the excellent yield safety factors for the compounds of Examples 5, 6, 9, 12 and 13 are accompanied by very small

GRg^ amounts, indicating high unit activity against Cyperus esculentus and quack. In these experiments, most of the compounds according to the invention were non-selective in maize crops, as were all of the reference compounds, with the exception of three. However, the compound according to example 14 showed markedly improved selectivity towards both quail and Cyperus esculentus in maize crops.

In other comparative trials, the herbicidal activity before germination of the reference compounds C and D and the compound according to example 1 was tested against various annual broad-leaved weed species in an applied amount of 3.36 kg/ha. Observations were made 6-7 weeks after the treatment

(UEB), and the percentage control of the weed species was noted. The data from these experiments are listed in Table III.

From the data in Table III, it will be seen that the compound according to example 1 showed a markedly improved activity compared to compound C against each of the tested annual broad-leaved weed species. In a similar way, the compound according to example 1 showed markedly improved activity compared to compound D against Sida spinosa, hemp sesbania, Polygonum and ambrosia, while at the same time it showed an equivalent activity against Datura stramonium and a somewhat smaller unit activity against purumelde and Chenopodium.

Open field trials were then conducted to determine

the relative herbicidal activities and selectivities before germination of the compound of Example 1 compared to the reference compounds C, D, E and I against chickpea, Cyperus esculentus and hemp sesbania in soybean crops. These experiments were carried out in separate pots of clayey (Sharkey) soil containing 2.0% organic matter, and which were treated with different concentrations of each individual herbicide, which was applied in the form of an emulsifiable concentrate in an amount of 280.5 kg/ha. Observations were made 4 weeks and 7 weeks after the treatment. The trial data, which is based on three replicates, shows that after 7 weeks the only compound that selectively controlled hemp sesbania was the compound of Example 1. This control (GRg5) was achieved with only 1.96 kg/ha,

while GRg^ for each of compounds C, E and I was 5.6 kg/ha and for compound D 5.0 kg/ha. GR15 in soybean crops was

3.9 kg/ha, which corresponds to a safety factor of 2.0

for the compound according to example 1. Thus, approximately three times as much of the reference compounds were needed to obtain GRO o Dc as for the compound according to example 1, but without achieving selectivity in soybean crops.

Compounds C and D were non-selective against Sida spinosa in soybean crops at 7 UEB. A quantity of 4.2 kg/ha of compound I was required, while 2.8 kg/ha of compound E was necessary to obtain GRg^ and selectivity factors of 1.1 and 1.5 respectively. In contrast, GRg^ was obtained for the compound of Example 1

with only 0.8 kg/ha, and this result was achieved with a selectivity factor of 4.7 in soybean crops.

Compounds C, D and E were non-selective to chickpea in soybean crops at 7 UEB. Compound I and the compound according to example 1 had largely equally high safety factors, namely 1.5 and 1.4 respectively.

The above-mentioned experiments carried out on open ground thus showed that the compound according to example 1 showed a significant improvement compared to the reference compounds C, D,

E and I with respect to selective control of all three annual weed species in soybean crops 7 weeks after treatment, except that it gave about the same control of chickpeas as compound I.

In further experiments to determine relative herbicidal activities and selectivities over even longer periods of time, the same herbicides as those used in the previous experiment were again tested in the open field, this time in separate pots with fine-grained clay/fine-grained soil sand-mixed clay containing from 3.0 to 3.5% organic matter. In parallel experiments, emulsifiable concentrates of the respective herbicides were applied to surfaces and incorporated into the soil before sowing for pre-emergence control, also in this case in an amount of 280.5 kg/ha. In these experiments, the herbicides were compared with regard to their effectiveness against the perennial weed species quack and the annual, broad-leaved weed species ambrosia, purumelde and Polygonum in soybean crops. These trials were conducted during a period of heavy rainfall, with 4.45 cm falling on the fifth day after treatment ("DEB") and 2.29 cm, 1.52 cm, 1.27 cm and 1.27 cm of rain the following days. The experimental data are listed in Table IV.

Referring to the data in Table IV, it will be seen

that in the experiments where the herbicide was incorporated into the soil before sowing, none of the reference compounds showed any selective control of any of the tested weed species in soybean crops at application rates up to 6.7 kg/ha, which was the maximum amount tested, in the observations made after 6 weeks and 9.5 weeks. As indicated above, the selectivity is indicated by a selectivity factor, or a ratio GR^/G<Rg>tj, which is 1.0 or greater, the selectivity being

the higher the greater the value. In contrast, the compound according to example 1 showed selective control of quack, purulent and Polygonum after 6.0 weeks and control of quack and Polygonum after 9.5 weeks. The herbicidal effect of the compound according to example 1 turns out to be of the order of magnitude three or more times greater than that of the reference compounds against quack and purumelde (with the exception of compound D) and about two or more times as high as that of the reference compounds (except compound D after 6 and 9.5 weeks and compound E after 9.5 weeks). None of the herbicides gave selective control of ragweed in this experiment, but the compound according to example 1 showed higher activity against this weed than the reference compound after 6 weeks.

As will be seen from the experimental data obtained by surface application of the herbicides, none of the reference compounds was able to selectively control any of the weed species used in the experiment in soybean crops at rates of 6.7 kg/ha or less after 6 weeks or 9.5 weeks, except compound D compared to purumelde in the assessment after 9.5 weeks.

In these experiments, selective weed control was observed for the compound according to example 1 with regard to quack and Polygonum after 6 weeks and with regard to purumelde after 9.5 weeks. The safety factor was here slightly larger than for compound D, namely 1.3 versus 1.1. Also in these experiments, the compound according to example 1 showed far higher herbicidal activity than the reference compounds.

From the data in Table IV, it will be seen that based on the criteria unit activity against weed species, tolerance of soybeans to the herbicides, safety factors and methods for applying the herbicide, the compound according to example 1 showed significantly better properties as a herbicide for use before germination than the comparison compounds.

The sustained weed control achieved

with the compound according to example 1 under the above-mentioned conditions of heavy rainfall, showed that the compound was not easily washed out.

In further comparison experiments conducted on open

field, the compound according to example 1 and the comparative compounds D and E were tested with regard to the selective control of Sida spinosa and finger millet in cotton crops, with application of the herbicide respectively on the surface and by incorporation into the soil before sowing. In the experiments where the herbicide was incorporated into the soil before sowing, Cyperus esculentus was among the weed species. The soil used in these experiments,

was fine-grained sand-mixed clay with 1.7% organic matter. Assessment was carried out 2, 6 and 9 weeks after the treatment. Data (based on three replicates) from the surface application experiments showed that the compound of Example 1 had more than twice the unit activity against Sida spinosa as compounds D and E after 6 weeks and a unit activity that was 1.5 times higher than the activity of these compounds after 9 weeks. Compound D was non-selective towards Sida spinosa in cotton crops after 6 and 9 weeks. The selectivity factors for compound E after 6 and 9 weeks

were 1.1 and 1.2, respectively, while they were respectively 3.3 and 1.8 for the compound of Example 1. Although the unit activities of the tested compounds against finger millet were comparable when evaluated after 6 weeks, the compound of Example 1 was more active than compound E after 9 weeks and more selective (selectivity factor >4.0) than compound D, which had a selectivity factor of 2.8.

In the tests carried out by incorporating the herbicide into the soil before germination, the unit activity of the compound according to Example 1 after 9 weeks was more than twice as high as that of the comparative compounds against Cyperus esculentus, slightly less than twice as high as the unit activity of the comparative compounds against finger millet and more than 1.33 times as high as the unit activity of the comparison compounds against Sida spinosa. In this test carried out on open ground, the compound according to example 1 gave selective control of Cyperus esculentus in cotton crops up to 6 weeks after the treatment, while the comparison compounds showed no selectivity even when evaluated after 2 weeks. Although none of the tested compounds showed any selective control of Sida spinosa in this attempt to incorporate the herbicide into the soil, the selectivity margin was much narrower for the compound according to example 1 than for the other compounds. The compound of Example 1 and compound E gave a highly selective control of finger millet at 2 weeks post-treatment, but were then non-selective. Compound D was not selective to finger millet on either

of the times when the assessment was made.

The striking conclusions that can be drawn from the above-mentioned tests on cotton fields are therefore that the compound according to example 1 was markedly more active than the comparison compounds against the weed species Cyperus esculentus and Sida spinosa, while retaining this activity for a longer time, and that the compound according to example 1 had higher selectivity factors with respect to these weed species. Moreover, the compound according to example 1 showed higher unit activity than compound E <p>g higher selectivity than compound D towards finger millet in cotton crops after 9 weeks.

Further tests were carried out where the compound according to example 1 was compared with compounds D and E, to determine the relative herbicidal activities and the duration of action in the soil against the perennial weed species Cyperus Esculentus and quack. Compounds D and E are among the most active selective herbicides among the known 2-haloacetanilides and have been considered standard compounds for this class when testing other herbicides against Cyperus esculentus, quack and other weed species. In the experiments to be discussed here, duplicates of each treatment were carried out, and 25 tubers of Cyperus esculentus and 25 rhizome fragments of quack were sown. The herbicides were incorporated into the cover soil layer in a sufficiently large amount to determine the GR,.q amount, i.e. the smallest amount (in kg/ha) required to achieve 50% control of the weed. The maximum amounts used in the case in question were 11.2 kg/ha and the smallest amount 1.4 kg/ha. Assessment was made after 3, 6, 12 and 18 weeks. After each assessment, the topsoil was removed, the old tubers and rhizome fragments removed and replanted and placed in a greenhouse to be propagated. The trial results are listed in table V. "UEB" stands for "weeks after treatment".

The data for Cyperus esculentus in Table V show that 3 weeks after treatment the amount of GR^ for each compound was less than 1.4 kg/ha, while some marked differences appeared after 6 weeks. After 12 weeks there was a significant difference in the control of Cyperus esculentus. Thus, only 1.4 kg/ha of the compound according to example 1 was required to control 50% of the weeds, while 5.9 kg/ha of compound D and 7.8 kg/ha of compound E were required to achieve the same degree of control of Cyperus esculentus. Likewise, after 18 weeks (UEB = 18) only 8.4 kg/ha of the compound of Example 1 was required to control 50% of Cyperus esculentus, compared to an undetermined amount higher than 11.2 kg/ha (the largest amount was used) of compounds D and E.

Similarly, the data for quail in Table V show that 6 weeks after the treatment (UEB = 6) the compound according to example 1 and compound D had somewhat higher activity than compound E. However, the superiority of the compound according to example 1 is shown at UEB 12, as the only 1.4 kg/ha of this is required to achieve the same control of quack as when using 5.6 kg/ha of compound D and 11.2 kg/ha of compound E. The higher herbicidal activity of the compound according to example 1 also made itself known at UEB 18.

A clear advantage of a herbicide is that it is effective

in a wide variety of soil types. Therefore, it is in Table VI

provided data showing the herbicidal action of the compound of Example 1 on Cyperus esculentus in cotton crops and soybean crops in a selection of soil types with varying organic matter and clay content. The treatment with the herbicide was carried out by incorporation into the soil, as the seeds were sown at a depth of 0.95 cm and sprinkled with water in an amount corresponding to 0.64 cm. Assessment was made 18 days after the treatment.

The data in Table VI show that the compound according to Example 1 appears to be quite unaffected by the type of soil and the content of organic matter, as it gives selective control of Cyperus esculentus in both cotton crops and soybean crops in soils with an organic matter content varying from 1.0 to 6 .8% and with a clay content varying from 1.8 to 9.6%. The selectivity factors were highest in Sarpy highly clayey soil.

Further tests were then carried out to determine the herbicidal properties of the compound according to Example 1 in soils containing a large amount of organic matter. In these experiments, which were carried out in the open field and in three repetitions, the activity of the compound according to Example 1 was tested against purumelde and Chenopodium in soybean crops sown in manured soil. Compounds C, D, E and I were also tested for comparison purposes. These experiments were carried out both by incorporating the herbicide into the soil before sowing and by surface application, in manured soil containing 23% organic matter. In these tests, the compound according to Example 1, both by the method of incorporation of the herbicide into the soil and by the method of surface application, showed the highest unit activity against Chenopodium 4 weeks after treatment (UEB 4) and, using the method of incorporation into the soil, the highest selectivity factor in soybean crops, namely a selectivity factor greater than 2.7, against a selectivity factor of 1.1 for each of compounds C and D. Compounds E and I were non-selective at UEB 4. All compounds were non-selective against Chenopodium at UEB 7 by both methods of applying the herbicide. Connection E

was slightly more active than the compound of Example 1 at UEB 7 by both application methods. Compared to pure compound D, compound D showed the highest unit activity and selectivity factor (1.9) at UEB 7 by both application methods. In the surface application method, the selectivity factor for compound D was almost twice as high as for the compound according to

example 1 and compound E. No other compounds were able to selectively control purumelde at UEB 7 using the soil incorporation method or the surface application method. The compound of example 1 (selectivity factor 2.0) and compounds C and E ( each with a selectivity factor of 1.0) were able to selectively control purumelde at UEB 4 by the method of incorporating the herbicide into the soil.

The experiments described above therefore show that the best selective control of Chenopodium in soybean crops in manured soil is achieved, compared to the comparison compounds, when the compound according to example 1 is applied by incorporation into the soil. This compound had the highest unit activity and the highest selectivity factor at UEB 4 of all the compounds examined. In addition, the compound according to example 1 gave selective control of purumelde up to approx. UEB 7 by the surface application method and up to UEB 4 by the method with incorporation into the soil. Compound D gave the best control of purumelde at UEB 7

by both application methods. The relative performance of the compound according to example 1 and compound D in fertilized soil should also be compared with the relative performance of these two compounds in soil with a lower content of organic matter, e.g. a content of 3.0 - 3.5%, where the compound according to example 1 has a higher unit activity and a longer duration of action in the soil, while at the same time it shows selectivity in soybean crops, both by the surface application method and by the method by incorporation into the soil, as shown of Table IV.

The foregoing description clearly demonstrates the remarkable effectiveness of the compounds of the invention as herbicides for controlling perennial weeds and annual broadleaf weeds in soybean crops and cotton crops. Moreover, it is also indicated above and occasionally demonstrated, e.g. in the experiments where chicken millet and finger millet were used, that the compounds according to the invention also have outstanding herbicidal action against annual, narrow-leaved weed species, i.e. grass of various varieties. As will be shown below with respect to certain annual grasses, the compounds of the invention actually exhibit markedly improved properties compared to the herbicidally most effective and/or commercially available 2-haloacetanilides of the prior art. As will be clear from the experimental data presented here, there are cases where a relevant, previously known 2-halogenacetanilide exhibits better herbicidal activity than the inventions according to the invention with regard to specific annual weed species under comparable conditions. However, it will also

it is clear from the presented comparison data that the compounds according to the invention, taken as a whole, are at least comparable to and often better than, and sometimes even significantly better than, the best known 2-haloacetanilides as selective herbicides for the control of annuals and perennial narrow-leaved weed species in crops of soybean, cotton, peanut, etc.

In a pre-germination greenhouse experiment, the compounds of Examples 1 and 10 were compared to compounds C and I (both commercial 2-haloacetanilides) for relative herbicidal activity against annual, narrow-leaved weeds, namely soybean grass crops. In this experiment, the herbicides were incorporated into the soil before sowing, and evaluation was carried out 17 days after the treatment. The experimental data are listed in Table VII and indicate the average values of two identical experiments.

With respect to the data in Table VII, the following features are noteworthy: (1) compound I exhibited the lowest unit activity and the lowest selectivity of all compounds against each of the weed species included in this experiment, and showed no selectivity in soybean crops with respect to " wild proso" millet, Oryza sativa or "itchgrass"; (2) compound C was as active as the most active of the compounds of Examples 1 and 11 against shattercane and wild proso millet; (3) the compounds of Examples 1 and 16 both outperformed the known compounds in controlling sorghum and itchgrass seedlings; (4) the compound according to example 10 was more active against brachiaria and the compound according to example 1 was more active against Oryza sativa than the previously known compounds.

As a summary of the comparison data listed in Table VII, it can thus be said that one or both of the compounds according to the invention had as good a herbicidal effect as the best of the previously known comparison compounds against two annual, narrow-leaved weed species ("shattercane" and "wild proso" millet) and showed a markedly better effect against four narrow-leaved weed species (seedlings of sorghum, brachiara, Oryza sativa and "itchgrass"). Particularly noteworthy is the outstanding unit activity of the compound according to example 1 against seedlings of sorghum (GRg^= 0.14 kg/ha), as the compound exhibits a selectivity factor of approx. 8.0 in soybean crops, which is outstanding compared to a selectivity factor of > 2.0 for compound C, which is the best of the known compounds tested. Similarly, the compound of Example 10 showed excellent unit activity against brachiaria and "itchgrass",

and gives selectivity factors of > 8.0 and *4.0, respectively

in soybean crops, compared to corresponding selectivity factors of > 4.0 and > 1.0, respectively, for compound

C.

A further trial was then carried out in soybean crops. This time seeds of Texas panicum and Fall panicum were used, together with seeds of the other annual grass species mentioned in the text below. In this experiment, the compounds according to examples 1 and 11 were compared with the previously known compounds C, D and I with regard to herbicidal action before germination. The herbicides were incorporated into the soil and watered from below as needed. The maximum herbicide used during the experiment was 1.12 kg/ha, and consequently the exact amounts for GRg,. and GR^ above 1.12 kg/ha become somewhat inaccurate. Assessment was carried out two weeks after the treatment. The data from this experiment are listed in Table VIII. An analysis of the data in Table VIII shows that the new compounds according to Examples 1 and 11 exhibit the highest unit activity and the highest selectivity of all compounds tested against seedlings of sorghum and "shattercane". The compound according to Example 11 had the highest activity

and selectivity against "itchgrass", and the compounds of Examples 1 and 11 shared the highest activity against "Wild proso" millet with compound D and against Fall panicum with each of the previously known compounds. However, the compounds of the invention were more selective in soybean crops than compound D with respect to "wild proso" millet. Moreover, the compound according to Example 11 was the second most active compound against Texas panicum and Oryza sativa, and the compound according to Example 1 had, in common with compound D, the second highest activity against "itchgrass". Connection

D was the most active of the compounds tested against Texas panicum, brachiaria and Oryza sativa.

It will therefore appear: from the above comparative data regarding herbicidal activity against annual grass species, that the compounds according to the invention are more effective as herbicides than the best of the previously known compounds against certain annual grass species, e.g. millet, finger millet (S.I.) "shattercane" and "itchgrass" and have equivalent or largely equivalent herbicidal action against others, e.g. finger millet (for surface application), the millet species, brachiaria and Oryza sativa.

Other experiments carried out in greenhouses and/or in the open field

have shown that with the help of compounds according to the invention selective control is also achieved of other weed species in soybean crops, cotton crops and/or other crops. For example, the compound according to example 1 has been shown to

provide selective control of Cyperus rotundus<1> and Setaria faberii in cotton crops and of Setaria faberii and Abutilon theophrasti in soybean crops. Furthermore, the compound according to Example 1 has been shown to provide improved suppression of such resistant weed species as ragweed, wormwood and hookworm, compared to relevant known acetanilide herbicides. Other weed species against which the compounds

according to the invention have been shown to have herbicidal action, include Cirsium arvense, Convolvulus arvensis, takfas, Polygonium convovulus, etc.

As stated above, the compounds according to the invention have been shown to be effective herbicides in a number of crops. The above explanation and the experimental data concern first

and primarily weed control in soybean crops and cotton crops, which crops are of particular interest in this context. Other experiments have shown that the compounds according to the invention are also useful in other crops, as will be apparent from the following.

In an experiment carried out in a greenhouse, the herbicidal effect of the compounds according to examples 1.0 and 11 against quack in crops of rapeseed, creeping beans, sorghum and wheat, after incorporation of the herbicide into the soil before germination. Both of the tested compounds gave selective control of weevil in rapeseed and creeping beans, the selectivity factor for the compound according to example 1.0 being 3.5 in both crops and the selectivity factor for the compound according to example 11 being 3.0 in both crops. In this experiment, both compounds proved to be non-selective towards quack in crops of sorghum and wheat.

In separate experiments in greenhouses, the compound according to example 1 was also tested with respect to herbicidal action against Cyperus esculentus and quack respectively in crops of rapeseed, peanuts, sugar beet, sorghum, wheat and barley. The herbicide was incorporated into the soil. In these experiments, compound D was used as a comparison compound with regard to the effect against quack, while compound E was used as a comparison compound when testing the effect against Cyperus esculentus. In the experiment with quacks, the assessment was made 19 days after the treatment (DEB 19), and in the experiment where the effect against Cyperus esculentus was tested, the assessment was made at DEB 18. The test data are listed in Table IX. Selectivity factors for the herbicides are listed in parentheses after the GR^ amounts for the respective crops.

From the data in Table IX, it will be seen that the compound according to example 1 and compound D both exerted selective control of quack in crops of peanuts, rapeseed, sugar beet, wheat and barley, while the selectivity factor for the compound according to example 1 was significantly higher than for compound D for crops of groundnuts, rapeseed and sugar beet, while it was of equivalent size for wheat crops and lower for crops of barley. The compound according to Example 1 gave selective control of Cyperus esculentus in each of the crops examined, with the exception of sugar beet, while compound E did not give any selective control of Cyperus esculentus in crops of sugar beet, sorghum or wheat.

The high unit activity of compounds D and E which

is shown in Table IX, is generally characteristic of the short-term action in greenhouses (2-6 weeks) of these compounds against quack and Cyperus esculentus. However, all relevant experimental data (as stated here), both from experiments in a greenhouse and from experiments carried out in the open field, show that the compound according to example 1 has better unit activity against quack and Cyperus esculentus and better crop selectivity over a longer period of time, compared to compounds D and E In this connection, reference should again be made to: (1) table IV which contains comparative data obtained on open ground for up to 9.5

weeks in terms of the effect of these compounds against quack and other weeds in soybean crops (neither compound D nor compound E gave selective control of quack in soybean crops, even when evaluated after 3 weeks); (2) the above statement of comparative data obtained by attempting to

open field regarding the effect of these compounds against Cyperus esculentus and other weed species in cotton crops for up to 9 weeks (neither compound D nor compound E gives selective control of Cyperus esculentus in cotton crops, even when evaluated after 2 weeks); and (3) table V, where there is given comparative data for the time of action in the soil for the compound according to example 1 and the compounds D and E against Cyperus esculentus and quack for the time periods of 3, 6, 12 and 18 weeks,

and where the compound according to example 1 had a higher activity figure than the compounds D and E at UEB 3. It should also be mentioned here that the combined improved activity figure,

time in the soil and crop selectivity, for the compound according to example 1 vis-à-vis compounds D and E with respect to Cyperus esculentus and quack also applies in terms of the relative performance of these compounds against many other weed species, especially seedlings of sorghum, hemp sesbania, Sida spinosa, Polygonum, Chenopodium, etc. in an experiment with several crops and several weed species, the activity before germination of the compound according to example 1 against certain annual weed species in various crops was further tested on

open field. In parallel experiments, the herbicides were surface applied and incorporated into the soil before sowing. Determination was made -33 days after the treatment in the experiment where the herbicide was incorporated into the soil before sowing, and 34 days after the treatment (DEB 34) in the experiments where the application was made on the surface. In both experiments, the compound according to Example 1 gave selective control of chick millet and Setaria faberii in crops of corn, soybeans, cotton plants, creeping beans and peanuts. Chenopodium was also controlled in soybean crops. In the experiments where the herbicide was incorporated into the soil before germination, chicken millet and foxtail were also selectively controlled in crops of sorghum and sweet corn.

It will therefore be seen from the above detailed description of the compounds according to the invention that they have been shown to have unexpected and very superior herbicidal properties, both in isolation and relative to the structurally most closely related compounds, other related homologous and analogous and known commercial 2-haloacetanilides. More specifically, the compounds according to the invention have been shown to have outstanding properties with regard to unit activity, duration of action in the soil and safety for the crops with regard to perennial and annual broad-leaved and narrow-leaved weed species in crops of soybeans, cotton plants, peanuts, rapeseed, creeping beans, etc. More specifically, the compounds according to the invention have been shown to possess improved herbicidal activity against the perennial weed species Cyperus esculentus and quack, annual broad-leaved weeds such as hemp sesbania, Sida spinosa, Chenopodium and Polygonum and annual narrow-leaved weeds such as chickpea, finger millet ( by incorporating the herbicide into the soil before germination), "shattercane" and "itchgrass". Furthermore, the compounds according to the invention have been shown to be generally comparable to the best of the relevant prior known compounds with regard to the control of other annual grass species, such as seedlings of sorghum, finger millet (surface applied), the genus reverumpe, Texas panicum, fall panicum , "wild proso" millet, brachiaria and Oryza sativa, and annual broadleaf weeds such as purumelde and Datura stramonium. Finally, the compounds according to the invention have also been shown to have increased activity against resistant annual broad-leaved weed species, such as wormwood, hook seed, ambrosia and Abutilon theophrasti.

Toxicological investigations of the compound according to example 1 have shown that the compound is fairly safe. It was mildly toxic when ingested through the throat (single dose OLD|-q - 2,600 mg/kg), mildly toxic when applied to the skin (DLD..Q - 5,010 mg/kg) and mildly irritating to

eye and skin. It is not considered necessary to have special regulations for handling, as it is sufficient to take the usual precautions.

The herbicidal preparations according to the invention, including concentrates that require dilution before use, contain at least one active ingredient and an auxiliary substance in liquid or solid form. The preparations are made by mixing the active ingredient with an auxiliary substance including diluents, extenders, carriers and conditioners, and preparations can be made - in the form of finely divided particles -

shaped solids, granules, pellets, solutions, dispersions or emulsions. The active ingredient can thus be used together with an auxiliary substance, such as a finely divided solid, a liquid of organic origin, water, a wetting agent, a dispersing agent, an emulsifying agent or any suitable combination of these.

The preparations according to the invention, especially liquids and wettable powders, preferably contain as a conditioning agent one or more surfactants in a sufficient amount to make a given preparation easily dispersible in water or oil. The inclusion of a surfactant in the preparations makes the preparations far more effective. The term "surfactant" means that this includes wetting agents, dispersing agents, suspending agents and emulsifying agents. Anionic, cationic and nonionic agents can

just as conveniently used.

Preferred wetting agents are alkylbenzene and alkylnaphthalene sulfonates, sulfated fatty alcohols, amines or acid amides, long-chain acid esters of sodium isothionate, esters of sodium sulfosuccinate, sulfated or sulfonated fatty acid esters, petroleum sulfonates, sulfonated vegetable oils, ditertiary acetylenic glycols, polyoxyethylene derivatives of alkylphenols (especially isooctylphenol and nonylphenol) and polyoxyethylene derivatives of the monoesters of higher fatty acids and hexitolanhydrides (eg sorbitan). Preferred dispersing agents are methyl cellulose, polyvinyl alcohol, sodium alkyl sulfonates, polymeric alkyl naphthalene sulfonates, sodium naphthalene sulfonate, and polymethylene bisnaphthalene sulfonate.

Wettable powders are preparations that are dispersible in water and that contain one or more active ingredients,

an inert, solid extender and one or more wetting and dispersing agents. The inert, solid extenders are usually of mineral origin, such as the natural clay species, diatomaceous earth and synthetic minerals derived from silicic acid and the like. Examples of such extenders are kaolinites, attapulgite clay and synthetic magnesium silicate. The wettable powders according to the invention usually contain from 0.5 to 60 parts (preferably from 5 to 20 parts) active ingredient, from 0.25 to .25 parts (preferably from 1 to 15 parts) wetting agent, from 0.25 to 25 parts (preferably from 1.0 to 15 parts) dispersant and from 5 to 95 parts (preferably from 5 to 50 parts) inert, solid extender, all parts being calculated on a weight basis. If necessary, from 0.1 to 2.0 parts of the solid, inert extender may be replaced with a corrosion inhibitor and/or an antifoam agent.

Other preparations include dust concentrates, comprising from 0.1 to 60% by weight of the active ingredient on a suitable extender. These dust preparations can be diluted for application in concentrations in the range from 0.1 to 10 wt. Aqueous suspensions or emulsions can be prepared by stirring an aqueous mixture of a water-insoluble active ingredient and an emulsifier until the mixture is uniform, after which the mixture is homogenized to form a stable emulsion of very fine particles. The resulting concentrated aqueous suspension is characterized by an extremely small particle size, so that when it is diluted and sprayed, the coverage is very even and good. Suitable preparations

rates of this type contain from 0.1 to 60% by weight, preferably

show 5 to 50% by weight, active ingredient, the upper limit being determined by the limit of solubility of active ingredients therein

part in the solvent.

In another type of aqueous suspensions, one becomes with water

immiscible herbicide encapsulated, so that a microencapsulated phase dispersed in a water phase is formed. In one embodiment, tiny capsules are formed by combining an aqueous phase containing a lignin sulphonate as an emulsifier with a water-immiscible chemical and polymethylene-poly-phenyl isocyanate, after which the water-immiscible phase is dispersed in the aqueous phase, and then added a multi-functional amine. The isocyanate and the amine react with each other to form a solid urea shell around particles of the water-immiscible chemical, so that micro-capsules are formed of this. Usually the concentration of the micro-encapsulated material will be from 480 to 700 g/litre of the total preparation, preferably from 480 to 600 g/litre.

Concentrates are usually solutions of the active ingredient in water-immiscible or partially water-immiscible solvents, together with a surface

active agent. Suitable solvents for the active ingredient

part according to the invention, includes dimethylformamide, dimethylsulfoxide, N-methylpyrrolidone, hydrocarbons and water-immiscible ethers, esters and ketones. However, other strong liquid concentrates can also be prepared by dissolving the active ingredient in a solvent. Dilution to spray concentration is carried out e.g. with the kerosene.

The concentrated preparations contain from 0.1 to 95

parts (preferably from 5 to 60 parts) active ingredient, from

0.25 to 50 parts (preferably from 1 to 25 parts) of surfactant and, if necessary, from to 94 parts of solvent, all parts being parts by weight calculated on the basis of the total weight of the emulsifiable oil.

Granules are physically stable particulate preparations comprising an active ingredient that adheres to or is distributed in a base material consisting of an inert, finely divided, particulate extender. In order to facilitate the leaching of the active ingredient from the particles, a surface-active agent, such as one of those indicated above, may be present in the preparation. Naturally occurring clay species, pyrophyllite, illite and vermiculite are examples of applicable particulate mineral extenders. The preferred extenders are the porous, absorbent, preformed particles, such as preformed and screened particulate attapulgite or heat-expanded particulate vermiculite, or the finely divided clays,

such as kaolin clay, hydrated attapulgite or bentonite clay. These extenders are sprayed on or mixed with the active ingredient to form the herbicide granules.

The granular preparations according to the invention can contain from 0.1 to 30 parts by weight, preferably from 3 to 20 parts by weight, of active ingredient per 100 parts by weight of clay and from 0 to 5 parts by weight of surfactant per 100 parts by weight particulate clay.

The preparations according to the invention may also contain other additives, e.g. fertilisers, other herbicides, other pesticides, safety enhancing agents and the like, which are used as auxiliaries or together with any other of the auxiliaries mentioned above. Chemicals which are useful together with the active ingredients according to the invention are e.g. triazines, urea compounds, carbamates, acetamides, acetanilides, uracils, acetic acid or phenol derivatives, thiol carbamates, triazoles, benzoic acids, nitriles, biphenyl ethers and the like, such as: Heterocyclic nitrogen/sulfur derivatives 2-chloro-4-ethylamino-6-isopropylamino- s-triazine 2-chloro-4,6-bis-(isopropylamino)-s-triazine 2-chloro-4,6-bis-(ethylamino)-3-triazine 3-isopropyl-1H-2,1,3-benzothiadiazine -4-(3H)-one-2,2-dioxide

3-amino-1,2,4-triazole

6,7-dihydrodipyrido-d,2-a:2',1'-c)-pyrazidinium-5-bromo-3-isopropyl-6-methyluracil

1,1<1->dimethyl-4,4'-bipyridinium

U rea connections

N'-(4-chlorophenoxy)-phenyl-N,N-dimethylurea N,N-dimethyl-N'-(3-chloro-4-methylphenyl)-urea 3-(3,4-dichlorophenyl)-1,1- dimethylurea 1,3-dimethyl-3-(2-benzothiazolyl)-urea 3-(p-chlorophenyl)-1,1-dimethylurea 1-butyl-3-(3,4-dichlorophenyl)-1-methylurea Carbamate/ Thiolcarbamate

2- Chlorallyl diethyldithiocarbamate

S-(4-chlorobenzyl)-N,N-diethylthiolcarbamate isopropyl-N-(3-chlorophenyl)-carbamate S-2,3-dichloroallyl-N,N-diisopropylthiolcarbamate

ethyl N,N-dipropylthiol carbamate

S-propyl dipropyl thiol carbamate

Acetanides) acetanilides/ Anilines/ Amides 2-chloro-N,N-diallylacetamide

N,N-dimethyl1-2,2-diphenylacetamide

N-(2,4-dimethyl-5-[[(trifluoromethyl)-sulfonyl]-amino]-phenyl)-acetamide

N-isopropyl1-2-chloroacetanilide

2',6'-diethyl-N-methoxymethyl-2-chloroacetanilide 2'-methyl-6'-ethyl-N-(2-methoxyprop-2-yl)-2-chloroacetanilide

a,a,a-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine ' N-(1,1-dimethylpropynyl)-3,5-dichlorobenzamide Acids/ Esters/ Alcohols

2,2-dichloropropionic acid

2-methyl-4-chlorophenoxyacetic acid

2,4-dichlorophenoxyacetic acid

methyl 2-[4-(2,4-dichlorophenoxy)-phenoxy]-propionate 3-amino-2,5-dichlorobenzoic acid

2-Methoxy-3,6-dichlorobenzoic acid

2,3,6-Trichlorophenylacetic acid-N-1-naphthylphthalamic acid sodium 5-[2-(chloro-4-(trifluoromethyl)-phenoxy]-2-nitrobenzoate

4,6-dinitro-o-sec-butylphenol

N-(phosphonomethyl)-glycine and its -monoalkylamine and alkali metal salts and combinations of such Ethers

2,4-dichlorophenyl-4-nitrophenyl ether

2-chloro-α,α,α-trifluoro-p-tolyl-3-ethoxy-4-nitrodi-phenyl ether

Diverse

2,6-dichlorobenzonitrile

Acidic monosodium methanearsonate

disodium methanearsonate

Fertilizers that can be used together with the active ingredients are e.g. ammonium nitrate, urea, pot ash and superphosphate. Other useful additives are materials in which plant organisms can take root and grow, such as compost, dung, humus, sand and the like.

In the following, some examples of the forms of delivery of the herbicidal preparations described above are given.

Effective amounts of the acetanilides according to the invention are applied to the soil containing the plants, or they are incorporated into aqueous media in any suitable manner. The application of liquid preparations and particulate solid preparations to the soil can be carried out in any conventional manner, e.g. using dust spreaders, boom spreaders and hand spreaders and atomizing spreaders. The preparations can also be applied from airplanes as a dust or as a shower, because they are effective in small quantities. The application of the herbicidal preparations to aquatic plants is usually carried out by adding the preparations to the aqueous medium in the area where control of the aquatic plants is desired.

Applying an effective amount of the compounds according to the invention at the place where the unwanted weeds occur is of decisive importance in the utilization of the invention. The exact amount of active ingredient that should be used in each individual case depends on a number of factors, including the plant species and the plants' stage of development, the type of soil and its condition, the amount of rainfall and the specific acetanilide used. When selectively applied before germination to the plants or to the soil, an amount of from 0.02 to 11.2 kg/ha is usually used, preferably from 0.04 to 5.60

kg/ha or most preferably, from 1.12 to 5.6 kg/ha of the acetanilide. -Smaller or larger quantities may be desirable in certain cases. A person skilled in the art will easily be able to determine the optimal amount in any given case from this description.

The terms "soil" and "soil" used in this description are to be understood in the broadest sense and include all conventional soils as defined in Webster<1>'s New International Dictionary, Second Edition, Unabridged (1961). The terms thus refer to any substance or medium in which plants can take root and grow and thus include not only soil, but also compost, dung, humus, sand and the like which are adapted for plant growth.

Claims (5)

1. New 2-haloacetanilides, characterized in that they have the formula: where R is ethyl, n-propyl, isopropyl, isobutyl, sec-butyl, cyclopropylmethyl, allyl or propargyl, R1 is methyl, ethyl, n-propyl or isopropyl, and R2 is hydrogen, methyl or ethyl, with the proviso that: when R2 is hydrogen, R1 is ethyl and R allyl, when R2 is ethyl, R1 is methyl and R is isopropyl, when R1 is methyl, R is ethyl, isopropyl, isobutyl, sec-butyl or cyclopropylmethyl, when Rx is ethyl, R is sec -butyl, allyl or propargyl/ when R 1 is n-propyl, R is ethyl, and when R 1 is isopropyl, R is ethyl or n-propyl. 2. Connection according to claim 1, characterized in that it is 2'-methoxy-6'-methyl-N-(isopropoxy-methyl)-2-chloroacetanilide. 3. Connection according to claim 1, characterized in that it is 2'-methoxy-6<1->methyl-N-(ethoxy-methyl)-2-chloroacetanilide. 4. Connection according to claim 1, characterized in that it is 2'-isopropoxy-6'-methyl-N-(ethoxy-methyl)-2-chloroacetanilide. 5. Herbicidal preparation containing as an active ingredient a 2-halogenacetanilide, characterized in that it contains as active ingredient one or more 2-haloacetanilides according to one of claims 1 - 4.