CS258135B2 - Herbicidal agent - Google Patents

Abstract

The herbicidal composition contains as herbicidally active substance 5 to 65% by weight of chloroacetanilide of formula IV, where R7 and R8 are C1-5alkyl, R9 are C1-5alkyl or C2-5alkenyl, and 0.2 to 32% by weight of an antidote active substance of formula I, where R1 and R2 are hydrogen, C1-10alkyl, C2-10alkenyl, Cy or C6cycloalkyl, phenyl, optionally substituted with C1-3alkyl or halogen, or together hexamethylene, and when R1 is hydrogen, R2 has a meaning other than optionally substituted phenyl, R3 is C1-5alkyl or C2-5alkenyl. The herbicidal composition has reduced phytotoxic effects on cultivated plants.

Description

This invention relates to a herbicidal composition comprising chloroacetanilide as the herbicidally active substance, together with an antidote active substance represented by N-(dichloroacetyl)glycinamide.

The new N-(dichloroacetyl]glycinamides have the general formula I

R ¹ Cl \ /

N—C—CH2—N—C—CH

Z II I II \ r ² o R ³ o Cl (I) where

R ¹ and R ² independently represent a hydrogen atom, an alkyl group with 1 to 10 carbon atoms, an alkenyl group with 2 to 10 carbon atoms, a cycloalkyl group with 5 or 6 carbon atoms, a phenyl group, a phenyl group substituted once or twice with an alkyl group with 1 to 3 carbon atoms, a halophenyl group or together a hexamethylene group, and when R ¹ is a hydrogen atom, R ² has a meaning other than phenyl or substituted phenyl,

R ³ represents an alkyl group with 1 to 5 carbon atoms or an alkenyl group with 2 to 5 carbon atoms.

Chloroacetanilide derivatives of the general formula IV have long been widely used in plant protection against undesirable weeds, especially monocotyledonous weeds.

X.

/

6'

R ⁹

I do ^n't want to.

II 2 o

dV) where

R ⁷ and R ⁵ independently represent an alkyl group with 1 to 5 carbon atoms and

R ⁹ represents an alkyl group with 1 to 5 carbon atoms or an alkenyl group with 2 to 5 carbon atoms.

Particularly well-known representatives of these chloroacetanilides of the general formula IV are 2-chloro-N-isopropylacetanilide (Propachlor), 2-chloro-2',6'-diethyl-N-(methoxymethyl)acetanilide (Alachlor), 2-chloro-2'-methyl-6'-ethyl-N-(ethoxymethyl)acetanilide (Acetochlor) and 2-chloro-2',6'-diethyl-N-butoxymethyl)acetanilide (Butachlor).

Chloracetanilides of the general formula IV, when used in the amount necessary to destroy monocotyledonous weeds, also damage protected crops. These phototoxic properties limit the possibilities of use, or allow use only in doses that do not harm crops and thus reduce the effectiveness of these herbicidal substances.

About twenty years ago, Hoffmann discovered that there are compounds (derivatives of 1,8-naphthoic acid anhydride) that reduce this phytotoxic effect and, when used together with herbicidally active substances, compensate for their poisonous effect on cultivated plants. Compounds with such an effect are called antidotes, or substances with the opposite effect or antidotes, i.e. antitoxic substances.

Since then, numerous other such compounds have been discovered and patented, acting as antidotes. Hungarian Patent No. 168,977 describes oxazolidine and thiazolidine derivatives as antidotes; Hungarian Patent No. 170,214 recommends substances based on thiazolidine sulfoxide and thiazolidine sulfone as antidotes. Sulfides are used as antidotes according to Hungarian Patent No. 173,755. Oxazolidine derivatives are also recommended as antidotes in Hungarian Patent No. 176,867. Hungarian Patent No. 179,643 describes N-(benzoylsulfonyl)carbamates, Hungarian Patent No. 180,069 describes N-(benzoylsulfonyl)thiocarbamate, and Hungarian Patent No. 180,068 describes 2,3-dibromopropionamide derivatives as antidotes.

Antidotes based on dichloroacetamide compounds are described in Hungarian patent documents Nos. 176,458 and 176,784. Hungarian patent documents Nos. 176,669, 176,796, 178,883, 178,892, 178,985, 179,092 and 179,093 describe the action of dicarboxylic acid derivatives as antidotes.

The large number of antidotes known from the state of the art, however, proves that despite diligent research, it has not yet been possible to find a compound by which cultivated plants could be protected from the harmful effects of individual herbicidally active substances. Relative evidence of the failure to solve this problem is also that there is no unified opinion on the biochemical processes taking place when adding antidotes and on the mechanism of action of such compounds in the plant organism. The harmful effects of herbicidally active substances are also influenced in various ways by factors acting in parallel (such as temperature, soil moisture, soil pH value) and by the physical properties of herbicidal agents (for example, vapor pressure, solubility in water).

It has now been found that the new N-substituted or N'-substituted N-(dichloroacetyl)glycinamides of the general formula I compensate for the phytotoxic action of the herbicidally active substances of the general formula IV.

The subject of the present invention is a herbicidal composition which contains 5 to 65% by weight of chloroacetanilides of the above-mentioned general formula IV, where R ⁷ , R ⁸ and R ⁹ have the above-mentioned meaning and 0.2 to 32% by weight of an antidote of the above-mentioned general formula I, where R ¹ , R ² and R ³ have the above-mentioned meaning.

The method for producing antivenom-active substances, i.e. N-substituted or N'-substituted N-(dichloroacetyl) glycinamides of the general formula I, where R ¹ , R ² and R ³ have the above-mentioned meaning, consists in reacting an N-substituted or N'-substituted glycinamide of the general formula II

Ri \l~~C—CH2—NH -R ³ / II

R ² O (II) where R ¹ , R ² and R ³ have the above-mentioned meaning, in the presence of an acid acceptor and optionally in the presence of a solvent, with dichloroacetyl chloride.

The method of producing antivenom active substances is the subject of our Czechoslovak patent No. 258,781. This patent also provides detailed information on the conditions used in the production of such antivenom active substances, as well as a number of specific examples of the method.

The herbicidal compositions according to the invention are preferably in the form of emulsion concentrates, wettable powders, granules, aqueous or oily suspensions. The preparation of herbicidal compositions containing the antidote according to the invention is illustrated by the following examples, which do not limit the invention in any way.

Example 1

5 parts by weight of Alachlor [2',6'-diethyl-N-(methoxyethyl)-chloroacetanilide] and 0.8 parts by weight of the active ingredient, a compound of the general formula I, where R ¹ is phenyl], R ² is ethyl and R ³ is tert.-butyl (mp 100 to 101 °C), are dissolved in 10 parts by weight of dichloromethane. The solution is sprayed onto 24.2 parts by weight of amorphous silicic acid with stirring. The solvent is then removed in a liquid evaporator at a temperature of 30 to 40 °C. 60 parts by weight of diatomaceous earth, 3 parts by weight of sodium salt of alkylsulfonic acid as a wetting agent, 3 parts by weight of cresol-formaldehyde condensate and 6 parts by weight of sulfite liquors in powder form as a dispersing agent are added to the powder mixture. The mixture is finely ground in a mill (Kontraplex Alpina 63 C). A wettable powder is obtained with a content of 5.8% by weight of the active substance. The ability to maintain buoyancy (at a concentration in water with a hardness of 19.4° DH of 1% after half an hour) is 81.6%. The residue on the sieve (in the case of a mechanical sieve 325) is 0.82% by weight.

Example 2 ru and 0.25 parts by weight of the active substance, a compound of the general formula I, where R ¹ and R ³ denote aylyl and R ² is hydrogen (n _D ²⁰ = 1.5250) (hereinafter referred to as active substance A), in a mixture consisting of 22 parts by weight of xylene and 21.75 parts by weight of dichloromethane. An emulsifier is added to the solution in an amount of 6 parts by weight, which contains a mixture of calcium salt of alkylarylsulfonic acid and polyglycol esters of fatty acids. The solution is homogenized by stirring and filtered. The emulsion concentrate contains 50.25% by weight of active substances.

Example 3

In a mixture consisting of 21.75 parts by weight of xylene and 21.75 parts by weight of dichloromethane, 50 parts by weight of Alachlor and 0.5 parts by weight of active ingredient A are dissolved. While stirring, 6 parts by weight of an emulsifier mixture consisting of calcium salt of alkylarylsulfonic acid and polyglycol esters of fatty acids is added to the mixture. The obtained emulsion concentrate contains 50.5% by weight of active ingredients.

Example 4 parts by weight of Alachlor and 1 part by weight of active ingredient A are dissolved in a mixture consisting of 21.5 parts by weight of xylene and 21.5 parts by weight of dichloromethane. 6 parts by weight of the same emulsifier mixture as in Example 3 are added to the solution. The emulsion concentrate contains 51 parts by weight of active ingredients.

Example 5

50 parts by weight of Alachlor and 2 parts by weight of active ingredient A are mixed together and dissolved in a solvent mixture consisting of 20 parts by weight of xylene and 20 parts by weight of dichloromethane. The same emulsifier as in the example is added to the solution in an amount of 8 parts by weight.

3. After homogenization, the solution is filtered. The emulsion concentrate contains 52% by weight of active ingredients.

Example 6

46.3 parts by weight of Alachlor and 3.7 parts by weight of active ingredient A are dissolved in a solvent mixture consisting of 19 parts by weight of xylene, 19 parts by weight of dichloromethane and 4 parts by weight of dimethylformamide. 8 parts by weight of the same emulsifier mixture as in Example 3 are added to the solution with stirring. The solution is filtered. The emulsion concentrate contains 50% by weight of active ingredients.

Dissolve 50 parts by weight of Alachlo7

Example 7 parts by weight of Alachlor, 7 parts by weight of active ingredient A are homogenized with 18 parts by weight of xylene, 18 parts by weight of dichloromethane and 5 parts by weight of dimethylformamide together with 8 parts by weight of the emulsifier mixture according to Example 3. The solution is then filtered. The emulsion concentrate contains 51% by weight of active ingredient.

Example 8

In a solvent mixture consisting of 18 parts by weight of xylene, 18 parts by weight of dichloromethane and 6 parts by weight of dimethylformamide, 38 parts by weight of Alachlor and 12 parts by weight of active ingredient A are dissolved. After the addition of 8 parts by weight of the emulsifier mixture according to Example 3, an emulsion concentrate with an active ingredient content of 50% by weight is obtained. Example 9

30.5 parts by weight of Alachlor and 19.5 parts by weight of active ingredient A are dissolved in a solvent mixture consisting of 16 parts by weight of xylene, 16 parts by weight of dichloromethane and 8 parts by weight of dimethylformamide. 10 parts by weight of the emulsifier mixture according to Example 3 are added to the solution. The solution is further homogenized for 15 to 20 minutes and then filtered. The emulsion concentrate contains 50% by weight of active ingredients.

Example 10 parts by weight of Alachlor and 32 parts by weight of the active ingredient, a compound of the general formula I, where R ¹ and R ³ are isobutyl and R ² is hydrogen (n _D ²⁰ = 1.4880), are dissolved in a solvent mixture consisting of 25 parts by weight of xylene, 20 parts by weight of dichloromethane and 15 parts by weight of dimethylformamide. 6.5 parts by weight of Emulsogen IP and 1.5 parts by weight of Emulsogen EL are added to the solution. The mixture is homogenized and then filtered. The emulsion concentrate contains 37% by weight of the active ingredient.

Example 11 parts by weight of Acetochlor [2-chloro~2-methyl-6'-ethyl-N-(ethoxymethyl)acetanilide] and 0.2 parts by weight of the active ingredient, a compound of general formula I, where R ¹ is allyl, R ² is hydrogen, R ³ isobutyl (mp 60 to

6.3 ^C C), is dissolved in a solvent mixture consisting of 22 parts by weight of xylene and 11 parts by weight of dimethylformamide. After adding 4.5 parts by weight of Emulsogen IP and 3.5 parts by weight of Emulsogen EL, the mixture is homogenized for 15 minutes and then filtered. The obtained emulsion concentrate contains 65.2% by weight of the active substance.

Example 12 parts by weight of Alcetochlor and 32 parts by weight of the active ingredient, a compound of the formula I, where R ¹ and R ² are ethyl and R ³ is isobutyl (mp 59.5 to 62.5 °C), are dissolved in a solvent mixture consisting of 20 parts by weight of xylene, 15 parts by weight of dichloromethane and 10 parts by weight of dimethylformamide. 6 parts by weight of Emulsogen IP and 2 parts by weight of Emulsogen EL are added to the solution with stirring. The mixture is homogenized and filtered. The emulsion concentrate contains 37% by weight of the active ingredient.

In the above examples, the following emulsifiers are used:

-Emulsogen EL is oxyethylated castor oil,

Emulsogen IP is an alkyl phenol polyethylene glycol ether.

(In both cases, the manufacturer is Hoechst AG.)

It has now been found that the compounds of the general formula I protect maize in particular against the harmful effects of the acetanilides of the general formula IV. Tests carried out to clarify the relationship between dose and effect have shown that the compounds of the general formula I significantly improve the effect at doses of 0.5 to 64% (based on the herbicidally active substance used, which is considered to be 100%). The following examples describe the biological effect.

Example 13

Dose and action

The effect of the compound of general formula I was investigated at various doses using active ingredient A. The tests were carried out as follows:

Test series are carried out in growing containers with an area of 1.13 dm ² , each repeated four times. The boxes are filled with 400 g of air-dried meadow soil, sieved through a 2 mm mesh sieve, with a humus content of 1.4% and a pH value of 7.5. (Soil according to Arana: 61.) The test plants are sown in these boxes: maize MVTC 596 (Zea maysj, 15 grains per box; green fescue (Setaria viritus) 0.5 g per box. Then the seeds are covered with 200 g of soil and finally treated chemically by spraying. The amount of chemical spray used is converted into a hectare. 20 ml of water is used to prepare the spray suspension.

After chemical treatment, 100 g of soil is added to the boxes and they are watered up to 65% kapa23 8135

IQ city water intake. During the growing period, constant humidity is maintained by daily watering.

Irradiation is provided daily for 14 hours using a high-pressure mercury lamp (ILGMI/D 400 W). The average daily temperature is maintained at 25 ^° C (minimum 23°C, maximum 27°C). Untreated controls are used for the evaluation of the tests.

In order to allow comparison with known antidotes, the widely used compound R-25 788 (N,N-diallyl-2,2-dichloroacetamide) is used as a reference substance in practice.

Evaluation is carried out on the tenth day after treatment by measuring the length of the shoots and evaluating morphological changes.

The following rating scale is used to assess morphological changes:

100% healthy corn, % slight leaf curl, slight deformation, % perfect deformation, cessation of plant growth and cessation of plant development.

As a monocotyledonous weed, the green sedge used is always destroyed by the action of a herbicide in the presence of an antidote, that is, it is protected by the action of the antidote active substance of the general formula.

ce I does not work.

The tests involve spraying the usable emulsions of Examples 1 to 12. For comparison, tests are also carried out with Alachlor and Acetochlor as active ingredients of herbicidal compositions without antidote and tests with herbicidal compositions containing the said herbicidally active substances and the known antidote R 25 788. During the evaluation, the length of the shoots was measured and morphological changes were evaluated. The test results are given in the tables below.

The symbols "a" and "b" in the tables always have the following meaning:

a active substance A, b antidote R 25 788.

The corn was treated with Alacholrena, applied at a rate of 1.5 l/ha, or with the antidote R 25 788. The results in percentages, with respect to the untreated control, are shown in Table 1.

TABLE I

Antidote 1/ha % Corn shoot length Appearance b A a—b and b A a—b and 0.008 0.5 91 81 + 10 97 87 + 10 0.015 1.0 98 87 + 11 98 84 + 14 0.030 2.0 104 105 — 1 98 97 + 1 0.060 4.0 97 107 — 10 99 94 + 5 0.120 8.0 97 114 — 17 99 100 — 1 0.240 16.0 96 100 — 4 100 97 + 3 0.480 32.0 93 97 — 4 100 100 0 0.960 64.0 86 97 — 11 100 99 + 1 sd ₅ % = 9.9% among any SDs% = 9.6% among any combinations combinations shoot length (without antidote) appearance (without antidote) 81% 80% Same test repeated with Acetochlor, used in an amount of 1.5 I/liu. Results expressed as a percentage, it is quarry on untreated control, are listed in Table II. TABLE II Antidote % Corn shoot length Appearance 1/ha and b A a—b and b A a—b 0.008 0.015 0.5 73 54 + 19 82 66 + 16 1.0 73 57 + 16 86 68 + 18 0.030 2.0 76 71 + 5 72 81 — 9 0.060 4.0 75 83 — 8 75 88 — 13 0.120 8.0 98 78 + 20 84 80 + 4 0.240 16.0 80 85 . — 5 91 84 + 7 0.480 32.0 78 89 — 11 94 98 — 4 0.960 64.0 88 87 + 1 93 98 — 5

SD ^5% = 9% between any combinations

SD ₅ °/„ = 14 % between any combinations shoot length (without antivenom) 44 % appearance (without antivenom) %

258

From the values in the tables it is clear that the active ingredients of the general formula I are, especially in the dosage range of 0.5 to 2.0%, more advantageous than the known and widely used agent R 25 788. At higher doses, no difference between the two antacids was proven in statistical tests. When used in amounts of 4 to 16%, the corn remained healthy, without any symptoms.

The active ingredients of the general formula I promote the selectivity of chloroacetanilides. The phytotoxic action of these compounds is not manifested, while the herbicidal action of these herbicidal compounds remains preserved.

Claims (1)

Subject A herbicidal composition comprising chloroacetanilides and an antidote as herbicidal active ingredient, characterized in that it contains 5 to 65% by weight of chloroacetanilide of the general formula IV v. · - i: Z 'C-CuCp ii Z o (where R ⁷ and R ³ are independently C 1 -C 5 alkyl and R ⁹ represents a C 1 -C 5 alkyl group or a C 2 -C 5 alkenyl group, and 0.2 to 32% by weight of an antioxidant of formula I OF THE INVENTION R ¹ Cl \ Z N - C - CH 2 -N ------ C - CH / ^z II! \ R ² O R 3 O Cl (I) wherein R ¹ and R ² are each independently hydrogen, C 1 -C 10 alkyl, C 2 -C 10 alkenyl, C 5 -C 6 cycloalkyl, phenyl, phenyl mono- or di-substituted alkyl having 1 to 3 carbon atoms, a halophenyl group or together a hexamethylene group, and when R ¹ is a hydrogen atom, R ^{2 has} a meaning other than phenyl or substituted phenyl, R ³ is C 1 -C 5 alkyl or C 2 -C 5 alkenyl.