NO880491L - INTERMEDIATES AND PROCEDURES FOR THEIR MANUFACTURING. - Google Patents

Abstract

Compounds with formula:. wherein R' and R' are such that OR' and OR3' are hydrolysable groups, r8 is a hydrogenolysable group and R is as indicated for R2' and R3'. The compounds are useful starting materials for the preparation of herbicidal compounds.i

Description

The present invention relates to new sulfonimide compounds with herbicidal action and with the general formula (I)

in which

R stands for an optionally substituted hydrocarbon radical R stands for a hydrogen atom or an optionally substituted one

hydrocarbon radical,

R 2 and R 3 each represent a hydrogen atom or are like this 2 3

that OR and OR are hydrolyzable groups,

R4 - stand. r- for a hydrogen atom or a group R 8 which is a hydrogenolysable group, and agriculturally tolerable salts thereof.

The invention also relates to a method for

preparation of compounds of formula (I) in which R 1 , R 2 , R 3 and R 4 have the above meaning, but R has a meaning other than hydrogen and the peculiarity of the method according to the invention is that a compound of formula

(III)

in which the various symbols have the above

is reacted with an ester of formula X-R, in which R has the above meaning with the exception of hydrogen and X is such that HX is a proton acid.

These and other features of the invention appear in the patent claims.

The invention thus relates to new herbicides which belong

to the chemical family of sulfonimides containing an aminomethylphosphon group, as well as starting products for the production of these herbicides, methods for producing the herbicides and starting products and use of the aforementioned herbicides in agriculture.

Numerous products containing an aminomethylphosphone group and having herbicidal properties are known, in particular from French Patents Nos. 2,129,327, 2,281,375, 2,251,569, 2,413,398, 2,463,149, European Patents Nos. 53,871, 54,382, 73,574, US Patent Nos. 3,160,632, 3,455,675, 3,868,407, 4,388,103, 4,397,676, British Patent No. 2,090,596, International Patent Application WO 83/03,608 and Belgian Patent Nos. 894,244, 894,245, 894,9495, , 894.592, 894.593, 894.594 and 894.595.

Numerous starting products for the manufacture of such herbicides are also known, particularly from European Patent Nos. 81,459, 97,522, 55,695, French Patent No. 2,193,830 and US Patent Nos. 3,835,000 and 4,422,982.

Nevertheless, it is still desirable to expand the range of available herbicides, to respond better to the needs of agriculture, as well as the range of starting products that make it possible to obtain herbicides so that new synthetic methods are available.

It is also desirable to have access to herbicides with a high and rapid activity, which preferably have low persistence and are easily biodegradable, and to have access to post-era pathogen herbicides with a large activity spectrum, a decreasing systemic effect and which, if appropriate, are selective for some crops.

The present invention provides new compounds which comprise an aminomethylphosphon group and have herbicidal action.

The invention also provides starting products and processes that give access to herbicides containing an aminomethylphosphone group, and a new process for the production of herbicides using relatively simple reaction components, especially glycine and its derivatives.

The invention thus provides compounds that can be used either as herbicides or as chemical starting products with the formula:

wherein R^ represents an optionally substituted hydrocarbon radical, especially alkyl, aryl or cycloalkyl, each of which may be substituted and suitable substituents include halogen atoms and phenyl and cyano groups, and alkyl, alkoxy and alkylcarboxylate groups in which the alkyl groups and the alkyl moieties preferably contain from 1 to 4 carbon atoms, R generally contains from 1 to 18 carbon atoms, preferably from 1 to 7 carbon atoms, and more particularly from 3 to 7 carbon atoms in the case of a cycloalkyl group. Preferably, R* represents an alkyl radical containing 1 to 4 carbon atoms, optionally

substituted with halogen, especially boron or fluorine, e.g. trifluoromethyl, R represents the hydrogen atom or has one of the meanings given for R<1>, preferably an alkyl group with 1 to 4 carbon atoms which is optionally substituted

2 3

with halogen, especially chlorine or fluorine. R and R

2 each represents a hydrogen atom or is such that OR and

3 2 3

OR are hydrolyzable groups. R and R can in particular be aryl or cycloalkyl or preferably alkyl, optionally substituted. Suitable substituents are those indicated in

12 3

the definition for R . R and R generally contain each from

1 to 12 carbon atoms and preferably from 1 to 8 carbon atoms. R 4 represents a hydrogen atom or a hydrogenolizable group R 8 and R 8 can in particular be a radical of the formula Ar(R^)(R<6>)C- in which Ar is an aromatic group, preferably phenyl, and R^ and R6 each represent a hydrogen atom, an Ar group or an alkyl group preferably containing no more than 6 carbon atoms, further salts thereof, preferably agriculturally tolerable salts.

Salts of the compound of formula I can be formed by the P-OH groups and also by the nitrogen atom to which the group R^ is attached, and which can be converted into an ammonium group.

Agriculturally acceptable salts include alkali metal (eg sodium or potassium), alkaline earth metal, ammonium (eg the ammonium salts and primary, secondary, tertiary and quaternary ammonium salts) and sulfonium salts. Other salts are acid addition salts, e.g. that which is formed with hydrochloric acid, sulfuric acid, phosphoric acid and other acids with a pK value less than 2.5.

Compounds of the general formula (I) which are of particular interest because of their herbicidal activity are

2 3 4

the products of formula (I) in which R , R and R are hydrogen atoms and R and R<*> are optionally substituted (especially with halogen) alkyl radicals containing from 1 to 4 carbon atoms, preferably methyl, and agriculturally tolerable salts thereof.

The invention also relates to intermediate products with formula

2' 3' 2 3 in which R and R are previously defined for R and R,

but does not represent the hydrogen atom, i.e. that they are such that OR and OR are hydrolyzable groups, with R and R preferably being alkyl radicals, most preferably with 1 to 4 carbon atoms. R 8 is as previously defined, and R 7 is as 2' 3'

previously defined for R and R

In the various preceding formulas, Ar denotes an aromatic group, preferably aryl and more particularly phenyl. This radical Ar can, if desired, carry one or more substituents that are not harmful to the reactions involved in the process (e.g. alkyl, alkoxy, nitro and halogen, with the number of carbon atoms in the alkyl and alkoxy substituents preferably being at most 6) .

Suitable radicals R g include benzyl, -phenylethyl, 1-phenylpropyl, naphthylmethyl, 1-naphthylethyl, 1-naphthylpropyl, diphenylmethyl, and trityl (ie triphenylmethyl) radicals. Benzyl is preferred.

In accordance with a feature of the invention, compounds of formula (I) in which R has a meaning other than a hydrogen atom can be prepared from compounds of formula (III)

(where the different symbols are as previously defined)

by reaction with an ester of formula X-R where R is as previously defined with the exception of hydrogen and XH is a protonic acid (inorganic or organic), preferably a strong inorganic acid. X is advantageously a chlorine atom, bromine atom or iodine atom or a sulfate group. Preferably, X-R is an alkyl halide. This reaction is advantageously carried out in a solvent in the presence of an alkaline agent at a temperature of between -10 and +100°C. The reaction component with formula (III) used is

2 3 4

preferred so that R , R and R have a meaning other than hydrogen atoms. It would also be possible to use a compound of formula (III) in which R 2 and R 3 are H, but in this case a substantial part of X-R would be used up by esterification of the OH groups in the product of formula (III).

In a feature of the invention, a compound of formula (III) is prepared in which R 2 , R 3 and R 4 have a meaning other than hydrogen atoms, i.e. compounds of formula

2' 3' 2 3 (in which R and R are as previously defined for R and R , but do not represent hydrogen and R p is as previously indicated) generally by reacting compounds of formula (II)

7 2' 3' 8

wherein R is replaced by H, and R , R and R are as previously defined, with a sulfonyl isothiocyanate of formula R<1->SO2~N=C=S wherein R 1 is as previously defined, preferably in a solvent and in presence of an alkaline agent, preferably a tertiary amine. The reaction is advantageously carried out between 10 and 120°c.

In a further feature of the invention is produced

2' 3' 8 compounds of formula (II) in which R , R and R have it

above meaning and R<7> is replaced by H, in general

2' 3' by hydrolysis of a compound of formula (II) in which R , R ,

7 8

R and R are as previously defined, i.e. compounds with formula

2' 3' 7 8

wherein R , R , R , and R are as previously defined, to convert the group ^DR 7 to a hydroxy group. In practice, this hydrolysis is a saponification which generally employs a molar amount of an alkaline agent substantially equivalent to the molar amount of the compound of formula

(II).

In a further feature of the invention is produced

2' 3' 7 8 compound with formula (II) hbori R , R , R and R are as previously defined by reaction of a phosphite (or phosphonic acid ester) with formula:

2' 3'

wherein R and R are as previously defined, with formaldehyde and an N-substituted derivative of glycine with

8 7 8 7

formula R -NH-C_2-CO-0-R where R and R are as previously defined.

The reaction is generally carried out between 0 and 100°C, preferably between 20 and 90°C, by mixing the reaction components. Although a large excess (3/1 to 1/3 in molar ratio) of one of the reaction components relative to the other is possible, in practice it is more advantageous to use approximate stoichiometry as close as possible and not to deviate more than 20 molX from this stoichiometry. It is of course clear that the essential advantages of the invention do not require an excess of one or more of the reaction components in relation to the others. Another advantage of the invention lies in the good yields obtained in the preparation of the compounds of formula (II).

Formaldehyde is used in any of its available forms. In a preferred method, it is used in the form of an aqueous solution with a concentration of between 1% weight/volume and saturation, preferably 30 to

40* weight/volume.

The reaction can be carried out in the presence of an inert solvent, but in general such a solvent is unnecessary and it is clearly another advantage of the invention that a solvent is not required for the preparation of the compounds of formula (II) (with the exception of the water in the aqueous solution of formaldehyde, formalin, which is used in accordance with the preferred method).

The reaction product is separated using any methods known in and of themselves.

Connection with formula:

wherein the various symbols are as previously defined can be converted into herbicidal products (which may be known) of formula (V)

(where the different symbols are as previously defined)

by hydrogenolysis of the R g group (which is preferably a benzyl group, removed by debenzylation). The hydrogenolysis is advantageously carried out in an aqueous or alcoholic medium at normal or elevated temperature, at or above atmospheric pressure. The catalyst used can be a known hydrogenolysis catalyst for the relevant R g radicals. Suitable catalysts include palladium, platinum and Raney nickel. The catalyst can be used with or without an inert carrier. It is also possible to use the above-mentioned metals, especially palladium and platinum, in the form of salts, hydroxides or oxides, which are converted into the corresponding metal by the action of hydrogen. Palladium-based catalysts such as palladium on charcoal or palladium on barium sulphate or palladium hydroxide on charcoal are used as the preferred debenzylation catalyst. At the end of the reaction, the catalyst can be separated by filtration and the filtrate evaporated. The product of formula (V) is obtained in this way

in essentially pure condition. A significant advantage of the invention lies in the fact that the reaction time for this debenzylation is relatively short and this makes it possible to use smaller quantities of catalysts.

When it is desired to produce non-esterified forms of known herbicides, such as e.g. N-phosphonomethylglycine in itself, it is possible to completely or partially hydrolyze the product of formula (V) in a known manner, e.g. by heating with an aqueous solution of an acidic or alkaline agent, especially a hydroxide or carbonate of an alkali metal or alkaline earth metal, or a strong inorganic or organic acid, such as hydrochloric acid, sulfuric acid, phosphoric acid, perchloric acid or arylsulfonic acid. This hydrolysis can also be followed by a salt formation (to form agriculturally tolerable salts) or a conversion to other herbicidal derivatives.

The compounds according to the invention of formula (VI)

(in which the various symbols are as previously defined) are generally prepared by deacylation of the compounds of formula (I) in which R 2 and R 3 have a meaning other than hydrogen atoms, to convert the groups OR 2 and OR 3 into hydroxy groups. This dealkylation is advantageously carried out by the action of a hydrogen halide acid in a protic polar organic solvent medium, such as e.g. a lower aliphatic carboxylic acid.

The compounds of formula (VII)

(where R and R<*> have the previously indicated meaning) and which are preferred compounds in accordance with the invention are generally prepared by hydrogenolysis of the R g group in

the compounds of formula (VI) in which R Å represents a group R g, i.e. compounds of formula:

1 8 in which R, R and R have the previously stated meaning. The hydrogenolysis conditions are generally similar to the conditions described earlier for the preparation of the compounds of formula (V). In formula (VII) and in other compounds in accordance with the invention, alkyl groups represented by R and R1 contain preferably from 1 to 6 carbon atoms and optionally substituted cycloalkyl or aryl groups represented by R and R^ containing preferably up to 10 carbon atoms. Compounds of general formula (VII) in which R has a meaning other than hydrogen are preferred. Compounds of general formula (VII) in which R and R , which may be the same or different, each represent an alkyl group containing from 1 to 4 carbon atoms and R 2 is optionally substituted with chlorine or fluorine, and agriculturally tolerable salts thereof, are preferred compounds according to the invention. In a further feature of the invention, 12 3 4 compounds of formula (I) are prepared in which R, R , R , R and R have a meaning other than hydrogen atoms, i.e. compounds with the general formula:

wherein R is as previously defined for R, but does not represent hydrogen, R 1' is as previously defined for

1 2' 3' 8

R , but does not represent hydrogen and R , R and R are as previously defined, by reacting a sulfonamide of the formula Ro-NH-SO 2~R - # with a mixed anhydride of the formula

(VIII)

wherein the various symbols are as previously defined and the alkyl group preferably contains 1 to 4 carbon atoms. Compound of formula (VIII) can be obtained by reacting a compound of formula (IX)

(in which the various symbols are as previously defined), preferably in the form of a salt, with an alkyl chloroformate (Cl-CO-0-alkyl in which the alkyl group preferably contains from 1 to 4 carbon atoms). The product with formula (IX) is preferably used in the form of an ammonium salt and especially in the form of a salt of a tertiary amine, such as e.g. triethylamine. The reaction is preferably carried out at a temperature of between -30 and +10°C in the presence of a solvent. If a solvent is used in which the salts formed during the reaction are insoluble, it is sufficient to separate the reaction product by filtration. It is thus possible to use ethers and esters

as solvents, especially tetrahydrofuran and ethyl acetate.

The compounds of formula IX can be prepared by hydrolysis of a compound of formula (II), preferably in the presence of an alkaline agent in an amount of at least approximately the stoichiometric amount.

The reaction of the mixed anhydride of formula (VIII)

with the sulfonamide R -SC^-NH-R<0> is advantageously carried out in a two-phase water/organic solvent medium in the presence of an alkaline agent and a phase transfer catalyst, preferably a quaternary ammonium salt. The temperature is generally between 0 and 50°C. Quaternary ammonium salts of a strong acid, such as e.g. tetraalkylammonium or trialkylaralkylammonium halides or sulfates. The alkaline agent used is preferably an alkali metal hydroxide or carbonate or an alkaline earth metal ammonium hydroxide or carbonate, preferably an alkali metal hydroxide.

Suitable water-immiscible organic solvents include methylene chloride.

The compounds according to the invention, especially the

with formula (I) can be in the form of agriculturally tolerable salts. These salts can be produced by methods known per se. The salts can also form or be formed with components in the mixtures or compositions which contain the active ingredient in accordance with the invention and which are used in practice and which are described below.

The expression "in and of itself known methods" means methods that have previously been used or described in the chemical literature.

The following examples illustrate the invention and show how it can be utilized.

Examples 1 to 11 illustrate synthesis and physical properties of the herbicidal compounds and chemical starting compounds in accordance with the invention. The melting points shown generally correspond to a phenomenon of melting with cleavage. When spectral characteristics are given, these are either infrared (IR) absorption bands expressed in cm or proton chemical shifts in nuclear magnetic resonance (NMR). In the latter case, the displacements are expressed in ppm (parts per million) and the measurements are carried out in deuterium-containing chloroform in the presence of tetramethylsilane as a reference.

Example 12 illustrates the use of the products in accordance with the invention during post-sprouting (the terms post-shooting and post-sprouting are synonymous).

Example 1

The starting material used is N-benzyl-N-(diethyl-phosphonomethyl)glycine with the formula:

whose preparation is described in example 7.

The product of formula (X) (56.3 g) is dissolved in acetonitrile (200 ml). Triethylamine (0.1 mL) is added and methylsulfonyl isothiocyanate (CH 3 -SO 2 -NCS) (24.5 g) is added dropwise. Released COS is captured in a methanolic solution of sodium hydroxide. The temperature rises from 20 to 35°C. After the addition, the mixture is refluxed for 1 hour and then concentrated under reduced pressure.

An oily product with formula:

(70.5 g) is obtained.

Example 2: Compound No. 1

The product of formula (XI) (23.5 g) is dissolved in dimethylformamide (100 ml). Sodium hydride (80* purity, 1.8 g) is added to the reactor which is maintained at 25°C under a nitrogen atmosphere. After the addition, the reaction is allowed to continue for 30 min. at 20°C and then methyl iodide (9.9 g) is added. The temperature rises from 21 to 24°C. Heating to 70°C is carried out for 1/2 hour. The solvent is evaporated, Cr^C^ (200 ml) is added, the material is washed with aqueous carbonate solution and then with water, dried and concentrated. 16 g of an oily product with formula:

Example 3: Compound No. 19

Anhydrous HBr (50 g) is dissolved in acetic acid (100 ml) at 15°C and the temperature is maintained using an ice-water bath. A solution containing the product of formula (XII) (45 g) and acetic acid (45 ml) is added. The reaction is allowed to continue for 30 hours at 20°C. The material is concentrated, dissolved in methanol, precipitated with propylene oxide, filtered, washed with methanol and dried. A product is obtained (36 g, 93* yield) with formula:

This product is a white powder that melts at 205°C.

Example 4: Compound No. 37

Palladium catalyst deposited on carbon black (10* w/w Pd) (1 g) is mixed with concentrated HCl (20 ml) and methanol (150 ml). The product of formula (XIII) (8.4 g) dissolves. A stream of hydrogen is passed through and stopped when the temperature is brought back from 24 to 21°C. The mixture is filtered and the filtrate is concentrated. The concentrate is dissolved in methanol (50 ml). Propylene oxide (2 ml) is added and causes salting out. The precipitate is filtered off and washed with acetone. A product with a formula

(4.8 g) is obtained.

Example 5;

An aqueous formaldehyde solution (30 wt*) (1,466 g,

14.66 mol) is poured under stirring at normal temperature during 1 hour and 30 minutes. into a mixture of ethyl N-benzyl glycinate (2.830 g, 14.66 mol) and diethyl phosphite [(C2H50)2P(O)H] (2.028 g, 14.17 mol). During the slope, the temperature rises to 41°C. The mixture is heated at 90°C for 1 hour and 30 minutes. and cool.

To extract the reaction product, CH2C12 is added

(7 1) and the mixture is washed with water (3x6 1). The solvent is removed. A light brown oil (4.647 g) with a refractive index nD 20 of 1.491 is obtained in this way. The yield is 9 2.4*. The product obtained has the formula:

Example 6:

The procedure is as in example 5, but the diethyl phosphite is replaced with dimethyl phosphite (also called methyl phosphonate) with the formula (CH^O)2P(0)H.

The product with formula:

is obtained with 87* yield. Refractive index nD 20 is 1.499.

Example 7;

An aqueous solution containing 5 weight* of sodium hydroxide (6.8 1) is poured at 40°C over the course of 1 1/2 hours into the compound of formula (XV) (2,915 g). The mixture is then heated at 80°C for 1 1/2 hours, decanted and washed with CH 2 Cl 2 (4 1). The aqueous solution is acidified to pH 2 with 10 N hydrochloric acid (800 ml). The product is separated from the aqueous layer in the form of an oil which is extracted with Cr^C^ (5 1). The methylene chloride solution is washed with water (2 x 2.5 L). The solution is evaporated to dryness and the product of formula (X) (2.012 g, 75% yield) which crystallizes on storage (m.p. 37°C) is obtained in this way.

Example 8:

The procedure is as in example 7, in that the product of formula (XVI) is used instead of the compound of formula (XV) as starting material. The product with formula:

which melts at 73.8°C is thereby obtained in 36* yield.

Example 9:

A solution of the compound of formula (XV) (68.6 g) in methanol (150 ml) is introduced into a 500 ml reactor. A paste prepared with water (10 ml) and activated charcoal containing 10 wt* palladium (9 g) is added. The atmosphere is purged with nitrogen and then hydrogen is circulated for 5 hours at 20°C. The material is filtered, the filtrate is evaporated and the product by formula

(49 g, 97% yield) is then obtained in the form of a liquid with

20

refractive index nD of 1.451. This compound of formula (XVIII) (12.7 g) is dissolved in an aqueous solution (50 ml) containing 20 weight* of hydrochloric acid. The solution is boiled under reflux for 20 hours. It is concentrated under reduced pressure and the residue is washed with methanol. After drying, N-(phosphonomethyl)-glycine is obtained (6.5 g, 77* yield).

Example 10:

The compound of formula (X) (10 g) is dissolved in methanol

(50 ml) in a 250 ml reactor. The catalyst paste used

in example 9 (0.3 g) is added. The atmosphere is purged with nitrogen and then hydrogen is circulated for 2 hours at ordinary temperature (20 to 25°C). The material is filtered, the filtrate is evaporated and the product with the formula (C2H50)2P(O)-CH2-NH-CH2-COOH

(7.5 g, 100% yield) is obtained. After recrystallization, the product melts at 115°C.

Example 11:

N-benzyl-N-(diethylphosphonomethyl)glycine of formula (X)

(189 g) is dissolved in anhydrous tetrahydrofuran (600 ml). Triethylamine (60.6 g) is gradually poured into this first solution at ordinary temperature. After 15 min. the temperature is lowered from room temperature to -10°C and ethyl chloroformate (66 g) is gradually poured into the mixture over the course of 20 min. The temperature is then allowed to rise to +10°C and the mixture is filtered, the precipitate is washed with tetrahydrofuran. The combined filtrates are evaporated. The product with formula:

(225 g) is thereby obtained.

This mixed anhydride is dissolved in CE₂ Cl₂ (500 mL). Triethylbenzylammonium chloride (3 g) and N-methylmethanesulfonamide (72 g) are added. The mixture is cooled to +10°C. An aqueous solution (51 g) containing 50% by weight of sodium hydroxide is then added dropwise. Stirring is continued for 1 hour at 20°C. Water (300 ml) is added. After stirring, the layers are separated. The organic phase is washed

with water, dried and concentrated. An oily product of formula (XII) (202 g, 83% yield) with refractive index

22

n^ of 1.507 is obtained.

The various compounds of formula (I) shown in table (I) are prepared by methods in accordance with examples 3, 4 and 11 from the corresponding starting materials.

Example 12:

Herbicide application during post-spirinq of plant species

A number of seeds, determined depending on the plant species and seed size, are sown in 9 x 9 x 9 cm pots filled with a light agricultural soil.

The seeds are then covered with a layer of soil approximately 3 mm thick and the seeds are left to germinate until they have formed a small plant of suitable size. The treatment step for the sprouting plants is the "second leaf formation" step. The processing stage for the dicotyledon plants is the stage where "the cotyledons open, first true leaf develops".

The pots are then sprayed with a spray mixture in an amount corresponding to a volumetric application rate of 500 l/ha and containing the active ingredient in the required concentration.

The spray mixture used for the treatment is an aqueous suspension or solution of the active ingredient containing 0.1 weight* "Cemulsol" NP 10 (surfactant consisting of a polycondensate of ethylene oxide with an alkylphenol, especially a polycondensate of ethylene oxide with nonylphenol) and 0. 04 weight* "Tween 20" (a surfactant consisting of an oleate of a polycondensate of ethylene oxide derived from sorbitol)-

The active ingredient was applied in a quantity of 4 kg/ha.

The treated pots are then placed in a designated trough

to receive the moisture water, by sub-irrigation, and is maintained for 28 days at normal temperature below 70* relative humidity.

At the end of 28 days, the number of living plants is counted

in the pots treated with the spray mixture containing the active ingredient to be tested, and the number of live plants in a control pot treated under the same conditions, but using a spray mixture that does not contain the active ingredient. The percentage destruction of the treated plants in relation to the untreated control plants is then determined. A destruction percentage of 100* shows that a complete destruction concerning the plant species has taken place and a percentage of 0* shows that the number of living plants in the treated pots is identical to the number in the control pots.

The plants used in the tests are:

The results obtained are shown in table (II).

The compounds illustrated in Table (II) were also used

in an amount of 1 kg/ha and showed good activity at this clearly smaller amount. They also showed a good activity on a larger number of plants which are of such different species as those shown in table (III).

The tests that were carried out thus show the remarkably advantageous properties of the compounds according to the invention, as herbicides with broad-spectrum activity and active during post-germination. These products are generally inactive during pre-germination.

In practical use, the compounds according to the invention are rarely used alone. Most often these compounds form parts of mixtures. The invention thus provides herbicidal mixtures which preferably comprise a compound of general formula (I) in which R<2>, R<3> and R<4> each represent hydrogen and R preferably has a meaning other than hydrogen as active ingredient in association with a agriculturally acceptable carrier and/or an agriculturally acceptable surfactant.

These compounds may also contain other components such as e.g. protective colloids, adhesives, thickeners, thixotropic agents, penetrating agents, stabilizing agents and sequestering agents, as well as other known components with pesticidal properties

(especially insecticides, fungicides or herbicides)

or with properties that regulate the growth of the plants.

More generally, the compounds used in accordance with the invention can be combined with solid or liquid additives corresponding to the usual methods of composition. Mixtures comprising ammonium salts,

like for example. ammonium sulfate (eg 0.1 to 7%, preferably 0.5 to 5%) are particularly advantageous.

The application doses of the compounds used in the invention can vary within wide limits, especially depending on the nature of the plants that are expected to be eliminated and the usual interference in the crops of these harmful plants.

In the following, percentages are given on a weight basis, unless otherwise stated.

In general, preparations in accordance with the invention usually contain about 0.05 to 95% (weight basis) of one or more of the active ingredients in accordance with the invention, about 1 to 95% of one or more solid or liquid carrier substances and optionally about 0.1 to 50% of one or more surfactants.

In accordance with what has already been stated, the compounds used in accordance with the invention are generally combined with carriers and possibly surface-active agents. In the present context, "carrier" denotes an organic or inorganic component, natural or synthetic, with which the active ingredient is associated to facilitate its application to the plant. This carrier is therefore generally inert and must therefore be agriculturally tolerable, especially for the treated plant. The carrier can be solid (clay, natural or synthetic silicates, silica, resins, waxes and solid fertilizers) or liquid (water, alcohols,

especially butanol, esters, especially methyl glycol acetate,

ketones, especially cyclohexanone and isophorone, petroleum fractions, paraffinic or aromatic hydrocarbons, especially xylenes, aliphatic chlorinated hydrocarbons, especially trichloroethane, or aromatic chlorinated hydrocarbons, especially chlorobenzenes, water-soluble solvents such as dimethylformamide, dimethylsulfoxide, or N-methylpyrrolidone, and liquefied gases) .

The surface-active agent can be an emulsifier, dispersant or wetting agent of ionic or non-ionic type or a mixture of such surface-active agents. As such can be mentioned e.g. salts of polyacrylic acids, salts of lignosulfonic acids, salts of phenolsulfonic acids or naphthalenesulfonic acid, polycondensates of ethylene oxide with fatty alcohols or fatty acids or fatty amines, substituted phenols (especially alkylphenols or arylphenols), salts of sulphauric acid esters, taurine derivatives (especially alkyl taurates), phosphoric acid esters of alcohols or of polycondensates of ethylene oxide with phenols, esters of fatty acids with polyols, and sulfate, sulfonate and phosphate functional derivatives of the above compounds. The presence of a surface-active agent in the mint is generally of significant importance when the active ingredient and/or the inert carrier is only slightly water-soluble or is non-water-soluble and the carrier in the herbicidal preparation is water.

For their use, the compounds of formula (I) are therefore generally available in the form of preparations. These preparations in accordance with the invention are therefore in themselves in different solid or liquid forms.

Solid forms of preparations that may be mentioned are dusting powders (with a content of the compound of formula (I) which can be up to 80") and granules, especially those obtained by extrusion, compaction, impregnation of a granulated carrier, or granulation by proceed from a powder

(content of the compound of formula (I) in these granules is between 0.5 and 80% in the latter cases).

Solutions, especially emulsifiable concentrates, emulsions, flowable mixtures, aerosols, wettable powders (or powders for spraying), dry flowable mixtures and pastes, can be mentioned as preparation forms which are liquid or are intended to form liquid preparations upon application.

The emulsifiable or soluble concentrates also generally comprise 5 to 80% active ingredient, while the emulsions or solutions which are ready for application generally contain 0.01 to 20% active ingredient. Next to the solvent, the emulsifiable concentrates can, if necessary, contain 2 to 50% suitable additives such as e.g. stabilizers, surfactants, penetrants, corrosion inhibitors, dyes or adhesives.

Emulsions of any required concentration, particularly suitable for application to plants,

can be obtained from these concentrates by dilution with water.

The composition of some emulsifiable concentrates is given

in the following.

Example 13:

Example 14:

According to a further composition of an emulsifiable concentrate is used:

The concentrated suspensions, which can be applied by spraying, are prepared so that they produce a stable fluid product that does not settle (fine grinding) and usually contain from 10 to 75% active ingredient, from 0.5 to 30% surfactants, from 0 .1 to 0% thixotropic agents, from 0 to 30% suitable additives such as antifoam agents, corrosion inhibitors, stabilizers, penetrants, adhesives and as a carrier, water or an organic liquid in which the active ingredient is poorly soluble or insoluble. Some organic solids or inorganic salts may be dissolved in the carrier to help prevent deposition or as anti-freeze agents for water.

The composition of a flowable mixture is given below.

Example 15:

The wettable powders (or powders for spraying) are usually prepared so that they contain 10 to 80% active ingredient and they usually contain, in addition to the solid carrier, from 0 to 5% of a wetting agent, from 3 to 10% of a dispersing agent and if necessary from 0 to 80* of one or more stabilizers and/or other additives such as penetrants, adhesives or anti-caking agents, and colorants.

The composition of some wettable powders is given below.

Example 16:

Example 17:

A further example of a wettable powder with 80% content of active ingredient is given in the following:

Example 18;

A further example of a wettable powder is given below:

Example 19:

A further example of a wettable powder is given below:

Example 20:

A further mixture of a 40% strength wettable powder uses the following components:

Example 21:

A further composition of a 25% strength wettable powder uses the following components:

Example 22;

A further formulation of a 10X strength wettable powder uses the following components:

To obtain these wettable powders, the active ingredient(s) are thoroughly mixed in suitable mixers with additional substances that can be impregnated on the porous filler and ground using mills or other suitable grinding devices. This produces wettable powders where wettability and suspendability are advantageous. They can be suspended in water to give any desired concentration and this suspension can be used very advantageously especially for application to plant leaves.

The "water-dispersible granules (WG)" (granules that can be easily dispersed in water) have a composition almost similar to the wettable powders. They can be prepared by granulating mixtures described for the wettable powders, either by means of a wet process (by bringing finely divided active ingredients into contact with the inert filler and a small amount of water, e.g. 1 to 20%, or with a aqueous solution of dispersant or binder, followed by drying and sieving), or by means of a dry process (compaction followed by grinding and sieving).

The composition of water-dispersible granules is given below.

Example 23;

As already indicated, they are aqueous dispersions and emulsions, e.g. mixtures obtained by diluting with water a wettable powder or an emulsifiable concentrate in accordance with the invention, included in the scope of the mixtures for which the present invention may find application. The emulsions can be of the water-in-oil or oil-in-water type and can have a thick paste-like consistency.

All of these aqueous dispersions or emulsions or spray mixtures may be applied to weeds to be controlled by any suitable means, generally by spraying, in quantities generally of the order of 100 to 1,200 liters of spray mixture per hectares.

The invention enables local control of weed growth by applying to the weed or more generally plants to be destroyed an effective amount of a compound with

2 3 4

the general formula (I) in which R , R , and R each represent hydrogen and R preferably has a meaning other than hydrogen. Application of such a compound in conjunction with ammonium sulfate is particularly advantageous.

Products and mixtures according to the invention are applied to suitable vegetation and especially to weeds which can be removed when the latter has developed green leaves. Their resistance is low so that it is possible to work so that what is grown is sown before or after treatment to control the growth of weeds in an area to be used for growing a crop, but germinates shortly after treatment (2 to 3 weeks) , i.e. after cleavage of the products in accordance with the invention.

The herbicidal mixtures and their application for local

to control the growth of weeds is also suitable for pre-harvest use. Before this application, the herbicidal compound is applied to the crop and the weeds before harvesting, e.g. a few days before harvest. The crop is harvested before the herbicide has destroyed it and weed roots are destroyed after harvest by the herbicide that has been translocated into the plant before harvest.

The amount of active ingredient applied is generally between 0.1 and 10 kg/ha, preferably between 0.5 and 8 kg/ha.

The most important function of the various additives or auxiliaries mentioned above is generally to facilitate handling and dispersion of the products in accordance with the invention. In some cases, they can also promote the penetration of the active ingredient into the plant and can therefore increase the normal activity of the active ingredient in accordance with the invention.

The compounds summarized in Table I are as follows:

The compounds 37, 38, 39 and the compounds with formulas XI, XII, XIII, XV and XVI are preferred compounds in the context of the invention.

Claims (8)

1. A compound of formula: 2 in 3 in 2' 3' in which R and R are such that OR and OR are hydrolysable groups, R gives a hydrogenolysable group and 7 2' 3' R is as indicated for R and R 2. A compound as stated in claim 1, 2 <1> 3' 7 characterized in that R , R and R are g alkyl radicals and R is a benzyl radical. 3. Ethyl-N-benzyl-N-diethylphosphonomethylglycinate or ethyl-N-benzyl-N-dimethylphosphonomethylglycinate. 4. Procedure for the preparation of the compounds of formula: 2' 3' 7 8 wherein R , R , R and R are as stated in claim 1, characterized in that formaldehyde is reacted with a compound of formula R -0-P(0)H-OR and a compound of formula R <8> -NH-CH_- CO-0-R <7> wherein R 2' , R <3> ', 7 8 R and R are as stated in claim 1. 5. Procedure as stated in claim 4, characterized in that the turnover is carried out at temperatures between 0 and 100°C. 6. Procedure for the preparation of compounds of formula: wherein R 2 and R 3 each stand for hydrogen or a group 21 3' 7 R or R as stated in claim 1 and R is as stated in claim 1, characterized by hydrogenolysis of a compound of formula: 2 3 7 in which R and R have the above meaning and R and g R is as stated in claim 1. 7. Method as stated in claim 6, followed by the step of hydrolysis of the compound obtained to convert group OR^ to a hydroxy group and optionally convert the compound thus obtained into a salt thereof. 8. Procedure for the preparation of compounds of formula: 2 in 31 g wherein R and R and R are as stated in claim 1, characterized by hydrolysis of a compound of formula: 2' 3' 7 8 in which R , R , R and R are as stated in claim 1, for conversion of the group OR^ to the hydroxy group. 2' 3' 7 A compound of formula II wherein R, R, R g and R is as stated in claim 1, characterized in that it is produced using a method as stated in any of claims 4 and 5. 10. A compound of formula V as set forth in claim 6, wherein 2 3 7 R and R are as set forth in claim 6 and R is as set forth in claim 1, characterized in that it is produced using a method as stated in any of claims 6 and 7.