IT8422035A1 - Derivatives of aryloxybenzoic acids and their use as herbicides - Google Patents

Description

DOCUMENTATION

BOUND

PH 1 953 I Eng. Barzan? If Zanardc

D E S C R I C E S 0 N E

of the industrial invention entitled:

Derivatives of aryloxybenzoic acids and their uses

as herbicides"

of the Company: RHONE?POULENC AGROCHIMIE, nationality? French, based in Lyon France

Inventors: Bertrand CARBONI

filed on 25 July 1984 Nc 22035A/84

SUMMARY

The invention relates to new derivatives of aryloxybenzoic acids.

These compounds correspond to the following formula (I):

?-\??- (I)

in which the symbols used have the following meanings respectively:

X : halogen or lower alkyl possibly halogenated

Y: hydrogen, halogen CP, CN, MO? or CH_

- 2 - ' Eng.Barzan? & Zanardo

D : -N= or ?C(Z)= in which Z represents hydrogen or halogen

W : hydrogen, halogen or nitro-group

R : H, halogen, possibly substituted alkyl,

possibly substituted aryl, alkenyl, alkynyl, possibly substituted alkylthio, possibly substituted amino group, -CO-R', -SO2-R", OH or CN.

They can be used as herbicides in agriculture.

DESCRIPTION

The invention concerns new herbicidal compounds

with a tetrazole group, derived from aryloxybenzoic acids. It also concerns the preparation of these new compounds and the compositions for agricultural use that contain them.

2-nitro-5-[2'-chloro-4,-(trifluoromethyl)phenoxy]benzoic acid, also known as acifluorfen, and its salts are known to be used as herbicides, particularly for weed control of soybeans.

In this description, chemical compounds are indicated by their name according to the French nomenclature but, in accordance with the Anglo-Saxon nomenclature, the numbers indicating the position of the substituents have been placed before the substituent and not after according to the French nomenclature.

j.ng. tsctrzaiiu oc 4 dii cu. -uu

Furthermore, numerous derivatives of acifluorfen have already been proposed, in particular alkyl, cycloalkyl, thioalkyl, phenyl esters, and even mono- or dialkylated amylides. These compounds are described in U.S. patents 3,652,645, 3,784,635, 3,873,302, 3,983,168, 3,907,866, 3,798,276, 3,928,416, and 4,063,929.

The present invention relates to derivatives of aryloxybenzoic acids, different from those described in the prior art and which exhibit excellent herbicidal activity.

The new products according to the invention are characterized by the fact that they correspond to the general formula (I):

(I) x-\OV ???

in which:

X represents a halogen atom, or a lower alkyl radical substituted with one or more halogen atoms,

Y represents a hydrogen or halogen atom, or a CF^, CNf N0? or CH^ radical,

D represents the nitrogen atom or the radical

?c(z) = in which Z represents a hydrogen atom

or halogen,

W represents a hydrogen or halogen atom

or the nitro radical,

R represents a hydrogen atom or a carbon atom.

halogen, or a radical chosen from the radicals

aliphatic or aromatic, alkylthio or amino, or acyl or alkylsulfonyl or arylsulfonyl or hydroxyl or cyano, these different radicals being possibly substituted;

The following atoms or radicals can be cited as possible substituents: halogen, ?alkoxy, ?alkoxy, hydroxyl, lower alkyl or acyl, carboxyl, salts and esters (carboxylates) of this carboxyl group such as, for example, lower alkoxycarbonyls.

More specifically, R can take one or the other

of the following meanings:

? possibly substituted alkyl, for example alkyl?

the lower one replaced or not replaced with one

0 more than the atoms or radicals previously

cited;

- aryl possibly replaced, for example with

1 substituents similar to those previously mentioned;

- 5 - Eng.Barzan? & Zanardo - lower alkenyl;

- lower alkynyl;

- lower alkylthium possibly substituted, for example with one or more halogen atoms;

- amino group possibly substituted, for example with one or more lower alkyl radicals or with an acyl radical;

- CO-R* in which R' represents a substituent, for example the OH radical or a lower alkoxy radical or an aryloxy radical or the amine radical itself possibly substituted; - SO^-R" in which R" represents a substituent, such as for example an alkyl or aryl radical; - or a radical -OH or -CN.

In the meaning of this text, the adjective "inferior", when it qualifies a radical, means that this radical contains a maximum of 6 carbon atoms.

The dotted lines in formula (I) indicate the existence of a tautomerism.

Compounds according to the formula (I) for which R represents the hydrogen atom are acidic and can therefore form, with suitable bases, salts acceptable in agriculture. These salts can also be used as herbicides and are therefore 6 - Eng. Barzan? & Zanardo

also included within the scope of the invention. Examples of such salts include metal salts, preferably alkali metals such as sodium, potassium or lithium, or alkaline earth metals such as calcium or magnesium, or ammonium salts, or mono- or polysubstituted ammonium salts such as isopropyl ammonium, triethanolammonium, morpholinium, etc.

Depending on the position of the R substituent on the tetrazole ring, the compounds according to the formula (I) can exist in two isomeric forms (IA) and (IB) which are also within the scope of the invention and. in which the different substituents have the same meaning as in the formula (I).

- N-R

OW O

(IB)

?-<0> ?-\OV w

Among the compounds that correspond to the formulas

(I), (IA) and (IB), a preferred subfamily due to its notable herbicidal properties, consists of compounds for which:

X represents the trifluoromethyl radical

Y represents 1*chlorine atom

D represents the radical -CH=

W represents the nitro group

R represents an alkyl radical possibly substituted (for example with a lower alkoxycarbonyl radical).

The invention also relates to the preparation of compounds according to formula (i) and of salts of these compounds, usable in agriculture.

Compounds according to formula (i) can be prepared by acting on phenyltetrazole of formula (ii)

N .

R

(there)

in which w and R have the same meaning as indicated in formula (I) and A represents the hydroxyl radical or a halogen atom (preferably fluorine or chlorine),

? 8 ? Eng. Barzan? & Zanardo

on the compound of formula (ili)

X B (III)

in which X, Y, D have the same meaning as indicated in formula (i) and B represents a halogen atom (preferably fluorine or chlorine) or the hydroxyl radical, it being understood that B is chosen so that it is different from A, i.e. B represents a halogen atom when A represents the hydroxyl radical and B represents a hydroxyl radical when A represents the halogen atom.

When it is desired to prepare a compound according to formula (i) for which w represents the hydrogen atom, the other substituents or symbols having the same meaning as indicated in formula (l), one preferably chooses as starting products a phenyltetrazole (11) in which A represents the hydroxyl radical and a compound (11) in which B represents the halogen atom.

When one wishes to prepare a compound according to formula (i) for which W represents the radical j.xiy . DCLL'^CU?U et Zjcuiax'u.tj

nitro, and other substituents or symbols having the same meaning as indicated in formula (i), as starting products preferably a phenyltetrazole (II) in which A represents the halogen atom and a compound (III) in which B represents the hydroxyl radical are chosen.

The reaction between phenyltetrazole (11) and compound (111) is generally carried out in the presence of a basic agent, at a temperature of about 80 to 180°C, in a polar aprotic solvent, such as for example dimethyl sulfoxide, dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, acetonitrile, acetone or other equivalent polar aprotic solvents.

As basic agents, sodium or potassium hydroxides or carbonates are advantageously used. On the other hand, compounds of formula (11) or (111) with a hydroxyl group in the form of a previously formed alkaline phenate can be used.

Phenyltetrazole of formula (II), used as a starting substance, can be prepared by acting on a nitrile of formula (V) by NaN^.

CN

(V)

- 10 - Eng. B'arzan? & Zanardo

in which A and w have the same meaning as indicated in formula (11), with the condition that when V7 represents the nitro radical, A necessarily represents a halogen atom. This reaction is carried out according to the method described by

E. Kadaba in Synthesis - 1973 - p. 71-84.

. > Thus we obtain phenyltetrazole which corresponds to the formula (11) in which A and V have the same meaning indicated previously and R represents the hydrogen atom.

Phenyltetrazoles according to the formula (II) for which R represents a substituent other than the hydrogen atom can be prepared starting from the phenyltetrazole obtained previously, by the action of a reagent of formula (VIII).

R - T (Vili)

in which R has the same meaning as indicated above and T represents a cleavable reactive group such as for example a halogen atom (preferably the iodine or bromine atom) or an arylsulfonic radical such as the benzenesulfonyloxyl, toluenesulfonyloxyl, xylenesulfonyloxyl radicals.

Compounds according to formula (I) for which w represents a halogen atom or the nitro radical, 11 ing.Barzan? & Zanardo

the other substituents or symbols having the same meaning as reported in formula (I) can similarly be obtained respectively by halogenation or by nitration of the compound according to formula (i) for which W represents the hydrogen atom and which corresponds to the following formula (IV):

N N

R

(IV)

in which X, Y, D and R have the same meaning as indicated in formula (I).

The nitration of compound (IV) can be carried out using a usual nitrating agent, such as nitric acid or potassium nitrate in the presence of sulfuric acid, possibly in an inert organic solvent, advantageously a chlorinated hydrocarbon, such as methylene chloride, perchloroethylene, chloroform, etc., generally operating at low temperatures (between -20°C and 20°C),

The halogenation of compound (IV) can be achieved by: - 1 2 - Eng. Barzan? & Zanardo

carried out for example by the action of a halogen, in a solvent such as acetic acid and by heating (for example by boiling under reflux).

Compounds according to formula (I) for which W and R represent the hydrogen atom, the other substituents and symbols having the same meaning as indicated in formula (I) can similarly be prepared by acting with NaN^ on a nitrile of formula (Vi):

CN

or (VI) D>?<o

in which X, Y and D have the same meaning as indicated in formula (i), operating according to the method of K. Kadaba described above. The compounds corresponding to formula (VII) are thus obtained:

//* ? ?

C H

(VII) ? 13 - Eng. Barzan? & Zanardo

in which the different symbols and substituents have the same meaning as indicated above.

Compounds according to formula (1), for which R represents a substituent other than the hydrogen atom, can also be prepared starting from compounds according to formula (VII), the preparation of which is described above, by the action on this compound of a reagent of formula (VIII).

R - T (Vili)

in which R and T have the meanings previously mentioned.

The reaction is generally carried out in an inert organic solvent medium, at a temperature of the order of 20°C to approximately 150°C.

As indicated above, salts of the compounds according to formula (i) for which R represents the hydrogen atom, can be obtained by treating these compounds with a suitable base, preferably soda.

At the end of the operation, according to one or other of the procedures described above, the compound (i), or the salt of this compound, is separated from the reaction mixture by the usual techniques such as, for example, by distillation of the solvent or by crystallization of the compound starting from the reaction medium. If necessary, it is subsequently purified by the usual methods such as recrystallization starting from a suitable solvent or by liquid or vapor chromatography.

The following examples illustrate the invention without, however, limiting it. The structures of the compounds described in these examples have been characterized by infrared spectrometry, nuclear magnetic resonance (NMR) spectrometry, and elemental analysis.

Example 1; Preparation of 5-[3,-(2n-chloro-4,,-trifluoromethylphenoxy)phenyl]tetrazole (compound N? 1).

In a one-liter three-necked flask, add 0.15 liters of methanol, then 13.2 g of potassium pellets are added portionwise, then 18 g, or 0.1 mole, of 5-(3'-hydroxyphenyl)tetrazole (crystallized with one mole of water), are added all at once, keeping the temperature below 30°C. The mixture is kept at this temperature for about half an hour and the solvent is distilled under a reduced absolute pressure of about 1 millifarad. The potassium salt of 5-(3'-hydroxyphenyl)tetrazole is thus obtained in the form of a brown oil.

- 15 - ing. Barzan? & Zanardo

Then dissolve this brown oil in 100 ml

of dimethyl sulfoxide and to the solution add 21.5 g (0.1 mole) of 3,4-dichloro(trifluoromethyl)benzene and heat the reaction mixture to 130?C

for 5 hours, then the temperature is allowed to return to room temperature (about 25°C). The reaction mixture is then poured into 500 ml of water.

The aqueous phase is extracted with 2 x 100 ml of methylene chloride, then the aqueous phase is collected and acidified to pH - 1 with concentrated aqueous hydrochloric acid. The formation of crystals consisting of unreacted tetrazole is observed.

and an oil that is dissolved in 200 ml of methylene chloride. The resulting organic phase is washed several times with water and then dried over sodium sulfate. The solvent is then distilled and the resulting oil is stirred with 100 ml of water. The resulting dark crystals are filtered by suction and washed.

with water and then they are dried in an oven and finally they are recrystallized from a 50/50 mixture of water and ethanol.

Thus, 13.2 g of compound N? 1 with formula: ? 16 ? ing.Barzan? & Zanardo

N? N

CI H

/C\

cp3 N 'N

Yield: 38%

Casting plinth: 173?C.

The 5-(3-hydroxyphenyl)tetrazole used as a starting product was prepared by reacting NaN^ on cyano-3-phenol, in dimethylformamide, in the presence of ammonium chloride, according to a method analogous to that described in Synthesis, 1973 - pp. 71 to 84.

Compound N? 1 was similarly obtained according to a second procedure described below:

In a three-necked flask, charge 17#6 g (0.059 moles) of 3-(2*-chloro-4'-trifluoromethylphenoxy) benzonitrile; 4.2 g (0.065 moles) of NaN^; 3.4 g

(0.065 mole) of ammonium chloride and 30 ml of dimethylformamide. The reaction mixture is brought

at 100°C for 4 hours, let it return to room temperature and pour it into 500 ml of water. A solution is obtained to which HC16N is added.

until pH = 1 and stir for 10 minutes.

- 17- Eng. Barzan? & Zanardo

A white precipitate forms, which is filtered and then washed with water. After filtration by suction and drying in air, 19.5 g of compound N? 1 are obtained.

3-(2-Chloro-4'-trifluoromethylphenoxy)benzonitrile was obtained by the action of trifluoroacetic anhydride on 3-(2'-chloro-4'-trifluoromethylphenoxy)benzamide.

Example 2: Preparation of the

5-[2 '-nitro-5'-(2"-chloro-4"-trifluoromethylphenoxyphenyl]tetrazole (compound N? 2).

In 40 ml of concentrated sulfuric acid, 9.2 g (0.027 mole) of compound N? 1 are dissolved and 40 ml of dichloro-1,2-ethane are added to the solution thus obtained.

Keeping the reaction mixture at 0°C, under stirring, 2.7 g (0.027 moles) of potassium nitrate are gradually added over 15 minutes, then the mixture is kept at this temperature for half an hour and finally for an hour at room temperature.

The resulting reaction mixture is poured into 400 g of a mixture of ice and water. After extraction with 2 x 100 ml of dichloromethane, the organic phase is dried, and the solvent is then distilled off. 8 g are obtained. - 18 - Ing. Barzan? & Zanardo

(78% yield) of an 80/20 mixture of 5-[2'-nitro-5'-(2,r-chloro?4"-trifluoromethylphenoxy)phenyl]-tetrazole and

5-[2 '-nitro-3*-(2"-chloro-4"-trifluoromethylphenoxy)phenyl]-tetrazole.

By chromatography on silica (eluent: ethanol/CH^Cl^/acetic acid in the respective proportions by volume 1.5/15/0.1, 4.2 g of the desired compound (compound N? 2) of formula are obtained:

N ? U

H CF ->- O o N^ :N

NO

2

Yield: 47%

Melting point: 142?C.

and 0.4 g of

5-[2 f-nitro-3'-(2n-chloro-4"-trifluoromethylphenoxy)phenyl]tetrazole which melts at 206?C.

Example 3: Preparation of the sodium salt of compound N? 2.

This salt is compound No. 3.

In 10 ml of water and an equivalent of 1N soda, 1.16 g of compound N? 2 are dissolved.

The water is removed by distillation under vacuum at 60°C, thus obtaining 0.9 g of the desired compound in the form of a yellow solid with the formula:

Na or

Yield: 75%

Melting point above 250?C

Example 4: Preparation of the

2-methyl-5-[2'-nitro-5 '-(2',-chloro-4,1-trifluoromethylphenoxy)phenyl]tetrazole (compound N? 4A) and

1?methyl?5?[2'?nitro?5'-(2"?chloro?4M?trifluoromethylphenoxy)phenyl] tetrazole (compound N? 4B).

In a 250 ml three-neck flask, charge 7.72 g (?.02 mole) of compound N? 2, 14.2 g of methyl iodide (0.1 mole), 50 ml of dimethylformamide, and 2.76 g (0.02 mole) of anhydrous potassium carbonate and heat the reaction mixture at 70?C for 15 hours. The solvent is then removed by distillation under partial vacuum (10 millibars), and the mixture is made up with 100 ml of water and 2 x 100 ml of CH^Cl^?. The organic phase is collected and then dried over sodium sulfate. After distillation of the solvent under vacuum, 8 g of an oil is obtained which is chromatographed on silica (eluent: diisopropyl ether).

We thus obtain 5.1 g of the compound N?4A, with formula:

Yield 63%

Melting point: 90-92?C

and 0.5 g of the compound N? 4B of formula

OVN02>

which melts at 148?C.

According to another method of preparation, the compound N? 4A could be obtained by nitration of 2-methyl-5-[3'-(2"-chloro?4"-trifluoromethyl phenoxy)phenyl] tetrazole (melting point: 80? Yield 72%), the latter compound having been obtained - 21 - Ing.Barzan? & Zanardo

in turn by alkylation of the compound N? 1 Example 5: Preparation of the

2-methyl-5~[2'-nitro-5 *?(2'*,4?'-dichlorophenyl)phenyl] tetrazole (compound N? 5).?

In a 100 ml three-necked flask, add 5.4 g (0.024 mol) of 2-methyl-5-(2'-nitro-5'-fluorophenyl)tetrazole, 3.9 g (0.024 mol) of 2,4-dichlorophenol, 3.3 g (0.024 mol) of potassium carbonate, and 50 ml of dimethylformamide. The reaction mixture is stirred for 30 minutes at room temperature and then heated to 80°C for 7 hours. It is allowed to cool and then the solvent is evaporated under vacuum. An oil is obtained which is taken up with 150 ml of CHgClg, then washed three times with 50 ml of water each time; it is decanted. After drying the organic phase over Na^O^, it is filtered, then evaporated, and the resulting oil is obtained. A yellow oil that crystallizes in a mixture of equal volumes of diisopropyl ether/hexane. After filtration, rinsing with 2 x 15 ml of diisopropyl ether, suction filtration, and air drying, 5.8 g of the desired compound, with the formula (compound N? 5), are obtained.

- 22 - eng. Barzan? & Zanardo

N - N? CH3

/ I

cl >c

r< /^>?=??

o2

Melting point: 115?C

Yield: 66#.'

2-methyl-5-(2'-nitro-5'-fluorophenyl)tetrazole, used as a starting substance, was prepared by alkylation of (2-nitro-5-fluorophenyl)tetrazole in acetone, using CH^I, ?-in the presence of K CO-. 5-(2-nitro-5-fluorophenyl)tetrazole

2 3

in turn, it was prepared by nitration of 5-(3 *-fluorophenyl)tetrazole with nitric acid.

Examples 6 to 15:

Operating according to the method of Example 4 starting from appropriate raw materials, compounds N? 6 to 15 were prepared.

The different compounds obtained in the various examples from 1 to 15, with the exception of the compound N? 4B (a compound has the number of the example that corresponds to it) have the formula:

23 - Eng. Barzan? & Zanardo

- N? R

ri c

x_<oy ? <o (X )

The meaning of the substituents X, W and R for the different compounds and also the yield (RDT) of the example melting point of the product (or its spectral characteristics) are summarized in table (i). Compounds that have an asymmetric carbon atom exist in the two enantiomer forms R or s. In this case, it must be well understood that the formula (j?) [as well as the formula (i)] defines one or the other of these two forms or defines the mixture of the two forms in proportions that are either equivalent (racemate), or preponderant for one or the other.

for the other among them.

The following compounds can be prepared by a procedure similar to that of Example 4:

2-(methoxycarbonyl-1-ethyl)-5-[2*-nitro-5 *-(2"-chloro-4"-trifluoromethyl 1-phenoxy)phenyl]tetrazole

(R-enantiomer),

? 24 ? ing.Barzan? & zanardo

2-(methoxycarbonyl-1 -ethyl)-5-[2'-nitro-5 '-(2"-chloro-4"-trifluoromethyl)phenoxy]tetrazole (s-enantiomer),

2-(methoxycarborxyl-1 ethyl)-5-*[2'-nitro-5'-(3"-chloro-5 "-trifluoromethyl pyridyl-2"-oxy)phenyl]tetrazole (racemate, and also its R-enantiomer and its s-enantiomer). ' "

The following examples, Nos. 16 to 20, illustrate

the herbicidal properties of the compounds according to the invention. The terms "pre-emergence" and "pre-emergence" are synonymous; the terms "post-emergence" and "post-emergence" are synonymous.

they are synonyms.

Example 16 - Herbicide activity in greenhouses, during the pre-emergence phase of plant species

An aqueous suspension having the following composition is prepared:

- active substance to be tested . . . 40 mg ? Tween 80 . . . . , 50 mg - distilled water containing 1 per 1,000 by weight

of Scurol 0. enough to 40 ml by grinding the active substance and then suspending it in water containing Tween 80 and Scurol 0.

Tween 80 is a humectant made up of

from polyoxyethylened sorbitan monolaurate.

Scurol 0 is a surfactant consisting of

from polyoxyethylated alkylphenols, mainly ot

- 25 - ing. Barzan? & Zanardo

polyoxyethylened ethylphenol with 10 moles of oxide

of ethylene.

The aqueous suspension described above

if necessary it is then diluted with distilled water.

sheet containing 1 pore000 of Scuro10, so as to obtain

maintain the desired concentration.

Pots with a diameter of 6.5 cm are used

>

and a height of 8 cm containing half of the earth

half silty clay and half river sand.

In each pot, sow 30 seeds of one of the

plant species listed below:

Symbols

Wheat (Triticum sativum), variety Caton. .. TRIT Alopecurus (Alopecurus myosuroides)....*. . ALOP Wild oats (Avena fatua) . . AVEN Lentil (Lens culinaris), variety Broad light. .. LENS Radish (Raphanus sativus), variety round pink with

white top.. RAPH Beetroot (Beta vulgaris), variety Ceres..... BETA Lettuce (Lactuca sativa), variety Golden Yellow Drop..?.. LACT Buckwheat (Polygonum fagopyrum). ...'FAG Amaranth (Amaranthus caudatus). . ??...?. AMA

Pre-emergence treatment is carried out

carried out by spraying the sown surface with the so-

aqueous suspension of the active substance, in the con-

desired centering, each vessel receiving approximately

!

0.3 ml of the aqueous suspension.

- 26 - Eng. Barzan? & Zanardo

After treatment, the sown surface is left to dry and then the seeds are covered with a layer of soil approximately 2 mm thick.

Twice a day, the pots are watered by sprinkling and the pots are kept in the greenhouse at a temperature of 22-24°C.

under a relative humidity of 70-80%, and under a

>

artificial lighting that provides approximately 5000 lux

at plant level, for 16 consecutive hours

over 24 hours.

21 days after treatment, the number and height of living plants in the pots treated with the tested active substance and the plants are observed.

the number and height of the same plants in the pots

control that were treated under the same conditions, without the active substance.

It is determined like this:

- the percentage reduction in number N %, calculated as follows:

number of living plants in the treated pots

N % - - - - x 1?0 number of living plants in control pots

? the percentage reduction in height H % calculated as follows:

? 27 - Eng.Barzan? & Zanardo average height of living plants in treated pots

H % = ????? - - - i- ?x 100 mean height of living plants in control pots

Starting from N % and H %, the PERCENTAGE is calculated

IN RELATION TO CONTROL, equal to:

N % x H %

100

>

The values thus obtained are reported in table (11). In this table, a value equal to 0 means full herbicidal activity and a value equal to

equal to 100 means the total absence of herbicidal activity.

Example 17 - Herbicidal activity in greenhouses, during the post-emergence phase of plant species.

The method described in example 16 is followed, however with the following differences:

- after sowing the seeds, they are covered with a

layer of earth having a thickness of approximately 5 mm,

the pots are placed in the greenhouse and the seeds are left to germinate in order to obtain seedlings

desired stage of development,

- treatment with the compounds according to the invention

It is carried out when the plants are at the following

stadium

- 28 - Eng. Barzan? & Zanardo

. 2- to 3-leaf stage for wheat, alopecoro, lettuce and amaranth,

. stage of 3 true leaves for lentils,

.. stage of 2 well-developed cotyledonary leaves for buckwheat, beetroot and radish;

- according to this post-emergency treatment

(or post-growth according to an equivalent denomination), the solution or suspension containing the active substance is sprayed on the plants and the plants are then left to dry.

As in the previous example, the results are observed 21 days after the treatment and the percentage is determined in relation to the comparison according to the method described in the previous example.

The values thus determined are reported in table (III).

Example 18 - Herbicidal activity and selectivity towards greenhouse crops, in the post-emergence phase of plant species.

We proceed according to the method described in example 17, using the following plants:

Crops

Rice (Oryza sativa)

? 29 ? engineer Barzan? & Zanardo

Wheat (Triticum vulgare)

Weeds

Alopecorus (Alopecurus myosuroides)

Panic (Echinochloa crus-galli)

Silkworm (Setaria viridis)

Abutilon (Abutilon theophrasti)

Hard grass (Sida spinosa)

Annual chrysanthemum (Chrysan-?hemum.annuum) Matricaria (.Matricaria matricarioides)

Veronica of Persia (Veronica persica)

Plantain (Plantago lanceolata)

Foxtail amaranth (Amaranthus caudatus) Black nightshade (Solanura nigrum)

White mustard (Sinapis alba)

Bindweed (convolvulus arvensis)

Stellaria (middle stellaria).

The percentages in relation to the control are determined according to the method described in example 17. The values thus determined are reported in table (IV).

Example 19s

Pre-emergence herbicide application of plant species

In 9 x 9 x 9 cm pots filled with light agricultural soil, a certain number of seeds is sown, determined according to the plant species and the size of the seed.

The pots are treated by spraying the mixture in a quantity corresponding to an application volume dose of 500 litres/hectare and containing the active substance in the desired concentration.

The treatment with the pulp is therefore carried out on seeds not covered with soil (the term pulp is used to generally indicate the compositions diluted with water, such as those applied to plants).

The slurry used for the treatment is an aqueous suspension of active substance containing 0.1% by weight of Cemulsol NP 10 (surfactant consisting of polyethoxylated alkylphenol, in particular polyethoxylated nonylphenol) and 0.04% by weight of tween 20 (surfactant consisting of a polyoxyethylened sorbitol derivative oleate).

This suspension was obtained by mixing and grinding the ingredients in a micronizer to obtain an average particle size of less than 40 microns.

Depending on the concentration of active substance - 31 Ing.Barzan? & Zanardo of the mixture, the dose of active substance applied was 0.125 up to 2 kg/hectare.

After treatment, the seeds are covered with a layer of soil about 3 mm thick.

The pots are then placed in trays intended to receive watering water via subirrigation and are kept for 21 days at room temperature with a relative humidity of 70%.

At the end of 21 days, the number of living plants in the pots treated with the mixture containing the active substance to be tested is counted, as well as the number of living plants in a control pot treated under the same conditions but with a mixture that does not contain the active substance. This determines the percentage of destruction of the treated plants in relation to the untreated control. A percentage of destruction equal to 100% indicates that there has been complete destruction of the plant species under consideration, and a percentage of 0% indicates that the number of living plants in the treated pot is identical to that in the control pot. The results obtained in this example 19 are presented in table (v).

Example 20:

Post-emergence herbicide application of plant species

- 32 - Eng. Barzan? & Zanardo

In 9 x 9 x 9 cm pots filled with light agricultural soil, a certain number of seeds is sown, established according to the plant species and the size.

seed dryness.

The seeds are then covered with a layer of soil about 3 cm thick and the seed is left to germinate until it produces a seedling at the appropriate stage. The treatment stage for grasses is the "second leaf developing" stage. The appropriate stage for soybeans is the "first trifoliate leaf developed" stage. The treatment stage for other dicots is the "cotyledons developed, first true leaf developing" stage.

The pots are then treated by spraying the mixture in quantities corresponding to

*

an application dose in volume of 500 litres/hectare and containing the active substance in the desired concentration.

The pulp was prepared in the same way as in Example 19.

Depending on the active substance concentration of the slurry, the dose of active substance applied was 0.125 up to 2 kg/hectare.

The treated vessels are then placed in trays - 33 - Eng.Barzan? & Zanardo

intended to receive irrigation water through sub-irrigation and are kept for 2 days at room temperature with a relative humidity of 70%.

At the end of 21 days, the results are evaluated as indicated in example 19. The results obtained in this example 20 are presented in table (V).

The plant species used in examples 19 and 20 are grouped in table (VI).

The products according to the invention generally have excellent anti-dicot activity in the pre-emergence phase but especially in the post-emergence phase, on important weeds of the spy plant, such as Abutilon, Ipomea or Xanthium.

?For their use in practice, the compounds according to the invention are generally employed in the form of compositions equally within the scope of the present invention.

These compositions usually include, in addition to the active substance (compound of formula I), one or more carrier substances (or diluents), solid or liquid, acceptable in agriculture and one or more surfactants equally acceptable in agriculture.

If necessary, they may also contain various additives that are equally acceptable in agriculture.

- 34 - engineer Barzan? & Zanardo

Typically, these compositions comprise about 0.05 to 99% by weight of active substance, about 0.01 to 20% by weight of one or more surface-active agents, and about 1 to 99.95% by weight of one or more liquid or solid carrier substances (or diluents).

As solid carrier substances, natural or synthetic silicas such as diatomaceous earth can be used; natural or synthetic clays and silicates such as talc, attapulgite, vermiculite, kaolinites, montmorillonite, calcium and aluminium silicates; calcium carbonates; natural or synthetic resins such as polyvinyl chloride,

etc.

As liquid carrier substances, the following can be used: water; alcohols such as isopropanol and glycols; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.; ethers; aromatic or arylaliphatic hydrocarbons such as benzene, toluene, xylenes, petroleum fractions such as kerosene, chlorinated hydrocarbons such as carbon tetrachloride, perchloroethylene, etc.

When the carrier substance is water or a usual organic solvent, the compositions according to the invention advantageously contain a surfactant in addition to the active substance.

- 35 - Eng.Barzan? & Zanardo The surfactant can be an emulsifying, dispersing, deflocculant or wetting agent, of the ionic or non-ionic type.

As surfactants, polycondensation products of ethylene oxide with fatty acids or fatty alcohols or substituted phenols (especially alkylphenols or arylphenols) or fatty amides or fatty amines can be used to advantage. Fatty acid and sorbitan esters, sucrose derivatives, can also be used to advantage.

salt of alkali or alkaline earth metals

of lignosulfonic acids, of alkylarylsulfonic acids; salts of esters of sulfosuccinic acids; alkylbetaines or sulfobetaines, etc.

"Me Cutcheon's Detergents and Emulsifiers 1975 Annual," MC Pubi. Corp. Ridgewood, New Jersey, USA, describes numerous surfactants and provides instructions for their use.

U.S. Patent No. 3,713,804 describes numerous anionic, cationic, or nonionic surfactants for use in agriculture. The surfactant to be used in the compositions according to the invention can be advantageously selected by one skilled in the art from among the compounds or - 36 - ing.garzano & zanarao

groups of compounds described in these two documents or elsewhere.

In addition to the active substance, the carrier substance and the surfactant, the compositions according to the invention may contain other additives such as non-surfactant dispersing agents, peptizers, protective colloids, thickeners, adhesives that increase rain resistance, stabilizing agents, preservatives, corrosion inhibitors, colorants, sequestering agents, antifoaming agents, anti-caking agents, antifreeze, etc.

The compositions according to the invention can be in quite different forms, solid or liquid.

Solid compositions include powders for sprinkling (with an active ingredient content of up to 100%) and granulates and microgranulates, particularly those obtained by extrusion, compaction, impregnation of a granulated support, or granulation from a powder (the active ingredient content in these granulates ranges from 1% to 80% in the latter cases). These solid forms are generally used dry, without further dilution.

37- Ing.Barzan? & Zanardo As forms of liquid compositions or those intended to form liquid compositions upon application, we can mention humidifiable powders (or sprayable powders), emulsifying solutions or concentrates, concentrated (or free-flowing) suspensions, solutions, in particular water-soluble concentrates, emulsions and dispersions.

Powders for pulverization typically contain 0.1 to 5% by weight of active ingredient, an inert carrier substance, which may be an impregnation carrier such as silica, and, where necessary, 0 to 10% by weight of one or more stabilizing agents and/or other additives such as penetrating agents, adhesives, anti-caking agents, or colorants. They are usually prepared by first mixing the active ingredient with the inert carrier substance and then grinding the mixture in a grinding device.

Granules and microgranules, generally with a low active substance content, can be prefabricated and then impregnated, or they can be manufactured in bulk, for example, by atomization or extrusion. In the latter case, they require the addition of binding agents. 38 - Eng. Barzan? & Zanardo

agents and surfactants to ensure their rapid disintegration in the soil. They generally contain 0.5 to 10% by weight of active substance, 0 to 10% by weight of additives such as stabilizers, slow-release modifying agents, binding agents and i.v. solvents.

Wettable powders (or spray powders) are usually prepared so that they contain 20 to 95% active substance and usually contain, in addition to the solid carrier substance, 0 to 5% of a wetting agent, 3 to 10% of a dispersing agent and, where necessary, 0 to 10% of one or more stabilizing agents and/or other additives such as penetrating agents, adhesives or anti-caking agents, colorants, etc.

As an example, the composition of a 50% humidifiable powder is given below:

? active substance . .. . *...?... 50% ? sodium lignosulfonate. .. 5% ? sodium dibutylnaphthalene sulfide. . ...v 1% - clay (kaolin). . . . 44% Another example of a moisturizing powder has the following composition:

- active substance . .. . ?........ 50% - sodium and/or calcium lignosulfonate (deflocculant) 5%

? jy - ?ng. garzano cc ic-cuidu-uu - isopropyl naphthalene sulfonate (anionic wetting agent). ? . .1%

*

- anti-caking silica . 5% - kaolin (filler) . . . 39% To obtain these sprayable powders or wetting powders, the active substance is thoroughly mixed with the additives in suitable mixers and ground in mills or other suitable grinding devices. This results in sprayable powders that are advantageous for wetting and suspending. They can be suspended in water at any desired concentration, and this suspension can be used very advantageously, particularly for application to the leaves of plants.

Emulsifiable solutions or concentrates contain the active substance dissolved in a solvent (generally an aromatic hydrocarbon) and, when necessary, an auxiliary solvent or co-solvent which may be a ketone, an ester, an ether oxide, etc.

In general, they contain 5 to 60% w/v active substances, 2 to 20% w/v emulsifying agent and can be prepared, for example, by dissolving the active substance. 40 ? ing.Barzan? & Zanardo

active, in the solvent or in the mixture of solvents and emulsifiers, under good stirring with heating or cooling.

Starting from these emulsifying solutions or concentrates, emulsions having any desired concentration can be obtained by dilution with water, which are particularly suitable for the use of the compounds according to the invention.

Concentrated suspensions (or "flovables") consist of a suspension of fine solid particles of the active substance in water or a non-solvent oil, prepared to obtain a stable, non-sedimentable fluid product. They typically contain 10 to 75% by weight of the active substance, 0.5 to 15% surfactants, 0.1 to 10% thixotropic agents, 0 to 10% suitable additives such as antifoaming agents, corrosion inhibitors, stabilizers, penetration agents and adhesives, and as a carrier, water or an organic liquid in which the active substance is sparingly soluble or insoluble; certain organic solids or mineral salts may be dissolved in the carrier to help prevent sedimentation or as additives.

i

antifreeze for water.

- 41 - Eng.Barzan? & Zanardo These concentrated suspensions are prepared I

By grinding the active substance very finely, it is then dispersed in a liquid carrier containing the auxiliary ingredients. The resulting dispersion is then ground in a ball mill. Starting from concentrated suspensions, suspensions of any desired concentration can be obtained by diluting them with water.

These aqueous suspensions or emulsions of the active substance described above, for example the compositions obtained by diluting with water a moisturizing powder, or an emulsifiable concentrate or a concentrated suspension, are included in the general scope of the compositions according to the invention.

Emulsions can be of the water-in-oil or oil-in-water type and they can have a thick consistency like that of a "mayonnaise" sauce.

Finally, the present invention relates to a process for selective weed control of crops, particularly rice and wheat. This process is characterized by the fact that it consists of applying to the soil, during the pre-emergence phase of the aforementioned crops, a quantity of a compound according to formula (I) that is effective against weeds but not phytotoxic towards the crops. The quantity of active substance to be used may vary depending on the compound used, the type of crop, the climatic conditions, and the nature of the weeds to be destroyed.

- 43 - Eng. Barzan? & Zanardo

TABLE (I)

Characteristics Point-Compo RDT

X W R that spectral -: sto (%) fusions ?c) IR O NMR

No.

1 CF_ H H 38 173

3

2 NO2 47

<*3 H 142

3 NO2 Na 75 < 250

4A N02

^3 63 92

-?3 .

5 CI NO2 -CH3 66 115

6 CF3 NO2 -C2H5 45 67

7 CF NO2 37 oil

8 CF-. N02 50 127

3 -a^cooc^

9 CF

3 NO2 65

CHCOOC2H5 (R,S) oil RJ^J 1.25 - 2.00

4.23 - 5.68 10 CF3 NO -COOC2H5 95 140

2

11 CF3 NO2 -CH2CH2COOC2H5 65 132

12 CF3 NO2 66 . or lio NMR 2 .03 - 3.75 (?COOCH3 (R,S) 5.74

13 ro2 71 oil RNN 0.98 - 2.47 SC?OCH3 (R,S) 3.78 - 5.53 14 CF3 ^J02 -O^COOCH-J 61 132

15

^3 *? -CH20CH2CH2OCH3 47 oil IR 1588, 1536,

1327, 1270, 1130, 1082 - 44 - Eng. Barzan? & Zanardo In table (l) the spectral characteristics indicated are the following:'

- with the IR indication, are these absorption bands?-

??

chin in the infrared xn cm,

- with 11NMR indication, it is the chemical displacement of protons, the measurement being carried out in deuterated chloroform in the presence of tetramethylsilane as a reference.

- 45 - Eng. Barzan? & Zanardo

TABLE (II)

Greenhouse herbicide activity in the pre-emergence phase

Percentage in relation to controls

100 : identical to control **? no herbicidal activity

0: total herbicidal activity

PI?NTE

? Compounds n? Dose

kg/ettc TRIT ALOP AVEN LENS RAPH BETA LACT FAG AMA r? the

1 10 32 36 55 85 100 37 100 60 15

2 1 70 29 75 29 7 3 16 100 0

4A 2.2 34 0 11 35 26 44 0 1 0

6 1 80 14 76 100 90 56 2 60 0

7 1 83 32 66 41 100 100 100 100 0

8 1 ? 80 63 90 100 5 5 0 75 0

10 1 .100 100 100 46 13 3 13 60 0 - 46 - Eng. Barzan? & Zanardo

TABLE (III)

Postemergence herbicidal activity in greenhouses...

Percentage in relation to controls,

100%: identical to control - no herbicidal activity 0%: full herbicidal activity. .

PLANT

.

Compounds -n* Dose

kg/et TRIT ALOP ' AVEN LENS RAPH BETA LACT FAG taro

1 10 100 100 100 75 0 57 100 -

2 1 64 56 73 32 0 10 ? 0 0

4A 2.2 39 0 22 17 0 0 0 0

6 1 77 10 73 8 9 3 4 0

7 1 100 34 80 67 25 16 0 6

8 1 83 75 83 8 0 or 2 0

10 1 100 88 100 54 6 4 10 1 - 47 _ ing.Barzan? & Zanardo

TABLE (IV)

Post-emergence herbicide activity in greenhouses. Percentages in relation to controls.

100 identical to control - no herbicidal activity 0 total herbicidal activity. .

Compound

ne 3 ne 4A ne 8 Dose Kg/?t 0.5 0.5 0.5 _ taro .

Oryza sativa 54 88 Triticum vulgate 100 61 85 Alopecurus myosuro'ides 13 67 Echinochloa crus-galli 34 46 Setaria viridis 96 0 15 Abutilon theophrasti 50 0 47 Sida spinosa 20 20 Chrysanthemum annuum 23 8 0 Matricaria ma tricar ioides 15 15 Veronica persica 0 0 Plantago lanceolata 0 4 Amarantus Caudatus 0 0 Solanum nigrum 8 0 0 Sinapis alba 0 0 Convolvulus arvensis 0 3 Stellaria media 7 54 - 48 - Eng. Barzan? & Zanardo

TABLE (V)

Ne.Com-? Doses > Pre-emergence Post-emergence placed in

kg/etEDI LX AEU IPO SIN ??? OX SQJ BCH LDL A2U IPO SIN ??? BLE SOJ taro

2 100 20 100 50 100 100 0 50 60 20 95 100 100 ioo 0 0

9 0.5 80 0 100 30 100 30 0 0 30 20 90 100 100 100 0 0

0.125 30 0 80 0 80 0 0 0 20 0 80 100 90 30

| or 0

2 0 30 100 50 100 100 0 0 90 30 100 100 100 100 0 ? 0

11 0.5 0 20 100 30 100 100 0 30 0 100 100 100 50 0 0

0

0.125 0 0 100 0 80 0 0 0 20 0 80 100 100 50 ?

2 100 100 100 L00 100100 40 0 100 30 L00 100 100 100 20 30

12 0.5 100 50 100 30 100 50 0 20 L00 ?oo 100 100 0 0

0.125 80 20 100 0 100 0 0 0 | 9I0o 20 L00 ioo 100 100 0 0

;o

2 80 0 100 30 100 50 0 o |ir?30 0 90 100 100100 0 50 13 0.5 20 0 50 30 100 0 0 0o | 30 0 90 100 100 100 0 50

0.125 0 0 80 0 90 0 0 0 | 20 0 30 100 100 100 0 0

2 100 0 90 70 100 30 0 0 | 80 0 30 100 100 100 0 0

J " "" " 14 0.5 50 0 0 0 100 0 0 0 |20 0 20 100 100 L00 g 0

0.125 0 0 0 0 95 0 0 0 0 0 0 90 95 L00 0 0

Note: 0: identical to control.

100: complete destruction of the plants

- 49 - Eng. Barzan? & Zanardo

TABLE (VI)

Name Name Name Abbreviation Italian American r Latin

Crop Wheat BLE Soybean SOJ

Panic. Barnyardgrass Echinochloa ECH crus-galli

Velvet leaf Abutilon ABU theophrasti

Plants Cocklebur Xanthium XAN infestan pennsy1vanicum

ti Wild mustard Wild mustard Sinapis arvensis SIN Bindweed purpu Morningglory Ipomea purpurea IPU reo (annual)

perennial Rye-grass Lolium multi LOL

flora

Cocklebur Xanthium pennsylvandcum XAN 50 Ing.Barzan? & Zanardo

1. Products, usable in particular as herbicides, characterised by having the following formula:

?,? - N

in which:

X represents a halogen atom or a lower alkyl radical, substituted with one or more halogen atoms,

Y represents a hydrogen or halogen atom, or a CF^, CN, N02 or CH^ radical,

D represents the nitrogen atom or the radical -C(Z)= in which Z represents a hydrogen or halogen atom,

W represents a hydrogen or halogen atom or the nitro radical,

R represents a hydrogen atom or a halogen atom, or an aliphatic or aromatic radical, alkylthio, amine, acyl, alkylsulfonyl, aryl? J I jLi-iy ? UQI Z/CU-iw a. UUUU? u.w

sulfonyl, hydroxyl or cyano, possibly substituted,

and also their salts are acceptable in agriculture.

2. Products according to claim 1, characterized

raised by the fact that R is a radical substituted with

imo or more of the atoms or radicals such as halogen, alkoxy, hydroxyl, lower acyl, carboxyl, carboxylate.

3. Products according to one of the claims

1 or 2, characterized by the fact that R represents

1? hydrogen atom or a halogen atom, or a radical chosen from the radicals: alkyl possibly substituted* aryl possibly substituted; lower alkenyl; lower alkynyl; alk?ltio

lower possibly replaced; amino group possibly replaced;

- CO-R1 in which R* represents a substituent such as the OH radical, or a lower alkoxy radical, an aryloxy radical or the amine radical substituted by itself

- SOg-R" in which R" represents a substituent

which alkyl or aryl;

-OH and -CN;

and the agriculturally acceptable salts of these compounds.

4. Products according to one of the claims

from 1 to 3 characterized by the fact that:

X ? CF3,

52 Eng. Barzan? & Zanardo

Y ? Cl,

D ? ?CH=,

W ? nitro or H,

and R represents an alkyl radical, possibly substituted.

5. Process for preparing a product according to one of claims 1 to 4, characterised in that it consists in reacting a phenyl tetrazole of formula (II)

N-N

(there)

wherein ? and R have one of the meanings set forth in claims 1 to 4 and A represents the hydroxyl radical or a halogen atom, with ? a compound of formula (III)

in which x, Y, D have one of the meanings indicated - 53 ? Ing.Barzan? & Zanardo

in claim 1 and B represents a halogen atom or the hydroxyl radical, it being understood that B is chosen different from A and that the hydroxylated reagent may be in the form of phenate.

6. Preparation process of a product of formula (I)

//N N

- -N the)

wherein W represents a halogen atom and X, Y, D and R have one of the meanings indicated in claims 1 to 4? characterized in that it consists in halogenating a compound of formula (IV)

4-? (iv)

wherein X, Y, D and R have one of the meanings set forth in claims 1 to 4.

7. Product preparation process - 54 - Eng. Barzan? 8cZanardo

of formula:

//N - N

C V.N= rf<

Not

in which X, Y, D and R have one of the meanings indicated in claims 1 to 4? characterized in that it consists in subjecting to nitration a compound of formula (IV):

NN= I (IV)

?-# ? -<2>

8. Preparation process of a product of formula (VII)

Y .C //*?- sir- H

(VII)

in which Xf Y and D have one of the meanings indicated - 55 Ing.Barzan? & Zanardo in claims 1 to 4, characterized in that it consists in reacting NaN^ on the nitrile of formula (VI):

(VI)

9. Process for preparing a salt of a product of formula (ix):

(IX)

wherein X, Y, D and W have one of the meanings indicated in claim 1, characterised in that it consists in reacting this compound of formula (IX) with a suitable base, preferably soda:

10. Procedure for preparing a compound of formula (I)

56 Eng. Barzan? & Zanardo

3

//N? N

y

x or ?-?- \N=^=N

w (i)

in which R, X, Y, D and W have one of the meanings

indicated in claims 1 to 4 and R ? different

from the hydrogen atom, characterized by the fact that

it consists in reacting a compound of formula

(Vili)

R - T (Vili)

in which R has the same meaning as indicated

previously and ? represents a leaving group,

on the compound of formula (VII)

y*N- N

(VII) KOW or

11. Herbicide composition characterized by the fact-

to contain as an active substance at least one product

according to one of claims 1 to 4.

12. Composition according to claim 1,

characterized by the fact that, in addition to the active substance,

Claims (1)

- 57 - Eng. Barzan? & Zanardo ??*.. * t it includes one or more agriculturally acceptable solid or liquid carrier substances and one or more agriculturally acceptable surfactants. 13. Composition according to claim 12, characterized in that it comprises 0.5 up to 95% active substance. 14. Composition according to claim 13, characterized in that it comprises from 1 to 95% carrier substance and 0.1 up to 20% surfactant. 15. Procedure for selective weed control of crops, characterised by the fact that a effective dose of an active substance according to one of claims 1 to 4. 16. Process according to claim 15, characterised in that a composition according to one of claims 11 to 14 is applied, the active substance being applied in a dose of 0.01 up to 5 kg/hectare, preferably 0.1 up to 2 kg/hectare. 17. Process according to one of the claims 15 and 1 characterized by the fact that the crop is? soy / 1 MANDATORY AGENTS Tr.8130/C0 R/C/ %tj??]W