EP0000852A1 - Treatment of herbicid containing cultures with derivatives of dichloroacetamide or of thrichloroacetamide, novel derivatives of dichloroacetamide or trichloroacetamide and process for their preparation - Google Patents

Abstract

The subject of the present invention is new derivatives of dichloroacetamide and trichloroacetamide, their methods of preparation and their application as herbicide antidotes.

The herbicides currently existing can be classified into two categories: total herbicides, which destroy all the plants, and selective herbicides. The latter, which are the most precious in agriculture, allow to destroy the weeds present in the crops without harming the cultivated plant and are said, for this reason, selective of the cultivated plant. Unfortunately it sometimes happens that this selectivity is not perfect at the dose of use and that the selective herbicides present a certain phytotoxicity with respect to the cultivated plant.

So we use, in combination with herbicides, so-called herbicide antidote products which have the property of giving herbicides increased selectivity or new selectivities, without harming their herbicidal quality. In other words 1 the antidote makes disappear completely or at least in large part, the phytotoxicity of the herbicide with respect to the cultivated plant without reducing its phytotoxicity with respect to undesirable plants.

Description

The subject of the present invention is new derivatives of dichloroacetamide and trichloroacetamide, their methods of preparation and their application as herbicide antidotes.

Currently existing herbicides can be classified into two categories: total herbicides, which destroy all plants, and selective herbicides. The latter, which are the most precious in agriculture, allow to destroy the weeds present in the crops without harming the cultivated plant and are said, for this reason, selective of the cultivated plant. Unfortunately it sometimes happens that this selectivity is not perfect at the dose. of use and that the selective herbicides have a certain phytotoxicity with respect to the cultivated plant.

So we use, in combination with herbicides, so-called herbicide antidote products which have the property of giving herbicides increased selectivity or new selectivities, without harming their herbicidal quality. In other words, the antidote makes disappear completely or at least in large part, the phytotoxicity of the herbicide with respect to the cultivated plant without reducing its phytotoxicity with regard to undesirable plants.

Such herbicide antidote products have for example been described in French patents Nos. 2,133,793, 2,212,336, 2,215,170, 2,228,065, 2,309,546 and 2,310,348 and in US'Nos patents 3,867,444 ; 3,923,494, 3,931,313 and 3,959,304.

The present invention aims to obtain chemically new and active compounds also as antidotes to herbicides.

* The compounds according to the invention can be represented by the general formula:

dans laquelle R₁ représente un groupe dichlorométhyle ou trichlorométhyle, X₁ représente un atome de chlore ou de fluor, X₂ représente un atome de chlore ou de fluor, X₃ représente un atome d'hydrogène, de chlore ou de fluor, R₂ représente un groupe amino HH₂ ou un groupe

dans lequel R₃ est un atome d'hydrogène ou un groupe alkyle, haloalkyle, alkényle, haloalkényle, arylalkyle, arylhaloalkyle, cycloalkyle, halocycloalkyle, alcoxyalkyle, haloalcoxyalkyle ou aryle, ce dernier étant éventuellement substitué par un ou deux atomes d'halogène ou par un groupe alkyle, alcoxy, nitro ou haloalkyle.

in which R ₁ represents a dichloromethyl or trichloromethyl group, X ₁ represents a chlorine or fluorine atom, X ₂ represents a chlorine or fluorine atom, X ₃ represents a hydrogen, chlorine or fluorine atom, R ₂ represents an amino group HH ₂ or a group

in which R ₃ is a hydrogen atom or an alkyl, haloalkyl, alkenyl, haloalkenyl, arylalkyl, arylhaloalkyl, cycloalkyl, halocycloalkyl, alkoxyalkyl, haloalkoxyalkyl or aryl group, the latter optionally being substituted by one or two halogen atoms or by an alkyl, alkoxy, nitro or haloalkyl group.

In the definitions given above for R ₃ , the alkyl, alkenyl, alkoxy chains of the alkyl, haloalkyl, alkenyl, haloalkenyl, arylalkyl, arylhaloalkyl, alkoxyalkyl and haloalkoxyalkyl groups preferably have 1 to 5 carbon atoms, the cycloalkyl and halocycloalkyl groups preferably have 3 to 6 carbon atoms, haloalkyl, haloalkenyl, arylhaloalkyl, halocycloalkyl, haloal coxyalkyle ^p nt preferably 1 to 7 halogen atoms taken from the chlorine, bromine or fluorine atoms, aryl and aryl preferably denote phenyl and phenyl respectively and the halogen substituent of the aryl group is preferably a chlorine atom.

dans lequel R'₃ est un atome d'hydrogène, un groupe alkyle ayant 1 à 5 atomes de carbone, un groupe alcényle ayant 2 à 5 atomes de carbone, un groupe haloalkyle ayant 1 à 5 atomes de carbone et 1 à 7 atomes d'halogène, ou un groupe phényle substitué par un ou deux atomes de chlore. Quant R'₃ est un groupe haloalkyle, il est de préférence un groupe

dans lequel Y₁ est un atome de chlore ou de fluor, Y₂ est un atome de chlore ou de fluor et Y₃ est un atome d'hydrogène, de chlore ou de fluor.Although the present invention relates to all of the compounds of formula (I), it relates more particularly to those of these compounds for which R ₂ is NH ₂ or a group

wherein R ' ₃ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, a haloalkyl group having 1 to 5 carbon atoms and 1 to 7 d atoms 'halogen, or a phenyl group substituted by one or two chlorine atoms. When R ' ₃ is a haloalkyl group, it is preferably a group

wherein Y ₁ is a chlorine or fluorine atom, Y ₂ is a chlorine or fluorine atom and Y ₃ is a hydrogen, chlorine or fluorine atom.

peuvent être préparée par plusieurs méthodes, à savoir :

• 1) action d'un chlorure d'acide de formule
  
  un composé aminé de formule (II) ci-dessous suivant la réac- tio_{n :}
  
• 2) action d'un chlorure d'acide de formule
  
  sur un composé aminé de formule (III) ci-dessous suivant la réaction :
  
  3°) action d'un amide de formule
  
  sur un dérivé chloré de formule (IV) ci-dessous suivant la réaction :
  
  4°) action d'un amide de formule
  
  sur un dérivé chloré de formule (V) ci-dessous suivant la réaction :
  
  

The compounds of formula (I) for which R ₂ is a group

can be prepared by several methods, namely:

• 1) action of an acid chloride of formula
  
  an amino compound of formula (II) below according to the reaction _:
  
• 2) action of an acid chloride of formula
  
  on an amino compound of formula (III) below depending on the reaction:
  
  3) action of an amide of formula
  
  on a chlorinated derivative of formula (IV) below depending on the reaction:
  
  4) action of an amide of formula
  
  on a chlorinated derivative of formula (V) below depending on the reaction:
  
  

. In formulas (II), (III), (IV), (V) above as well as in those of acid chlorides and amides, X ₁ , X ₂ , X ₃ , R ₁ and R ₃ have the same meanings as in formula (I).

The reactions (1), (2), (3), (4) are preferably carried out in an inert solvent such as for example a linear or cyclic ether, an aliphatic or aromatic hydrocarbon or a chlorinated derivative of an aliphatic or aromatic hydrocarbon , at a temperature between -30 ° C and + 60 ° C and preferably between - 15 ° C and + 30 ° C. The hydrochloric acid formed in the reaction is neutralized, as it is formed, by a mineral base such as for example an alkali or alkaline earth metal hydroxide or by a tertiary amine such as for example triethylamine or pyridine. After separation by extraction with water or by filtration of the chloride of the mineral base or of the hydrochloride of the mine, the product of formula (I) formed is isolated in the brot state by elimination of the solvent by distillation. It can be purified, for example by recrystallization, or used as it is.

The compounds of formula (I) for which R ₂ is an NH ₂ group, which are identical to the compounds of formula (II), and the compounds of formula (III) can be prepared by the action of ammonia on the chlorinated derivatives of formulas (IV) and (V). The reaction is carried out in the same solvents as those used for reactions (1) to (4) and preferably in a cyclic ether such as, for example, tetrahydrofuran. The chlorinated derivative of formula (IV) or (V) is introduced into the solvent saturated with am oniac, at a temperature of between -30 ° C. and + 30 ° C. The ammonium chloride formed is removed by filtration and the compound of formula (II) or (III) is isolated in the raw state by elimination of the solvent. It can be purified by recrystallization or used as such, in particular for carrying out reactions (1) or (2).

dans lesquelles R₁, R₃, X₁, X₂, X₃ ont les mêmes significations que dans la formule (I). La réaction peut être réalisée, en présence ou non d'un solvant, avec un excès de chlorure de thionyle, à une température comprise entre 50°C et 80°C. Le solvant utilisé peut être identique à ceux utilisés pour effectuer les réactions (1) à (4). Dans le cas où on opère sans solvant, et aussi quand on opère avec certains solvants comme par exemple CCl₄ ou l'hexane, le composé de formule (IV) ou (V) précipite et peut être isolé par filtration. Dans le cas où on opère avec d'autres solvants comme par exemple le tétrahydrofuranne, le composé de formule (IV) ou (V) ne précipite pas. On peut alors soit isoler le produit en évaporant sous vide le solvant, soit utiliser directement le milieu obtenu en fin de réaction pour la suite du processus conduisant aux composés (I), sans isoler les produits (IV) ou (V).The compounds of formula (IV) and (V) can be prepared by the action of thionyl chlorur on the hydroxylated compounds of formulas:

in which R ₁ , R ₃ , X ₁ , X ₂ , X ₃ have the same meanings as in formula (I). The reaction can be carried out, in the presence or not of a solvent, with an excess of thionyl chloride, at a temperature between 50 ° C. and 80 ° C. The solvent used can be identical to those used to carry out reactions (1) to (4). In the case where one operates without solvent, and also when one operates with certain solvents such as CCl ₄ or hexane, the compound of formula (IV) or (V) precipitates and can be isolated by filtration. In the case where one operates with other solvents such as for example tetrahydrofuran, the compound of formula (IV) or (V) does not precipitate. It is then possible either to isolate the product by evaporating the solvent under vacuum, or to directly use the medium obtained at the end of the reaction for the continuation of the process leading to the compounds (I), without isolating the products (IV) or (V).

sur un aldéhyde halogéné de formule

suivant les procédés décrits par Joseph P.LAROCCA, John. M. LEONARD, Warren. E. WEAVER [Journal of Organic Chemis- try 16, 47-50, (1951)] et par A. BOUCHERLE, G. CARRAZ, J. VIGIER [Bull. Trav. Soc. Pharm. Lyon 10 (1), 3-10, (1966)].The hydroxylated compounds of formulas (VI) or (VII) can be prepared by the action of an amide of formula

on a halogenated aldehyde of formula

following the procedures described by Joseph P.LAROCCA, John. M. LEONARD, Warren. E. WEAVER [Journal of Organic Chemistry 16, 47-50, (1951)] and by A. BOUCHERLE, G. CARRAZ, J. VIGIER [Bull. Trav. Soc. Pharm. Lyon 10 (1), 3-10, (1966)].

The compounds of formula (III) for which R ₃ is other than a hydrogen atom are new and form part of the invention as such. As examples of new compounds of formula (III), mention may be made in particular of those for which there is simultaneously X ₁ = X ₂ = X ₃ = Cl and R ₃ = monochloromethyl, trichloromethyl, 1,2,3,3,3,3-pentachloro, propyl, trifluoromethyl, methyl, o-chlorophenyl, p-chlorophenyl, p-methylphenyl, m-trifluoromethylphenyl, 2,4-dichloro or 3,4-dichloro-phenyl .

dans laquelle X₁, _X2, _X3 ont la même signification que dans la formule (I), Y est un atome de chlore ou un groupe hydroxy, Z est un groupe n-heptyle, n-nonyle, trifluorométhyle, pentachloro-1,2,3,3,3 propyle, p-méthylphényle, m-trifluoro- méthylphényle et peut être en plus, quand X₁, X₂, X₃ ne sont pas simultanément des atomes de chlore, un groupe dichlorométhyle.Some of the compounds of formulas (IV), (V), (VI), (VII) are also new products. As such, mention may in particular be made of the compounds corresponding to the formula:

in which X ₁ , _X2 , _X3 have the same meaning as in formula (I), Y is a chlorine atom or a hydroxy group, Z is an n-heptyl, n-nonyl, trifluoromethyl, 1,2-pentachloro group , 3,3,3 propyl, p-methylphenyl, m-trifluoromethylphenyl and can be, when X ₁ , X ₂ , X ₃ are not simultaneously chlorine atoms, a dichloromethyl group.

The compounds of formula (I) can be used, as herbicide antidotes, for the treatment of crops. They protect cultivated plants against damage caused by herbicides, and this at doses of herbicides effective against undesirable plants.

The compounds of formula (I) can in particular be used in combination with herbicides belonging to the families of chloroacetanilides, ureas, triazines, carbamates, uracils and more especially thiolcarbamates. As such there may be mentioned for example ethyl N, N-dipropyl thiolcarbamate (EPTC), ethyl N, N-diisobutyl thiolcarbamate (butylate), N, N, N-dipropyl thiolcarbamate propyl, N, N- ethyl diethyl thiolcarbamate (ethiolate), ethyl N, N-cyclohexamethylene thiolcarbamate (molinate), ethyl N-ethyl N-cyclohexyl thiolcarbamate (cycloate), dichloro- N, N-diisopropyl thiolcarbamate 2,3 propenyl (dialate), ethyl N, N-diisopropyl thiolcarbamate, chloro-4-butynyl-2 (barban) N- (3-chloro-phenyl) carbamate, (3-chloro-4-methyl-phenyl) -3 dimethyl-1,1 urea (chiobitruron), (3,4-dichloro phenyl) -3 methoxy-1 methyl-1 urea (linuron), (3,4-dichloro phenyl) -3 dimethyl-1,1 urea, N-chloroacetyl N-isopropyl aniline (propachlor), 2,6-diethyl N-chloroacetyl N-methoxymethyl aniline (alachlor), 2-chloro-4-ethylamino isopropylamino-6 triazina-1,3,5 (atrazine), chloro-2 bis (ethylamino) -4,6 triazine-1,3,5 chloro-2 cyclopropylamino-4 isopropylamino-6 triazine-1,3,5 and combinations thereof . The weight ratio of the antidote product to be used as a herbicide can vary greatly depending on the nature of the herbicide concerned. This ratio is generally between 0.001 and 10, and most often between 0.01 and 5.

For their use, the compounds of formula (I) can be incorporated, jointly with the herbicide or separately, in compositions which contain, in addition to the active material (that is to say the antidote compound and optionally the herbicide ), inert additives usually used in agriculture to facilitate the conservation, implementation and penetration into plants of active products, such as mineral fillers (talc, silica, kieselguhr, diatomaceous earth, clay, etc.), diluents various organic (mineral oils, organic solvents), surfactants, antioxidants and stabilizers. Such com ^p OSi tions can be in the form of wettable powders, emulsifiable solutions in water, granules or any other form in use in the field of herbicides. In the compositions containing only an antidote compound according to the invention and inert additives, the content of antidote compound can vary from 10% to 90% by weight. In the compositions containing an antidote compound according to the invention, a herbicide and inert additives, the content of antidote compound can vary from 0.09% to 50% by weight, that in herbicide from 1% to 90% by weight, the ratio by weight of antidote products being between 0.001 and 10. herbicide

The antidote compounds according to the invention can be applied to the soil at the same time as the herbicide, pre-emergence or post-emergence of the crop. The dose of antidote product provided can vary from 100 g to 5000 g per hectare. For such an application, it is advantageous to use compositions containing the antidote product and the herbicide simultaneously, such as those mentioned above.

The antidote compounds according to the invention can also be applied to the soil at a time different from that of the treatment with the herbicide, pre-emergence or post-emergence of the crop, the dose of antidote product provided being the same as above. They can in particular be applied to soils containing herbicide residues in order to protect crops against the residual activity of these residues.

Finally, the antidote compounds according to the invention can also be applied to the seed of the crop to be protected, said seed then being sown in soil already treated with the herbicide or which will be treated with the herbicide. For the treatment of seeds, the dose of antidote provided can vary from 10 g to 500 g per quintal of seed.

The following examples illustrate the invention without limiting it.

EXAMPLE N ⁸ 1 Preparation of the compound of formula:

19.15 g (0.1 mol) of N- [2,2,2-trichloro-1) ethyl] formamide are dissolved in 200 ml of tetrahydrofuran (THF). 10.1 g of triethylamine (0.1 mole) are added. Maintaining the temperature at 15 ° C., 14.75 g of dichloroacetyl chloride (0.1 mol) dissolved in 100 ml of THF are added with stirring over approximately 30 minutes. Then maintained for 1/2 hour with stirring, leaving to return to the ambient temperature. The precipitate of triethylamine hydrochloride is filtered. THF is removed by vacuum distillation. During distillation, a crystallized product is formed which is separated. This product is recrystallized from a benzene-hexane mixture 50-50. 24.5 g are thus obtained (ie a yield of 81%) of N- [2,2,2-trichloro-dichloroacetamido-1) ethyl] formamide, with a melting point of 141-142 ° C.

EXAMPLE 2 - Preparation of the compound of formula:

On sature 300 ml de tétrahydrofuranne par de l'ammoniac gazeux et on maintient cette saturation pendant toute la durée de l'opération.En maintenant la température à -5°C, on ajoute sous agitation, en environ 1 h 30 minutes, 150 g (0,5 mole) de N-[(tétrachloro-1,2,2,2) éthyl]dichlorea- cétamide. Il se forme tout au long de l'addition un précipité de chlorure d'ammonium. Celui-ci est séparé du milieu par filtration. Le THF est ensuite séparé par distillation sous vide. On obtient de cette façon 130 g de N-[(trichloro-2,2,2 amino-1) éthyl]dichloroacétamide (soit un.rendement de 94,7 %), sous la forme d'un solide blanc de point de fusion 132-133°C.

300 ml of tetrahydrofuran are saturated with gaseous ammonia and this saturation is maintained throughout the duration of the operation. Maintaining the temperature at -5 ° C., 150 g are added with stirring, in approximately 1 h 30 minutes. (0.5 mole) of N - [(tetrachloro-1,2,2,2) ethyl] dichlorea-ketamide. A precipitate of ammonium chloride is formed throughout the addition. This is separated from the medium by filtration. THF is then separated by vacuum distillation. In this way 130 g of N - [(2,2,2-trichloro-1 amino) ethyl] dichloroacetamide (i.e. a yield of 94.7%) are obtained in the form of a white solid with a melting point. 132-133 ° C.

EXAMPLE 3 - Preparation of the compound of formula

10.2 g of dichloroacetamide (0.08 mole) are dissolved in 150 ml of chloroform. 10 g of triethylamine (0.1 mol) are added. Maintaining the temperature in the region of 0 ° C., 23.5 g of dissolved N - [(tetrachloro-1,2,2,2) ethyl] dichloroacetamide (0.08 mol) are added with stirring over approximately 1 hour. in 150 ml of chloroform. The mixture is allowed to return to ambient temperature with stirring, then it is taken up in 1 liter of water. After decantation, the organic phase is separated and washed twice with 500 ml of water, then dried over magnesium sulfate. The chloroform is distilled under vacuum and a solid is obtained which is recrystallized from hexane. 24.5 g of N - [(2,2,2-dichloroacetemido-1) ethyl] dichloroecetemide (ie a yield of 79.5%), with a melting point of 249 ° -250 ° C., are thus obtained.

EXAMPLE 4 - Preparation of the compound of formula:

En opérant comme dans l'exemple No 1, mais en remplaçant les 14,75 g de chlorure de dichloroacétyle par 18,2 g de chlorure de trichloroacétyle (0,1 mole), on obtient 25,2 g (soit un rendement de 74,8 %) de N-[(trichloro-2,2,2 trichloroacétamido-1) éthyl] formamide, de point de fusion 157-158°C.

By operating as in Example No 1, but replacing the 14.75 g of dichloroacetyl chloride with 18.2 g of trichloroacetyl chloride (0.1 mole), 25.2 g are obtained (a yield of 74 , 8%) of N - [(2,2,2-trichloroacetamido-1) ethyl] formamide, m.p. 157-158 ° C.

EXAMPLE 5 - Preparation of the compound of formula:

By operating as in Example No. 3, but replacing the 10.2 g of dichloroacetamide with 6.96 g of isobutyramide (0.08 mole), 21 g are obtained (ie a yield of 76.3 %) of N - [(2,2,2-trichloro-dichloroacetamido-1) ethyl] isobutyramide, mp 264-265 ° C.

EXAMPLE N ° 6 - Preparation of the compound of formula

The procedure is as in Example 1, replacing the 19.15 g of N - [(2,2,2-trichloro-1 amino-1) ethyl] formamide with 24.7 g of N- [(2,2-trichloro) , 2 amino-1), ethyl] trichloroacetamide (0.08 mole). 21.8 g are thus obtained (ie a yield of 65%) of N - [(2,2,2-trichloro-dichloroacetamido-1) ethyl] trichloroacetamide with melting point 184-185 ° C.

• On sature 300 ml de THF par de l'ammoniac gazeuxtet on maintient cette saturation pendant toute la durée de l'opération. En maintenant la température à 0°C, on ajoute sous agitation, en environ 1 h, 100 g de N-[(tétra- chloro-1,2,2,2) éthyl]trichloroacétamide (0,3 mole). Le précipité de chlorure d'ammonium qui s'est formé est séparé par filtration. Le THF est ensuite séparé par distillation sous vide. On obtient ainsi 59 g de N- [(trichloro-2,2,2 amino-1) éthyl]trichloroacétamide (soit un rendement de 62,7 %) sous la forme d'un solide blanc de point de fusion 132-133°C. EXEMPLE N° 7 - Préparation du composé:
  

The N - [(trichlorc-2,2,2 amino-1) ethyl] trichloroacetamide used as starting material can be prepared as follows:

• 300 ml of THF are saturated with gaseous ammonia and this saturation is maintained throughout the duration of the operation. Maintaining the temperature at 0 ° C., 100 g of N - [(tetra-chloro-1,2,2,2) ethyl] trichloroacetamide (0.3 mole) are added, with stirring, in approximately 1 hour. The precipitate of ammonium chloride which has formed is separated by filtration. THF is then separated by vacuum distillation. 59 g of N- [(2,2,2-amino-1 trichloro) ethyl] trichloroacetamide are thus obtained (ie a yield of 62.7%) in the form of a white solid with melting point 132-133 ° vs. EXAMPLE N ° 7 - Preparation of the compound:
  

The procedure is as in Example 1, replacing the 19.15 g of N - [(trichlorc-2,2,2 amino-1) ethyl] formamide with 18.2 g of N - [(trichlorc-2,2 , 2 amino-1) ethyl] o-chlorobenzamide (0.06 mole) and using 10.3 g of dichloroacetyl chloride (0.07 mole) instead of 14.75 g. 23 g (ie a yield of 79.5%) of N - [(trichlorc-2,2,2 dichloroacétamido-1) ethyl] o-chlorobenzamide, melting point 214-215 °, are thus obtained, after evaporation of the solvent. vs.

• On opère comme pour la préparàtion du N-[(trichloro-2,2,2 amino-1) éthyl]trichloroacétamide Mais en remplaçant les 100 g de N-[(tétrachloro-1,2,2,2) éthyl]trichloroacétamide par 100 g de N-[(tétrachloro-1,2,2,2) éthyl] o-chlorobenzamide (0,31 mole). On obtient 89 g (soit un rendement de 94,7 %) de N- [(trichloro-2,2,2 emino-1) éthyl] o-chlorobenzamide, solide blanc de point de fusion 169-170°C.

The N- [(2,2,2,2-amino-1 trichloro) ethyl] o-chlorobenzamide used as starting material can be prepared as follows:

• The procedure is as for the preparation of N - [(2,2,2,2-amino-1-amino) ethyl] trichloroacetamide But replacing the 100 g of N - [(1,2,2,2-tetrachloroethyl) trichloroacetamide by 100 g of N - [(tetrachloro-1,2,2,2) ethyl] o-chlorobenzamide (0.31 mole). 89 g (a yield of 94.7%) of N- [(2,2,2-trichloro-1 emino) ethyl] o-chlorobenzamide, a white solid with a melting point of 169-170 ° C., are obtained.

EXAMPLE No. 8 L Preparation of the compound of formula:

Cl

24 g of N- [2,2-dichloro-1 amino-1) ethyl] dichloroacetamide (0.1 mol) are dissolved in 300 ml of tetrahydrofuran (THF). 10.1 g of triethylamine (0.1 mole) are added. Maintaining the temperature at 20-25 ° C., 17.5 g of o-chlorobenzoyl chloride (0.1 mol) dissolved in 50 ml of THF are added with stirring over about 15 minutes. Then maintained for 1 hour with stirring while allowing to return to room temperature. The precipitate of triethylamine hydrochloride is filtered. The THF is separated by vacuum distillation. A brown solid is obtained which is recrystallized from a 50/50 carbon tetrachloride-hexane mixture. 15.3 g are thus obtained (ie a yield of 40.4%) of N - [(2,2-dichloroacetamido-1) ethyl] o-chlorobenzamide, melting point 179-180 ° C.

The N - [(2,2-dichloro-1 amino-1) ethyl] dichloroacetamide used as starting material can be prepared as indicated in Example 14.

EXAMPLE N ° 9 - Preparation of the compound of formula:

The procedure is as in Example 8, replacing the 17.5 g of o-chlorobenzoyl chloride with 11 g of isobutyryl chloride (0.103 mole). 17.7 g are thus obtained (ie a yield of 57.1%) of N - [(dichloro-2,2-isobutyramido-1) ethyl] dichloracetamide with melting point 189-190 ° C. EXAMPLE 10 - Preparation of the compound of formula

The procedure is as in Example B, replacing the 17.5 g of o-chlorobenzoyl chloride with 10 g of acryloyl chloride (0.11 mole). 12.8 g are thus obtained (ie a yield of 43.5%) of N - [(2,2-dichloro-1 acrylamido-1) ethyl] dichlcroacetamide.

EXAMPLE 11 - Preparation of the compound of formula:

6.4 g of dichloroacetamide (0.05 mole) are dissolved in 50 ml of THF. 7 g of triethylamine (0.07 mole) are added. Keeping the temperature at 0 ° C., 12.3 g of N - [(trifluoro-2,2,2 chloro-1) ethyl] dichloroacetamide (0.05 mol) dissolved in about 15 minutes are added with stirring. 20 ml of THF. Then stirred for three hours while allowing to return to room temperature. The triethylamine hydrochloride is filtered. THF is removed by vacuum distillation. 15 g (a yield of 89%) of N - [(2,2,2-trifluoro-dichloroacetamido-1) ethyl] dichloroacetamide are thus obtained in the form of a brown viscous liquid.

• On dissout dans 150 ml de benzène 19,2 g de dichloroacétamide (0,15 mole) et on ajoute, en 15 minutes environ, 22 g d'hydrate de fluoral (0,2 mole) et 1 ml d'acide sulfurique. On porte à reflux pendant 6 h sous agitation. Après refroidissement et filtration, on obtient 26,5 g de N-[(trifluoro-2,2,2 hydroxy-1) éthyl] dichloroacétamide (soit un rendement de 78 %), sous la forme d'un solide blanc de point de fusion 70-71°C.

The N- [(2,2,2-trifluoro-1 chloro-1) ethyl] dichloroacetamide used as starting material can be prepared as follows:

• 19.2 g of dichloroacetamide (0.15 mole) are dissolved in 150 ml of benzene and 22 g of fluorine hydrate (0.2 mole) and 1 ml of sulfuric acid are added over approximately 15 minutes. The mixture is brought to reflux for 6 h with stirring. After cooling and filtration, 26.5 g of N - [(2,2,2-trifluoro-1-hydroxy) ethyl] dichloroacetamide are obtained (ie a yield of 78%), in the form of a white solid with a point of melting 70-71 ° C.

5.5 g of N - [(2,2,2-trifluoro-1) ethyl] dichloroacetamide (0.025 mol) and 7.5 g of chloride are introduced into a 100 ml reactor. thionyl (0.06 mole). The mixture is refluxed for 3 hours, then 30 ml of hexane are added to facilitate precipitation during cooling. After filtration, nn obtains 4.4 g of N [(2,2,2-trifluoro-1,2 chloro-1) ethyl] dichloroacetamide (ie a yield of 72%), in the form of a white solid with melting point 54- 55 ° C.

EXAMPLE 12 - Preparation of the compound of formula

By operating as in Example 1, but by replacing the N - [(2,2,2-amino-trichloro-1) ethyl] formamide by the N - [(2,2,2-amino-trichloro-1) ethyl] acetamide, N - [(2,2-trichloro-2,2,2, dichloroacetamido-1) ethyl] acetamide is obtained, with a yield of 61.5%, of melting point 239-240 ° C.

The N - [(2,2,2-trichlora-1 amino-1) ethyl] acetamide used as starting material is prepared according to the method used to prepare the N - [(trichlbro-2,2,2 amino-1) ethyl] trichloroacetamide, but by replacing the 100 g of N - [(tetrachloro-1,2,2,2) ethyl] trichloroacetamide with 320 g of N - [(tetrachloro-1,2,2,2) ethyl] acetamide (1, 42 mole). The addition to THF saturated with ammonia is carried out in 1 h 45 '. 262 g of N - [(2,2,2-trichloro-1-amino) ethyl] acetamide are obtained (ie a yield of 89.6%), in the form of a white solid with melting point 134- 135 ° C.

EXAMPLE 13 - Preparation of the compound of formula:

By operating as in Example 0, but replacing the o-chlorobenzoyl chloride by the p-methoxybenzoyl chloride, the N - [(2-dichloro, 2 dichloroacetamido-1) ethyl] p-methoxybenzamide, mp 171-172 ° C.

EXAMPLE 14 - Preparation of the compound of formula:

64 g of dichloroacetamide (0.5 mol) are dissolved in 60 ml of benzene and 68 g of dichloroacetaldehyde (0.6 mol) and 1 ml of sulfuric acid are added over approximately 10 minutes. The mixture is refluxed for 5 hours and the solvent and the excess of dichloroacetaldehyde are evaporated in vacuo. 118 g of N - [(2,2-dichloro-1 hydroxy-1) ethyl] crude dichloroacetamide are thus obtained (ie a yield of 98%), in the form of a practically colorless viscous liquid.

'' 210 g of N - [(2,2-dichloro-1-hydroxy) ethyl] dichloroacetamide (0.87 mole) prepared as indicated above and 300 g of thionyl chloride are introduced into a 500 ml reactor, with stirring. (2.5 moles). We bring to reflux for 2 h 3D. 300 ml of hexane are added to facilitate precipitation during cooling. After filtration, 175 g of N - [(2,2,2-trichloro) ethyl] dichloroacetamide are obtained (ie a yield of 77.5 in the form of a white solid with melting point 77-78 ° C.

600 ml of THF are saturated with gaseous ammonia and this saturation is maintained for the duration of the following operation. Maintaining the temperature at 0 ° C., 130 g of N - [(2,2,2-trichloro) ethyl] dichloroacetamide (0.5 mol) prepared as indicated above are added with stirring over approximately 1 hour. The ammonium chloride formed is separated by filtration. THF is then evaporated in vacuo. 95.4 g of N - [(2,2-dichloro-1 amino) ethyl dichlornacetamide are thus obtained (i.e. a yield of 79.5%) under the form of a white solid with a melting point of 96-97 ° C. EXAMPLE 15 - Preparation of the compound of formula:

By operating as in Example 3, but replacing the dichloroacetamide and the N - [(tetrachloro-1,2,2,2) ethyl] dichloroacetamide by respectively the formamide and the N - [(1,2-trichloro, 2) ethyl] dichloroacetamide, N - [(2,2-dichloroacetamido-1) ethyl] formamide, with melting point 79-80 ° C., is obtained with a yield of 74.6%.

EXAMPLE N ° 16 - Preparation of the compound of formula:

By operating as in Example 3, but replacing the dichloroacetamide and the N - [(tetrachloro-1,2,2,2) ethyl] dichloroecetamide by acetamide and the N - [(1,2-trichloro, respectively, 2) ethyl] dichloroacetamide, N - [(2,2-dichloroacetamido-1) ethyl] acetamide, melting point 63-64 ° C., is obtained with a yield of 78%.

EXAMPLE No. 17 - Anditate activity of herbicides of the compounds according to the invention.

A soil, consisting of two parts by weight of clay and three parts by weight of sand, is spread in plastic trays of dimensions 18 x 12 x 5 cm. On this soil we sow, in 4 furrows of 0.5 cm deep, 10 corn seeds, variety "Sandrina", and 10 barley seeds, variety "Rika".

The seedlings thus produced are separated into 3 batches, each batch containing 5 trays. On the 1st batch spread a layer, 2 cm thick, of soil that has not undergone any treatment. On the 2nd batch spread a layer, 2 cm thick, of soil in which a naturally phytotoxic herbicide has been incorporated by careful mixing. corn but at the dose where it is applied. Finally, on the 3rd batch, spread a layer, 2 cm thick, of soil in which the same herbicide has been incorporated as for the 2nd batch, at the same dose, and an antidote product according to the invention.

For their incorporation into the soil, the herbicide and the antidote are formulated in the form of aqueous suspensions. The quantities of herbicide applied correspond to doses of herbicides of 5 kg and 10 kg / ha. The amounts of antidote product provided correspond to doses equal to one tenth of the doses of the herbicide, ie 0.5 and 1 kg ^g / ha. The herbicide used is EPTC or ethyl N, N-dipropyl thiolcarbamate. The antidote products tested are the compounds of Examples 1 to 15.

dans laquelle A désigne la taille moyenne des plants de mais dans les lots témoins non traités, B la taille moyenne des plants de mais dans les lots traités avec l'herbicide seul et C la taille moyenne des plants de mais dans les lots traités avec l'herbicide et le produit antidote. Une efficacité antidote égale à 0 correspond donc à C = B et une efficacité antidote égale à 100 correspond à C=A.The batches of trays, once treated, are placed in a greenhouse maintained at 20 ° C and at a humidity rate of 70%. 12 and 20 days after treatment (D + 12; D + 20), the batches are examined and the herbicidal efficacy of the "antidote + .herbicide" combination is determined on the one hand, and the efficacy on the other hand antidote for the compound according to the invention tested. The antidote E efficacy is evaluated by measuring the average height of the maize plants in the three batches. It is given by the formula:

in which A denotes the average size of the maize plants in the untreated control lots, B the average size of the maize plants in the lots treated with the herbicide alone and C the average size of the corn plants in the lots treated with l herbicide and antidote. An antidote efficiency equal to 0 therefore corresponds to C = B and an antidote efficiency equal to 100 corresponds to C = A.

It can be seen that, in all the tests carried out with the low-dose or high-dose “antidote + herbicide” associations, the barley, which is used here as reference weed plants, is 100% destroyed, which proves , that the herbicidal efficiency with respect to gramineae is not reduced by the products according to the invention.

The results concerning the antidote E efficacy are collated in the table on page 20.

It can be seen that the compounds of Examples 1, 3, 4, 9, 11 and 14, associated with the E.P.T.C., have a particularly marked antidote efficacy.

EXAMPLE 18 - Antidote activity of herbicide of the compound of Example 1.

In the present test, the product of Example 1 was tested according to the method described in the previous example, but by varying the dose of the antidote product relative to that of the associated herbicide (E P T C).

The herbicide was applied at a dose of 5 kg / ha and the product of Example 1 at the doses 0 kg / ha (tests with herbicide alone), 0.312 kg / ha, 0.625 kg / ha, 1.250 kg / ha and 2,500 kg / ha.

The ratings, carried out on day_D + 20, gave the results of the table below for the antidote E effectiveness:

This table shows that the antidote efficacy increases with the dose of the compound of Example 1 and that this compound does not exhibit phytotoxicity with respect to maize, even at the highest dose.

As for the herbicidal power of EPTC ^t against weeds (barley), it is not reduced by the increasing doses of antidote compound.

Claims (23)

1.- The compounds of formula:

in which R ₁ represents a dichloromethyl or trichloromethyl group, X ₁ represents a chlorine or fluorine atom, X ₂ represents a chlorine or fluorine atom, X ₃ represents a hydrogen, chlorine or fluorine atom, R ₂ represents an amino group NH ₂ or a group

represents a hydrogen atom that an alkyl, haloalkyl, alkenyl, haloalkenyl, arylalkyl, arylhaloalkyl, cycloalkyl, halocycloalkyl, alkoxyalkyl, haloalkoxyalkyl or aryl group, the latter optionally being substituted by one or two halogen atoms or by an alkyl group, alkoxy, nitro or haloalkyl. 2.- Compounds according to claim 1) characterized in that, in the definition of R ₃ , the alkyl, alkenyl, alkoxy chains of the alkyl, haloalkyl, alkenyl, haloakenyl, arylalkyl, arylhaloalkyl, alkoxyalkyl and haloalkoxyalkyl groups have 1 to 5 atoms of carbon, the cycloalkyl and halocycloalkyl groups have 3 to 6 carbon atoms, the haloalkyl, haloalkenyl, arylhaloalkyl, halocycloalkyl, haloalkoxyalkyl groups have 1 to 7 halogen atoms chosen from the chlorine, bromine or fluorine atoms, aryl and aryl denote phenyl and phenyl and the halogen substituent on the aryl group is a chlorine atom. 3.- Compounds according to claim 1, in which R ₂ is NH ₂ or a group

in which R ' ₃ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, a haloalkyl group having 1 to 5 carbon atoms and 1 to 7 halogen atoms or a phenyl group substituted by one or two chlorine atoms. 4.- Compounds according to claim 3) characterized in that R ₂ is an amino group NH ₂ or a formamido, acetamido, isobutyramido, acrylamido, dichloroacetamido, o-chlorobenzamido group. 5.- The compound N - [(2,2,2-trichloro-dichloroacetamido-1) ethyl] formamide. 6.- The compound N - [(2,2,2-trichloro-dichloroacetamido-1) ethyl] dichloroacetamide. 7.- The compound N - [(2,2-dichloro-isobutyramido-1) ethyl] dichloroacetamide 8.- The compound N - [(2,2,2-trifluoro-dichloroacetamido-1) ethyl] dichloroacetamide 9. A process for the preparation of the compounds defined in claim 1 in which R ₂ is an amino group, characterized in that a chlorinated derivative of formula is reacted:

in which R ₁ , X ₁ , X ₂ , X ₃ have the same meanings as in formula (I) with ammonia. 10.- Method as defined in claim 9 characterized in that the reaction is carried out in an inert solvent at a temperature between -30 ° C and + 30 ° C. 11.- Process for the preparation of the compounds defined in claim 1) in which R ₂ is a group

characterized in that an amino compound of the formula is reacted:

with an acid chloride of formula

X ₂ , X ₃ having in the formulas above the same meaning as in formula (I). 12.- Method as defined in claim 11, characterized in that the reaction is carried out in an inert solvent, at a temperature between -30 ° C and + 60 ° C and in the presence of an inorganic base or a tertiary amine. 13.- Application as antidotes of herbicides of the compounds defined in each of claims 1 to 8. 14.- Antidote compositions of herbicides containing 10% to 90% by weight of an antidote product, the complement to 100% consisting of inert additives suitable for agriculture, characterized in that the antidote product is a compound such as defined in each of claims 1 to 8. 15.- Herbicidal and antidote compositions of herbicides simultaneously containing 0.09% to 50% by weight of an antidote product and 1% to 90% by weight of a herbicide, the weight ratio of the antidote product being between 0.001 and 10 and the 100% complement herbicide consisting of inert additives suitable for agriculture, characterized in that the antidote product is a compound as defined in each of claims 1 to 8. 16.- Compositions according to claim 15 characterized in that the herbicide belongs to the family of thiolcarbamates. 17.- Compositions according to claim 16 characterized in that the herbicide is N, N-dipropyl thiolcarbamate ethyl. 18.- The compounds of formula:

in which X ₁ , X ₂ , X ₃ are as defined in claim 1 and R ₃ has the same meanings as in the claimed cation 1 except hydrogen. 19.- Compounds as defined in claim 18, characterized in that X ₁ , X ₂ and X ₃ are chlorine atoms and R ₃ is a monochloromethyl, trichloromethyl, pentachloro + 1,2,3,3,3 group, propyl, trifluoromethyl, methyl, o-chlorophenyl, p-chlorophenyl, p-methylphenyl, m-trifluoroethylphenyl, 2,4-dichloro-phenyl or 3,4-dicmoro-phenyl. 20.- The compounds of formula:

in which X ₁ , X ₂ , X ₃ are as defined in claim 1, Y is a chlorine atom or a hydroxy group, Z is an n-heptyl, n-nonyl, trifluoromethyl, 1,2-pentachloro group, 3,3,3 propyl, p-methylphen le, m-trifluoromethylphenyl and may also be, when X ₁ , X ₂ , X ₃ are not simultaneously chlorine atoms, a dichloromethyl group. 21.- Process for the preparation of omposés defined in claim 1) in which R ₂ is a group

characterized in that an amino compound of the formula:

with an acid chloride the formula

X ₂ , X ₃ having in the formulas above the same meaning as in formula (I). 22.- Process for the preparation of the compounds defined in claim 1) Which R ₂ is a group

characterized in that one reacts a derivative of formula:

with an amide of formula

having in the formulas above the same meaning as in formula (I). 23.- Process for the preparation of the compounds defined in claim 1) in which R ₂ is a group

characterized in that the nn reacts a chlorinated derivative of formula:

with an amide of formula R ₁ -C-NH ₂ , R ₁ , R ₃ , X ₁ , X ₂ , X ₃ having in the formulas above the same meaning as in formula (I). The compounds of formula (I)

in which R ₁ represents a group, dichloromethyl or trichloromethyl, X ₁ represents a chlorine or fluorine atom, X ₂ represents a chlorine or fluorine atom, X3 represents a hydrogen, chlorine or fluorine atom, R ₂ represents an amino group NH ₂ or a group

in which R3 represents a hydrogen atom or an alkyl, halcalkyl, alkenyl, halcalkenyl, arylalkyl, arylhaloalkyl, cycloalkyl, halocycloalkyl, alkoxyalkyl, haloalkoxyalkyl or aryl group, the latter optionally being substituted by one or two halogen atoms or by a alkyl, alkoxy, nitro or haloalkyl group are described. These compounds are antidotes to herbicides. They can be used more especially in combination with thkicarbamates. These compounds are prepared by reaction of compounds of formula II

in which R ₄ represents the radical R ₁ and R ₂ (R ₁ and R ₂ have the same meanings as in formula I), and R ₅ is a chlorine atom with ammonia or the appropriate amide or by acylation with an appropriate acid chloride of a compound of formula (II) in which _R4 has the same meaning as above and R ₅ is NH ₂ . Intermediate compounds of formula (II) in which R ₅ is a chlorine atom or a hydroxy radical and R ₄ has the meaning above, are also described. Provided that R ₅ is hydrox ^y, they are prepared by reacting an amide of a halogenated aldehyde.