GB2166955A - Preparation and herbicidal compositions of N,N-diallyl-2,6-dinitro-4-trifluoromethyl aniline - Google Patents

Abstract

A herbicidal composition, particularly for selective control of monocotyledonous weeds in maize, comprises 0.1-75% by weight of N,N-diallyl-2,6-dinitro-4-trifluoromethyl-aniline of the Formula I <IMAGE> in admixture with 25-99.9% by weight of carriers, additives and other auxiliary agents. The N,N-diallyl-2,6-dinitro-4-trifluoromethyl-aniline is prepared by reacting 2,6-dinitro-4-trifluoromethyl- chloro-benzene of the Formula II <IMAGE> with diallyl-amine of the Formula III [CH2=CH-CH2]2-NH [III] The composition of the present invention is particularly suitable for pre-planting application by being incorporated into the soil prior to planting.

Description

SPECIFICATION Herbicidal Composition and Process for the Preparation of the Active Ingredient This invention relates to herbicidal compositions and a process for the preparation of the active ingredient. More particularly it is concerned with herbicidal compositions for the selective control of monocotyledonous weeds of maize and a process for the preparation of the active ingredient.

According to an aspect of the present invention there are provided herbicidal compositions for the selective control of monocotyledonous weeds on maize comprising 0.175% by weight of N,N-díallyl-2,6- dinitro-4-trifluoromethylaniline of the Formula I

in admixture with 2599.9% by weight of usual carriers, additives and other auxiliary agents.

According to a further aspect of the present invention there is provided a process for the preparation of N,N-diallyl-2,6-dinitro-4-trifluoromethylaniiine of the Formula I which comprises reacting 2,6-dinitro-4trifluoromethyl-chloro-benzene of the Formula II

with diallyl amine of the Formula Ill (CH2=CH-CH2)2-NH (III) The compositions of the present invention may be preferably used in a preplanting manner i.e. by incorporating into the soil prior to planting.

There are known herbicidal active ingredients suitable for preplanting selective weed control of maize by applying into the soil. Thus N,N-di-n-propyl-S-ethyl-thiourea (EPTC) being extremely volatile and liable to photochemical decomposition, S-ethyl-diisobutyl-thio-carbamate (Butylat) and S-propyl-N,N-di-propylthiourea (Vernolat) can be mentioned. The main disadvantage of the said compounds is that in order to achieve proper selectivity they are to be admixed with an antidotum in a suitable ratio and can be applied onto the soil only in the form of the said mixture otherwise substantial damages of maize would occur. A further drawback resides in the fact that the effective dose is a rather high value, at least 5 kg of active substance material pro hectare.

It is also to known to add compounds to the composition which have a structure chemically more related to the active ingredient and possess a higher activity than thiocarbamates. Thus in US patent No.

3.257.190 N,N-di-n-propyl-2,6-dinitro-4-trifluoromethyl-aniline (trifluraline) or N-ethyl-N-n-butyl-2,6-dinitro 4-trTfluoromethyl-aniline (benfluralin) are disclosed. Although the said compounds are more active than thiocarbamates their use is accompanied by the disadvantage that the effective dose on pre-emergent application is six to eight times higher than on pre-planting use. This fact is supported by practical experiments and the disclosure of the US patent referred to. Thus in weed-control of peanut on sand and adobe soil the effective dosage in pre-planting application amounts to 0.5--0.75 pounds/acre and in pre-emergent use to 4 pounds/acre, respectively. On loamy-adobe and clay soil the corresponding values amount to 0.751 pound/acre and 6 pounds/acre, respectively.According to further practical experiments in post-emergent application suitable weed control can not be achieved even by applying the composition in a dosage being several times higher than the efficient pre-emergent dose. According to prior art and hitherto known data N,N-disubstituted-2,6-dinitro-4-trifluoromethyl-aniline derivatives are unsuitable for weed control in maize when applied into the soil because the dosage being effective for weed control causes considerable damages of maize.

Summarized it can be declared that the most expedient mode of application of N,N-disubstituted-2,6 dinitro4-trifluoromethyl-anilines (incorporation into the soil because of the high volatility and photochemical decomposition) which readily works on sun-flower, soya and other cultures, is completely insuitable for weed-control in maize as a result of the sensitivity of maize.

Further efforts were made to use members of the said compound-group as antidotum in maize culture, however, without any result.

According to Hungarian patent No. 169,865 the simultaneous use of N,N-di-n-propyl-2,6-dinitro-4trifluoromethyl-aniline and 3-methylthio-4-amino-6-tert.butyl-1,2,4-triazin-5-one led to promising results but only in soya culture.

It is the object of the present invention to make N,N-disubstituted-2,6-dinitro-4-trifluoromethyl-anilines suitable forthe selective pre-planting weed control of maize under preserving the advantageous properties of the said compound-group being different from the activity of other active ingredients (rapid decomposition in the soil, relatively lower doses etc).

In order to achieve the said object a large number of glasshouse, small plot and large parcel experiments have been carried out whereby particularly large attention has been devoted to combinations having preferable synergistic effect.

It has been found in a surprising manner that the desired advantageous effect and the object of the present invention can be achieved by a composition comprising a single active ingredient rather than by means of combinations of more active ingredients.

The composition of the present invention comprises N,N-diallyl-2,6-dinitro-4-trifluoromethyl-aniline as active ingredient.

Although a large number of various N,N-disubstituted-2,6-dinitro-4-trifluoromethyl-anilines has been tested it has been found that only the compound of the Formula I possesses the outstanding activity and selectivity and this compound is highly superior to chemically strictly related derivatives. Thus the compound of the Formula I is suitable for pre-planting superselective weed control of maize by incorporating a composition comprising the said compound into the soil in very low doses.The N,N-diallyl-2,6-dinitro-4-trifluoromethyl-aniline exhibits an outstanding new effect, as compared to the structurally most related known N,N-disubstituted-2,6-dinitro-4-trifluoromethyl-anilines and when applied into the soil in a dose of 0.81 kg of active ingredient per hectare it is highly suitably for the selective control of a wide range of weeds without causing any substantial damages of maize.

According to a further feature of the present invention there is provided a process for the preparation of N,N-diallyl-2,6-dinitro-4-trifluoromethyl-aniline of the Formula I which comprises reacting the 2,6-dinitro-4 trifluoromothyl-chloro-benzene of the Formula II with diallyl amine of the Formula Ill.

The reaction may preferably be carried out in benzene as medium. When the reaction is completed, the solvent and the eventual excess of diallyl amine are removed by distillation in vacuo and the distillation residue is recrystallized twice from ethanol.

According to the above method further structurally related N,N-disubstituted-2,6-dinitro-4trifluoromethyl-aniline derivatives can also be prepared by replacing allyl amine by the corresponding secondary alkyl or alkenyl amino.

The composition of the present invention comprises as active ingredient 0.175% by weight of N,N-diallyl-2,6-dinitrn4-trifluornmethyl-anili no of the Formula I in admixture with 2599.9% by.weight of usual carriers, additives and auxiliary agents. The active ingredient may be formulated in the form of usual herbicides and the actual form depends on the circumstances of application. The composition of the present invention may be in the form of an aqueous suspe;.rion, concentrate, emulsifiable concentrate (with water), granules etc.

The compositions may contain solid carriers or liquid diluents. As liquid diluent e.g. polar or apolar solvents (e.g. water, aliphatic and aromatic alcohols and polyols, esters, aliphatic and aromatic ketones, aliphatic and aromatic hydrocarbons, chloro substituted aliphatic and aromatic hydrocarbons etc.) may be used. As solid carrier e.g. minerals (such as silicic acid, China-clay, caoline, bentonite, dolomite, diatomaceous earth) or synthetic materials (e.g. silicic acid derivatives, precipitated calcium ca rbonate) or materials of vegetable origin (e.g. wood-flour) may be used.

The compositions of the present invention may also comprise anionic and/or non-ionic surfactants, wetting and dispersing agents, e.g. the sulfonic acid sodium salt of a condensation product of cresol and formaldehyde, ethoxylated nonyl-phenol, phosphate ester of ethoxylated nonyl phenol, a condensation product of ethylene oxide and propylene oxide, an alkyl phenyl ether, lauryl alcohol sulfonate, a sodium or ammonium salt of lignine sulfonic acid etc. The compositions may comprise further additives as well, e.g.

adhesion improving agents, additives regulating viScosity, anti-freezing agents etc.

The advantage of the compositions of the present invention is that they are suitable for the pre-planting selective control of monocotyledonous weeds of maize when applied in very low doses into the soil without causing any substantial damages to maize. Thus the compositions of the present invention are on one hand economical because of the low dosage while on the other they are advantageous from the point of view of environmental pollution as well. The relatively rapid decomposition of the active ingredient enables an expedient selection of rotation of crops, thus the exclusive monocultured production of maize can be avoided.

Further details of the present invention are to be found in the following Examples without limiting the scope of protection ofthe said Examples.

EXAMPLE 1 N,N-diallyl-2,6-dinitro-4-trifluoromethyl-aniline Into a 3000 litres enamelled autoclave 700 kg (2.69 kilomoles) of 4-chloro-3,5-dinitro-benzotrifluoride and 1286 kg (about 14901) or xyleneareweighed in.Tothemixture252kg (about 3171,2.59 kilomoles) of diallyl amine and thereafter 34 kg (about 21.5 1,0.26 kilomoles) of 75% phosphoric acid are added under stirring at such a rate that the temperature of the reaction mixture should not exceed 80 C.760830 kg (650--710 1, 2.85--3.11 kilomoles) of a 15% sodium hydroxide solution are added at a constant rate whereupon the reaction mixture is stirred for a further period of 2 hours. Thus 858 kg of N,N-diallyl-2,6dinitro-4-trifluoromethyl-aniline are obtained in a 40% by weight xylene solution.

EXAMPLE 2 Preparation of Compositions Comprising N,N-diallyl-2,6-dinitro-4-trifluoromethyl-aniline as Active Ingredient (a) Aqueous suspension concentrates The composition of the said concentrates is disclosed in Table 1.

TABLE 1 Composition g/l Component 300 g/l 500 g/l Technical grade active ingredient 306 510 (purity 98%) Ethylene glycol (anti-freezer) 100 80 Tensiofix XN6 (ethoxylated 40 nonylphenol+phosphate ester of ethoxylated nonyl phenol dispersing agent) Tensiofix B7453 (calcium 30 dodecyl benzene sulfonate+ condensation product of nonyl phenol with ethylene oxide+ propylene oxide) Hoe S1494 (sulfonic acid - 70 sodium salt of a condensation product of cresol and formaldehyde) Rhodopol 23 (xanthane gum type 2 1 polysaccharido viscosity modifying additive) Silicon SRE (silicon oil, 5 5 aqueous emulsion) antifoam additive lon-exchanged water ad 1 liter 1 liter (b) Emulsifiable concentrates The composition of the said emulsifiable concentrates is disclosed in Table 2.

TABLE 2 Composition, g/l Component 1 g/l 250 9/l 300 g/l 600 g/l Technical grade active 1.02 255 306 612 ingredient (purity 98%) Tensiofix B7453 (calcium 20 40 50 dodecyl benzene sulfonate and a condensation product of nonyl phenol with ethylene oxide+propylene oxide Tensiofix 87438 - 30 50 (calcium dodecyl benzene sulfonate and a condensation product of nonyl phenol with ethylene oxide+ propylene oxide) Tensiofix MS - - - 60 (calcium dodecyl benzene sulfonate+ethoxylated castor oil) Tensiofix LS 20 10 - 40 (calcium dodecyl benzene sulfonate and ethoxylated castor oil) Xylene (solvent) ad 1 1 1 1 1 I - Cyclohexanone (solvent) ad - - - 11 (c) Granules The composition of the granules is set forth in the following Table 3.

TABLE 3 Composition at the Beginning of Manufacture Component 0.1% 5% 10% by weight Technical grade active ingredient 0.1 4.5 8.3 (purity 98%) Acetone (solvent) 2 10 20 Tensiofix LS (calcium dodecyl 0.5 0.5 0.5 benzene sulfonate+ethoxylated castor oil) Pearlsiliceousearth (granuiate 100 100 100 carrier additive) ad =the acetone evaporates in the course of the manufacturing procedure and therefore it does not figure in the final composition of the granules EXAMPLE 3 Biological Testing of Compositions Comprising N,N4iallyl-2,6-dinitro-4-trifluoromethyl-aniline as Active Ingredient Well-cultivated medium-heavy adobe soil is sprayed with 25% emulsifiable concentrate (EC), 500 g/l aqueous suspension concentrate (FW) and 5% granule (G) comprising as active ingredient a N,Ndisubstituted 2,6-dinitro-4-trifluoromethyl-aniline derivative at a dose rate of 0.05, 0.1, 0.2, 0.4, 0.8, 1.6, 3.2 and 6.4 kg of active ingredient/hectare, respectively; 20 m2 plots are sprayed in 5 replicates. After spraying the compositions are immediately worked into the soil at a depth of 58cm whereupon maize is planted at a depth of 5 cm and barnyard grass (Echinochloa cruss-galli) at a depth of 1-2 cm.

The above test is carried out parallelly by pre-emergent treatment, too.

The test is evaluated on the 20th day after planting. The phytotoxical threshold values (kg of active ingredient (ha) are determined for maize and barnyard grass) and are determined both for the pre-planting and pre-emergent treatments.The data-relating to maize are disclosed in Table 4 and the results obtained for barnyard grass are set forth in Table 5.

The following active ingredients are used.

1 =N,N-di-n-propyl-2,6-dinitro-4-trifluoromethyl-anilino 2= N,N-di-chloroethyl-2,6-dinitro-4-trifluoromethyl-aniline 3= N-butyl-N-ethyl-2,6-dinitrn-44rifluornmethyl-aniline 4= N-ethyl-N-(2-methyl-propenyl )-2,6-dinitro-4trifluornmethyl-aniIino 5=N-propyl-N-(2-methyl-propenyl)-2,6-dinitro-44rifluoromethyl-aniline 6= N-propyl-N-chloroethyl-2,6-di nitro-4-trifluoromethyl-an iline 7= N,N-diallyl-2,6-dinitro-4trifluoromethyl-aniline The data disclosed in the Tables are the averages of five replicates.

TABLE 4 Phytotoxicity Threshold Values on Maize, Kg/Ha Test Pre-Planting Method Pro-Emergent Method Compound No. EC FW G EC FW G 1 0.1 0.1 0.1 0.4 0.5 0.5 2 0.3 0.3 0.3 2.0 2.1 2.1 3 0.1 0.1 0.1 0.8 0.9 0.8 4 0.3 0.3 0.2 1.7 1.8 1.8 5 0.3 0.3 0.3 2.1 2.2 2.3 6 0.3 0.3 0.3 2.0 2.0 2.0 7 1.3 1.4 1.5 1.9 2.0 2.1 TABLE 5 Phytotoxicity Threshold Values on Maize, Kg/Ha Test Pre-Planting Method Pre-Emergent Method Compound No.EC FW G EC FW G 1 0.2 0.2 0.2 1.1 1.1 1.4 2 0.3 0.3 0.3 2.5 2.6 2.7 3 0.1 0.1 0.1 1.9 2.0 2.0 4 0.2 0.3 0.3 0.9 1.0 1.2 5 0.2 0.3 0.3 1.0 1.1 1.2 6 0.3 0.3 0.3 2.3 2.4 2.4 7 0.2 0.2 0.3 2.2 2.3 2.1 It appears from the above Tables that in barnyard grass the efficiency of pre-planting treatment is about five to twenty times higher than that of pre-emergent method of application. Itcan also be seen that in maize the phytotoxical threshold value obtained on pre-emergent treatment is four to eight times lower than on pre-planting application with the exception of N,N-diallyl-2,6-dinitro-4-trifluoro-methyl-aniline of the present invention (No.7) which shows a high selectivity in both methods of application.Thus the difference of sensitivity obtained in using the above two methods does not even reach the value of 1.5.

By using active ingredients Nos. 1--6 the selectivity ratio is approximately 1.

phytotoxical dose on maize Selectivity ratio= phytotoxical dose on barnyard grass Thus treatment with compositions comprising test compounds Nos. 1-6 with doses suitable for weed control causes damages of maize.

On the other hand in the case of N,N-diallyl-2,6-dinitro-4-trifluoromethyl-aniline of the Formula I (Compound No 7) being structurally closely related to known compounds Nos. 1-6 the dose which is damaging to maize is about five to seven times hig her than the dose required for control of the barnyard grass. It also appears from the above Tables that there is no significant difference in the results obtained with various formulation types.

Claims (2)

1. Herbicidai composition, particularly for selective control of monocotyledonous weeds in maize comprising 0.175% by weight of N,N-diallyl-2,6-dinitro-4-trifluoromethyl-aniline of the Formula I

in admixture with 2599.9% by weight of usual carriers, additives and other auxiliary agents.

2. Process for the preparation of N,N-diallyl-2,6-dinitro-4-trifluoromethyl-aniline of the Formula I which comprises reacting 2,6-dinitro-4-trifluoromethyl-chloro-benzene of the Formula II

with diallyl amine ofthe Formula Ill (CH2=CH-CH2)2-NH (III)