IL31158A - N-3-bromo-4-chlorophenyl-n'-methoxy-n'-methyl urea,its preparation and its use as a herbicide - Google Patents

Description

31158/2 N-3-Bromo-4-chlorophenyl-lJ* nethoxy-N'-methyl urea, Its preparation, and its use ae a herbicide CIBA-GEIGT A,0 CJ 29363 The present invention provides the compound of formula which possesses herbicidal properties.

The present invention also provides a herbicidal preparation, which comprises as active ingredient a compound of the formula (I) together with a suitable carrier.

The preparation may contain one or more of the following additives: a solvent, a diluent, a dispersing agent, an emulsifier, an adhesive, a thickener as well as other known herbicides.

When larger quantities of the preparations of the invention are used it acts as a total herbicide and when used in smaller quantities, as a selectively active herbicide. It should be particularly emphasized that grass-like and broad-leaved weeds are destroyed whilst cotton, grain, maize and soya tolerate the preparation very well. The preparation can, however, also exert other inhibiting influences on plant growth. Thus it can, for example, be employed for accelerating ripening by premature drying-out, for example, in the case of potato plants, and also for the prevention of setting of fruit, retardation of flowering and lengthening the storage stability of harvest products. Furthermore, the use of the growth-inhibiting preparation not only leads to a increase in yield by suppressing the weeds, but also by the fact that this preparation counteracts influences which can stimulate the growth of the culture plants in an undesired direction, for example, high temperature or copious application of fertilizer. On the other hand, the use of the herbicidal preparation for the eradication 31158/2 ¾ - 3 - point of view, also be useful where, the selectivity of the preparation is not sufficient to exclude a reduction in yield of the plants which are being grown, at the time of its use..

The active substanoe of the above-mentioned formula (I) or the preparations which contain such an active substance also have a lethal effect on molluscs, especially gastropodes, water pests, for example, algae, sedenteria, proliferating water plants and slime bacteria.

Used in concentrations which do not have any phytotoxio side-effects, the preparations according to the invention can also be used for combating phytopathogenio bacteria- and fungi.

The active substances of formula (I), used in significantly smaller amounts than those necessary for herbicidal use, can also be employed in agents for combating plant-pathogenio nematodes (Turbatrix aceti, Meloidogyne aremaria, Moloidogyne javanica, Heterodera schachtii, Xiphenema index, and numerous others).

The high selectivity of the herbicidal activity of the compound of formula I, according to the invention, in cultures of wheat, barley,, maize and rice, is not exhibited by its 3,4-dichlorophenyl analogue ("Linuron") known from Israeli Patents NOB, 14367 and 14560 or by the 3,4-dibromophenyl analogue known from the latter patent. When these known compounds are used in the same amounts as the active compound I, .the" dichloro analogue acts as a total herbicide, while the dibrorao analogue shows no herbicidal activity. In this respect the compound I according to the invention is also superior to other knwon compounds of similar structure, e.g. the 3-chloro-4-bromo-phenyl isomer known from U.S. Patent 3» 288,851, the N-(3-chloro-4-bromophenyi)-N' ,Ν' -dimethyl-urea known from the "same source and the N- -bromo -chlorophenylJ-N' ,Ν' -dimethyl urea known from French Patent No. 1 0 .

The preparation according to the invention for influencing plant growth and for combating weeds may be employed in the form of solutions, emulsions, suspensions, granules or dusting agents. The form in which they are used depends entirely on the intended purpose. It is merely necessary that in all forms of use it is possible to distribute the active substance finely. The effect can, especially in the case of the total destruction of plants, in premature drying-out as well as'in defoliation, be reinforced by the use of carriers, which are in themselves phytotoxic, ' for example,' high-boiling mineral oil fractions or chlorinated hydrocarbons; on the other hand the selectivity of growth inhibition generally manifests itself ■ more distinctly when using carriers which are inert towards plants, for example, in the selective combating of weeds.

Substances that may be used in the manufacture of solutions are solvents, especially alcohols, for example, ethyl or isopropyl alcohol, ketones for example, acetone or cyclohexanone , aliphatic hydrocarbons, for example, kerosene and cyclic hydrocarbons, for example, benzene, toluene, xylene, tetrahydronaphthalene and alkylated naphthalenes, and also chlorinated hydrocarbons, for example, teirachlorethane and ethylene chloride, and finally also mineral and vegetable oils or mixtures of the above-mentioned substances.

The aqueous forms of the preparation are preferably emulsions and dispersions . The substances are homogenised in water as such or in one of the above-mentioned solvents, preferably by means of wetting agents or dispersing agents.

As examples of cationic emulsifiers or dispersing agents there may be mentioned quaternary ammonium compounds. As anionic materials, there may be used; soap, soft soap, aliphatic long-chain sulphuric acid monoesters, aliphatic aromatic sulphonic acids and long-chain alkoxy-acetic acids. As examples of non-ionic substances, there may be used: polyethylene glycol , ethers of1 fatty alcohols and ethylene oxide condensation products of p-tert .-alkylphenols. On the other hand, it is also possible to manufacture concentrates consisting of the active substance, emulsifier or dispersing agent and solvent if desired, these concentrates being suitable for dilution with water before use.

Dusting agents can preferably be manufactured by mixing or joint grinding of the active substance and a solid carrier.

Possible carriers that may be used are: talc, diatomaceous earth, kaolin, bentonite, The various forms in which the preparations are used can in the usual manner be improved if necessary by adding substances which aid the distribution, the adhesion, the rain resistance and where appropriate the penetrating power, for example, fatty acids, resins, wetting agents, glue, casein or alginates. Equally, their biological action can be broadened by adding substances having bactericidal or fungicidal properties or properties which also influence plant growth, as well as by adding fertilisers.

The active substance of formula (I) can, in the preparations according to the invention, be directly combined with other herbicidally active or fungicidally or nematocidally active compounds. The following are, for example, possible components for combination in the manufacture of herbicidally active agents: N-phenyl-N' ,N'-dimethylurea, N-p-chlorophenyl-N' ,Ν'-dimethylurea, N-3, 4-dichlorophenyl-N' ,Ν' -dimethylurea, N-3,4-dichlorophenyl-H1 -methoxy-K ' -methylurea, N~4-bromo-3-chloro-phenyl-N'-methoxy-N'-methylurea, trichloracetic acid, 2,6-dichlorobenzonitrile, 2,3,6-trichlorobenzoic acid, 2,4-D, 2,4,5-T, MCPB, MCPP, isopropylcarbanilate, isopropyl-3-chlorocarbanilafce, N-3-chlorophenylcarbamic acid-4'-chlorobutin-2-yl-l-ester, 2,3, 6-trichlorophenylacetic acid and salts, 2-chlorodiallylacetamide, 2-chloro-4, 6-bis-ethylamino-s-triazine, 2-methoxy-4, 6-bis-ethylamino-s-triazine, 2-azido-4-methyl-thio-6-isopropylaminotriazine, disodium monomethylarsenate salt, various arsenites, sodium metaborate, sodium chlorate and sulphamic acid.

The active substance of formula (I) can also be used in the form of its complexes or salts with halogenocarboxylic acids, for example, described in US Patent No. 2,782,112 or in the form of its sulphonic acid complexes, such as are described in US Patent No. 2,801,911 for monurone and diurone. It is also possible to use complexes with sodium borotetra-fluoride .

The active substance of formula (I) has not hitherto been described in the literature.

The compound of formula (I) can be manufactured by reacting a compound of formula with a compound of formula R in which two formulae Y represents a chlorine atom or a hydrogen atom X and Z represent residues which are capable of forming the urea grouping whilst undergoing addition or condensation, and R represents a methyl group or a hydrogen atom, and in the latter case replacing the hydrogen in the resulting urea of formula Br by the methyl group with the aid of methylating agents and, if Y represents hydrogen, replacing the latter by the chlorine atom with the aid of chlorinating agents.

A possible procedure according to the process described, is to react 4-chloro-3-bromophenylisocyanate with N,0-dimethylhydroxylamine; instead of the isocyanate one of the following groupings can. be used for the reaction: -X=NH-COOR' (acylation), R1 = alkyl, aryl; -X=NH-COHal (acylation); -X= -NH-CO-NHg (trans-amidisation) ; or -X= -N=C=S, whereupon a corresponding thiourea is produced which is converted to the desired urea by subsequent replacement of the sulfur atom by the oxygen atom, for example, with the aid of HgO.

Instead of the N, O-dimethylhydroxylamine, it is possible to use a non-methylated or an N-methylated or O-met.hyla-ted hydroxylamine and, after completion of the urea formation, to carry out the post-alkylation, for example, by using dime-thylsulphate or methylhalide . This reaction is carried out in a relatively strongly alkaline medium. This process is d'es- . cribed in detail in German Published Specification 1,196,639 so that it is not necessary to deal herewith the method in more detail.

The chlorination can be carried out in chlor,o-benzene or glacial acetic acid/sodium acetate, also in methylene chloride, dichloroethylene, dichlorethane and similar chlorinated hydrocarbons.

The following Examples illustrate the invention: Example 1 a) 64.5 g of 3-bromo-4-chloraniliniLwere reactjjis, in acetic acid- heating with further introduction of phosgene, whereby amine hydrochloride formed is expelled and the carbamic acid chloride is converted into the isocyanate). The purification of the isocyanate was carried out by distillation, b) 46·5 g of 3-bromo-4-chlorophenylisocyanate were rapidly added to a solution of 16 g of 8 /0 pure 0,N-dimethylhydroxyl-amine in 100 ccs of benzene in an Erlenmeyer flask. The product crystallised out during the strongly exothermic reaction. The crystal mass was recrystallised from benzene/petroleum ether. 50.5 g (= 86.5$ of the theoretical yield) of urea of formula (I), melting at 102 to 104°C, are obtained.

Example 2 Dusting; Agents Equal parts of the active substance according to the invention and precipitated silica are finely ground together. Dusting agents, which preferably contain 1 to 6<> of active substance, can be manufactured therefrom by mixing with kaolin or talc.

Spraying Powders In order to manufacture a spraying powder, the following components are, for example, mixed and finely ground: 0 parts of active substance according to the present invention, 20 parts of Hisil (highly adsorptive silica), 25 parts of Bolus alba (kaolin), 3· parts of a reaction product of p-tert .octyl-phenol and ethylene oxide and 1.5 parts of (sodium 1-benzyl-2--stearyl-benzimidazole-6, 3 ' -disulphonate) .

Emulsion Concentrate The easily soluble active substance can also be formulated as an emulsion concentrate in accordance with the following instructions: 20 parts of active substance, 70 parts of xylene and 10 parts of a mixture of a reaction product of an alkyl-phenol with ethylene oxide and calcium dodecylbenzenesulphonate, are mixed. On dilution to the desired concentration with water, a sprayable emulsion is produced.

Example 5 The following plant varieties were sown in earthenware pots in a greenhous: Triticu-m, Hordeum, Avena, Zea, Oryza, Bigitaria, Sorghum, Panicum, Poa, Alopecurus, Cyperus reg., Beta, Galium, Calendula, Chrysanthemum, Linum, Brassica, Ipomoea, Daucus, soja and cotton.

The test was carried out in the post-emergence process using amounts of 1,2 and 3 kg/ha, and in the pre-emergence process using amounts of 3,6 and 9 kg active substance/ha.

Post-emergent Effect The treatment was carried out 12 days after sowing, in the cotyledon to 1st foliage leaf stage of the various varieties.. The evaluation took place 18 days after treatment.

Pre-emergent Effect The treatment was carried out 1 day after sowing, and the evaluation 21 days after treatment.

The results are summarised in the table below: (Rating: 0 = no effect, as in control. 9 = plants completely killed).

Kind of Post-emergence Pre-emergence.-"^ kg active substance/ha kg active substance/ha 1 2 3 3 6 9 Triticum 3 5 8 7 7 8 Hordeum 3 4 9 4 5 5 Avena 3 8 6 6 7 8 Zea 4 4 Kind of Post-emergence Pre-emergence plant I £g active substance/ha kg active substance/ha 1 2 3 3 6 9 Digitaria 9 9 9 9 9 9 Sorghum 8 9 9 9 9 9 Panicum . 9 9 9 9 9 9 Poa 9 9 9 9 9 9 Alopecurus .. 5 8 8 7 9 9 Cyperus veg. 4 4 5 4 4 4 Cynodon veg. 4 4 8 - - - Beta 9 9 9 9 9 9 Salium 9 9 9 9 9 9 Calendula 9 9 9 9 9 9 Chrysanthemum 6 7 9 9 9 9 Linum 9 9 9 9 9 9 Brassica 9 9 9 9 9 9 Ipomoea 6 9 9 9 9 9 Daucus 1 2 4 2 2 2 Soja 8 9 9 6 7 7 Cotton 8 9 9 2 3 3 - = not tested Comments: The active substance of formula (I) shows a strong effect against grass-like and broad-leaved weeds in the pre -emergence process, whilst cotton is spared even when using the high quantity of 9 kg of active substance/ha. On the other hand, the post-emergent treatment is more advisable for wheat, barley, oats and maize. culture p ants n an undesired direction, for example, high temperature or copious application of fertilizer. On the other hand, the use of the herbicidal preparation for the eradicatio 31158/2 N-3-Bromo«- -chlorophenyl-N*-mothoxy-N*-methyl urea, its preparation, and its sq as a herbicide CIBA-GEIGY A,0, Ci 29363

Claims (2)

1. WHAT WE CLAIM IS: 1. A herbicidal preparation which as the active component contains the compound of formula as well as at least one of the following additives: solvents, diluents, dispersing agents, emulsifiers, adhesives, thickeners-, wetting agents as well as other herbicides.

2. Process for the manufacture of the compound defined in claim 1, characterised in that a compound of formula is reacted with a compound of formula In which formulae Y denotes chlorine or hydro.gen, X and Z denote residues which are capable of forming the urea grouping whilst undergoing addition or condensation, and R denotes methyl or hydrogen, and that in the 'latter case the hydrogen in the resulting urea of formula is replaced by the methyl group with the aid of methylating agents such as dimethylsulfate' or methyl halide and that if Y denotes hydrogen the latter is replaced by the chlorine V» 4. A method for combating weeds in maize, cotton and grain cultures which comprises applying to the cultures the compound of the formula