DE2724677A1 - 2-Benzyloxy-methyl-tetra:hydro-furan used as a herbicide - esp. against grassy weeds in crops such as beet, cotton, maize or rice - Google Patents

Abstract

New herbicidal agents contain 2-benzyloxymethyl-tetrahydrofuran of the formula (I). Depending on the rate of application, (I) can be used as a total or selective herbicide. It is particularly useful for combatting grassy weeds in a wide range of crop plants, esp. beet, soya beans, beans, cotton, rape, groundnuts, maize and rice. (I) also has fungicidal and insecticidal activity. At a rate of 1.5 kg/ha pre-emergence, (I) is without effect on sugar beet, soya beans, maize, and rape, but gives 100% eradication of Echinochloa crus-galli, 60% eradication of Alopecurus mysosuroides and 90% eradication of Poa annua. (I) may be made up into conventional formulations such as solutions, emulsions, suspensions, powders, pastes and granulates.

Description

Herbicidal agent

The present invention relates to the use of the known 2-benzyloxymethyl-tetrahydrofuran as a herbicidal, in particular selective herbicidal agent.

It has already become known that chloroacetanilides such as 2-ethyl-6-methyl-N- (l'-methyl-2'-methoxyethyl) chloroacetanilide, as herbicides, in particular for combating grass-like weeds can be used (compare DT-OS 2 328 340). These compounds are in their selectivity, however not always satisfactory.

It has been found that the known 2-benzyloxymethyl-tetrahydrofuran of the formula has good herbicidal, especially selective herbicidal properties.

Surprisingly, 2-benzyloxymethyl-tetrahydrofuran is the known herbicides, such as 2-ethyl-5-methyl-N- (l'-methyl-22-methoxyethyl) chloroacetanilide, superior in terms of herbicidal action and also shows significantly better selectivity in important crops. The new use of the active ingredient thus represents a essential enrichment of herbicidal agents against grasses.

The substance of the formula (I) to be used according to the invention is known (see J.Am.Chem.Soc. 2gS 3251-56 (1930)} also its production the compound when you put tetrahydrofurfuryl alcohol in an inert organic Solvent, for example dioxane, with benzyl chloride or bromide in the presence strong bases such as potassium hydroxide or sodium hydroxide, preferably 60 to 1000C converts.

The compound (I) can also be prepared by adding tetrahydrofurfuryl alcohol in an inert organic solvent, e.g. an ether such as dioxane, first with sodium hydride (formation of the corresponding alcoholate) and then with a Benzyl halide, e.g. benzyl chloride, reacted and worked up in the usual way; these reactions are preferred in the temperature range between room temperature and reflux temperature carried out (see. Preparation example).

The active ingredient according to the invention influences plant growth and can therefore be used as a defoliant, desiccant, haulm killer, sprout inhibitor and particularly used as weed killers. Under weeds in the broadest sense all plants are to be understood that grow in places where they are undesirable. Whether the substances according to the invention as total or selective The effect of herbicides depends essentially on the amount used.

The active ingredient according to the invention can be used, for example, in the following plants are used: dicot weeds of the genera: mustard (Sinapis), cress (Lepidium), Bedstraw (Galium), chickweed (Stellaria), chamomile (Matricaria), dog chamomile (Anthemis), Button herb (Galinsoga), goose foot (Chenopodium), nettle (Urtica), ragwort (Senecio), foxtail (Amaranthus), purslane (Portulaca), pointed burdock (Xanthium), Morning glory (Convolvulus), morning glory (Ipomoea), knotweed (Polygonum), sesbania (Sesbania), Ambrosia (Ambrosia), scrub thistle (Cirsium), thistle (Carduus), goose thistle (Sonchus), Nightshade (Solanum), pond cress (Rorippa), Rotala, boxweed (Lindernia), Dead nettle (Lamium), speedwell (Veronica), beautiful mallow (Abutilon), Emex, thorn apple (Datura), violets (Viola), hemp nettle, hollow tooth (Galeopsis), poppy seeds (Papaver), knapweed (Centaurea).

Dicot cultures of the genera: cotton (Gossypium), soybean (Glycine), turnip (Beta), carrot (Daucus), kidney bean (Phaseolus), pea (Pisum), Potato (Solanum), flax (Linum), morning glory (Ipomoea), bean (Vicia), tobacco (Nicotiana), Tomato (Lycopersicon), peanut (Arachis), cabbage (Brassica), lettuce (Lactuca), cucumber (Cucumis), Pumpkin (Cuburbita).

Monocot weeds of the genera: barn millet (Echinochloa), bristle millet (Setaria), millet (Panicum), fingergrass (Digitaria), timothy grass (Phleum), bluegrass (Poa), fescue (Festuca), Eleusine, Brachiaria, Lolch (Lolium), Trespe (bromus), oats (Avena), sedge grass (Cyperus), black millet (sorghum), couch grass (Agropyron), dog tooth grass (Cynodon), monocharia, fimbristylis, arrowhead (Sagittaria), Sumpfried (Eleocharis), cornices (Scirpus), Paspalum, Ischaemum, Sphenoclea, Dactyloctenium, Ostrich grass (Agrostis), foxtail grass (Alopecurus), wind stalk (Apera).

Monocot cultures of the genera: rice (Oryza), maize (Zea), wheat (Triticum), barley (Hordeum), oats (Avena), rye (Secale), black millet (sorghum), Millet (Panicum), sugar cane (Saccharum), pineapple (pineapple), asparagus (Asparagus), leek (Allium).

However, the use of the active ingredient according to the invention is by no means limited to these genera, but extends in the same way to other plants.

Depending on the concentration, the compound is suitable for Total weed control e.g. on industrial and rail systems and on paths and squares with and without trees. Likewise, the connection to weed control in permanent crops e.g. forest, ornamental wood, fruit, wine, citrus, nut, banana, coffee, tea, Rubber, oil palm, cocoa, berry fruit and hop plants and for selective weed control be used in annual crops.

The active ingredient according to the invention has, in particular, strong herbicides Effects against grasses without damaging a number of important crops. It can therefore preferably be used for selective weed control. The following crops are particularly suitable: beets, soybeans, beans, cotton, Canola, peanuts, vegetables, corn and rice.

The active ingredient according to the invention can be used in the customary formulations such as solutions, emulsions, suspensions, powders, pastes and granulates. These are made in a known manner, e.g. B. by mixing the active ingredients liquefied pressurized liquids with extenders, i.e. liquid solvents Gases and / or solid carriers, optionally using surface-active substances Agents, that is to say emulsifiers and / or dispersants and / or foam-generating agents Means. In the case of the use of water as an extender, z. B. also organic Solvents can be used as co-solvents. As a liquid solvent are essentially: aromatics, such as xylene, toluene, benzene or alkylnaphthalenes, chlorinated aromatics or chlorinated aliphatic hydrocarbons, such as chlorobenzenes, Chlorethylene or methylene chloride, aliphatic hydrocarbons such as cyclohexane or paraffins, e.g. B. petroleum fractions, alcohols such as butanol or glycol and their Ethers and esters, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone or Cyclohexanone, strongly polar solvents such as dimethylformamide and dimethyl sulfoxide, as well as water; with liquefied gaseous extenders or carriers such liquids are meant which are at normal temperature and under normal pressure are gaseous, e.g. B. aerosol propellants such as dichlorodifluoromethane or trichlorofluoromethane; as solid carrier materials: natural stone powders such as kaolins, clays, talc, Chalk, quartz, attapulgite, montmorillonite or diatomaceous earth and synthetic rock flour, such as finely divided silica, aluminum oxide and silicates; as an emulsifier; non-ionic and anionic emulsifiers, such as polyoxyethylene fatty acid esters, polyoxyethylene fatty alcohol ethers, e.g. alkylaryl polyglycol ethers, alkyl sulfonates, alkyl sulfates, aryl sulfonates and Protein hydrolysates; as a dispersant: e.g. B. Lignin - sulphite waste liquors and methyl cellulose.

The active ingredient according to the invention can be used as such or in its formulations to reinforce and supplement its range of effects depending on the intended use can be combined with other herbicidal active ingredients, with finished formulation or Tank mixing is possible.

Particularly noteworthy is the combination of the active ingredient according to the invention with 4-amino-3-methyl-6-phenyl-1,2,4-triazin-5 (4H) -one (Metamitron) for beet crops, 4-Amino-6-tert-butyl-3-methylthio-l, 2,4-triazin-5 (4H) -one (Metribuzin) for soybeans, Tomatoes and potatoes and 2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine (atrazine) for maize and sorghum with 3- (3,4-dichloro = phenyl) -1,1-dimethylurea (diuron) and 3- (3-trifluoromethylphenyl) -1,1-dimethylurea (fluomethuron) for cotton.

The formulations generally contain between 0.1 and 95 percent by weight Active ingredient, preferably between 0.5 and 90 percent by weight.

The active ingredient can be used as such, in the form of its formulations or the application forms prepared from it, such as ready-to-use solutions, emulsions, Suspensions, powders, pastes and granules can be used. The application happens in the usual way, e.g. by spraying, spraying, dusting, scattering and watering.

The active ingredient according to the invention can both after and in particular be applied before the emergence of the plants, it can also be applied before sowing in the Soil to be incorporated.

The amount of active ingredient used can fluctuate over a wide range. It essentially depends on the type of effect desired. In general the application rate is between 0.1 and 10 kg of active ingredient per hectare. Preferably between 0.1 and 5 kg / ha.

The active ingredient according to the invention not only has herbicidal properties, but also a fungicidal and insecticidal activity.

The good herbicidal effects of the active ingredient according to the invention and its selective uses can be seen from the following examples.

Example A Pre-emergence test Solvent: 5 parts by weight of acetone Emulsifier: 1 part by weight of alkylaryl polyglycol ether Active ingredient preparation is mixed 1 part by weight of active ingredient with the specified Amount of solvent, add the specified amount of emulsifier and dilute the concentrate with water to the desired concentration.

Seeds of the test plants are sown in normal soil and after Doused with the active ingredient preparation for 24 hours.

The amount of water per unit area is expediently kept constant. The concentration of active ingredient in the preparation is irrelevant, only the amount of active ingredient applied per unit area is decisive. After three weeks, the degree of damage to the plants is rated in% damage in comparison to the development of the untreated control. The figures mean: 0% = no effect (like untreated control) 100 = total destruction Active ingredients, application rates and results are shown in the table below: Table: A Pre-emergence test active ingredient- sugar- soy- maize- rape- echino- alope- poa effort beet beans chloa curus annua kg / ha crus myosu- Active ingredients galli roides CH3 CH3 CH-CH2-O-CH3 1.5 10 30 20 30 90 50 70 # -N 1.0 10 20 10 10 90 40 50 CO-CH2Cl C2H5 (known) 1.5 0 0 0 0 100 60 90 # -CH2-O-CH2 # 1.0 0 0 0 0 90 50 80 Manufacturing example 6.0 g of sodium hydride (0.2 mol of 80% sodium hydride in paraffin) are dissolved in 300 ml of absolute dioxane, and 20.4 g (0.2 mol) of tetrahydrofurfuryl alcohol are added under nitrogen. When the addition is complete, the mixture is refluxed for a further 30 minutes, cooled to room temperature and 29.2 g (0.2 mol) of benzyl chloride are added dropwise. The mixture is then refluxed for a further 3 hours, cooled, mixed with 10 ml of methanol and concentrated by distilling off the solvent in vacuo. 100 ml of ice water are then added to the residue and the mixture is extracted twice with 50 ml of methylene chloride each time. The combined inorganic extracts are dried over sodium sulfate; it is then filtered, the solvent is drawn off and the residue is distilled in vacuo. 33.6 g (87% of theory) of 2-benzyloxymethyl-tetrahydrofuran with a boiling point of 81 ° C./0.1 mm are obtained.

Claims (1)

Claims Herbicidal agents, characterized by a content of 2-bezyloxymethyl-tetrahydrofuran of the formula 2.) A method of combating weeds, characterized in that 2-benzyloxymethyl-tetrahydrofuran according to Claim 1 is allowed to act on weeds or its habitat. 3.) Use of 2-bezyloxymethyl-tetrahydrofuran according to claim 1 for weed control. 4.) Process for the preparation of herbicidal agents, characterized in that that 2-benzyloxymethyltetrahydrofuran according to claim 1 with extenders and / or surfactants mixed.