IL28514A

IL28514A - Substituted phenylureas and phenylthioureas,their manufacture and herbicidal compositions containing them

Info

Publication number: IL28514A
Application number: IL28514A
Authority: IL
Original assignee: Ciba Geigy Ag
Priority date: 1966-08-26
Filing date: 1967-08-16
Publication date: 1972-02-29
Also published as: NL6711741A; GB1181847A; DE1643798B1; BE703129A; FR1533815A; CA927396A; CH487585A

Description

28514/2 Substituted phenylureas and phenylthioureas , their manufacture and herbicidal compositions containing them CIBA-GEIGY LIMITED C 527062 - 3 - 28514/2 The invention also provides herbicidal compositions which comprise a compound of the formula I together with a suitable carrier. The compositions, for example, may contain at least one of the following additives: a solvent, a diluent, a dispersing agent, a wetting agent, an adhesive, another pesticide.

T e compounds of the general formula I may be prepared by known methods, for example, by reacting 3,4-dibromophenylisocyanate v/ith an amine of the general formula in which R represents a hydrogen atom, a loxer alkyl group or the methoxy group, or by brominating a compound of the general formula in which X represents an oxygen or a 3ulphur atom and R has the same meaning as above, in an organic solvent, for example, acetic acid. - 4. 28514/2 A special advantage of the compounds of the formula (I) above or preparations which contain the said oompounds as active principles is that the can be used not only as . all-purpose herbicides, but also as selective herbicides when'applied in appropriate concentrations. For example, they may be used to combat undesired plant growth in beds or fields of crop plants, without notioeably damaging the crop plants, , n The preparations of the invention can be made up in a very wide variety of forms. Solutions of the compounds of the general formula (I) which may be used, directly, for spraying are prepared, for example, with mineral oil fractions having a high to medium boiling range, preferably about 100°C, for example, Diesel oil or kerosene, ooal-tar oils and oils of vegetable or animal origin, and also hydrocarbons, for example, alkylated naphthalenes, and tetrahydronaphthalene if necessary, with the use of xylene mixtures, oyolohexanols and ketones, and also chlorinated hydrocarbons, for example, trichloroethane, tetrachlo oethane, trichloroethylene, triohlorobenzene and tetrachlorobenzene.

Aqueous preparations may be prepared, for example, from emulsio concentrates, pastes or wettable powders for sprays by adding water* Suitable emulsifying agents or dispersing agents are, for example, non-ionic products, for example, condensation products obtained from aliphatic ■ · i! alcohols, amines or carboxylic acids having a long-chain j hydrocarbon radical containing about 10 to 20 carbon atoms and ethylene oxide, for example, the condensation product obtained from octadecyl alcohol and 25 to 30 mols of ethylene oxide, or that obtained from soybean fatty acid and 30 mols of ethylene oxide, or that obtained from technical oleylamine and 15 mols of ethylene oxide, or that obtained from dodecylmercaptan and 12 mols of ethylene oxide. Anionic emulsifying agents that may be used are,, for example, the sodium salt of dodecylalcohol sulphuric acid ester, the sodium salt of dodecylbenzene sulphonic acid, the potassium or triethanolamine salt of oleic acid or abietic acid or mixtures of these acids, or the sodium salt of a petroleum sulphonic acid. Suitable cationic dispersing agents are quaternary- ammonium compounds, for example, cetylpyridinium bromide, or dihydroxyethylbenzyldodecylammonium chloride.

Dusting and strewing preparations may be prepared with solid carrier substances., for example, calcum, kaolin, bentonite, calcium carbonate,, charcoal, cork meal and other materials of vegetable origin. It is also especiall advantageous to make the preparations in the form of grains. The preparations in their various forms may also contain the usual additives which improve dispersion, adhesion, rain-resistance and penetrating power; substances of the kind, mentioned are, for example, fatty acids, resins, glues-,-, casein and alginates.

The preparations of the invention may be used either alone or together with known pesticides, especially - - 28514/2 insecticides, acaricides, nematicides, bactericides or other fungicides or herbicides.

The term "undesirable plant growth" , that is used herein to describe growth which may be combated by the preparations of the invention, includes, for example, crop plants which have been grown, at an earlier period on the area'to be treated. The preparations may be used for bot -pre-emergence and post-emergence treatment.

In addition to a herbicidal action, the compounds of. the general formulae (I) · (· } display other biocidal activity, for example, microbicidal, insecticidal, acaricidal, nematicidal and molluscicidal activity.: They may also be used as defoliants for cotton plants.

The following Examples illustrate the invention.

Unless otherwise stated, the parts and percentages are by weight.

Example 1 a) 41.7 Parts of 3,4-dibromophenylisocyanate are dissolved in 100 cc of dioxane and the solution is added drop by drop, while stirring, to a solution of 15 cc of methylamine (35 aqueous solution) in 200 cc of dioxane.

The reaction product is precipitated with water and isolated by filtration. The residue is recrystallized from a mixture of acetone and water. Melting point: 148-151°C» 28514/2 ■ „· Example 2 A powder for the preparation of a spray which has the :. following composition is prepared: 50$ of one of the active principles listed in Example 1 under (a) to (e) ^ of . Bolus alba (Kaolin) $ · of finely divided Si02 (commercially available under the Registered Trade-Mark "Hisil") 3.5$ of a condensation product obtained from 1 mol of dodecylmercaptan and 12 mols of ethylene oxide 1.5$ of a condensation product obtained from para- ; nonylphenol and 9 mols of ethylene oxide. \ The finely ground mixture so obtained may be. diluted with water as required, to form a spray which is ready for use, Example 5 · ■ . . . — --· The following seeds: triticum, hordeum, avena, zea, oryza digitaria, panicum, beta, calendula, linum, brassica, ipomoea, stellaria, amaranthus, galium, gossypium, are sown in earthenware pots filled with soil and placed in a greenhouse. a) Pre-emergent treatment was carried out 1 day after sowing with a spray prepared in accordance with Example 2 and containing, as active principle, the compound of the formula shown under -la) . The rate of application was 1.2 to 3 kg of active principle per hectare. Assessment was made 20 days after the treatment, b) Post-emergent treatment of the said plants was carried out in the manner described under (a), but about 10 days after sowing, when the plants were at the two-leaf to three-leaf stage. The rate of application was 1,2 to 3 kg of, aotive prinoiple per hectare. Assessment was made 20 days - 9 - 28514/2 after the treatment.

The results are shown in the following tables- Table 1 pre = preemergent treatment post = postemergent treatment 0 = no effect » complete destruction of plant.

Similar good results are obtained with the other compounds described in Example 1. - io ' 28514/2.

Example 4 . · , ' Bromination of meta-bromo-phenylisocyanate ' · 99 Grams of meta-bromophenylisocyanate are dissolved in 100 ml of ethylene chloride. A pinch of iron powder is added and then 79.9 grams of "bromine are added drop by drop, in a manner such that the temperature does not exoeed 40°C. , The batch is stirred for 2 hours at 40°C and then for 2 hours at reflux temperature. The precipitate which forms is :i isolated by filtration, the solvent is distilled by means of {■' a rotary evaporator and the residue obtained is subjected to high-vacuum distillation. 95.5 Grams of 3, 4-dibromophenyl-■·'■''. isooyanate having a boiling point of 120°0/ 0.06 mm H and a melting point of 45 to 46°C are . obtained. This product is reacted with raethylaraine to yield -dibromo-phenyl-N' -methyl-urea. ' '. - 11 - 28514/2 Example 5 The compound la H-( 3» -dlhromophenyl)-!'-methyl- urea, has been compared with the previously known compounds N-(3,4-dichlorophen l)-iT,-methyl-urea (A) and I-(3-chloro-4- bromophenyl)-N'-methyl-urea (B).

The test was a post-emergence application with an amount corresponding to 2 kg of active substance por hectare as d scribed in Example 3· The results are as follows: 1 = no damage 2 - 4 = recoverable damage - 8 =s severe damage n this test the compound la shows a selective herbicidal activity with rice and soya which the compound A does not have. - 12 - 28514/2

Claims

1. Compounds of the general formula in which X is an oxygen or sulphur atom; R is a hydrogen atom, a lov/er alkyl group of 1 to 4 carbon atoms or the methoxy group; with the proviso that R cannot be methyl or methoxy when X is an oxygen atom.

2. The compound of the formula

3. The compound of the formula S Ϊ formula I in Claims 1 to 5:, wherein a compound of the general formula '.· ■'■ in which R and X have the same meaning as in Claim 1, is brominated. - 14 - 28514/2

8. A process according to Claim 6 , substantially as described in any one of the Examples herein.

9. Herbicidal compositions comprising as active principle a compound of the general formula I in Claim 1, together with a carrier.

10. A composition according to Claim 9 » wherein the active principle is the compound of the formula given in Claim 2.

11. A composition according to Claim 9 » wherein the active principle is the compound of the formula given in Claim 3.

12. A composition according to Claim 9» wherein the active principle is the compound of the formula given in Claim 4 i 13· A composition according to Claim 9, wherein the active principle is the compound of the formula given in Claim 5.

14. A composition according to Claim 9 » and substantially as described in Example 2 herein,

15. A composition according to any one of Claims 9 to 14 , wherein there is also present one or more of the following additives: a solvent, a, diluent, a dispersing agent, a wetting agent and an adhesive as well as other pesticides.

16. A method of combating weeds or undesired plants in a crop area, which comprises applying to the crop area a compound according to Claim 1.

17. A method of combating weeds or undesired plants in - 15 - 28514/2 a crop area., which comprises applying to the crop area a composition according to Claim 9.

18. A method for preparing a compound of the general formula I in Claim 1, wherein X represents oxygen and R has the same meaning as in Claim* 1, wherein metabromophenyliso-cyanate is brominated to 3t4-dibromophenylisocyanate and is further reacted with an amine of the formula wherein E has the same meaning as in Claim 1, but cannot be methyl or methoxy. 19· method according to Claim 18, substantially as described in Example

4. For the Applicants PARTNERS SJD/rb