IL31333A - 1,3,4-thiadiazolyl urea compounds,their preparation,and herbicidal compositions containing them - Google Patents

Description

.,Μνιη η ιικ *»ViT »nr»n-4.,3.,l maiai'n New 1,3,4-thiadiazolyl urea compounds, their preparation, and herbicidal compositions containing them AGRIPAT S.A 0:29475 The present invention concerns new l,3»4-thiadia-zolyl ureas , processes for their production, also herbi-cidal compositions, which contain as active substances such ureas, and processes for controlling weeds and wild grasses using the new active substances or compositions which contain them.

Th© neif 1, 3 »4-thiadiazoly1 ureas correspond to the formula Is wherein R^ represents a perfluoroalkyl radical with 1 or 2 carbon atomsI, Rg represents hydrogen or a lower alkyl radical, ^ represents hydrogen or a lower alkyl radical with the. proviso that at least one of the symbols ≥ and -j represent hydrogen, and ^ represents a lower alkyl radical with 1 to 4 carbon atoms optionally substituted with chlorine or bromine or a cyano, methoxy or methylthlo group; an alkenyl or alkinyl radical with 3 or 4 carbon atoms, a cycloalkyl radical with 3 to 6 carbon atoms, or a lower alkoxy radical with 1 to 4 carbon atoms.

In formula I in the definition of ^, the perfluoroalkyl radical denotes preferably the t ifluorometh l radical. Suitable as lower alkyl radicals 2, ^ and are straight and branch chain radicals having 1 to 4 carbon atoms, preferably the methyl and the ethyl radicals.

The compounds according to this invention are thus characterized by the perfluoroalkyl substituent on - 2 - 31332/2 the one hand and the ureyl substituent on the other hand, in the 2- and 5- positions/of the thiadiazole ring.

Thiadiazole compounds having different substituents Danish in the same positions are known f rom/patent specifications Hos. 86270 and 103»051. They are also destined for use as weed killers. The compounds of the present invention have superior properties. On the other hand, (5-lower-alkyl-1,3»4- hiadiazolyl) ureas and 1,3-bis( 5-lower-alk l-l,3*4-thiadiazolyl) ureas have been d escribed in Farmaco, Ed.

Sci. 22(6), 393-401, as substances having hypoglycemic properties.

The new 1,3»4-thiadiazol 1 ureas of formula I are produced according to the invention by reacting a 2-amino-1, 3» -thiadiazole of the formula lis wherein R1 and have the meanings given under formula I, with a halooarbonic acid ester in the presenco of an acid-binding agent to form the carbamic acid derivative and reacting the latter with an amine of the formula III: wherein R^ and R^ have the meanings given under formula I.

The new 1,3» -thiadiazolyl ureas of the formula la: H-—-N Ri - 3 31333/2 wherein R^ represents a perfluoroalkyl radical with 1 or 2 carbon atoms, represents hydrogen or a lower alkylradical, and R^' represents a lov/er alkyl radical any substituent of which is selected from chlorine, bromine, lower alkoxy or lower alkylthio; or a cycloalkyl radical with 3 to 6 carbon atoms0 can also bo produced according to th© inven- of the formula II: wherein ^ and ≥ have the meanings given under formula la-, with an isocyanate of the formula IV: R »-HCO (IV) wherein R^* has the meanings given under formula la.

As a carbonic acid half ester halide, preferably phenyl chlorocarbonate is used.

As amines of the formula III the following, for example, can be used: Heth lamine, dimethylamine, ethylamine, diethyl-amine, isopropylamine, n-buylamine, sec.-but lamine, eyelo-propylamine, cyclopent lamine, cyclohex lamine, H-methyl-K-cyclohex lamine, l-eyano-l-mothyleth l-amine, 2-chloro-eth lamine, 2-bromoethylamine, 2-methoxyethylamine, 2-ethox thylamine, 2-methylthioethylamine, allylamine, methylallylamine, N-methy1-K-all lamine, I-methyl-H-l1-meth lpropargylamine, O-meth Ihydroxyamine, 0,N-dimethyl~ hydroxylamine.

Tertiary amines are preferably used as acid-binding agents, e.g. trialkyl amines, pyridine bases, etc., also inorganic bases, such as hydroxides and carbonates of alkali and alkaline earth metals. The reaction temperatures lie in each case between 0° and 150°C.

The reaction of the resultant intermediate carbamic acid derivatives with a primary or secondary amine of the formula. Ill and the reaction of a 2-amino-l, 3 , 4-thiadiazole of the formula II with an isocyanate of the formula IV are performed at temperatures between -40 and 150°C, preferably between 0 and 100°C. The thiadiazolyl ureas according to the invention are obtained in good yields and high purity. The new compounds are stable and soluble in the usual organic solvents, but have low solubility in water.

The processes described are carried out in the presence of solvents or diluents which are inert to the reactants. For example, the following can be used: Aliphatic and aromatic hydrocarbons and halogen hydrocarbons, such as benzene, toluene , xylenes, chloroform, chlorinated ethylene; N, -dialkylated amides, such as dialkyl formamides; ether and ethereal compounds; higher ketones, such as methyl-ethyl ketone, nitriles, etc..

In addition, the new 1 , 3 , 4-thiadiazolyl ureas can be obtained by reacting a 2-amino-l , 3 , 4-thiadiazole of the formula II wherein R« represents hydrogen, with a carbamoyl halide of wherein R- represents lower alkyl, in the presence of acid-binding agents.

In a further procedure, the new compounds of the for zole of the formula II with phosgene into the thiadiazolyl carbamoyl chloride, and then reacting the latter, which, in case represents hydrogen, is present in equilibrium with the iso-cyanate, with an amine of the formula III.

Of the 2-amino-l, 3, 4-thiadiazoles of formula II used as starting compounds, the 2-amino-5-trifluoromethyl-thiadiazole was hitherto known [J. Lalezari et al., J. heterocycl. Chem. _3. 336-337 (1966 )]. The new 2-amino-thiadiazoles of formula II can be obtained from corresponding fluoroacyl thiosemicarbazides by ring-closure reaction with polyphosphoric acid in accordance with the process described by E. Hoggarth in J.chem.Soc. 1949 , 1163-1167. Fluoroacyl thiosemicarbazides have not been known hitherto. They are obtained by reacting equimolar amounts of a corresponding aliphatic fluorocarboxylic acid derivative, par-ticularly the anhydride, with a thiosemicarbazide in the presence of a solvent or diluent. 4-Alkylthiosemicarbazides are known compounds. To obtain 1, 3, 4-thiadiazoles, the fluoroacyl thiosemicarbazides can be used as such or produced in situ.

As fluoroacylthiosemicarbazides the following, for example, can be used: 1-trifluoroacetylthiosemicarbazide , 1-trifluoroacetyl-4-methylthiosemicarbazide , 1-trifluoroacety1-4-ethylthiosemicarbazide , 1- rifluoroacety1-4-isopropyl-thiosemicarbazide , 1-trifluoroacety1-4-n-butyl-thiosemicarbazide, 1-pentafluoropropionylthiosemicarbazide.

The new 1 , 3 , 4- hiadiazolyl ureas of the formula I mono- and dicotyl weeds and wild forms of grass. In high concentrations, the new ureas act as total herbicides, and in lower concentrations, i.e., of from 0.1 to 5 kg per hectare, they act. as selective herbicides. Deep rooted types of weeds and those difficult to control, e.g. leguminosae and umbelliferous plants are attacked by these active substances. They can be applied equally successfully both as pre-emergence and post-emergence agents. It is thus possible to destroy or prevent field weeds such as, e.g. Panicum sp. , Sinapis sp., Chenepodiaceae , Alo-percurus sp., Matricaria sp. , without causing damage to cultivated plants, such as corn etc..

The new 1,3,4-thiadiazolyl ureas of the formula I are. used, mixed with usual additives, as herbicidal compositions. Moreover, the new active substances can also be mixed with fertilizers and applied in this form. In order to broaden the range of activity of the ureas according to the invention, they can be applied in admixture with other herbicides: e.g. with halogen-, alkoxy- and alkylthio- diamino-s-triazines ; halogenated phenols, nitrophenols , aliphatic, aromatic and araliphatic carboxylic acids as well as with the salts of such compounds; ureas, carbamic acid esters, uracils, inorganic salts, etc., such as: 2-chloro-4, 6-bis- (ethylamino)-s-triazine, 2-chloro-4-ethylamino-6-isopropylamino-s-triazine, 2-chloro-4, 6-bis- (methoxypropylamino) -s-triazine, 2-methoxy-4, 6-bis- (isopropylamino) -s-triazine , 2-diethylamino-4-isopropylacetamido-6-methoxy-s-triazine , 2-isopropylamino-4-methoxypropylamino-6-methylmercapto-s- > I thio 2-methylmereaptO-4-ethylamino-6-isopropylamino-s-triazine , 2-methoxy-4, 6-bis- (ethylamino) -s-triazine, 2-methoxy-4-ethylamino-6-isopropylamino-s-triazine, 2-chloro-4, 6-bis- (isopropylamino) -s-triazine, dinitro-sec . -butyl phenol and salts thereof, pentachlorophenol and salts thereof, 2, 3, 6-trichlorobenzoic acid and salts thereof, 2, 3 , 5 , 6-tetrachlorobenzoic acid and salts thereof, 2-methoxy-3 , 5 , 6-trichlorobenzoic acid and salts thereof, 2-methoxy-3, 6-dichlorobenzoic acid and salts thereof, 3-amino- 2, 5-dichlorobenzoic acid and salts thereof, 3-nitro-2, 5-dichlorobenzoic acid and salts thereof, 2-methyl-3 , 6-dichlorobenzoic acid and salts thereof, 2 , 4-dich orophenoxyacetic acid and salts and esters thereof, 2, 4, 5-trichlorophenoxyacetic acid and salts and esters thereof, (2-methyl-4-chlorophenoxy) -acetic acid and salts and esters thereof, 2- (2, 4, 5-trichlorophenoxy) -propionic acid and salts and esters thereof, 2- (2, 4, 5-trichlorophenoxy) -ethyl-2, 2-dichloropropionic acid esters, 4- (2,4-dichlorophenoxy)-butyric acid and salts and esters thereof, 4- (2-methyl-4-chlorophenoxy) -butyric acid and salts and esters thereof, 2,3,6-trichlorobenzyloxypropanol, 2, 6-dichlorobenzonitrile, trichloroacetic acid and salts thereof, - 3- (3,4-dichlorophenyl)-l, 1-dimethyl-urea, 3- (4-chlorophenyl) -1, 1-dimethyl-urea, 3-phenyl-l, 1-dimethyl-urea, 3- (3, 4-dichlorophenyl) -3-methoxy-l, 1-dimethyl-urea, 3- (3, 4-dichlorophenyl) -1-n-butyl-l-methyl-urea, 3- (3 , 4-dichlorophenyl) -1-methoxy-l-methyl-urea, 3- (4-chlorophenyl) -1-methoxy-l-methyl-urea, 3- (3, 4-dichlorophenyl) -1, 1, 3-trimethyl-urea, 3- (3, 4-dichlorophenyl) -1, 1-diethyl-urea, 3- (4-chlorophenoxyphenyl) -1, 1-dimethyl-urea, N,N-Di- (n-propyl) -O-ethyl thiocarbamate, N,N-Di- (n-propyl) -O-n-propyl thiocarbamate, N-ethyl-N- (n-butyl) -O-ethyl thiocarbamate, N-ethyl-N- (n-butyl) -O-n-propyl thiocarbamate, N-phenyl-O-isopropyl carbamate, N- (m-chlorophenyl) -O-isopropyl carbamate, N- (m-chlorophenyl) -0-4-chloro-2-butyryl carbamate , maleic hydrazide.

The following examples describe' the production of new 1, 3, 4-thiadiazolyl ureas of the formula I. The temperatures are given in degrees centigrade.

Example 1 a) A mixture of 91.1 g of thiosemicarbazide and 125 g of trifluoroacetic acid in a sulphonating flask is heated to reflux temperature (72°). 1 kg of polyphosphoric acid is then added cautiously with stirring.

The reaction mixture is kept at the reflux temperature of trifluoroacetic acid until all of the latter is bound. The reaction mixture is then slowly heated to 130°, and, after keeping it for 1 hour at this temperature, cooled to 80°. The mixture is poured into about 3 1 of ice water and the reaction \ product precipitated by adding concentrated sodium hydroxide solution (until pH 5-6). The crude product is recrystallised from aqueous ethanol. The 2-amino-5-trifluoromethyl-1, 3 , 4-thiadiazole thus obtained melts at 212-214°. b) To the solution of 6.75 g of 2-amino-5-trifluoromethyl-1, 3,4-thiadiazole in 10 ml of dimethyl formamide at about 50-60°, 2.8 ml of methyl isocyanate are added. Following completion of the reaction, the N- [ 5-trifluoromethyl-1, 3, 4-thiadiazolyl (2) ] -N' -methyl urea separates in crystalline form. Melting point 186-189°.

Example 2 a) 46.8 g of trifluoroacetic acid anhydride are added dropwise at 0° to a suspension of 27.3 g of 4-methyl-thiosemi-carbazide in 300 ml of ether. The mixture is then stirred for at 163-164°. b) 25 g of 1-trifluroacetyl-4-methyl-thiosemicarbazide are introduced in portions within 15 minutes into 125 g of polyphosphoric acid at 80°. The reaction, mixture is then heated to 120° and stirred for about 30 minutes at this temperature.

The reaction mixture, previously cooled to about 70°, is then poured into 500 ml of ice-water, and the product is precipitated >,and washed _ by adding aqueous concentrated ammonia solution, separated \ ith water. After recrystallising from ethanol/water , the 2-methyl-amino-5-trifluoromethyl-1, 3, 4-thiadiazole has a melting poirit of 115-116°. c) 12 g of 2-methylamino- 5-trifluoromethyl-1, 3, 4-thiadiazole are dissolved at about 50-60° in 30 ml of dimethyl formamide, and 4 g of methyl isocyanate are then added. Following completion of the reaction, the N- [ 5-trifluoromethyl-1, 3, 4-thiadiazolyl (2) ] -M, N' -dimethyl urea separates in crystalline form. Melting point 134°.

Example 3 a) 31.5 g of phenyl chlorocarbonate are added dropwise at room temperature to a suspension of 34 g of 2-amino- 5-tri-fluoromethyl-1 , 3 , 4-thiadiazole in 300 ml of acetonitrile and 20 g of triethylamine . The mixture is stirred for 15 hours at room temperature and subsequently evaporated to dryness in vacuo. The residue is taken up in 100 ml of water and heated for 15 phenyl N- [ 5-trifluoromethyl-l, 3, 4-thiadiazolyl (2) ] -carbamate has a melting point of 180 to 182°. b) Gaseous dimethylamine is passed at 80° through the suspension of 14.5 g of 0-phenyl N- [ 5-trifluoromethyl-l, 3,4-thiadiazolyl (2) ] -carbamate in 300 ml of benzene until the reaction is completed. The course of the reaction is observed by means of thin layer chromatography. The N- [ 5-trifluoromethyl-1,3,4-thiadiazolyl (2) ] -N' , ' -dimethyl urea crystallises from the reaction mixture. Melting point 159.- 160°.

The same compound is obtained when the S-phenyl thio-carbamate is prepared according to Example 3, a) and then reacted as described above under b) .

In the manner described in the previotas examples, the following 1,3,4-thiadiazolyl ureas are obtained.

Table I No. Compound Melting point 1 N- [5-trifluoromethyl-l,3,4-thiadiazolyl(2) ] - N' -ethyl urea 180-181° 2 N- [ 5-trifluqromethyl-1, 3 , 4-thiadiazolyl (2) ] - N' -isopropyi urea 158-161° 3 N- [5-trifluoromethyl-l,3,4-thiadiazolyl(2) ] - N' -n-butyl urea 152-154° 4 N- [ 5-trifluoromethyl-l, 3 , 4-thiadiazolyl (2) ] - N' -cjclohexyl urea 175-177° N- [ 5-trifluoromethyl-l, 3, 4-thiadiazolyl (2) ] - N1 -cyclopropyl urea 191-192° - - - - - Compound Melting point The production of herbicidal compositions according to the invention is carried out in a known manner by the intimate mixing and grinding of the active substances of formula I with suitable carriers, optionally with the addition of dispersion agents or solvents which are inert to the active substances. The active substances can be used for the production of dusts, sprinkling agents, granulates, coated granules, impregnated granules, homogeneous granules, wettable powders, pastes, emulsions, aerosols and solutions.

To produce the solid forms for application (dusts, sprinkling agents, granulates), the active substances are mixed with solid carriers. Examples of carriers are kaolin, talcum, bole, loess, chalk, limestone, ground limestone, ataclay, dolomite, diatomaceous earth, precipitated silicic acid, alkaline earth silicates, sodium and potassium aluminium silicates (feldspar and mica), calcium and magnesium sulphates, magnesium oxide, ground synthetic plastics; fertilisers, such as ammonium sulphate, ammonium phosphate, ammonium nitrate, urea; ground vegetable products , . such as cereal-flour, bark-flour, sawdust, ground nut shells, cellulose powder, residues from plant extractions', active charcoal, etc., used either alone or as mixtures.

The grain-size of the carriers is, for dusts advantageously up to about 0.1 mm, for sprinkling agents about 0.075 to 0.2 mm and for granulates from 0.2 mm upwards.

The concentrations of active substances in the solid preparations are 0.5 to 80%.

To these mixtures additives can also be added which adhesiveness of the active substances on plants and parts of plants (adhesives) and/or ensure better wettability (wetting agents) and also dispersibility (dispersing agents). The follow ing are examples of adhesives: olein-chalk mixture, cellulose derivatives (methyl cellulose, carboxymethyl cellulose), hydroxy ethylglycol ethers of mono- and dialkyl-phenols having 5 - 15 ethylene oxide radicals per molecule and 8 - 9 carbon atoms in the alkyl radical, lignin-sulphonic acids, the. alkali and alkaline earth metal salts thereof, polyethyleneglycol ethers, fatty alcohol polyethyleneglycol ethers having 5 - 20 ethylene oxide radicals per molecule and 8 - 18 carbon atoms in the fatty alcohol part, condensation products of ethylene oxide, propylene oxide, polyvinylpyrrolidones, polyvinyl alcohols, condensation products of urea-formaldehyde as well as latex products.

Active substance concentrates dispersible in water, i.e. wettable powders, pastes and emulsion concentrates, are compositions which can be diluted with water to give any desired concentration. They consist of active substance, carrier, optionally additives which stabilise the active substance, surface-active substances and anti-foaming agents and, optionally solvents. The concentration of active substance in these composiions .is .5 - 80 .

Wettable powders and pastes are obtained by mixing and grinding the active substances with dispersing agents and pulverulent carriers in suitable devices until a homogeneous mixture is obtained. Carriers which can be employed are for example those mentioned above for solid preparations. In some naphthalene derivatives with formaldehyde, condensation products of naphthalene or naphthalene sulphonic acids with phenol and formaldehyde, also alkali, ammonium and alkaline earth metal salts of lignin sulphonic acid, and also alkylaryl sulphonates, alkali and alkaline eatth metal salts of dibutyl naphthalene sulphonic acid, fatty alcohol sulphates, salts of sulphated fatty alcohol glycol ether, sodium oleoylethionate, sodium oleoylmethyltauride , diter&ary acetylene glycols, dialkyl dilauryl ammonium chloride and fatty acid alkali and alkaline earth metal salts. Suitable as anti-foaming agents are for examples silicones.

The active substances are mixed, ground, sieved and strained with the above mentioned additives in such a way that the grain-size of the solid material does not exceed 0.02 - 0.04 mm in the case of the wettable powders and 0.03 mm in the case of pastes. To produce the emulsion concentrates and pastes, dispersing agents, such as those described in the previous sections, organic solvents and water are used. Suitable solvents are, e.g. alcohols, benzenes, xylenes, toluene, dimethyl sulphoxide and mineral oil fractions having a boiling point: bet-ween 120 and 350°. The solvents must be practically without smell, not phytotoxic, inert to the active substances and not readily inflammable.

In addition, the compositions according to the invention can be applied in the form of solutions. In this case, the active substance, or several active substances, of formula I are dissolved in suitable organic solvents, mixtures of solvents or water. Suitable for use as organic solvents are aliphatic and aromatic h drocarbons chlorinated derivatives thereof, alk l- Other biocidally active substances or agents can be mixed with the above-described compositions according to the invention. Thus the new compositions may contain, in addition to the aforesaid compounds of formula I, e.g. insecticides, other fungicides, bactericides, fungistatics, bacteriostatics or nematocides to give a wider effective range.

The compositions according to the invention can also contain plant fertilizers, trace elements, etc..

The following examples serve to illustrate the forms of application of the new ureas. The term "parts" denjiotes parts by weight.

Granulate The following materials are used to produce a 5% granulate : parts of N- [ 5-trifluoromethyl-1, 3, -thiadiazolyl (2) ]-N' ,Ν' -diethyl urea, 0.25 part of epichlorohydrin, 0.25 part of cetylpolyethylene glycol ether with 8 moles of ethylene oxide, 3.50 parts of polyethylene glycol (molecular weight 380-420), 91 parts of kaolin (grain size 0.3 - 0.8 mm).

The active substance is mixed with epichlorohydrin and dissolved in 6 parts of acetone. Polyethylene glycol and cetyl-polyethyleneglycol ether are then added. The. solution thus obtained is sprayed on to kaolin and then evaporated in vacuo. ettable powder The following constituents are used to produce a) a 50%, b) a 25% and c) a 10% wettable powder, respectively: a) 50 parts of N- [ 5-trifluoromethyl-1, 3, 4-thiadiazolyl (2) J-N-ethyl-N' -methyl urea, * *5 parts of sodium dibutylnaphthalene sulphonate, - 3 parts of naphthalene sulphonic acid/phenol sulph- onic acid/formaldehyde condensate (3:2:1), parts of kaolin, 22 parts of Champagne chalk; b) 25 parts of N- [ 5-trifluorometh l-1 , 3, 4-thiadiazol l 2.5 parts of naphthalene sulphonic acid/formaldehyde condensate, 0.5 part of carboxymethyl cellulose, parts of neutral potassium aluminium silicate, 62 parts of kaolin; c) 10 parts of N- [ 5-trifluoromethyl-1, 3, 4-thiadiazolyl (2)ΐ-Ν,Ν' -dimethyl urea, 3 parts of mixture of the sodium salts of saturated fatty alcohol sulphates (with 12 to 18 carbon ctoms) , parts of naphthalene sulphonic acid/formaldehyde condensate, j 82 parts of kaolin. \ The active substance is added to the appropriate carriers (kaolin and chalk) and then mixed and ground with the additives. Wettable powders are obtained exhibiting excellent wettability and suspension properties. Suspensions of any desired concentration of active substance can be obtained from such a wettable powder by dilution with water. Such suspensions are used for controlling weeds and wild grasses in cultivated plantations .

Paste The following materials are used to produce a 45% paste : 45 parts of N- [ 5-trifluoromethyl-1, 3 , 4-thiadiazolyl (2) ]-N',N' -dimethyl urea, parts of sodium aluminium silicate, 2 parts of spindle oil, parts of polyethylene glycol (molecular weight 380 - 420), 23 parts of water.

The active substance is intimately mixed and ground, in suitable equipment, with the additives. A paste is obtained from which suspensions of any desired concentration can be produced by dilution with water. The suspensions are suitable for the treatment of vegetable plantations.

Emulsion concentrate The following constituents are mixed together to produce a 10%, emulsion concentrate: parts of N- [ 5-trifluoromethyl-1, 3, 4-thiadiazolyl (2) ] N' -ethyl urea, parts of oleylpolyethylene glycol ether with 8 moles of ethylene oxide, 75 parts of isophorone.

This concentrate can be diluted with water to give emulsions of required concentration. Such emulsions are suitable for controlling weeds in cultivated plantations, such as e.g. cotton, maize, etc..

The following 1, 3, 4-thiadiazoly1 ureas are used as test compounds to determine theii- herbicidal activity: 1. N- [ 5-trifluoromethy1 -1,3, 4-thiadiazoly1 (2 -N1 -methyl urea 2. N- [ 5-trifluoromethyl-1,3, 4-thiadiazoly1 (2 -Ν' ,Ν' -dimethyl urea 3. N- [ 5-trifluoromethyl -1, 3, 4-thiadiazoly1 (2 -Ν' ,Ν' -diethyl urea 4. N- [ 5-trifluoromethyl -1, 3, 4-thiadiazoly1 (2 - ' -isopropyl urea . N- [ 5-trifluoromethyl -1 , 3, 4-thiadiazoly1 (2 - ' -allyl urea 6. N- [ 5-trifluoromethyl-1, 3, 4-thiadiazoly1 (2 -N-methyl-N' - ' cyclopropyl urea 7. N- [ 5-trifluoromethyl -l,3,4-thiadiazolyl(2 - ' -cyclohexyl urea 8. N- [ 5-trifluoromethyl -1,3, 4-thiadiazolyl (2 -N1 -methyl-N1 -1- methylpropargyl urea 9. N- [ 5-trifluoromethyl -1, 3, 4-thiadiazoly1 (2 -N' -2-methoxy- ethyl urea . N- [5-trifluoromethyl -1, 3,4-thiadiazolyl(2 -N-methyl-N' -2- chloroethyl urea 11. N- [ 5-trifluoromethyl -1, 3 , 4-thiadiazolyl (2 -N-methyl-N' -n- butyl urea 12. N- [5- trifluoromethyl •1, 3, 4-thiadiazolyl(2)]-N,N» -dimethyl urea. a) Germination test Method : The active substance is mixed with an inert carrier concentration of 0.5 g per liter of soil. The soil is filled into flower pots, and oats, ray grass, mustard and vetch are sowed therein. The results observed 20 days after sowing are expressed according to the following values: = normal growth 9-1 = graduated increase in damage 0 = all plants destroyed. b) Contact test Method: \ Flowerpots filled with soil are sowed with oats and mustard. The active substance is applied in the form of an emulsion prepared from a 25 % emulsion concentrate. The concentration is 0.5 g of active substance in 100 ml of water per 2 m . The treatment is effected when the mustard reaches the 4 - 6 leaf stage. The results are observed 14 days after treatment and are expressed as above under. ) .

Results of germination and contact tests Used instead of oats or mustard. - 23 31333/2

Claims (1)

1. CLAIMS ureas of the formula wherein represents a perfluoroalkyl radical with 1 or 2 represents hydrogen or a lower represents hydrogen or a lower aikyl with the proviso that at least one of the symbols R2 nd represents and represents an alkyl radical with 1 to 4 carbon atoms optionally substituted with chlorine or bromine or a or methylthio an alkenyl or alkinyl radical with 3 or 4 carbon a cycloalkyl radical with 3 to carbon or a lower with 1 to 4 carbon The compound compound h compound ure The compound Process the production of ureas of the formula I in Claim comprising reacting a of the formula II 24 wherein and have same meanings as in Claim with a halocarbonlo acid ester in the presence of an binding to form the carbamic acid dorivativo and reacting latter with an amine of the formula wherein and have the same meaning as in Claim Process for the production of ureas of formula xiherein and 2 have the same meaning as in Claim 1 and represents an radical viith 1 to carbon atoms optionally substituted with chlorine or bromine or a methoxy or methylthio or a radical with 3 to 6 carbon comprising reacting a thladiazole of the formula II with an isocyanate of the formula R ICO 4 25 where and have the same meaning as Processes according to Claims or wherein the reaction is carried out in a solvent or Process according to Claim wherein the carbonic acid ester reactant is a halogen carbonic acid phenyl Herbicidal compositions as a cidally active at least one compound according to any of Claims 1 to together dispersing agents carriers other biocidal and herbicidal active substances suitable for the control of Process for controlling weeds or wild wherein a compound according to any of Claims 1 to 5 or a composition according to Claim is applied to the weeds or wild For the Applicants insufficientOCRQuality