DD154522A5 - HERBICIDE COMPOSITIONS - Google Patents

Abstract

The invention relates to novel herbicidal compositions based on imidazolidinone derivatives. It is an object of the invention to enrich the state of the art with new broad spectrum herbicides in crops. According to the invention, 3- (5- (1- (alkoxy- or alkylthio) alkyl, alkynyl, alkenyl or haloalkyl) -1,3,4-thiadiazol-2-yl) -4-hydroxy-1-methyl- 2-imidazolidinones of the general formula where X = O or S, R = C, deep 1 - C deep 4-alkyl, C deep 2-C deep 3-alkenyl, C deep 2-C, deep 3-alkynyl, haloalkyl, R '= C deep 1- C deep 4- alkyl. The new herbicides are used in common formulations.

Description

2 2 3 178 _v_ 5.2.1981

AP C 07 D / 223 178 (57 964/12)

Field of application of the invention

Invention relates to a ^ out for the preparation of i »^ 3,4 iiiadiazol-2-yl-4-hydroxy-1-methyl-2-imidazolidinones, in particular of 3- ^ 5- ^ 1-alkoxy or ^T hioalkyl) alkyl , alkenyl-, alkynyl- or haloalkyl-substituted 7-1,3,4-thiadiazol-2-y 1-4 -hydroxy-1-methyl-2-imidazolidinones and the use of these novel compounds as herbicides. «

Characteristic of the known technical solutions

Imidazolidinones have been widely described in the patent and scientific literature, but no information is given which gives an indication of the new herbicidal compounds and their use in control of weeds.

Object of the invention

The aim of the invention is the provision of new compounds with very good herbicidal activity and a broad spectrum of activity for weed control in crop plants,

Explanation of the essence of the invention

The invention is based on ^the object of finding compounds with the desired properties that he active ingredient contained as a "useful in herbicidal compositions and to provide methods for their preparation are available ·

2 23178 4 * - 5.2.1981

, - AP C 07 D / 223

(57 964/12)

The invention relates to a process for the preparation of a compound of formula I.

• - ΧΙ R

in which 1 is oxygen or sulfur, R is an alkyl radical having up to 4 carbon atoms, an alkenyl radical having up to 3 carbon atoms, an alkynyl radical having up to 3 carbon atoms or a haloalkyl radical from the group of chloromethyl, bromomethyl, 2-chloroethyl or 2-bromoethyl and R is an alkyl radical having up to 4 carbon atoms, this process being characterized in that a compound of the formula V is

2 2 3 178

H O

I ii

N - C _w $ - CH ₂ CH (OCH ₃ ) 2 CH ₃

(V)

in which the general symbols have the already defined meanings under reflux in the acidic medium until a compound of the formula I has formed and then the compound of the formula I is separated from the solution.

The invention is also directed to the use of the novel compounds obtained in this process as herbicides for control of weeds or herbicidal compositions containing an effective amount of the novel herbicidal compounds and a carrier.

The process according to the invention also includes the preparation of intermediates of the following formulas III, IV and V.

NH ₂ (HD

R ¹ - XC

NCO

(IV)

H O

--CN-CH ₂ -CH (OCH ₃ ) ₂ (V)

CH ₃

2 23 178

05/02/1981

AP C 07 D / 223

(57 964/12)

in which formulas the general symbols X, R and R ^{1 have} the same meaning as in the formula I.

For example, a compound of formula IV

X

HCO

(IV),

in which the general symbols have the already defined meaning, reacted with Methylaminoacetaldehyddimethylacetal until a compound of formula V is formed, and the compound of formula V is separated from the reaction mixture,

Furthermore, a compound of formula III

Rt X

(III)

R H:

in which the general symbols have the already defined meaning, reacted with phosgene in a solvent for phosgene and the compound of formula III until a compound of formula IV has formed, and the compound of formula IV is separated from the reaction medium.

2 23 178 J ^ 5.2.1981

AP C 07 D / 223 (57964/12)

Examples of compounds corresponding to the formula I,

3- / 5- / Γ1-methylthioethyl / -, 3,4-thiadiazol-2-yl / 4-hydroxy-1-methyl-2-imidazolidinone, 3- / 5- / Ϊ-butylthio ~ 2-bromoethylethyl 1,3,4-thiadiazol-2-yl] J-4-hydroxy-1-methyl-2-imidazolidinone, 3- / 5- / Vfc-butoxy-2-bromoethyl7-1,3,4-thiadiazol-2 yl7-4-hydroxy-1-methyl-2-imidazolidinone, 3- / 5-Z "1-methoxy-3-chloropropyl-1,3,1,3,4-thiadiazol-2-yl7-4-hydroxy-1-methyl- 2-imidazolidinone, 3- / 5- / Ί-ethylthio-3-bromopropyl-1,3,1,3,4-thiadiazol-2-yl7-4-hydroxy-1-methyl-2-imidazolidinone, 3-yl - ethoxy-2-propynyl / -1,3,4-thiadiazole-2-yl7-.

4-hydroxy-1-methyl-2-imidazolidinone, 3_ / 5 - / 1-isopropylthio-2-butynyl-7-1,3,4-thiadiazol-2-yl-4-hydroxy-1-methyl-2-imiaaz ouiuinone, H> ~15- £ \ -isopropoxy-3-butynyl-7-1,3,4-thiadiazol-2-yl7-4-hydroxy-1-methyl-2-imidazolidinone, 3- / 5- / 1-methoxy- 2-propenyl / -1,3,4-thiadiazol-2-yl / 4-hydroxy-1-methyl-2-imidazolidinone, 3-3-0 -methylthio-2-butynyl-7-1,3, 4-thiadiazol-2-yl? - 4-hydroxy-1-methyl-2-imidazolidinone, 3- / 5- / i-ethoxy-2-chloroethyl7,1,3,4-thiadiazol-2-yl7-4- hydroxy-1-methyl-2-imidazolidinone, 3-lb-ethoxy-2-chloroethyl-1,3,1,3,4-thiadiazol-2-yl-4-hydroxy-1-methyl-2-imidazolidinone, 3 - / 5/1-ethylthio-2-bromäthy17-1,3,4-thiadiazol-2-yl7-4-hydroxy-1-methyl-2-iEiidazolidinon,

2 2 3 17 8

S-ZS-Zl-propoxy-S-chloropropyl Ij-1 , 3,4-thiadiazol-2-yl / 4-hydroxy-1-methyl-2-imidazolidinone, 3- / 5-A-Propylthio-3-bromopropyl 7 -l, 3,4-thiadiazol-2-yl / 4-hydroxy-1-methyl-2-imidazolidinone, 3- / 5- / 1-isopropoxy-3-butenyl-7-l, 3,4-thiadiazol-2 yl7-4-hydroxy-1-methyl-2-imidazolidinone, 3- / 5- / 1-isopropylthio-1-pentenyl 17-1,3,4-thiadiazol-2-yl-4-hydroxy-1-ylethyl -2-imidazolidinone, 3- / 5- / 1-BUtOXy-1- (3-methylbutylX / 1, 3,4-thiadiazol-2-yl-4-hydroxy-1-methyl-2-imidazolidinone, 3- / 5 - / l -butylthio-2- (2-methylbutyl) 7-l, 3,4-thiadiazol-2-yl7x4-hydroxy-1-ethyl-2-imidazolidinone, 3- / 5-A-sec-butoxy- l- (2,2-diraethylpropyl) Jl, 3,4-thiadiazole · 2-y] _t 7-4-hydroxy-l-methyl-2-imidazolidinone, 3- / B / l-sec-butylthio-l- butyl 7-l, 3,4-thiadiazol-2-yl-4-hydroxy-1-methyl-2-imidazolidinone, 3- / 5- / lt-butoxy- (2-methylpropyl) -7-l, 3,4-thiadiazole -2-yl7-4-hydroxy-1-methyl-2-imidazolidinone, 3- / 5-tert-butylthiopropyl-7-, 3,4-thiadiazol-2-yl / 4-hydroxy-1-methyl-2-imidazolidinone ,

Although all of these compounds are useful as herbicides, some compounds are more effective than the others. Compounds in which R in the general formula I is an alkynyl radical generally have a good activity and compounds in which R is an alkenyl radical, an even better activity. Compounds in which R is a haloalkyl radical have a high activity, and among these compounds, those in which R is a chloromethyl or bromoethyl radical are preferred. Compounds in which R in the formula I is an alkyl radical are particularly

2 2 3 178

ders preferred and in particular those compounds in which the alkyl radical is a methyl, ethyl or isopropyl radical. R ¹ is preferably a methyl radical and X is generally oxygen. The most preferred specific compounds are: 3- / 5- (1-methylthioethyl) -1, 3,4-thiadiazol-2-yl7-4-hydroxy-1-methyl-2-iraidazolidinone and 3-Z5- methoxyethyl) -1,3,4-thiadiazol-2-yl7-4-hydroxyl-methyl-2-imidazolidinone.

The preparation of the novel compounds is carried out according to the general reactions 1, 2, 3, 4 and 5, which are explained below by way of formula.

X ^- --M ⁺

(VI)

Y - C - i R

¹ I

COH

(1)

(VII)

H 0

I 1

-C COH

R (II)

+ POCl ₃ + H ₂ NCNHNH ₂ (2)

1. dioxane, reflux cooling

2. NaOH / H ₂ O

(3)

(III)

COCl ₂ ethyl acetate

2 2 3 17 8

(IV)

NCO

(4)

CH ₃ N-CH ₂ -CH (OCH ₃ ) 2

(V)

R ¹ X

H ₃ O ⁺

H 0

-. CN-CH ₂ CH (OCH ₃ ) 2 CH "

(5)

The preparation of 5-substituted-2-amino-1,3,5-thiadiazoles will now be explained in more detail. A suitable metal salt M, such as a sodium, potassium or lithium salt of an alkyl alcohol or alkyl thiol according to the formula VI in which R ¹ and X have the already defined meaning, is reacted with a 2-halo-substituted alkanoic acid or its ester corresponding to the formula VII implemented, wherein R has the already defined meaning and Y is chlorine, bromine or iodine, preferably bromine. It forms according to the reaction 1 diec <-substituted alkoxy or alkylthiocarbon

2 2 3 17 8

acid according to formula II, in which R, R ¹ and X have the already defined meaning.

The ^ -substituted alkoxy- or alkylthiocarboxylic acid of formula II (typically 0.4 to 0.5 moles), an equimolar amount of thiosemicarbazide and 30 ml of dry dioxane are placed in a 100 ml reactor equipped with a thermometer, a effective stirrer, a pressure equalizer, an addition funnel and a condenser with) drying tube is equipped. The addition funnel is charged with about a 10% excess of phosphorus oxychloride, and this is added dropwise so that a reaction temperature of 85-95 ° C is maintained. The reaction according to equation 2 occurs. The mixture is then refluxed for about 1 hour, after which time the solvent is removed under reduced pressure, e.g. using a water jet pump, is driven off. To the residue is then added 50 ml of water to obtain an emulsion which is made basic by the addition of 50% sodium hydroxide solution. If a solid product according to formula III in which X and R are as defined above is obtained, the product is isolated by filtration and recrystallized if necessary. In other cases, the reaction mixture is extracted with ether, the ether layer is separated from the heavy layers, dried over magnesium sulfate, filtered and concentrated in vacuo to a viscous oil.

To prepare the isocyanate dimer of the formula IV, 10 g of the 2-amino-l, 3,4-thiadiazole of the formula III to a solution of phosgene in ethyl acetate or another

223178

given appropriate solvent. This solution is obtained by saturating 50 to 100 ml of the solvent with phosgene at room temperature and then adding another 50 to 100 ml of solvent. The mixture is stirred overnight at room temperature and then purged with nitrogen or argon to remove the unreacted phosgene. When the reaction product IV, the isocyanate dimer of the appropriately substituted 1,3,4-thiadiazole, is solid, it is isolated by filtration and then dried. If the product is not a solid, the volatiles of the reaction mixture may be removed to yield a viscous or glassy product.

To prepare the acetal ureas, the corresponding isocyanate dimers of formula IV and an equivalent amount of methylatninoacetaldehyde dimethyl acetal are refluxed (5 to 15 minutes) in an inert solvent such as ether, benzene or toluene. The reaction proceeds to form an acetalurea of formula V. Some of these products can be obtained directly as crystals from the solution, while others require the addition of hexane for isolation. The product of formula V can be purified by washing with ether or hexane or by recrystallization from hexane / benzene or from ether / benzene or from ether / chloroform / benzene. Some products or compounds that comply with Formula V are given as oils that do not require cleaning.

2 2 3 178-bis 5.2.1981

AP C 07 D / 223 (57 964/12)

For the preparation of the compounds of the formula I, a corresponding acetalurea of the formula V (about 3 to 4 g) is added to 150 to 200 ml of water containing 1.5 to 2 ml of concentrated hydrochloric acid. The mixture is stirred vigorously and heated to reflux with refluxing. The hydrolysis is monitored by thin-layer chromatography (aluminum oxd-ethyl acetate) until complete and a product of formula I is obtained. In some cases, the product crystallizes out immediately by cooling the reaction mixture. In other cases, the compounds of formula I are extracted with chloroform and isolated by stripping off the solvent in vacuo. The compounds which solidify on concentration can be further purified. In some cases, however, the compounds can also be used as such. In other cases, the crystallization is accelerated by seeding the ether solution. The resulting crystals can be further purified.

embodiment

The invention will be explained in more detail in the examples.

example 1

This example demonstrates the synthesis of compounds according to the invention.

Synthesis of 3-Z5- (1-methoxyethyl) -1-C8-thiadiazol-1-ylyl-4-hydroxy-1-methyl-2-imidazolidinone

a Preparation of 2-methoxypropionic acid

A two liter flask equipped with a paddle stirrer, thermometer, condenser, and an introduction of nitrogen,

2 2 3 1 78 - »-

was charged with 1 liter of absolute methanol. 23, Og of sodium metal were added slowly. Once the metal had completely dissolved, the solution was cooled and, starting at a temperature of 8 C, 190 g (1.05 mol) of ethyl 2-bromopropionate was added dropwise over 55 minutes, the final temperature being 2 C was. The solution was cooled in an ice bath for 45 minutes with stirring, then 250 ml of water and 42 g of sodium hydroxide flakes were added and the reaction mixture was stirred for an additional 75 minutes, during which the temperature rose to 20 ° C. The reaction mixture was distilled at 90 ° C to remove the methanol. Then, it was acidified with 85% phosphoric acid and extracted twice with 200 ml of chloroform. The extracts were combined and dried over anhydrous magnesium sulfate, filtered and concentrated on a rotary evaporator at 50 ° C. There were obtained 81.1 g of 2-methoxypropionic acid as a colorless liquid.

b. Preparation of 5- (1-methoxyethyl) -2-amino-1,3,4-thiadiazole

Into a 150 ml three-necked flask equipped with a Claisen attachment, paddle stirrer, thermometer, addition funnel and condenser, 10.5 g (0.10 mol) of the 2-methoxypropionic acid prepared as above, 9.1 g (0 , 10 moles) of thiosemicarbazide and 50 ml of dioxane. The slurry was heated to 90 ° C and the addition funnel was charged with phosphorus oxychloride (POCl ₃ ). The POCl ₃ (16.9 g, 0.11 mol) was added slowly in

2231 78. "

Was added over a period of 23 minutes, the temperature at 85-95 C was maintained. The resulting mixture was refluxed for 60 minutes and then volatilized in the vacuum of a water aspirator. To the resulting residue was added 75 ml of water, and so much 50% sodium hydroxide solution was added that the solution had a pH of 10 to form an aqueous phase. The mixture was placed in a continuous Extraktionsvorrich- J tung and extracted with diethyl ether 150 minutes.

The extract was dried over anhydrous magnesium sulfate, filtered, and formed some white crystals. The extract was concentrated on a rotary evaporator at 70 ° C to give 7.0 g of a white solid. The extractor was recharged with diethyl ether and, after 16 hours of extraction, the diethyl ether solution was concentrated in a rotary evaporator to yield an additional 6.3 g of a white solid. The white solids were combined and recrystallized from ethanol / chloroform to give $ 6 g of pale yellow crystals of 5- (1-methoxyethyl) -2-amino-1,3,4-thiadiazole (mp 155-159 ° C). ,

• ψ

c. Preparation of 5- (1-methoxyethyl) -1,3,4-thiadiazol-2-yl isocyanate dimers

A 500 ml three-necked flask equipped with a magnetic stirrer, thermometer, dry ice condenser / drying tube and phosgene inlet over a calibrated gas knife was charged with 100 ml of ethyl acetate

2 2 3 1 78 -S-

was saturated with phosgene at 20 ° C (about 1.0 mole of phosgene). An additional 100 ml of ethyl acetate was added. Then, 7.9 g of 5- (1-methoxyethyl) -2-amino-1, 3,4-thiadiazole (prepared as indicated above) was added at a temperature of from 0 C to room temperature to give an oily substance. The resulting mixture was stirred for 17 hours and then the bottle was purged with argon until no more COGl ₂ could be detected. The solution was filtered through a Whatman # 42 filter paper to give a cloudy yellow solution which was concentrated in a rotary evaporator at 70 ° C. There were obtained 8.4 g of 5- (1-methoxyethyl) -l, 3,4-thiadiazol-2-yl isocyanate dimer in the form of a yellow viscous oil.

d. Preparation of 3- / 5- (1-methoxyethyl) -1,3,4-thiadiazol-2-yl7-i-methyl-1- (2,2-dirnethoxyethyl) urea

At ambient temperature, 5.4 g (0.045 mol) of methylaminoacetaldehyde dimethyl acetal was added slowly to 50 ml of a benzene solution containing 5.4 g (0.045 mol) of the 5- (1-methoxyethyl) -1,3,4-thiadiazole-2 prepared previously -yl isocyanate dimers. The resulting solution was refluxed for 20 minutes. Hexane was added to give an oil. The mixture was concentrated on a rotary evaporator of volatiles at 70 ° C. This gave 13.2 g of a cloudy viscous oil, which was dissolved in diethyl ether and filtered. The diethyl ether solution was concentrated on a rotary evaporator at 70 ° C. This gave 12.9 g of 3- (> - (1-methoxyethyl) -1,3,4-thiadiazol-2-yl-7-1-methyl-1- (2,2-dimethoxyethyl) urea as a red oil.

2 2 3 1 78. if.

e. Preparation of 3- / 5- (1-methoxyethyl) -1,3,4-thiadiazol-2-yl / -l-methyl-4-hydroxy-2-imidazolidinone

A solution prepared containing 5.4 g of the 3-.beta .- ( 1-methoxyethyl) -1,3,4-thiadiazol-2-yl-7-l-methyl- (2,2-dimethoxyethyl) urea as previously indicated The mixture was heated to reflux for 20 minutes under reflux cooling in 150 ml of water and 1.5 ml of concentrated hydrochloric acid. The aqueous phase was extracted three times with 50 ml of chloroform. The combined chloroform extracts were dried over anhydrous magnesium sulfate, filtered and concentrated on a rotary evaporator at 70 ° C to give 2.9 g of 3-Z5- (1-methoxyethyl) -l, 3.4 -thiadiazol-2-yl-7-methyl-4-hydroxy-2-imidazolidinone in the form of a yellow viscous oil. This new compound has the following properties: IR spectra: C = O band at 1720 cm ".

broad N-H band at 3300 cm "Nuclear magnetic resonance: (CDCL-)

6.62 / (br. Singlett, IH), 6.17 S (multiplet, IH), 4.69 J (quartet, IH), 3.90 ί (multiplet, 5H), 3.5OS (multiplet, 5H) , 3.32 £ (5H, singlet), 2.91 $ (singlet, 3H), 1.53 S (doublet, 3H).

'In a repeat of this experiment was obtained φίη r, OHES oil-like product resulting from ether / chloroform / hexane crystals having a melting point of 85-91 ° C.

2 2 3 1 78 -ro

Example 2

Synthesis of 3 / 5- / 1- (1-methylethoxy) ethylhyll-1, 3,4-thiadiazol-2-yl7-4-hydroxy-1-methyl-2-imidazolidinone

a. Preparation of 2- (1-methylethoxy) propionic acid

Into a 500 ml three-necked flask equipped with a magnetic stirrer, thermometer, addition funnel, condenser and nitrogen inlet, 250 ml of dry isopropyl alcohol was added. Then, 7.1 g (0.31 mol) of metallic sodium was added in small pieces, and the solution was refluxed to stop the reaction. After cooling to 60 ° C, 54.3 g (0.30 mol) of ethyl 2-bromopropionate in 50 ml of isopropanol was added dropwise over 20 minutes, and then the solution was refluxed for 2 hours and allowed to stand overnight. 150 ml of water and 13.0 g of sodium hydroxide in the form of flakes were added and then the mixture was distilled at 90 ° C, then cooled in an ice bath and acidified to pH 2 with concentrated hydrochloric acid. The resulting oil phase was extracted with 150 ml of dichloromethane and the extract was dried over magnesium sulfate, filtered and freed from volatiles in a rotary evaporator at 70 ° C. There were obtained 27.8 g of 2- (1-methylethoxy) propionic acid in the form of a pale yellow viscous oil.

2 2 3 1 78

b. Preparation of 5- / 1- (1-methylethoxy) ethyl-2-amino-1,3- t- 4-thiadiazole

Into a 150 ml three-necked flask equipped with a Claisen attachment, paddle stirrer, thermometer, addition funnel and condenser was added 7.9 g (0.060 mole) of the 2- (1-methylethoxy) propionic acid prepared as indicated above, 5.5 g (0.060 mol) of thiosemicarbazide and 50 ml of dioxane. The slurry was heated to 95 C ER- J, and the addition funnel was charged with 10.1 g (0.066 mol) of phosphorus oxychloride. The phosphorus oxychloride was added slowly over 17 minutes, maintaining the temperature at 85-95 ° C. The reaction mixture was refluxed for 24 minutes, and the volatiles (HCl, POCl ₃ and some dioxane) were removed in a water-jet vacuum. To the residue was added 50 ml of water and a 50% solution of NaOH until the pH of the solution became 10. A two-phase system was formed, which was placed in a continuous extractor and extracted there with diethyl ether for 17 hours. The extract was concentrated on a rotary evaporator at 70 ° C to give 10.2 g of white crystals which were recrystallized in a minimum of carbon tetrachloride / ethanol to give white flakes. After filtering, 8.1 g of 5- (1- (methylethoxy) ethyl) -2-amino-1,3,4-thiadiazole (m.p. 120-145 ° C) were obtained.

Αϊ

2 2 3 178 -

c. Preparation of 5-A- (1-methylethoxy) ethylsilo-1,3,4-thiadiazol-2-yl isocyanate dimers

Into a 200 ml three-necked flask equipped with a magnetic stirrer, thermometer, dry ice condenser / drying tube and a phosgene inlet from a tank via a calibrated rotometer was added 50 ml of ethyl acetate saturated with phosgene at 20 ° C (about 0, 5 moles of phosgene). An additional 100 ml of ethyl acetate was added and 8.1 g of the 5 - / * 1- (1-methylethoxy) -ethyl 7-2-amino-1,3,4-thiadiazole prepared as before. This addition was made at 0 ° C. The resulting solution was stirred overnight at room temperature and the flask purged with argon until no more phosgene could be detected. The cloudy solution was filtered through a Whatman # 42 filter paper to give a solution containing the 5- (1- methylethoxy) ethyl) -1,3,4-thiadiazol-2-yl isocyanate dimer.

d. Preparation of 3- / 5- / 1- (1-methylethoxy) ethyl-7-l, 3,4-thiadiazol-2-yl-7-l-methyl-1- (2,2-dimethoxyethyl) urea

There was added dropwise 5.6 g (0.047 mol) of methylaminoacetaldehyde dimethyl acetal to the 150 ml of ethyl acetate solution containing 0.047 mol of 5-A- (1-methylethoxy) ethyl 7,1,4,4-thiadiazol-2-ylisocyanate dimer (prepared as described previously), and the resulting solution was heated to reflux, then cooled, and then, after addition of hexane, the solution was placed in a refrigerator and devolatilized on a rotary evaporator at 70 ° C. There were 14.0 g of 3- / 5- / 1- (1-methyl-

2 2 3 17 8. g.

ethoxy) ethyl 7-l, 3,4-thiadiazol-2-yl7-l-methyl-l- (2,2-dimethoxyethyl) urea obtained in the form of an orange-colored oil.

e. Preparation of 3- / 5-A- (1-methylethoxy) ethyl 17-1,3,4-thiadiazol-2-yl7-l-methyl-4-hydroxy-2-iraidazolidinone

A mixture containing 4.2 g of 3- / 5- (1- (2-methylethoxy) ethyl) -1,3,4-thiadiazol-2-yl-7-methyl (2,2-dimethoxyethyl) urea ( prepared as before), 150 ml of water and 1.5 ml of concentrated hydrochloric acid was heated under reflux for 15 minutes, then cooled and extracted twice with 50 ml of chloroform. The chloroform solution was dried over dried magnesium sulfate, filtered and freed from volatiles in a rotary evaporator at 70 ° C. There was obtained 3.5 g of a yellow oil, which was dissolved in diethyl ether and seeded with crystals of Example Ie. After crystallization overnight, white crystals had formed which were filtered off over a filter and dried in a vacuum oven at 80 ° C. The yield was 1.6 g of 3- / 5- / 1- (1-methylethoxy) ethyl 17-1,3,4-thiadiazol-2-yl-7-1-methyl-4-hydroxy-2-imidazolidinone. The white crystals had a melting point of 106-109C.

The compounds of the formulas III and IV have no herbicidal properties, whereas the compounds of the formula V have herbicidal properties. However, the compounds of the formulas III, IV and V are valuable intermediates for the preparation of the novel compounds of the formula I.

2 2 3 1 78 _ ^.

The compounds of formula I are particularly useful for weed control because they are toxic to many undesirable plants and plant groups and non-toxic to crops. The required amount of herbicide depends on a variety of factors, such as the persistence of the particular weed species, the weather, the soil type, the type of application and the crops growing on the same soil. Under favorable conditions, the new herbicides can be sufficiently effective even at dosages of about 0.071 kg / hectare. In general, however, about 2.2 to 11 kg or more of active compound of the formula I per hectare are used to obtain a good control in a dense infestation by persistent Perennierende weeds.

Weeds are unwanted plants that grow where they are not wanted; they have no economic benefits and they disrupt the growth of useful and ornamental plants. Weeds can be divided into broad-leaved and grassy weeds. As examples of weeds that can be controlled by herbicidal amounts of the compounds according to the invention, the following plants are mentioned, which are cited by their English name: field pennycress, ryegrass, goosegrass, chickweed, purslane, - smartweed, knotweed, wild buckwheat, kochia, medic corn cockle, ragweed, sow thistle, croton, cuphia, dodder, fumitory, groundsel, hempnettle, gnome, spurge, spurry emex, jungle rice, pondweed, dogfennel, carpetweed, bedstraw, ducksalad, naiad, chestgrass, fall panicura, witchgrass , switchgrass, watergrass, teaweed, wild turnip and sprangletop; biennials, like wild carrot, matricaria, wild

2 2 3 1 78. U -

barley, campion, chamomile, burdock, mullein, roundleaved mallow, bull thistle, houndstongue, moth mullein and purple star thistle; or perennials, such as white cockle, perennial ryegrass, quackgrass, Canada thistle, bindweed, bermuda grass, sheep sorrel, curly dock, nutgrass, field chickweed, dandelion, campanula, field bindweed, Russian knapweed, mesquite, toadflax, yarrow, aster, gromwell , horsetail, ironweed, sesbania bulrush, cat-tail, wintercress, horsehettle, nutsedge, milkweed and sicklepod.

The herbicides according to the invention can be applied before or after the germination of the weeds. At a dosage of about 11 kg / hectare they are particularly suitable for combating the following weeds from the group "gainst": Sida, Datura, Brassica, Sorghum, Sesbania, Iporaoea, Avena and Echinochola. The herbicides according to the invention are most effective against the following plant species, especially when used after germination: Sida spinosa (L), Datura stramonium, Brassica kaber, Sorghum halepense, Sesbania spp., Iporaoea purpurea (L) (Roth), Avena fatua and Echinochola crusgalli.

The most preferred compounds of formula I in which R and R ^{1 are} methyl radicals and X is oxygen are especially effective against these weed species and have no deleterious side effects on commercial or ornamental plants when used before or after germination, with dosages from 2.2 to 3.3 kg / hectare usually be used.

When describing the control of weeds, the term "touching the weeds"

22 2 2 3 178 - »

wise for touching the weeds before germination and / or after germination understood. The herbicides may be incorporated as granules of the compounds in the soil prior to germination or may be applied as solutions of the compounds or in any other known manner for the application of herbicides. The term "herbicidally effective amount" is understood to mean the amount which, under the given environmental conditions, destroys the weeds or damages them so badly that they can no longer recover.

For practical use as herbicides, the compounds are generally added to herbicidal formulations containing an inert carrier and the herbicide in an effective amount. Such herbicidal formulations allow for convenient application of the active compounds at the weed-infested site in the desired dosage. These formulations may be solid, such as powdered formulations, granules or wettable powders, or they may be liquid, such as solutions, aerosols or emulsifiable concentrates.

In some cases, the active compounds are sufficiently soluble in common organic solvents such as kerosene or xylene so that they can be used directly as solutions in these solvents. Frequently, solutions of herbicides can be dispersed at low pressure as aerosols. However, the preferred liquid herbicidal formulations are emulsifiable concentrates which comprise an active compound according to the invention and, as inert carrier, a solvent and an emulsifier.

2 2 3 178 - »-

hold. Such emulsifiable concentrates may be diluted with water and / or oil, any desired concentration of the active compound for application by spraying. Nonionic or mixtures of nonionic with anionic emulsifiers are usually used as emulsifiers in such concentrates. When using some emulsifier systems, a reverse emulsion (water-in-oil) is obtained, which can be used directly for the control of weeds.

By the following example, a typical herbicidal formulation according to the invention is explained in more detail, wherein the amounts are given as weights.

Example 3

Dusty preparation

Starting materials:

Product of Example 1 10

Powdery Talcum 90

The above ingredients are treated in a suitable mechanical comminution and mixing device until a homogeneous, free-flowing dust of the usual particle size is obtained for such preparations. This dust is suitable for direct application at the place of infestation by weeds.

The compounds according to the invention can be used as herbicides both alone and in mixture. If mixtures are used, the ratio of one

2H

2 2 3 17 8 - 2 «-

Swing to the other in the range of 0.1 to 100.

In the herbicidal formulations, the concentration of the compounds of the invention may vary widely, with typical formulations having from about 0.05% to about 95% by weight of the active compound of the invention. In the herbicidal formulations, the compounds of the invention may also be used in combination with other pesticides, e.g. with insecticides, neraatocides and fungicides. In addition, these formulations may contain conventional additives such as stabilizers, extenders, deactivators, adhesives, fertilizers, activators and synergists.

Combinations with other herbicides and / or defoliants, desiccants and growth regulators are also possible with the compounds according to the invention. The other materials may constitute about 5 to about 95% of the active substance in the herbicidal composition. When using such combinations, particularly herbicidal formulations are obtained, which often show better results than the use of only one herbicide,

Examples of other herbicides, defoliants, desiccants and growth regulators that can be used in combination with the compounds according to the invention in the control of weeds are: chlorophenoxy herbicides, such as 2,4-D, 2,4,5-T, MCPA, MCPB, 4- (2,4-DB), 2,4-DEB, 4-CPB, 4-CPA, 5-CPP, 2,4,5-TES, 3,4-DA and Silvex; Carbamate herbicides such as IPC, CIPC, Swep, Barban, BCPC, CEPC, and CPPC; Thiocarbamate and

2 23 178 _ £ _

Dithiocarbamate herbicides such as CDEC, Metam-natriura, EPTC, diallate, PEBC, pergulate and vernolate; substituted urinary, substance herbicides such as norea, siduron, dichloroureas, chloroxuron, cycluron, fenuron, monuron, monuron TCA, diuron, linuron, monolinuron, neburon, buturon and trimeturon; symmetric triazine herbicides such as Simazine, Chlorazine, Desmetryn, Norazine, Ipazine, Prometry, Atrazine, Trietazine, Simeton, Prometon, Propazine and Ametryn; Chloroacetamide herbicides such as alpha-chloro-N, N-dimethylacetamide, CDEA, CDAA, alpha-chloro-N-isopropylacetamide, 2-chloro-N-isopropyl-acetanilide, 4- (chloroacetyl) morpholine, and! - (chloroacetyl) piperidine; chlorinated aliphatic acid herbicides such as TCA, Dalapon, 2,3-dichloropropionic acid and 2,2,3-TPA; chlorinated benzoic acid and phenylacetic acid herbicides such as 2,3,6-TBA, 2,3,5,6-TBA, dicamba, tricamba, amiben, fenac, PBA, 2-methoxy-3,6-dichlorophenylacetic acid, 3-methoxy 2,6-dichlorophenylacetic acid, 2-methoxy-3,5,6-trichlorophenylacetic acid, 2,5-dichloro-3-nitrobenzoic acid, dual and metribuzin, and further such compounds as aminotriazole, maleic hydrazide, phenylmercuric acetate, endothall, biuret, technical grade chlorodane , Dimethyl, JSjB-tetrachloroterephthalate, Diquat, Erbon, DNC, DNBP, Dichlobenil, DPA, Diphenamid, Dipropalin, Trifluralin, Solan, Dicryl, Merphos, DMPA, DSMA, MSMA, Potassium azide, Acrolein, Benefin, Bensulfide, AMS, Bromacil, 2- (3,4-dichlorophenyl) -4-methyl-l, 2,4-oxadiazolidine-3,5-dione, bromoxynil, cacodylic acid, CMA, CPMF, cyproraid, DCB, DCPA, dichlone, diphenatril, DT, DNAP, EXD, ioxynil, isocil, potassium cyanate, MAA, MAMA, MCPES, MCPP, MH, molinate, NPA, paraquat, PCP, picloram, DPA, PCA, phrichlor, seson, terbacil, terbutol, TCBA, LASSO, planavin, sodium tetrabor at,

2 2 3 1 78 - se -

Calcium cyanamide, DEF, ethylcanthogen disulfide, Sindon, Sindon B and propanil. Such herbicides can also be used in the herbicidal formulations according to the invention in the form of their salts, esters, amides or other derivatives.

In the following examples, the use of the compounds according to the invention for weed control in the form of herbicidal compositions will be explained.

These tests were carried out in a laboratory under laboratory conditions and using standard laboratory techniques.

Example 4

When using the compound 3- / 5- (1-methoxy) ethyl) -1,3,4-thiadiazol-2-yl7-4-hydroxy-1-methyl-2-imidazolidinone of Example 1 at a dosage of 2.2 In the following weeds, the following weeds, after germinating after 21 days, have achieved weed killing or serious damage from which the weed no longer recovered: Sida spinosa, Sesbania spp., Echinochola crusgalli (L), Gossypium hirsutum (L), Avena fatua (L), Datura stramonium (L), Sorghum halepense (L), Ipomoea purpura (L) Roth, Setaria glauca (L) and Brassica kaber (L).

Comparative test

When using the compound 3- / 5- / 2- (1-methoxy-ethyl) -äthyiy-l ^^ - thiadiazol ^ -yiy ^ -hydroxy-l-methyl ^ -imidazolidinone in a similar manner as in the compound of

223178

Example 1 was found on the same weeds and under the same conditions as in Example 4 that the weeds grew and were not destroyed.

Claims (17)

223178 - * - AP c 07 D / 223 17s (57 964/12) Invention claim A herbicidal composition, characterized in that it comprises a herbicidally effective amount of a compound of the formula in which Σ is oxygen or sulfur, R is an alkyl radical having up to 4 carbon atoms, an alkenyl radical having up to 3 carbon atoms, an alkynyl radical having up to 3 carbon atoms or a haloalkyl radical from the group of chloromethyl, bromomethyl, 2-chloroethyl or 2-bromoethyl and R ^{1 is} an alkyl radical of up to 4 carbon atoms and containing a carrier. 2 23 178 Ji AP C 07 D / 223 178 (57-964 / 12) Composition according to item 1, characterized in that X is sulfur, Composition according to item 2, characterized in that R ^{1 is} an alkyl radical having up to 4 carbon atoms. 4 · Composition according to item 3, characterized in that R is a methyl radical · 223178 _5_ APc 07 D / 223 178 (57 964/12) 5 · Composition according to item 2, characterized in that R 'is a methyl radical. Composition according to item 5, characterized in that R is a methyl radical. 7 «Composition according to item 1, characterized in that X is oxygen. 8th·. Composition according to point 7 », characterized in that R ^{1 is} an alkyl radical having up to 4 carbon atoms · 9. Composition according to item 8, characterized in that R is a methyl radical. 10 · Composition according to item ¹ J _9, characterized in that R ^{f is} a methyl radical · Composition according to item 10, characterized in that R is a chloromethyl, bromomethyl, 2-chloroethyl or bromoethyl radical. Composition according to item 10, characterized in that R is an alkynyl radical having up to 3 carbon atoms. - - * Composition according to item 10, characterized in that R is an alkenyl radical having up to 3 carbon atoms. ^: Composition according to item 10, characterized in that R is an alkyl radical having up to 4 carbon atoms. Composition according to item 10, characterized in that R is a methyl, ethyl or isopropyl radical. 16 · Composition according to item 10, characterized in that R is a methyl radical. A method for controlling weeds, characterized in that the weeds are brought into contact with a herbicidally effective amount of a composition according to item 1.