CS203091B2 - Herbicide and method of preparing active ingredients - Google Patents

Abstract

Weed control by applying a herbicidally effective amount of a herbicidally effective compound of the formula <IMAGE> in which R and R1 independently of one another denote lower alkyl having 2 to 4 carbon atoms or cyclohexyl or together form a heterocyclic ring structure having 4 to 10 carbon atoms, and R2 denotes hydrogen or methyl, to the site where the weeds occur.

Description

(54) Herbicidal composition and process for the preparation of active ingredients

SUMMARY OF THE INVENTION The present invention provides a herbicidal composition comprising, as active ingredients, a novel class of active compounds selected from S- (allyloxy) thiocarbamates derivatives of formula

CH ₂ O (R ²⁾ ₂ .CH OSC (= O). N (R 1) (R) (I) wherein

R @ ¹ and R @ ¹ are each independently straight or branched chain alkyl groups having from 2 to 4 carbon atoms, optionally

R ¹ and R ¹ together may form a piperidine ring or an azacycloheptane ring, or R ¹ is further a cyclohexyl radical and R ² is hydrogen or a methyl group, and a process for the preparation of these active compounds.

The compounds of this invention can generally be prepared by oxidizing S-allyl thiocarbamate in methylene chloride as solvent, with a small excess of m-chloroperbenzoic acid, first at -15 ° C and then at a temperature inlet of 15 ° C. The mixture was then cooled to 5 ° C and the m-chlorobenzoic acid precipitate was removed by filtration. The filtrate is washed with sodium carbonate solution to remove dissolved acids then water and finally dried over MgSO4. Evaporation of the solvent gave allyloxy thiocarbamate.

Further examples illustrate the advantages of the present invention.

Example 1

Preparation of allyloxy-N-cyclohexyl-N-i-propylthiocarbamate

To 7.2 g (0.03 mol) of allyl N-cyclohexyl-N-propylthiocarbamate dissolved in 30 ml of methylene chloride is added a solution of 6.3 g (0.031 mol 85%) of m-chloroperbenzoic acid dissolved in 140 ml of the same solvent at —15 ° C. The mixture was allowed to stand while warming to 15 ° C and stirred at this temperature for 45 minutes. It was then cooled to -5 ° C and filtered. The filtrate was washed with three portions of 5% sodium carbonate solution, twice with water and then dried. Removal of the solvent in vacuo afforded 6.4 g of the product as a yellow oil. Yield: 83%. The IR spectrum of the substance obtained confirms the structure ascribed.

Example 2

Preparation of methallyloxy-N, N-di-i-butylthiocarbamate

To a solution of 7.6 g (0.031 mol) methallyl203091

Of N, N-di-i-butylthiocarbamate in 40 mL. of methylene chloride is added 10.7 g. (0.0525 moles) of 85% m-chloroperbenzoic acid in 90 ml of methylene chloride according to the procedure described in Example 1. After completion of the reaction, the product is worked up as described previously in The yield is 7.5 g of a pale yellow oil, i.e. 93% of theory. IC- and NMR spectra were consistent with the proposed structure.

Example 3

Preparation of S-allyloxy-N-ethyl-N-butylthiocarbamate

To 10.1 g (0.050 mol) of S-allyl-N-ethyl-N-butylthiocarbataate dissolved in 20 ml of methylene chloride. 10.7 g (0.0525 mol) of 85% m-chloroperbenzoic acid are added in five equal portions. The starting mixture of thiocarbamate in methylene chloride was initially cooled to -15 ° C with a bath consisting of isopropanol and dry ice. To complete the reaction, the product was worked up as previously described in Example 1. It was obtained

9.3 g of a substance in the form of an oil nr> 30 1.4858 in a yield of 9.3 g. The IR spectrum showed that the prepared substance had an ascribed structure.

Other similar compounds are prepared in an analogous manner starting from suitable raw materials as described above. in the previous rows. The following table shows typical compounds represented by the present invention. The compounds have numbers that identify them in the description.

Table I

CH 2 = C (R ² ). CH 2 OSC (= O), N (R 1) (R)

Compound number R R1 R2 1 П-С3Н7 n-CsH7 -CH3 2 —CH2 — CH2 — CH2 — CH2 — CH2— -H 3 -C3H7 -C3H7 -H 4 -C2H5 -C4H9 -H 5 -C2H5 -CeHu (cycl.) -H 6 —CH2 — CH2— • CH2 — CH2 — CH2 — CH2- -CH3 7 n-C4H9 -C2H5 -CHs 8 I-C4H9 n-C 3 H 7 -H 9 C2H5 -C6H11 (cycl) -CH3 10 I-C 4 H 9 I-C4H9 -H 11 I-C4H9 n-C 7 H 7 -CH3 12 I-C 4 H 9 -C2H5 -CH3 13 1-C4H9 I-C4H9 -CH3 14 I-C3H7 1-C 3 H 7 -CH3 ...... 15 sec.-C4H9 sec-CiHa. -H 16 sec.-C4H9 sec-C 4 H 9 -CH3 17 I-C3H7 I-C3H7 . -CH3 18 1-C3H7 -C6H11 (cycl) -H / 19. . 1-C5H7 C6H11 (cycl) -CH3

Herbicidal screening tests

How .' already. was. said novel compounds described herein. They are phytotoxic substances and are useful. 'and' 'valuable. in regulating the growth of various. 'kinds .' plant. The compounds of the invention were. tested as herbicides by the following. 'way.

Pre-emergence herbicide screening test

20 mg of the compound to be tested is weighed on an analytical balance on a smooth weighing paper. The paper with the compound is placed in a wide-necked flask of 30 ml and 3 ml of acetone containing 1% Tween 20R (polyoxyethylene sorbitan monolaurate) surfactant is added to dissolve the compound. If the substance is not soluble in acetone, another solvent such as water, alcohol or dimethylformamide (DMF) is used instead. . If DMF is used, only 0.5 ml or less is added to dissolve the compound and then made up to a volume of 3 ml with another solvent. 3 ml solution. The soil, which is embedded in a flat sheet of expanded polystyrene, is evenly sprayed after one day of planting the weed seeds with the soil. The DeVilbiss No. 152 atomizer is used for spraying at a compressed air pressure of 34.5 kPa. The application rate is 8.8 kg / ha and the spray volume is 1358 l / ha.

The day preceding the experiment is a cardboard pad with a length of 17.8 cm, a width of 12.7 cm and a depth of 7. cm inches filled to a depth of 5 cm with clay sandy soil. Do individual. The seeds are planted with seven different weed species by placing one species in a row across the width of the mat. The seeds are covered with soil at a depth of 1.3 cm. These are the seeds of the blood finger (Digitaria sanguinalis), the gray scar (Setaria glauca), the hedgehog (Echinochla crusgalli), the oat (Avena sativa), the hairy amaranth (Amaranthus retroflexus), the rush beetles (Brassica juncea) crispus). The seeds are planted abundantly to produce 20 to 50 plants per row after appearing on the surface, depending on the size of the plants.

After spraying, the pads were placed in a greenhouse at 21-29 ° C and sprayed. Two and a half weeks after spraying, the degree of damage is compared or checked by comparison with untreated control plants of the same growth. The range of damage ranging from 0 to 100% is recorded for each species as a percentage, with 0% representing zero damage and 100% representing complete destruction.

Post-emergence herbicide screening test

Seeds of six plant species include the bloody ring finger, oats, sorrel and bean (Phaseolus vulgaris). The soils are placed in a greenhouse at 21-29 ° C and sprayed daily. Approximately 8 to 12 days after planting, when the bean plants were fully developed into the first leaves and three-leafed plants were first formed, the plants were sprayed. A spray was prepared by weighing 20 mg of the test compound, dissolving it in 5 ml of acetone containing 1% Tween 20 ^R and adding 5 ml of water. The solution is sprayed onto the leaves using a DeVilbiss No. 152 atomizer at an air pressure of 34.5 kPa. The spray volume is 4,522 l / ha, its concentration is 0.2 and the amount is 9 kg / ha. The damage rate is recorded two and a half weeks after spraying. The method of evaluation is the same as previously described in the preemergence test.

The results of these tests are shown in Table II.

Table II

Herbicidal efficacy - sorting results Compound number % control at 9 kg / ha Preemergence Postemergence 1 91 63 2 54 0 3 99.4 37 4 99 18 5 87 33 6 82 23 7 90 20 May 8 99.7 48 9 99 13 10 100 ALIGN! 51 11 100 ALIGN! 42 12 96 40 13 99 43 14 22nd 26 15 Dec 35 14 16 50 35 17 68 32 18 54 27 Mar: 19 Dec 53 37

The compounds of the invention can be used in any suitable form. They can therefore be converted into emulsifiable liquids, emulsifiable concentrates, liquids, wettable powders, powders, granulates or other suitable form and used on the soil to control undesirable vegetation.

Claims (21)

SUBJECT A herbicidal composition comprising, as active ingredient, an S- (allyloxy) thiocarbamate derivative of the formula I CH 2 = C '(R ² ), CH ² O, S, C (= O, N (R ¹ ) (R) (I) in which R ¹ and R ¹ are each independently C 2 -C 4 alkyl, straight or branched chain optionally R ¹ and R ¹ together with the nitrogen atom form a piperidine or azacycloheptane ring; or R ¹ is furthermore a cyclohexyl radical and R ² represents hydrogen or methyl. 2. A composition according to claim 1, characterized in that the · active ingredient, compounds of general formula I wherein R and R ¹ are n-propyl radicals and R ² is methyl. 3. A composition according to claim 1, wherein the active ingredient is a compound of formula I wherein R and R ¹ together with the nitrogen atom of the piperidine ring and R ² is hydrogen. The fourth compound according to claim 1, wherein the active ingredient is a compound of formula I wherein R and R ¹ are n-propyl radicals and R ² is hydrogen. Fifth compound according to claim 1, wherein the active ingredient is a compound of formula I wherein R is the ethyl radical, R ¹ is n-butyl and R ² is hydrogen. 6. A herbicide composition according to claim 1, wherein the active ingredient is a compound of formula I wherein R is the ethyl radical, R ¹ is a cyclohexyl radical and R ² is hydrogen. 7. A herbicide composition according to claim 1, wherein the active ingredient is a compound of formula I wherein R and R ¹ together with the nitrogen atom azacykloheptanový radical and R ² is methyl. 8. A herbicidal composition according to claim 1, wherein the active ingredient is a compound of formula I wherein R is n-butyl, R ¹ is an ethyl radical and R ² is methyl. 9. A herbicidal composition according to claim 1, wherein the active ingredient is a compound of formula I, wherein R is i-propyl ZBY [ek, R ¹ is n-propyl radical, and R ² is hydrogen. VYNALEZU 10th herbicidal composition according to claim 1, wherein the active ingredient is a compound of formula I, wherein R is i-propyl radical, R ¹ is a cyclohexyl radical and R ² is methyl. 11th herbicidal composition according to claim 1, wherein the active ingredient is a compound of formula I wherein R and R ¹ is i-butyl radicals and R ² is hydrogen. 12. A herbicidal composition according to claim 1, wherein the active ingredient is a compound of formula I, wherein R is i-propyl radical, R ¹ is n-propyl radical, and R ² is methyl. 13. A herbicidal composition according to claim 1, wherein the active ingredient is a compound of formula I, wherein R is i-butyl radical, R ¹ is an ethyl radical and R ² is methyl. - 14th herbicidal composition according to claim 1, wherein the active ingredient is a compound of formula I wherein R and R ¹ is i-butyl radicals and R ² is methyl. 15th herbicidal composition according to claim 1, wherein the active ingredient is a compound of formula I wherein R and R ¹ is i-propyl radicals and R ² is hydrogen. 16th herbicidal prositředek according to claim 1, wherein the active ingredient is a compound of formula I wherein R and R ¹ is sec-butyl radicals and R ² is hydrogen. 17th herbicidal pnoistředek according to claim 1, wherein the active ingredient is a compound of formula I wherein R and R ¹ is sec-butyl radicals and R ² is methyl. 18th herbicidal composition according to claim 1, wherein the active ingredient is a compound of formula I wherein R and R ¹ is i-propyl radicals and R ² is methyl. 19th herbicidal composition according to claim 1, wherein the active ingredient is a compound of formula I, wherein R is i-propyl radical, R ¹ is a cyclohexyl radical and R ² is methyl. 20th herbicidal composition according to claim 1, wherein the active ingredient is a compound of formula I wherein R ¹ is i-propyl radical, ^R2 is a cyclohexyl radical and R ² is hydrogen. 21. A process according to any one of claims 1 to 20, wherein the S-allyl thiocarbamates are oxidized in methylene chloride as a solvent at a temperature in the range of -15 to +15 [deg.] C with an excess of m-chloroperbenzoic acid to form S-allyloxy. -thiocarbamates.