DE1955892B2 - Use of a benzyl thiol carbamate as a herbicide - Google Patents

Description

15th

20th

25th

jo

HjCO

CH ₂ -SCN

C ₂ H ₅

ID

QH ₅

40

45

has excellent herbicidal properties and is particularly useful for weed control in rice fields, d. H. for combating chicken millet and rushes.

It can be described as surprising that 4-methoxy-benzyI-N, N-diethyl-thiol carbamate has a better herbicidal effectiveness than the previously known S-chloro ^ -methoxy-benzyl-N.N-di-isopropyl-thiol-carbamate, which is a constitutionally similar active ingredient of the same type of action This is one of the main reasons why the compound which can be used according to the invention is not effective expect because in GB-PS 9 95 497 it is expressly pointed out that such benzylthiol carbamates, in which the phenyl ring is not substituted, can be used advantageously for weed control as corresponding compounds with a substituted benzyl part. It is also apparent from US-PS 31 09 006, that in particular those benzyl thiol carbamates which are either unsubstituted or at least unsubstituted in the benzyl part are substituted by a halogen atom,; »! ;; Herbicides are suitable. On the basis of this technical teaching it could not be foreseen that 4-methoxybenzyl-N, N-diethyl-thiol-carbamate - which is substituted in Benzyiieii, but does not contain halogen - has excellent herbicidal properties

If chicken millet is in. Before emergence or at the stage where there are 1 to 3 leaves flooded with 4-methoxybenzyl-N.N-diethyl-thiol-carbamate is treated, this compound shows a strong herbicidal effect. This fact is of epoch-making importance since the most of the herbicides on the market only before or just after germination against barnyard grass are effective. In addition, the present compound is less phytotoxic to rice plants, it can be or two weeks after transplanting the rice plants for weed control in rice fields are used, for which point in time no suitable weed control method is known which results in significant labor savings in rice cultivation

Since the compound to be used according to the invention shows its strong herbicidal activity through absorption Developed in the roots, it can be effective as a selective or, depending on the application methods non-selective herbicide against weeds that also grow in places other than paddy rice fields, be used.

The compound which can be used according to the invention is defined by the formula (I). It boils below one Pressure of 0.9 - 1 mm Hg at 162 - 163 ° C.

The compound which can be used according to the invention is a colorless chemical which is hardly soluble in water, but in organic solvents, such as. B. in alcohol, ketones, benzene, etc. is soluble. The general Manufacturing processes for this compound are illustrated by the following reaction equations:

HjCO

CH,

SM ¹ + Cl -CNC ₂ H ₅

C ₂ II ₅

II., C () -

Il

S C N

IM ¹ CI

C ₂ Hs HjCO - <f> - CH ₂ - Ha! + COS + HN + M ² OH

H ₃ CO

H ₃ CO

OC ₁ H ₅

Il / "

CH ₂ -SC-CI + 2H -N

OC ₂ H ₅

C-N

C ₂ H ₅

+ M ² HaI - | H ₂ O

Are in these formulas

M ¹ for hydrogen or an aikaiimetaiiatom and
M ² for an aikaiimetaiiatom.

If the compound to be used according to the invention is used as a herbicidal composition, so this happens after dilution with water or in a mixture with carriers, whereby they according to the in the Agricultural chemistry usual methods for wettable powders, liquids, emulsifiable concentrates, Dusts, granules, tablets, Aufgasungsmittehi, Pastes etc. is processed.

As an example of solid supports, inert mineral Substances such as talc, clay, kaolin, montmorillonite, Diatomaceous earth, calcium carbonate, etc. can be mentioned. Either solvents can be used as the liquid carrier or even nonsolvents that disperse the active substance through the use of an adjuvant or can dissolve, be called, e.g. B. alcohols, Benzene, xylene, dimethylnaphthalene, aromatic petroleum fractions, Dimethylformamide, surfactants, etc.

In order to guarantee its effectiveness, it can be mixed with the following commonly used in agricultural chemistry: Auxiliaries used, such as spreading agents, emulsifiers, wetting agents and adhesives, etc. can be used. It can also be mixed with other herbicides, such as B. phenoxy compounds, chlorophenol compounds, Carbamates, diphenyl ethers, urea and triazine compounds or with plant growth regulators / Insecticides, nematocides ^., Acaricides, fungicides or fertilizers etc. used will.

The invention is now to be explained in more detail with the aid of the following working examples, but in no way be restricted.

Working example 1

5% of the compound (Π and 95% of a mixture of Talc and clay are formulated into a dust by mixing and grinding and are made into a dust by dusting brings.

Working example 2

20% of the compound (I), 75% of a mixture of; Zeeklit and clay, 3% sodium alkylbenzenesulfonic acid:

jo

J5

40

O CH ₅

Il / "

-CH ₂ -SCN + (C ₂ Hs) ₂ NH ₂ CI

\
CH ₅

and 2% sodium dinaphthyimethanedisulfonic acid were made wettable by mixing and grinding Powder processed and applied after dilution with water

Working example 3

20% of the compound (I), 75% xylene and 5% of the emulsifying agent Sorpol (registered trade name) are made into an emulsifiable concentrate by mixing and stirring and after diluting with Water applied

Working example 4

The compound (I) is dissolved in xylene with heating. The solution is poured onto rotating clay granules sprayed on until about 10% active ingredient has been absorbed. The granules were sprinkled on the Applied to the ground surface.

Now the herbicidal effectiveness of the compound to be used according to the invention by the the following test results illustrated

Application example 1 Investigation of the herbicidal effectiveness against Weeds in paddy fields and the Phytotoxicity to rice Investigation method (treatment of the soil)

Soil from pyddy fields was placed in a 1/5000 Wagner container. Seedlings of paddy rice were placed (Jukkoku-Art) were replanted in the three-leaf stadium in case of flooding. After the seedlings were rooted, were chicken millet seeds, rush seeds, and broad-leaved weeds sown. The earth was with the compound to be used according to the invention in the form of the wettable Powder or the emulsifiable concentrate treated in accordance with the information of Working Examples 2 and 3 had been prepared. After three weeks the effectiveness of the Compounds on barnyard grass, rush and broad-leaved weeds and their phytotoxicity in relation to Examined rice plants. The result shows an effect about the same under the test conditions as with the reference substance.

¹ SO

5 6

Table I.

Test results regarding the herbicidal effectiveness in paddy fields and the phytotoxicity in rice

link Active ingredient herbicidal efficacy phylo-

toxi / iiäl

Chicken millet swamp rush breilblallrigc Padd \ rice [!, Klii weeds

H ₃ CO

CH, - S - C - N

(according to the invention)
OCH ₃

500 250 C ₂ H ₅

_{3 o}

(V-CH ₂ -SCN

Cl

C ₃ H ₇ iso

\

"C ₃ H ₇ -ISO

(known from GB-PS 9 95497) T (comparison)

PCP (commercial product, comparison) MCP (commercial product, comparison) Un treated

4th
3
2

5
2
0

3 I 0

5 5 0

5 4 4

5
S.
4-5 0
0
0 5
3
2 0
0
0 5 5 5 4th 0 0

Notes to Table I:

1. Porridge I leafy weeds are monochoria. RoIaIa indica K och nc. wrong pimpernel etc.

2. Evaluation of the herbicidal effectiveness: 5 peopled

4. Strong effectiveness

.1 medium effectiveness

2 low effective wedge

1 weakest effectiveness

0 no effect

.1. Evaluation of the phytoloxicity:

5 highest Phyloloxiziläl
4 strong phytoloxicity

3 medium to strong phylotonic

2 minier Phyloloxiziläl

1 low phyloloxicity
0 no Phyloloxiziläl

4. T: Bcn / .yl-N.N-dimctiiyldilhiocarbamal

5. PCP: pentachlorophenol

6. MC ^p : 2-methyl-4-chlorophenoxy-acetic acid c.

Application example 2

Studies of soil treatment against various plants

To prepare suitable preparations of the active compounds, 1 part by weight of each active Compound with 5 parts by weight of solvent, acetone, and 1 part by weight of emulsifier, benzyloxy polyglycol ether, mixed and this emulsifiable concentrate then diluted with water to the desired concentration.

Seeds of the test plants were sown in normal soil and the preparation of the active ingredient in sprayed on at various concentrations 24 hours later. After three weeks the extent of the Damage to the test plants determined and rated with the numbers 0 to 5, which have the following meaning:

no effect 1 slight damage or slight growth inhibition

significant damage or stunted growth significant damage or germination of only 50%

μ 4 partial destruction of plants or germination

of only 25% complete death of the plants or none at all Germination.

Table 2
Investigations into soil treatment against various plants (pot test)

Active ingredient " concentration
of the real
fabric wheat barley rice cotton Corn Cabbage kg / ha (4) (invent
according to) 20th
10 5
1-2 5
2 5
1-2 5
2 5
2 5
2 5 0 0 0 0 0 0 2.5 0 0 0 0 0 0 1.25 0 0 0 0 0 0 T (ver
same) 20th
10 3
\ -> 3
■} 3
3 4th
■) 3
2 5
! -2 5 0 0 0 0 0 0 2.5 0 0 0 0 0 0 1.25 0 0 0 0 0 0

Table 2 (continued) Investigations on soil treatment against various plants (pot test)

Active ingredient concentration
of the active ingredient Fichinochloa Portulaca Chenopodium Stellaria Amaranthus Oigi-
taria kg / ha (I) (invent
according to) 20th
10 5
5 5
5 5
5 5
5 5
5 5 5 5 5 5 5 5 2.5 5 5 5 5 5 N 1.25 5 4th 4th 4th 4th 4th T (ver
same) 20th
10 5
5 5
S. 5
5 5
5 5
5 Ln Ln 5 4th 5 5 5 5 5 2.5 3 5 5 5 5 5 1.25 2 3 3 3 3 3

Note: T = benzyl-N.N-dimethyldithiocarbamate

Application example 3
Pre-emergence method

Solvent: 5 parts by weight of acetone
Emulsifier: 1 part by weight of benzyloxy polyglycol ether

To produce an appropriate preparation of active ingredient, 1 part by weight of active ingredient is mixed 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 pruned in normal soil and after 24 hours with the active compound preparation doused. After three weeks the extent of the

Damage to the test plants determined and rated with the numbers 0 to 5, which have the following meaning:

0 no effect

1 slight damage or slight growth retardation

2 significant damage or inhibition of growth

3 considerable damage or germination of only 50%

4 partial destruction of plants or germination of only 25%

5 Complete death of plants or none at all Germination.

Active ingredients, application rates and results are shown in the table below. The active substance according to the application shows under the test conditions (other than in Table 1) a superior effect.

ίο

Preliminary procedure
Table 3

Active ingredient conc

tration

d. Effective c _u °

substance -3 2 λ ^ ί 2

kg / hit SO Si & S 5

O CII ₅

Il / "

CH ₁ O <> CH, SC -N IO 12 2 12 2 2 2

^w - '\ 5 0 0 ο ο ο ο! ·,

C ₂ H ₅ 2.5 0 0 0 0 0 0

(invention) "1.25 0 0 0 0 0 0

V ^CHi OC ₁ H ₇ - (SO

<f / -CH ₂ -SCN

^ l C ₁ H ₇ -ISO

(known from GB-PS 9 95 497; Example 6)

Active ingredient conc

tration
el. active ingredient

kg / ha

10 I. 2 2 3 2 2 I 2 5 0 0 0 0 0 0 2.5 0 0 0 0 0 0 1.25 0 0 0 0 0 0

> -CH, - O
Il C, N \ C, H ₅ IO 5 5 5 5 5 5 CH ₁ O- -S-C- 5 5 5 5 5 5 5 2.5 5 5 5 5 5 5 H ₅ _ // ^> \ /

(according to the invention) 1.25

OCH ₁ ,, "...

ι Ο CH ₇ -ISo

A Ii / '

-. ^: y- CH ₂ -SCN

(I ₁ C ₁ H ₇ -ISO

(known from GB-PS 9 95 497; Example 6)

IO 5 4th 5 4th 5 5 5 5 3 4 5 3 4th 5 2.5 4th I. 3 0 1 4th 1.25 2 0 I. 3

Claims (1)

Claim: Use of 4-methoxybenzyl-N, N-diethylthiol carbamate as a herbicide. The present invention relates to the use of 4-methoxyben2yl-N, N-diethyl thiol carbamate as Herbicide. The active ingredient 4-methoxybenzyl-N.N-diethyI-thiolcarbamate and its use as an acaricide are already known (see SU-PS 2 01 380). Furthermore, it has already become known that numerous benzyl thiol carbamates have herbicidal properties own (see US-PS 31 09 006 and GB-PS 9 95 497). So z. B. the S-chloro ^ -methoxy-benzyi-N .N-di-äsopropyi-thiolcarbamate used to control weeds. The effect of this substance is however not always fully satisfactory. It is also known that pentachlorophenol (PCP) for Control of barnyard grass (Echinochloa cms gaili) can be used. However, PCP has shortcomings and causes troubles as it is considerably irritating to human skin and mucous membranes and to fish and shellfish has a specific toxicity which limits its application times and areas are. To combat marsh rushes (Eleocharis acicularis) growing at the same time 2-methyl-4-chlorophenoxyacetic acid (MCP) is used, but this is not used to control chicken millet suitable To combat both grassland and rushes at the same time, which are the main ones Weeds in rice fields are therefore usually a mixture of the compounds mentioned PCP and MCP used It has now been found that 4-methoxybenzyl-N, N-diethyl-thiol-carbamate the formula IO