DE2144700B2 - Benzyl-N.N-di-sec-burylthiol carbamate, its preparation and use - Google Patents

Description

15th

Il

CH ₂ -S-C -R

in which

R stands for monoalkylamino or dialkylamino and X Denotes chlorine, bromine or methyl; there is one of the

preferred compounds the S- (4-chlorobenzyl) N, N-

dietary thiocarbamate:

25th

The present invention relates to a compound belonging to the class of the benzyl-N.N-dialkylthiol carbamates, which has not yet been described, namely Benzyl-N.N-di-sec-butylthiolcarbamate, their production and their use to stimulate the Rice growth and the destruction of the plants growing in rice fields.

In the herbicide field there has been a great deal of looking for very effective products with highly specific products for many years Research has been carried out on effects that can destroy weeds and the structurally similar useful plants leave undamaged. These products should continue to have a special ratio of properties be characterized because they have a specific effect (selectivity) with other properties, such as: low Must combine toxicity to warm-blooded and cold-blooded animals, degradability in the soil, duration of action and reasonable production costs.

A complete selectivity of action is particularly difficult to achieve when the Unkrautver- v destruction in crops of useful plants is carried out, which are very similar from the botanical point of view to be destroyed the weeds and therefore against damage are more vulnerable by the herbicides.

This selectivity is especially necessary when considering rice from the most common, disruptive ones and its growth hindering weeds such as Panicum spp, Echinocloa spp .; and especially the latter Grass plants are morphologically very much like rice, at least during the first stages of life similar.

It is of course advisable to remove the weeds at the beginning, namely during the first stages of the Rice growth, destroy; the weed killing bo However, under these conditions is particularly difficult as the herbicide also easily affects the rice seedlings attacks Certain environmental problems also arise when weeding or weed killing is carried out in crops that are under water will.

Of the herbicides used on rice during the lead-up period, ethyl-1-hexa- Cl- < O

CH ₂ -SCN

C ₂ H ₅

QH ₅

These products, too, are not free from toxicity to crops, so they cannot be used in rice fields can be used before planting but only a few days after the rice has been transplanted, so that the herbicide only comes into contact with the crop when the crop is transplanted has survived and has grown so far that she no longer feels the effects of the herbicide

In the above patent, monothiocarbamates with a substituent in the benzene ring with the analogous monothiocarbamate, which is not substituted in the benzene ring, namely S-benzyl-N, N-diethylthio-carbamate, compared with the one against weeds is less active and more aggressive towards rice

According to the invention it has now surprisingly been found that the property is an effective herbicide facing weeds in the rice field and stimulating rice growth in an unusual way im S-benzyl-N.N-di-sec-butylthiolcarbamate, a new product not previously described in the literature.

Based on what we know so far, this fact was completely unexpected because of the aggressiveness of compounds of the same class, which are not substituted in the benzene ring, compared to rice.

S-Benzyl-NN-di-sec-butylthiolcarbamate is a liquid, oily product which is practically insoluble in water and soluble in most organic solvents such as benzene, ether, heptane, methanol, cyclohexanone, acetone, methylene chloride and dichloroethane the following properties: dn = 1.044; n ^? "= 1.5325; Kp.o. _lmm 130-132 ⁰ C.

The S-benzyl-N.N-di-selc-butylthiol carbamate can be prepared according to the reactions known for compounds of this class, such as. B .:

1) Reaction between di-selc-butylcarbamoyl chloride and benzyl mercaptan:

(QH, sec.) ₂ N - COCI + HS CH ₂ - ^ C?) - (QH ₉ SeM ₂ N-CO-S-CH ₂ - <^ cT)> + HCI

One works in a solvent or diluent; a tertiary base, such as pyridine, is used as the HCl acceptor. You can also use the 2)

Use mercaptan in salt form (eg as the sodium salt), which is obtainable from the reaction of the mercaptan ι ο with metallic sodium or better with alkali hydroxide in an aqueous medium and subsequent dehydration;
Reaction between di-sec-butylamine and carbon oxysulfide, NaOH and a senzyl halide, such as benzyl chloride, according to the following equation:

(QH, sec.) ₂ NH + COS + ClCH ₂ ^ f O> + NaOH - * (QH ₉ SCkO ₂ NCOSCH ₂ ^ O _> + NaCl + H ₂ O

The reaction takes place easily by reacting the carbon oxysulfide with the amine in the presence of a stoichiometric amount of alkali hydroxide (such as NaOH) in the first stage. The di-selec-butylthiol carbamate thus formed is then without isolation (QH ₉ sec.) ₂ NH + Cl-CO-SCH ₂

This reaction can take place in the presence of an inert solvent such as benzene, ether, dichloroethane, be performed. The hydrochloric acid can be replaced by a second mol amine or more expediently jo be neutralized by alkali hydroxide, such as NaOH in aqueous solution.

To kill weeds or to stimulate rice growth, the product according to the invention can be used without difficulty using solid or liquid diluents, solvents, emulsifiers or Dispersants are prepared; this is how preparations or formulations are obtained that have been stored and handled or, if necessary, can be further diluted until they are ready for use in the field have achieved the necessary concentration.

The formulations can be produced in solid, granulated, liquid form or as a paste with different concentrations. According to the 4 ^r> environmental conditions and the available technical means is preferred one or the other type of formulation.

Solid preparations in the form of tablets are made either by intimate mixing of the active product w with inert solid carriers such as bentonite, calcite, dolomite, vermiculite, attapuglite, pyrophyllite, sepiolite, Phosphorite Kieseiguhr, hydrated silicic acid or synthetic calcium silicates, as well as with fertilizers, such as ammonium sulfate, urea, phosphorite superphosphates, fertilizer complexes, among others Adding a surface active agent or absorbing it diluted in a solvent active ingredient made by a carrier.

Example of a granulated formulation:

Benzyl-NN-di-sec-butylthiol carbamate 55%
16/40 mesh bentonite 94%

surfactant
on the basis of
Sodium isooctyl sulfosuccinate 1%

The active ingredient and surfactant are dissolved in a little methylene chloride (which is used to wet the

bo

65 ren reacted in a second stage with the benzyl halide

3) reaction between benzylthiocarbonyl chloride (one from Chem. Ber. 80, pp. 2293-2301 (1956) known product) and Qi-sec.-butylamine:

(C ₄ H ₉ sec.) ₂ N - CO - S-CH ₂

HCI

total bentonite exactly the necessary amount) and the mass is in one with a Mixer equipped with a steam extractor until the methylene chloride has evaporated.

The active product content of the granulated formulation can be varied within wide limits, e.g. B. between 0.25-80%, preferably between 0.50-20%. The particle size of the granulated carrier can between 0.1-4 mm, preferably between 0.15-0.7 mm.

So-called "wettable powders" are obtained by mixing in one or more surface-active powders Agents in the powder. By dispersing these wettable powders in water, aqueous powders are obtained Suspensions of the desired concentration. These aqueous suspensions are then on the ground sprayed.

Example of a wettable powder:

Benzyl-N.N-di-sec-butylthiol carbamate 40%

Diatomaceous earth 53%
Polyoxyethylene derivative of an alkyl ether, mixed with fatty esters and

Fatty acids 4%

Sodium salt of a polycarboxylic acid 3%

Liquid emulsifiable formulations (emulsifiable concentrates) are made by diluting the active ingredient in a water-insoluble solvent or solvent mixture, and Addition of one or more surfactants.

The active ingredient content of these formulations is between 70-15%.

If these preparations are mixed with water, emulsions are obtained in which the solvent phase is dispersed in the aqueous phase and the active product in the dispersed phase in solution is held.

Thus, the achievement of a uniform distribution of the active product in the one used for spraying, aqueous preparation possible.

Example of an emulsifiable liquid formulation:

Benzyl-N.N-di-sec-butylthiol carbamate 50%

Xylene 25%

Tetrachlorethylene 15%
Mixture of organic

Plant ethoxylate sulfonate 10%

Example of a liquid concentrated formulation to be sprayed on the rice seeds:

Benzyl-N, N-di-sec-buty-thiol carbamate 70%
Mixture of polyether alcohol and
organic sulfonates 30%

As an emulsifying dispersion medium (surface-active Agents) used to produce wettable powders and emulsifiable concentration, one can use anionic, nonionic and cationic agents.

The anionic agents include: sodium dodecylbenzenesulfonate, calcium naphthalene sulfonate, Sodium lauryl sulfate; as cationic agents one can name: quaternary ammonium compounds, such as Cetylpyridinium bromide, dodecylbenzylmethylammonium chloride, di (hydroxyethyl) benzyldodecylammonium chloride; and the non-ionic agents include the condensation products of ethylene oxide with aliphatic alcohols, amines, fatty acids and alkylphenols.

Due to the excellent solubility of the compound according to the invention in numerous solvents the manufacture of any type of preparation containing the compound is not difficult; where appropriate, herbicides with a complementary effect or can be added to the preparations Algacides and / or pesticides and fertilizers are added as used in agriculture Achieving an additive effect of the individual components and saving otherwise necessary, multiple operations is common

The quantities used for weed killing can vary according to the content of active product, the plant species and treatment method vary widely. On average, these quantities should be that they contain 2-8 kg of active product per hectare of soil.

To achieve a higher stimulating effect than that which is sufficient for weed killing Doses is possible, higher doses than indicated above can be used.

The main object of the present invention is thus to provide a weed-killing product in rice fields in an effective and at the same time completely safe manner without any possible harm of crops; Another, no less important goal is the simultaneous stimulation of growth of crops so that they are in the best condition to overcome physical and biological Environmental harm and the inherent ability of the plant to absorb reinforce and assimilate the nourishing principles; furthermore, the invention becomes a versatile one Weedkillers created that are good under the most varied of climatic conditions Provides results and can be adapted to the most varied of cultivation methods Increase in production and considerable savings in seeds with the same investment - namely Number of plants per surface unit - possible The following examples illustrate di present invention.

example 1

2.3 g (0.1 mol) of metallic sodium, cut into small pieces, became anhydrous in 25 ecm Benzene suspended. There were 18.6 g (0.15 mol

to benzyl mercaptan was added and the whole thing heated in countercurrent with stirring until gas formation ceased. Then 19.1 g (0.1 mol) of di-sec-butylcarba moyl chloride were added, whereupon the mixture was heated under reflux conditions for 2 hours. After the cool down len to 20 ° C was filtered off and the formed Natriumchlork Benzoliösurtg under reduced pressure (about 15 mm Hg) evaporated at 50-60 ⁰ C. The residue was distilled at 0.1 mm and the fractions recovered at 130-132 ° C. This gave 20 μl of S-benzyl-NN-di-sec-butylthiol carbamate.

Analysis:

Ber .: N 5.01, S 11.47%
found: N 4.90, S 11.50%

Di-sec-butylcarbamoyl chloride has not yet been described in the chemical literature; it can durcl reacting phosgene with di-sec-butylamine wii be prepared as follows: 250 g (2.5 mol) were Phosgei biert sublingually at about 50 ⁰ C under substantially anhydrous conditions in 1000 cc of anhydrous benzene Then, 645 g of 5 mol ) anhydrous di-sec. butylamine introduced with stirring, the temperature door being kept at 0-5 ° C. A voluminous white amine hydrochloride consisting of amine hydrochloride formed:

Precipitation. After a further 3 hours of scrambled eggs, 500 ecm of ice water were introduced liquid phases were separated. The organic phases were washed with 500 ecm of ice water over CaCl dried and concentrated under reduced pressure (15 mm Hg at 50-60 ° C.

450 g of the liquid thus obtained were distilled under high vacuum. In this way, 425 g of di-sec were obtained. butylcarbamoylchlorid, diebeiO, l mm Hg and 85-90 ⁰ C were distilled. The yield corresponded to 89% of theory. Th.

Analysis:

Ben: Cl 18.5%

found: Cl 18.22-18.33%

Example 2

1000 cc benzene, 205 g (1.65 moles) benzyl mercaptai and 66 g (1.65 mol) of NaOH (dissolved in 500 ecm of water) in a with stirrer, thermometer, reflux cooler and device for azeotropic distillation provided 3-1 flasks. The whole thing was introduced heated to boiling with stirring, water being removed azeotropically. Then there were 3161 (1.65 MoT) di-sec-butyicarbamoyl chloride introduced and heated under reflux conditions with stirring for a further 4 hours

After cooling to 20 ⁰ C 1000 ccn water were added and the two liquid phase I separated and the benzene phase was washed twice with jt 500 cc of water and then at reduced pressure concentrated By working according to Example
one contained 415 g of distilled S-benzyl-NJi-di-sec. butyl thiol carbamate

Example 3

A mixture of 12.4 g (0.1 MoI) benzyl mercaptan, 7.9 g of anhydrous pyridine (0.1 mol) and 19,1g di-sec-butylcarbamoylchlorid was heated to 130 ⁰ C and held for 5 hours at this temperature . After cooling, 15 ecm of methylene chloride and 30 ecm of water were added.

The aqueous layer was removed while the organic layer was then washed with water and was concentrated under reduced pressure. Working according to Example 1 gave 13 g of S-benzyl-N.N-di-sec-butylthiol carbamate.

Example 4

27 g (0.45 mol) of carbon oxysulfide were passed into a mixture of 49 g (0.38 mol) of di-sec-butylamine, 15.2 g (0.38 mol) of NaOH and 65 g of water, the temperature at was kept between 0-3 ° C. Then 6.6 g (0.04 mol) of potassium iodide and 50.4 g (0.4 mol) of benzyl chloride were introduced. The whole was heated with vigorous stirring, first at 30 ° C, held for 2 hours at this temperature, and then heated to 50 ⁰ C and kept for 12 hours at this temperature. After cooling, 250 ecm of methylene chloride were mixed in and the layers were separated. The organic liquid was washed with water, concentrated under reduced pressure and finally distilled according to Example 1; 25 g of S-benzyl-NN-di-sec-butylthiol carbamate were obtained in this way.

Example 5

18.6 g of benzylthiocarbonyl chloride were in a solution of 25.8 g (0.2 mol) of di-sec-butylamine and 150 ecm of anhydrous benzene introduced, whereupon an exothermic reaction with subsequent formation of Di-sec-butylamine hydrochloride crystals took place.

The whole was heated to 65 ° C, held for 30 minutes at this temperature and then cooled to 20 ⁰ C were added 250 cc of water, and after separation of the layers, the aqueous 4 "liquid was removed. This treatment was repeated again with 250 ecm of water. The organic layer was treated as in Example 1 to give 25 g of distilled S-benzyl-NN-di-sec-butylthiol carbamate.

Example 6

To a solution of 14.2 g (0.11 mol) of di-sec-butylamine in 50 ecm of 1,2-dichloroethane were added 18.5 g (0.1 mol) of benzylthiocarbonyl chloride, dissolved in 26 ecm of dichloroethane, with vigorous stirring added at about 0 ⁰ C; then 40 g (0.1 mol) of a 10% strength aqueous NaOH solution were added, the temperature being kept at 0 ° C. The cooling bath was removed and the temperature was allowed to rise spontaneously to 20 ° C. The layers were separated, the organic solution was collected, washed twice with 50 ecm of water each time and then treated as in Example 1. This gave 21 g of distilled S-benzyl-N, N-di-sec-butylthiol carbamate

The Destructive Effect of S-BenzyI-N, N-di-sec-butylthiolcarbamate against weeds and especially against Echinocloa spp. (Chicken millet) occurs when using average amounts between 2–6 kg / ha; even when using only 4-6 kg / ha the stimulating effect for rice is evident, so that an unusual combination of weed killing and stimulant effects as opposed to the crop can be achieved. The stimulation is reflected in stronger plant growth and a further development of the root system; no malformations were found and the yield increases

Below are some data claimed on the stimulatory effects of treatments with dej Compound in rice seedlings under different conditions compared to means A and to homologous and isomeric products to the claimed compound indicated.

Stimulation and comparison with Molinate

The compound according to claim 1 is not only harmless to the rice, but it also stimulates the Germination and development of root systems and Sprouts, as can be seen from the following examples.

Example 7

In a set of cylindrical pots having ^{an inner surface area of 200 cm 2} , sifted rice paddy soil was placed in an amount of 1 kg / pot. After smoothing and pouring with 200 ecm of water, the surface of the earth was uniformly sprayed with a hydroacetone solution (acetone-water mixture) containing 0-0.2-0.3-0.4% active product; 4 ecm of solution were used per pot, which therefore corresponded to 0-4-6-8 kg of active product per hectare. Immediately thereafter, each pot was filled with water to a height of 7 cm above the surface of the earth, whereupon 15 pre-germinated rice seedlings were used per pot. Each treatment was repeated 3 times. The pots were kept in an air-controlled environment, the daily thermal differential between + 10 ⁰ C and 25 ° C fluctuated; the lighting time was 14 hours. After such treatment for days, the percentage of plants sprouted and the length of the sprouts were examined. The values determined are listed in the following table:

Results of a selectivity comparison for rice in underwater culture in air-controlled
Environment with the compound according to the invention and the comparison agent A

Treatment with Ha
Ha
Ha % ge
sprouted
plants average
actual values per
plant Sprout Ha
Ha
Ha Head
root cm cm 17.2 control 42.3 7.0 17.8
21.1
23.9 Registration subject
4 kg of active product per
6 kg of active product per
8 kg of active product per 60.0
53.3
77.7 8.3
10.4
10.1 15.3
8.2
6.6 Comparison means A
4 kg of active product per
6 kg of active product per
8 kg of active product per 42.3
20.0
11.0 7.4
3.9
4.6

From the data of Example 7 is the stimulatory effect on rice in underwater culture obviously, while agent A shows a narrow safety factor under the same conditions and the growth of the rice plant is adversely affected even with quantities of 6 kg active ingredient per hectare

ίο

example

On the basis of the above results, additional hectares were administered. The results were 33 days after Tests found through treatments according to the procedure of Example 7; the relative performs The compound according to claim 1, average values are given in the table below in quantities of 10-20-30 kg of active ingredient per "> listed:

treatment Sprouted
plants
% Ila main root
cm Sprout
cm Number of seconds
Roots per
plant control 46.6 3.8 9.9 1.07 Benzyl-r ^ N-di-sec.butylthiol-
carbamate 10 kg of active product per hectare 71.1 11.3 19.97 4.4 20 kg of active product per hectare 77.7 10.6 20.9 5.1 30 kg of active product per hectare 80.0 11.1 23.4 5.4 example 9

In the greenhouse, a test was ^{prepared with a set of boxes with an internal surface area of 1000 cm 2.} 18 kg of sifted rice field soil were placed in each box. After smoothing, the surface of the earth was sprayed uniformly with a hydroacetone solution which contained 0-0.5-0.75-1-1.25-1.5% of the compound according to the invention. Each box was given 20 ecm of solution, which corresponds to 0-10-15-20-25-30 kg of active product per hectare. Each box was flooded with a 10 cm layer of water measured from the surface of the earth. The planting took place immediately afterwards with pre-germinated cultivars (cv) RIBE rice seedlings in a number of 40 pieces per box. While

During the test, the greenhouse temperature was between + 10 ° C and + 28 "C. 27 days after the treatment, all rice plants were removed from each box and examined biometrically. The average values for the 40 rice seedlings placed in each box are in

«Ι indicated in the following table.

Invention Sprout plants Ila main root Test = 100 Sprout Test = Secondary root according to ver
binding; kg % Test = 100 cm cm 100 number Test = 100 active pro duct / ha 100 100 0 40.0 100 3.10 150 5.92 198 2.22 100 10 52.5 131 4.82 131 11.70 203 2.82 127 15th 57.5 144 4.06 267 11.99 205 2.95 133 20th 77.5 193 8.29 218 12.15 293 4.42 199 25th 85.0 212 6.77 285 16.77 246 4.66 210 30th 87.5 219 8.84 14.59 4.90 220

Example 9a

A second test is carried out under identical conditions using the same procedure in the greenhouse; the 66 days Results obtained after treatment are shown in the table below:

Test results with the compound according to the invention in rice in a culture under water Greenhouse, 66 days after treatment

Connection according to
Cont. 1; kg act.
Product per hectare

Sprouted
plants

Main root shoot

cm

cm

30.0
45.0
45.0
60.0
40.0
40.0

7.24 12.64 13.54 17.16 10.26

8.21

10.44 16.74 18.16 26.00 15.00 4.5Ο

Secondary Weight on a dry basis Shoot **) Root;
number Root*) 4,250 5.12 2.675 8,000 12.20 5.550 11,800 13.30 6,800 18,050 21.00 10,480 6.875 10.05 4,250 5.050 8.00 2,800

*) Weight of the roots of 100 plants. **) Weight of the sprouts from 100 plants.

An outdoor test was carried out on clay soil in the province of Novara, Italy. For each test, fields of 600 m ² with independent water supply were prepared. After the soil had been tilled and smoothed, the treatment took place on April 23, 1970, with formulations of the compound according to the invention and agent A in emulsifiable oils which were sprayed by means of mechanical devices. Only the field treated with Agent A was chopped immediately after treatment to incorporate the product and peeled 10

avoid any losses due to volatilization. Immediately afterwards the fields were placed under water at a water level of 10-12 cm. ^r ) On April 25, 1970, pre-germinated cv. RIBE rice set mechanically.

36 days after the treatment, 50 random rice plants were taken from each field and biometrically examined. The average results from it

ίο are listed in the following table.

Data from outdoor tests; Treatment with a water emulsion in not submerged soil with subsequent immediate flooding and setting

Treatment kg / ha act. product Main root shoot cm Secondary Average weight per plant, calculated cm Root;
number on a dry basis
Roots sprout all in all 25.99 g g G control 6.46 9.50 1.675 3.273 4.948 Comparison means A 25.72 4 kg / ha 7.67 9.06 1,866 3,257 5.123 Connection according to claim. 1 29.22 4 kg / ha 9.29 30.17 9.64 2,431 4,073 6,504 6 kg / ha 10.19 Investigations 10.42 3.123 4.209 7.341 On the four fields were periodic carried out , their results 2 months after the treatment were as follows: treatment Was standing*) Appearance of average Rice plants liche height: cm

Control normal normal 40-45

Comparison means A; 4 kg act. Product / ha normal normal 35-45 cm

According to the invention. Link; 4 kg act. Product / ha very high excellent about 60 cm

According to the invention. Link; 6 kg act. Product / ha very high excellent about 60 cm

*) Number of saplings per surface unit.

Example 11

Comparison between the stimulatory effect of benzyl N.N-di-sec-butylthiol carbamate and that of its lower homologues and its isomers.

In the province of Pavia, Italy, one treatment per test was carried out outdoors on poor clay soil on rice fields with a surface area of ^{12 m 2 each}

Formulations of 20% benzyl-N, N-di-sec-butylthiol carbamate were used with formulations of 20%

Ν, Ν-diisopropylbenzylthiol carbamate; N, N-diisobutyl benzyl thiol carbamate and Ν, Ν-di-n-butylbenzylthiol carbamate (all formulations in emulsifiable oil) in doses of 4.6 and 20 kg / ha compared.

The results of 20 plants per treatment were collected 21 days after planting and used in listed in the following table.

Treatment with

kg / ha act Main roots Sprc product number cm 4.36 6.07 4th 5.55 7.11 6th 5.73 7.34 20th 6.76 7.68 4th 3.45 5.36 6th 3.67 5.44 20th 2.79 4.03

Second Roots number

control
Benzyl N, N-di-sec-butyl thiol carbamate

Ν, Ν-diisopropylbenzylthiol carbamate 2.15 2.52 2.63 2.63 2.52 1.63 1.21

Fortset / urm

Treatment with

kg / ha akl. Product main root sprout
Number of cm

Second Roots number

Ν, Ν-diisobutylbenzylthiolcarbamal

NJvl-di-n-butylbenzylthiol carbamate

4th 3.21 5.25 , 68 6th 2.76 4.21 , 57 2G 2.59 3.96 , 52 4th 3.26 4.76 , 78 6th 2.81 5.24 1.94 20th 1.94 2.34: '05

From the data in the above tables it can be seen that benzyl N.N-di-sec-butylthiol carbamate stimulates rice growth favored by it the development not only of the part emerging from the ground, but in particular also of the roots, stimulated The roots are longer, larger and more numerous, like the enclosed ones Show drawings. F i g. A the appearance of the rice 21 days after treatment with 4 kg / ha r> Benzyl-N.N-di-sec-butylthiol carbamate (Fig. 1. 2, 3) versus control (Figs. 4,5,6). F i g. B shows the Rice 21 days after treatment with 6 kg / ha benzyl-N, N-di-sec-butylthiol carbamate (Fig. 7, 8, 9) versus control (10,11,12). «>

The stimulus does not modify the normal physiology of the plant; there are no deformities, what is the case when using products with parahormonal effects. The vegetative apparatus grows according to the normal proportions, but j> the development takes place faster, so that the plant the biological and physical hardships faster which threaten the plant in its first growth stages.

From the agronomic point of view, this observation is of the utmost importance, since the plant derives from it draws immediate and long-lasting benefits.

Due to the stronger development of the roots, the rice plant can get hold of the ground better and avoids it therefore the risk of being uprooted by the wind is easier, as is the case with rice fields under water often occurs during the first few weeks after setting.

Due to the faster development of the part above the ground, especially during the first Growth stages, the rice plants can more quickly escape the suffocating effects of algae that are there as is known, they can even prevent the rice from leaking out of the water surface.

The effect of stimulating the development of the part above the ground and the roots is long-lasting, making the rice plants stronger, sprouting better and the fertilizers added to the soil consequently can better exploit. Thus, in the bo treated with the product according to the invention Soil much smaller amounts of seedlings can be used than before. Appropriately one uses hence, as is also common practice in agriculture, the new means together with fertilizers at. t> 5

From an economic point of view, it can be advantageous to use the product in larger quantities than are sufficient to kill weeds, although the product - as stated - exerts a strongly stimulating effect even in these quantities. In this case , it can be useful to also to use larger amounts of fertilizer in order to influence production in the best possible way.

The properties of the new compound described above are completely new; and join others Weedkilling products used in rice do not include; there is nothing about it from literature either known. In the past herbicides have been found with good selectivity even in considerably higher doses known as the usual doses for the use of herbicides, which means that they do not affect the crops permanent damage. The product according to the invention is not so much about the selectivity that im essential is a lack of a negative biological effect on the useful plant, but that On the contrary, the product according to the invention has a biological effect that is valuable for the useful plant. the Weed-killing effect of benzyl-N, N-di-sec-butylthiol carbamate during the forerun period is extremely high in various Graminae and very high weak in Dicotyledoneri; the product is not volatile and therefore does not penetrate the soil to be incorporated, as is required for comparison agent A.

A) Effectiveness in dry culture
Example 12

Two sets of 11 cm square small containers Sides that were filled with field soil to which 30% sand was admixed, were to a depth from 0.5-1 cm sown with the following types of grass: Echinocloa cms galli, Setaria italica, Alopecurus myosiuroides, Lolium italicum, Digitaria sanguinalis, Avena fatua, Agrostis segetum, Dactylis glomerata. After sowing, the soil surface became uniform with 2.4 cc per container of a hydroacetone solution sprayed containing 0,0,05,0,10,0,20 and 0.30% benzyl-N, N-disec.-butylthiol carbamate and Agent A, respectively, so that doses of 0.1, 2.4 and 6 kg of active product per hectare revealed.

Only one set of the containers was covered with a 1 cm layer of earth immediately after treatment. Then were all containers kept in an air controlled room as in Example 7 and poured every day.

25 days after the treatment, the results were noted, the treatments being the following Rating was given:

0 = normal exit and development

1 = slightly negative difference to the control

2 = certain effectiveness with partial damage that

however in general the life of the plant is not threatened

3 = considerable effectiveness with damage that definitely threatens further growth of most plants; this activity is suitable for practical use 4 = thorough prevention of leakage or interruption of development at 0.5 cm and subsequent death of the plant

The corresponding data are given in Table 1. Table 1

treatment product kg / ha Weed killing effectiveness Digital Avena Agrostis Dactylis Echino- Setaria Alop- Lolium well sp. fatua sp. sp. cloa sp. curus sp. sp.

Surface treated

Benzyl-N, N-di-sec.

butyl thiol carbamate

Treated surface
with 1 cm layer of soil
Benzyl N, N-di-sec-butyl thiol carbamate
covered

Means A

Means A

6th 4th 4/3 4th 4th 4th 3 4th 4th 4th 4/3 4/3 3 4th 4th 3 - 4/3 2 3/4 3 2 4th 4th 3 4th 4th I. 3 3 1/2 4th 3 2/3 4th 3/4 6th 1/2 0/1 3 2/3 4th 4/3 4th 3 4th 1/2 0/1 2 2 3/4 3/2 4th 1/2 2 2 0/1 1/2 0/1 0 1 2 1/2 6th 4th 4th 4th 4th 4th 4th 4th 4th 4th 4th 4/3 4th 4th 4th 4th 4th 4th 2 4/3 3/4 4th 4th 4th 4th 4th 4th 6th 3/4 3 4/3 4th 4th 4th 4th 4/3 4th 3 3 4/3 3/4 4th 4th 4th 4/3 2 3 3 3 3/2 4th 4th 4th 3

B) Effectiveness in submerged cultures

In underwater cultures, benzyl-N, N-di-sec-butylthiol carbamate acts on Echinocloa spp. in the Preliminary stage has a strong effect that is at least the same as that of Agent A. The Echinocloa Plants emerge from the ground, their growth will however between 0.5-6 cm corresponding to the benzyl-Ν, Ν-di-sec-butylthiolcarbamate doses and the den The type of formulation administered to plants is interrupted. In either case, wilting and death ensues.

example

Example 7 was made with changed doses, i.e. H. 0,0,5,1, 2 and 4 kg active product / ha, different type of formulation and with Echinocloa spp. (25 slightly pre-germinated seedlings per pot) instead of rice.

Test 1 : test results 22 days after treatment

treatment

Sprouted plants main root shoot

Remarks

control

Benzyl-N, N-di-sec-butylthiolcarbamate hydroacetone solution

4 kg of active product per hectare

2 kg of active product per hectare

Comparative agent A, hydroacetone solution 4 kg of active product per hectare

84

11.7

viable plants

0 0 0 small plants, at 0 0 0 1.5-3 cm interrupted, who then died

small plants, at
1.5-3 cm interrupted, which then died

Test 2: Results 21 days after treatment

treatment was standing Main root Sprout Remarks % cm cm control 86 4.63 13.50 viable plants Benzyl N.N -di-sec-butylthiol carbamate Hydroacetone solution 2 kg of act product per hectare 0 0 0 small plants, at 4 kg of act product per hectare 0 0 0 2-5 cm height under
broke that then die off 0.5 kg of act product per hectare 62 3.28 8.81 viable plants

Test 3: Results 27 days after treatment

treatment

Stand main root shoot
cm cm

Remarks

control

Benzyl-N, N-di-sec-butylthiolcarbamate hydroacetone solution

4 kg act. Product per hectare

2 kg act. Product per hectare

Benzyl N.N -di-sec-butylthiol carbamate 50% emulsifiable oil

4 kg act. Product per hectare

2 kg act. Product per hectare

80

0.03 15.66 plants susceptible to life

small plants, interrupted at 0.5 cm, which then died

0 0 0 small plants, at 0 0 0 2-3 cm interrupted who then died

Example 14

Example 9 was made using Echinocloa spp. (40 slightly pre-germinated seedlings per box) Place of rice repeatedly. The results 24 days after treatment were as follows:

pre-germinated seedlings used per box. The results after a further 24 days were as follows:

4 ^r )

treatment

Sprout remarks

treatment was standing Sprout Remarks % cm control 98.7 15.4 all plants
lived Benzyl-N, N-di-sec.
butyl thiol carbamate,
active product
2 kg / ha
4 kg / ha
6 kg / ha
8 kg / ha 2.5
0
0
0 8.5
0
0
0 only 1 plant
lived

After the Echinocloa spp. Plants were grassed a second time in the same boxes for 24 days after treatment in a number of 20 easily

control

100

Benzyl N, N-di-sec-butyl thiol carbamate;
active product
2 kg / ha 100

b0

4 kg / ha

6 kg / ha
8 kg / ha

0
0

27.5

26.5 27.0

0 0

15th

all plants were alive

all plants

lived

all plants

lived

example

A clear confirmation of the effectiveness of benzyl Ν, Ν-di-sec-butylthiol carbamate against Echinocloa spp. was obtained outdoors, where the test was carried out under the conditions customary for Italian rice cultivation. The experimental conditions are described in Example 10. After the treatment, it was found:

treatment

Infested with

Echinocloa
spp.

Alisma sp.

Scirpus sp.

control
Means A

4 kg active product / ha
Benzyl N, N-di-sec-butyl thiol carbamate

4 kg active product / ha

6 kg active product / ha

considerably something
almost nothing anything

nothing
nothing

small amount*)
small amount*)

some
some

small amount*)
small amount*)

*) The limited presence of Alisma sp. and Scirpus sp. in those with benzyl-N, N-di-sec-butylthiol carbamate the fields treated is at least partly due to the particularly healthy state of the rice, which suffocated these weeds after they had sprouted.

Also the dams with the benzyl-N.N-di-sec-butylthiolcarbamate treated fields were completely free of barnyardgren.

2 months after the treatment, the following results were noted:

treatment

Infestation with Echinocloa spp. Number of plants per m ² were 70 seedlings Echinocloa spp. set per box. After the soil was saturated and as soon as the weed plants emerged, aJle 7 cm was placed under water. When the plants had reached a maximum height of 3-4 cm, the flooded water surface was sprayed with a hydroacetone solution as in Example 9. 33 days after treatment were the

2 '> the following results were found:

Control 150

Means A;
4 kg act. Prod./ha 1 -2

Benzyl N, N-di-sec-butyl'hiolcarbamate

4 kg act. Prod./ha 0.25

6 kg act. Prod./ha 0.33

Example 16

Benzyl N, N-di-sec-butylthiol carbamate affects Echinocloa spp. in the after-run stage a considerable amount Effect.

Testl

According to Example 9, a set of boxes with an inner surface of ^{1000 cm 2 was prepared in the greenhouse.} then

treatment il) control was standing Sprout Remarks cm Benzyl-N, N-di-sec. ! ■ "> butyl thiol carbamate 64 25-30 all plants 4, 6 and 8 kg act. lived Prod./ha 0 0 maximum height 3-4 cm, from die

Test 2

A second test was performed according to the above procedure; while the treatment was carried out as the Weed plants had reached a maximum height of 10 cm. 26 days after this treatment were made found the following results:

treatment

Stand scion remarks
% cm

control

Benzyi-N, N-di-sec-butylthiol carbamate

4, 6 and 8 kg act.

Prod./ha

66.5 25-32

all plants
lived

maximum height
10 centimeters; Die

Test 3

In the open, some fields of 12 m ² each, separated by artificial dams, were prepared.

After the soil had been tilled and smoothed, the fields were filled with Echinocloa spp. infected and then with 10 cm Flooded water; on May 20, 1970, rice was sown at 150 kg of seeds per hectare. Both rice as well as Echinocloa emerged from the ground 5 days after flooding.

When the Echinocloa plants had reached an average height of 12-14 cm, this was done Treatment by uniform spraying of the flooded water surface.

Test products: compound according to the invention and agent A, compounds in emulsifiable oil.

Dose: 0.4 and 6 kg active product / ha.

The first effect on Echinocloa spp. was found for both products 7 days after treatment. After 45 Taeen the following results appear:

treatment

rice

Echinocloa spp.

control

Benzyl l ^ N di-sec-butyl thiol carbamate, active product
4 kg / ha
6 kg / ha

Means A;
active product
4 kg / ha

6 kg / ha

35-40 cm high normal shoot, partial damage due to the presence of weeds

stronger and thicker than the control

and than the one treated with Molinate

rice

stronger and thicker than the control

and than the one treated with Molinate

rice

stronger than control

stronger than the control some plants 15-50 cm high

complete annihilation of the previously

existing plants; not a new one

Exit

complete annihilation of the previously

existing plants; not a new one

Exit

complete annihilation of the previously
existing plants; not a new one
Exit

complete annihilation of the previously
existing plants; not a new one
Exit

As is well known, the world's rice cultivation is carried out by the different rice-growing countries according to very different agronomic practices, which are used by the availability of labor, the local weather conditions, the level of technical development and the mechanization achieved in the different countries. Mention should be made the traditional system of cultivation with permanently submerged rice fields, their water level varies from country to country (with the exception of the harvest time) and the system of sowing in dry soil, whereby this is sown after more or less long time intervals during which the seed germination and subsequent development regulated or regulated by the frequency and regularity of precipitation being affected.

Echinocloa spp. is an amphibian plant that grows on submerged and non-flooded ground developed immediately; more precisely, water levels above 15-20 cm tend to limit their growth. Indeed, the presently proposed herbicides for killing the above weeds like be appropriate under some of the conditions mentioned. In contrast, benzyl has N, N-di-sec-butyl thiol carbamate proved that it can work under all possible conditions. the The following examples show this variety of uses.

jo B e i s ρ i e 1 17

Testl

As in Example 9, a set of boxes was prepared. 60 Echinocloa spp. Seeds and 40

3ϊ rice seeds sown, covered with 1 cm of fine soil became. Then the soil was saturated with water, and the surface in doses of 0,2,4,6,8,10 and 12 kg active product / ha with benzyl-N.N-di-sec-butylthiol carbamate sprayed.

On the following days, the boxes were poured as needed. For each attempt, the Weed and rice development examined after 14 days. Then all the boxes were at 10 cm level filled with water. The final exam 5 was done 87 days after treatment; the results are listed in the following tables.

treatment

Before flooding

Infestation 14 days after treatment

Echinocloa spp.

After flooding

Infestation with Echinocloa spp. 87 days after treatment

Stand sprout roots

% cm cm

control

BenzyI-N, N-di-sec-butylthiol carbamate; active
product

2 kg / ha

4 kg / ha

6 kg / ha

8 kg / ha
10 kg / ha
12 kg / ha

many plants 15-20 cm high

some plants 7-10 cm high, some plants 2-5 cm high, some plants 1-2 cm high some plants 1 cm high, some plants 1 cm high, some plants 1 cm high 8.3

20.7

10.5

11.7 27.7 15.6 1.7 36.0 13.0 0 0 0 0 0 0 0 0 0 0 0 0

Test 1

treatment Before flooding after treatment After flooding root after treatment Rice growth 14 days Rice growth 87 days cm Sprout Unit weight
on a dry basis was standing 18.4 cm G 15-20 cm high % 26.6 0.1457 control some plants of 85 23.5 Benzyl-N, N-di-sec.
butyl thiol carbamate;
active product 17-25 cm high 22.8 33.9 0.3010 2 kg / ha some plants of 15-25 cm high 95 23.1 36.3 0.2891 4 kg / ha some plants of 15-25 cm high 70 21.2 34.6 0.3160 6 kg / ha some plants of 15-20 cm high 62.5 19.0 31.7 0.2020 8 kg / ha some plants of 12-20 cm high 80 20.6 33.3 0.2564 10 kg / ha some plants of 12-20cm height 82.5 34.2 0.2800 12 kg / ha some plants of 80

Example 18

Benzyl-N, N-di-sec-butylthiol carbamate has a weed-killing effect not only without harming the rice, but it stimulates its development even when the product is on the too before sowing building surface is distributed.

Testi

As in Example 7, a set of glass pots was prepared and immediately thereafter with water up to a height of 7 cm from the floor area. Cv. RIBE rice seeds that had been swollen in water let were divided into 4 groups; each group was given a 70% active product Preparation of benzyl N, N-di-sec-butylthiol carbamate

yes treated what the following doses of active product per hectare corresponded to: 0,0,5,5 and 10 kg.

In each pot, 15 seeds coated with the compound were placed and a thin one Layer of earth covered. After 41 days, the

J5 achieves the following results:

treatment

was standing

Main root cm of shoot
cm

Secondary roots
number

control 55.50 7.92 11.97 3.11 2.5 kg / ha 68.80 8.93 17.16 3.90 5 kg / ha 62.20 8.48 16.83 4.02 10 kg / ha 62.20 10.07 16.92 4.24

Test 2

A similar test was carried out outdoors on clay soil with fields of 12 m ² divided by artificial and waterproof dams.

ίο After flooding, each field was treated with (see test 1) seeds sown with 0.5 and 10 kg active Product / ha corresponding doses were treated. In all cases the amount of semen is 150 kg active product / ha. 45 days after treatment, the following results were obtained:

treatment

Echinocloa infestation

Rice plants

control

Compound according to the invention; act prod.
5 kg / ha

10 kg / ha

many plants about 40 cm high

all plants stopped growing at 1 cm in height and died

all plants stopped growing at 1 cm in height and some plants around 40 cm in height died

some plants about 50 cm high
and considerable strength

some plants about 60 cm high
and considerable strength

Test 3

Another test was carried out outdoors on poor clay soil with fields with a surface area ^{of around 5000 m 2.} After flooding, each field was mechanically sown with treated (cf. Test 1) seeds which had been treated with doses corresponding to 0, 3.0 and 4 kg active product / ha. In all cases the amount of seeds was 150 kg / ha. 67 days after the treatment, the results of 5 test areas of 1 m ² each per treatment were collected, which are listed in the following table:

treatment rice Dry
weight Chicken Deer
(Echinocloa) Saplings 252.20 Saplings number 94.80 number control 351 143.53 23 145 120.20 99 Rice field curses: 3000 m ² 233 169.63 103 180 156.07 100 240 254.50
331.10 50 Average of 5 test areas for the
control 229.8 301.08 75.0 Benzyl I ^ N di-sec-butyl thiol carbamate;
3.6 kg act. Prod./ha 432
430 373.50 0
0 Rice field area: 4800 m ² 421 332.00 0 417 318.44 0 392 473.98
316.91 0 Average of 5 test areas for benzyl
Ν, Ν-di-sec-butylthiol carbamate; 3.6 kg act.
Prod./ha 418.4 484.50 0 Benzyl N, N-di-sec-butyl thiol carbamate;
5.0 kg act. Prod./ha 599
440 423.55 0
0 687 491.10 0 Rice field area: 5400 m ² 523 438.01 0 546 89.51 0 Average of 5 test areas for benzyl
Ν, Ν-di-sec-butylthiol carbamate; 5.0 kg act.
Prod./ha 559.0 130.24 0 LSD (0.05) 86.0 (0.01) 125.1

The possibility of weed killing in rice fields by distributing the herbicide along with the seed during sowing, d. H. the possibility of using the seed as a "carrier" for the herbicide (see Example 18), special attention must be paid as it is a technical achievement of is of unusual importance

The combination of sowing and weed killing in a single operation is real a significant technical simplification possible, which is particularly advantageous for large rice-growing areas, where sowing and weed killing treatments are carried out from the plane.

In addition to the numerous, unusually favorable properties of the product according to the invention, there is another important one, namely the lack of toxicity to warm-blooded animals; the oral LD ₅₀ of benzyl-NN-di-sec-butylthioIcarbamate in rats is 10,250 mg / kg and in mice is 8,000 mg / kg. Therefore, benzyl NN-di-sec-butylthiol carbamate can be considered practically non-toxic, particularly in view of the actual toxicity values reported in the literature for the herbicides mainly used or suggested for killing grass plants in rice fields.

Oral LD50 at Oral LD _5n at Rats Mice mg / kg mg / kg Means A 500-725 Medium B 1384 Middle C 552 Pentachlorophenol 78-280 Medium D 560 Means E 3000

Agent A = ethyl 1-hexamethyleneiminocarbothiolate Agent B = N- (3,4-dichlorophenyl) propionamide. Agent C = methyl-N- (3,4-dichlorophenyl) -carbamaL Agent D = S- (4-chlorobenzyl) -N, N-diethyl thiol carbamate Agent E = 1 ^ -DichlorphenyW-nitrophenyl ether.

1 sheet of drawings

Claims (3)

10 claims: 1. Benzyl-N.N-di-sec-butylthiolcarbamaL 2. A process for the preparation of N.N-di-sec-butyl-S-benzylthiol carbamate, characterized in that that one in a known manner a) Di-selc-butylcarbamoylchloride with benzyl mercaptan in the presence of HCl acceptors implements, b) converts di-selc-butylamine, carbon oxysulfide, sodium hydroxide and a benzyl halide or c) Reacts benzylthiol carbonyl chloride with di-sec-butylamine 3. Use of benzyl-N, N-di-3ek.-butylthiol carbamate, optionally with the usual additives and / or carriers, for killing weeds in rice fields and for stimulating the Rice growth, in particular by treating the rice seeds. methyleneiminocarbothiolate, henceforth "Medium A" for short called, became known. However, treatments with this frequently used product carried out in underwater cultures during the lead-up period can "shock" the rice seedlings and a cause more or less long growth retardation, which sometimes even affects the harvest BE-PS 7 28 265 deals with the use of preparations for selective weed removal Rice fields that are the active ingredient compounds the general formula contain: