DE1031571B - Herbicides - Google Patents

Description

GERMAN

It has been found that certain alkyl N, N-dialkylthiol carbamates have valuable herbicidal properties and especially as to be used before germination Plant killers are valuable.

The following is an exemplary list of compounds found useful. Are for convenience special designations have been given to the compounds, and these are also used in the following.

Herbicides

description

R-1608 R-1606 R-1607 R-1854 R-1857 R-1862 R-1866 R-1870 R-1891 R-1899 R-1903 R-1906 R4893 R-1905 R-1880 R-1908 R-1910 R-1912 R-1913

Surname

Ethyl N.N-di-n-propyl thiol carbamate

Methyl N.N-di-n-propyl thiol carbamate

n-propyl-N, N-di-n-propyl thiol carbamate

Isobutyl N.N-di-n-propyl thiol carbamate

n-butyl-N.N-di-n-propyl thiol carbamate

Allyl N.N-di-n-propyl thiol carbamate

Methyl N, N -di-n -butylthiol carbamate

Ethyl N.N-di-n-butylthiol carbamate

sec-butyl-NjN-di-n-propylthiol carbamate

n-amyl-N.N-di-n-propyl thiol carbamate

n-propyl-N.N-di-isopropyl thiol carbamate

n-butyl-N, N-di-isopropylthiol carbamate

sec-butyl-N.N-di-isopropylthiol carbamate

n-amyl-N.N-di-isopropyl thiol carbamate

n-propyl-N, N-di-n-butylthiol carbamate

Methyl N.N -di-isobutylthiol carbamate

Ethyl-NjN-di-isobutylthiol carbamate

n-propyl-N.N-di-isobutylthiol carbamate

Isopropyl N.N -di-isobutylthiol carbamate.

Thus, the compounds of the invention can be represented by the formula

R ₁ -SCN

wherein R _{1 is} a lower alkenyl or alkyl radical and R ₈ and R _{3 are} alkyl groups having at least 3 carbon atoms.

There is already the use of compounds of the general formula

; n -c -s -R ³

R * ^X If S

in which R ¹ and R ^{2 are} hydrogen, R ^1, R ³ and R ^{3 are} aliphatic, alicyclic or aromatic radicals; where R ¹ , R ² and R ^{a can be the} same or different, known as a germicidal agent in root crops.

Applicant:

Stauffer Chemical Company,
San Francisco, Calif. (V. St. A.)

Representative: Dr. E. Wiegand, Munich 9,

and Dipl.-Ing. W. Niemann, Hamburg 1, Ballindamm 26,

Patent attorneys

Claimed priority:
V. St. v. America January 17, 1956

Harry Tilles, El Cerrito, Calif.,

and Joe Antognini, Mountain View, Calif. (V. St. Α.), Have been named as inventors

However, this is a different class of Compounds than in the invention, namely dithiocarbamates with two sulfur atoms and not thiol carbamates with only one sulfur atom.

In contrast, the herbicide according to the invention serves a different purpose, namely Control of unwanted growth and is especially to be used before the seeds are sprouted suitable. The herbicide according to the invention also has a surprising and unknown one Selectivity within the cereal family. While it z. B. the germination and growth of If maize is not adversely affected, it leads to a complete inhibition of the growth of other cereal grasses, like rye and oats.

Typical compounds according to the invention can be prepared in the manner described below (parts = parts by weight).

R-1608: Sodium is dispersed in xylene using oleic acid as a stabilizer until one particle size from 5 to 200 microns in diameter. An amount of this dispersion equivalent to 16.9 parts (0.733 moles) of sodium, is then placed in a reaction vessel previously filled with argon or another inert gas, for example nitrogen, was flushed through. A solution of 50 parts (0.806 moles) of ethanethiol, dissolved in 86 parts of xylene, is then gradually added to the sodium dispersion over 30 minutes. the

809 529/477

3 4

Temperature is maintained at 25 to 36 ° C by cooling. carbamyl chloride can be used. The carbamyl The sodium ethyl mercaptide is formed in the form of fine chloride is added to the sodium allyl mercaptide at 60 to divided crystals, which make an easily stirrable paste at 70 ° C and the reaction mixture at 80 ° C. This suspension is refluxed, heated for 3 hours before the heat is removed from the reaction mixture and 120 parts (0.733 moles) of 5 are operated. 16 parts (53% yield) of di-n-propylcarbamyl chloride are added over 17 minutes to allyl-NjN-di-n-propylthiol carbamate (boiling point [19 mm]) to the refluxing mash. The 139 to 140 ° C., nf 1.4908). Heat of reaction is sufficient to obtain, under reflux, the R-1866: The general procedure of Example 1 will boil xylene. After all of the di-η- had been followed with the modification that 25 parts (0.52 mol) of mepropylcarbamyl chloride had been added, the io thanthiol was refluxed in small portions at 50 to 60 ° C. with the mixture for a further 3 hours. Sodium dispersion, equivalent to 2.3 parts (0.10 mol) of Na-She is then cooled, the sodium chloride is filtered off, trium is added. It is necessary to ensure that which is formed during the reaction and that unreacted mercaptan is removed in the reaction solvent under reduced pressure. The mixture can not accumulate because a violent Reakrestliche liquid is then distilled under vacuum 15 could tion occur when too much unreacted and gives 125.5 parts (90.6 ° / ₀ yield) of ethyl-N, N-di- mercaptan with unreacted dispersion present n-propyl thiol carbamate (boiling point [31.55 mm] 135.5 to. After the entire sodium dispersion has reacted, 137 ° C, n% 1.4770). The following analysis is obtained: as can be seen from the fact that the color of the reaction

Calculated on a mixture of purple in white, it will be on

C, H ₁₉ NOS Found 20 reflux condenser heated and 19.2 parts (0.10 mol) of di-

571 ° / '57 41 ⁰ I n-butylcarbamyl chloride added. After working up

· '"" 10 1 ° / ° 10 26 ⁰ I ^{in the usual way} 13.9 parts (68.5%

■ xj η'λ oi ° 7 * 17 0 / beute) methyl-NjN-di-n-butylthiol carbamate (boiling point

g ·. "" _{1 (} 5 9 "J ⁰ ₁₆ J ₁ of [20 mm] 144 to 146 ° C, n% ^s 1.4760).

i \ / f MiV ί ^^ -, ν / τ, '+ ma iaz ² 5 R-1870: The general procedure of Example 1 will

Molecular weight lev lob ",? T- jj η • · ο ^ · ι / η -in ■» «· '-η

^b followed with the modification that 6.2 parts (0.10 mol)

R-1607: Using the general procedure of Example 1, add ethanethiol to the sodium dispersion, equivalent to 2.3 parts

is repeated with the modification that 38 parts (0.10 mol) of sodium, at an initial temperature of

(0.50 mol) 1-propanethiol, sodium dispersion equivalent to 27 ° C are added and the temperature to 65 ° C

9.2 parts (0.40 moles) of sodium, and 65.5 parts (0.40 moles) of 30 is allowed to rise during the addition of Mereaptan. Di-n-propylcarbamyl chloride can be applied, then the mixture is then heated to reflux, and there are 70.3 parts (86.5% yield) of n-propyl 19.2 parts (0.10 moles) di-n-butylcarbamyl chloride Ν, Ν-di-n-propylthiol carbamate (boiling point [30 mm] 149 are added. 16.7 parts (76.8% yield) of up to 150 ° C., <1.4750) are obtained. The following analysis N, N-di-n-butylthiol carbamate (boiling point [22 mm] 154.0 is obtained; 35 to 154.5 ° C, n ^s _D ⁹ 1.4740).

Calculated on R-1606: 273 parts of anhydrous isopropanol are in

C ₁₀ H ₂₁ NOS Found a glass or steel reaction vessel and

Γ 591 ° / 59 22 ° / 3.5 parts (0.153 mol) sodium added. The mixture

τι- 10 * 3 ° / ° 10 * 41 ° / ° is heated under reflux, with the sodium

■ vT 6 * 9 ° / ° 701 ° / ° ⁴ ° a ^ äMch dissolves. This solution is then quickly poured into ice

e " λ r'g 0/15 * 77 ° / ° water-cooled. At 50 ° C a thick solid mass precipitates

'' Sodium isopropoxide from solution. The mix will

R-1880: When the general procedure of Example 1 is cooled to 30 ° C and then 9.17 parts (0.191 moles) of methane is repeated except that 9.12 parts of thiol are added quickly. The solid dissolves immediately. the (0.12 mol) 1-propanethiol, sodium dispersion equivalent 45 clear solution is heated to the boil and 198 parts

2.3 parts (0.10 mol) of sodium and 19.2 parts (0.10 mol) of isopropanol are distilled off. 89 parts of anhydrous di-n-butylcarbamyl chloride are used, then xylene is then added and 77 parts of isopropanol, 20.4 parts (88.3% yield) of the n-propyl-xylene mixture are distilled off. 89 further parts of xylene N, N-di-n-butylthiol carbamate (boiling point [15 mm] 156.5 are then added and 89 parts of isopropanol-xylene up to 159 ° C., n " 1.4742) are obtained. 50 mixture is distilled off. 89 further parts Be xylene

R-1854: When the general procedure of Example 1 is added again and 89 parts of solvent, true, except that 16.9 parts of apparently pure xylene are distilled off. 49 more (0.188 mol) 2-methyl-1-propanethiol, sodium dispersion parts of xylene are then added again, the mixture is equivalent to 3.45 parts (0.15 mol) of sodium, and 24.5 parts are heated under reflux and 25 parts of di- n-propylcarb- (0.15 mol) di-n-propylcarbamyl chloride is used, amyl chloride is added over 4 minutes. The reaction, then 25.2 parts (77.3% yield) of iso- is not very exothermic. The mixture is boiled under rebutyl-NN-di-n-propylthiol carbamate (boiling point [18 mm] flow for 14 hours, cooled, the salt is filtered off, 143 to 145 ° C., n ¹ g 1.4744). the cake washed with a little xylene and the solution

R-1857: If following the general procedure of Example 1 then remove medium under reduced pressure. The return is repeated with the exception that 16.9 parts of 60 was distilled in vacuo and 16.7 parts (0.188 mole) of 1-butanethiol, sodium dispersion is equivalent (62.5 ° / ₀ yield) of methyl N, N-di -n-propylthiol carbamate 3.45 parts (0.15 mol) sodium, and 24.5 parts (0.15 mol) (boiling point [30 mm] 128.5 to 129.5 ° C, nf 1.4808) di- n-propylcarbamyl chloride can then be obtained.

becomes 24.8 parts (76% yield) of n-Butyl-N, N-di-R-1905: If the general procedure of Example 9

n-propyl thiol carbamate (boiling point [19 mm] 151.0 to 65 is repeated with the change that 13.0 parts

151.5 ° C, n ² ™ 1.4766). (0.125 moles) 1-pentanethiol, 2.3 parts (0.10 moles) sodium

. R-1862: The general procedure of Example 1 is used and 16.4 parts of diisopropylcarbamyl chloride are used

followed with the modification that 13.3 parts (0.18MoI) den, 15.8 parts (68.3%) of n-amyl-N.N-di-isopropyl-

Allyl mercaptan, sodium dispersion equivalent to 3.45 parts of thiol carbamate (boiling point [22 mm] 145 to 149 ° C,

{0.15 mol) sodium, and 24.5 parts (0.15 mol) di-n-propyl-70 nl 1.4721).

The compounds of the invention have been extensively tested as herbicides and are particular recognized as a pre-germination herbicide. Such herbicides are usually applied by putting a narrow band of herbicide over the center of a sown row is brought at the time of sowing or before the seeds are sprouted. When the herbicide Harmless to the desired harvest, seeds or seedlings, but toxic to the seeds or Is the most common weed, the crop grows in an almost weed-free environment approach. Naturally, the herbicide to be used before germination can also be applied over the entire area Field, but it is usually used in a narrow band that extends across the Seed row lies, and the rest of the weeds are controlled by various cultivation methods held. The herbicides according to the invention are selective towards small-seeded annuals Grasses and broad-leaved plants and are therefore effective against most common weeds but little impact on such valuable row crops as corn and beans. The herbicidal composition can be applied to the ground in any suitable form. For example, it can be in a Solvent such as acetone can be dissolved or sprayed onto the floor in the form of an emulsion, or it can combined with a dry inert carrier and applied as dust or granules. Even though the composition can be applied to the entire area of a tilled floor, will generally preferred to place them in a narrow band, for example about 15 cm wide over the freshly sown row of the crop. In general, amounts applied will be from about 0.2 to 10 kg per acre actually cultivated area found to be suitable.

The following examples show the effect of R-1608, when used to protect corn against weeds.

example 1

One field trial consisted of applying the compounds in amounts of approximately 0.5, 1, 2, 4 and 5 kg (in 300 liters) per acre as a pre-germination treatment on maize. The connection in a small one Dissolved amount of acetone was emulsified in water and added in the desired amount by arranging a spray nozzle applied behind the planting wheel. A 15 cm wide tape was applied and the applied Quantities were based on the area actually cultivated and not on the total area of the treated field. The weather was sunny, air temperature 21 ° C, soil temperature 25 ° C, and the seedbed was well plowed and very dry. Immediately

& 5 after the check, the fields were irrigated. Any treatment was repeated three times. Before the test, the entire area was planted with rye and oats been. Dead nettle seed was present in the soil. In each case, the growth of the corn was normal by comparison with control panels. The following values were obtained:

Table I Results 16 days after application.

Quantity / acre

Maize stand I I II I III average

rye
I II I III

average

R-1608
0.5 kg

1 kg

2 kg

4 kg

5 kg

Control 0.

0.5 kg

1 kg

2 kg

4 kg

5 kg

Control 0.

10

11

12th

11

100
100
100
100
100

8th 10 15th 8th 10 12th 12th 3 12th 8th 6th 11

oats

100 100 100 100 100 100 100 100 100 100 0 0

9.3
10.6
11.0

9.3
10.3

8.6

100
100
100
100
100
0

100
100
100
100
100
0

100
100
100
100
100
0

100
100
100
100
100
0

Dead nettle 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 0 0 0

100
100
100
100
100
0

100
100
100
100
100
0

The corn stand was determined by counting the number of growing corn plants within 3 m of the row. The count was made three times and the three values obtained were averaged. aside from that a similar test was made on a row planted with maize, in which however, none of the tested compounds was applied. In the case of rye, oats, and dead nettle comparisons were made between an untreated and a treated field section and the Results expressed as a percentage of eradication. The percentage of eradication would be for the untreated Field section must of course be zero. In those cases where a complete eradication of weeds

60 has occurred, the value is 100 ° / ₀ . It can be seen that rye and oats were considered weeds in this experiment.

Example 2

A number of compounds were tested at application rates of 40 and 10 kg / acre. The test procedure consisted of planting the seeds in paper containers 7.5 cm in diameter and soaking the seedlings at 30 cm ³ per container. The seeds tested were peas, corn, radishes, cucumbers, and either rye or oats. The values given in Table II were obtained.

Quantity / acre Beans Size Tabel 10 5 II Size rye Size j Cucumber Size oats Ge. Size link Ge. 1 Corn 10 7th Ge. Ge. 2 0 80 kg 10 4th Ge. [Gr. 3 radish 10 50 8th 50 1 R-1606 20 kg 100 1 80 4th Ge. 10 100 - 0 - 80 kg 20th 2 100 70 7th 0 4th ⁰ - R-1607 20 kg 40 100 100 100 100 100 100

Example 3

Acre. It was applied with a spray nozzle under about 12 kg of pressure. The seeds tested were peas. A number of compounds were tested in 15 corn, pumpkin, snap beans, rye and oats. The surface areas in the greenhouse with 1.25 and 5 kg in 300 l per values are given in Table III.

Table III

link Quantity / acre peas
Ge. I Gr. 10
10 IV
Ge. ! ais
Size pumpkin
Ge. I Gr. 10
10 Snap beans
Ge. I Gr. 10
10 rye
Ge. I Gr. 10
8.5 I.
Ge. iafer
Size R-1606 1.25 kg
5 kg 100
100 8.5
6th 100
100 10
10 100
100 10
9.5 100
100 -9
10.5 100
100 1
1 100
50 10
2.5 R-1607 1.25 kg
5 kg 100
90 6.5
4.5 100
100 8.5
8.5 100
100 9.5
9 100
85 10
9.5 20th
10 100
100 8th
1 R-1854 1.25 kg
5 kg 75
100 6.5
5 100
100 10
10 100
100 10
10 100
100 10
10 0
0 0.5
0+ 100
100 0+
0+ R-1857 1.25 kg
5 kg 100
65 7.5
3 100
100 10
10 100
100 10
8.5 100
100 10
9 12.5
2.5 0+
0+ 100
2, 1
0+ R-1862 1.25 kg
5 kg 100
35 10
7.5 100
100 10
10 100
100 10
10 100
100 10
10 85
5 1
1 85
0 0+ R-1866 1.25 kg
. 5 kg 100
100 8.5
8.5 100
100 10
10 100
100 10
10 100
100 10
10 100
100 1.5
1 100
100 1
1 R-1870 1.25 kg
5 kg 100
100 5
5.5 100
100 10
10 100
100 8th
10 100
100 8.5
10 100
75 0+
0+ 100
75 1.5
1 R-1891 1.25 kg
5 kg 55
70 9
5.5 100
100 8.5
9.5 100
100 8.5
9.5 100
100 10
10 5
5 0+
0+ 100
100 0+
0+ R-1899 1.25 kg
5 kg 100
100 100
100 10
10 100
100 100
100 75
10 0.5 100
100 0+
0+ R-1903 1.25 kg
5 kg 30th
0 1.5 40
30th 2
0.5 R-1906 1.25 kg
5 kg 8th
6th 10
8.5 10
9.5 25th
0 6.5
5 75
20th 1
0+ R-1893 1.25 kg
5 kg 100
87.5 100
100 10
10 100
100 100
75 100
50 2
1.5 100
100 0.5
0+ R-1905 1.25 kg
5 kg 6th
6th 9
9.5 10
10 70
65 5
5 50
45 0+
0.5 R-1800 1.25 kg
5 kg 100
100 90
100 10
10 100
100 100
100 100
50 6th
0+ 100
100 1
0+ R-1908 1.25 kg
5 kg 80
10 4th
1 80
30th 9
0 + R-1910 1.25 kg
5 kg 55
30th 3
0.5 50
30th 1
1 R-1912 1.25 kg
5 kg 95
20th 3.5
3 25th
20th 2
1 R-1913 1.25 kg
5 kg 90
80 95
20th 7th
6.5

Ge. = Percent of germinating seeds.

Size = Growth, where 10 means normal growth and 0 means no growth.

Claims (9)

9 10 claims: r2 and R3 mean lower alkyl radicals, as active 1. Plant fertilizers containing a compound. preparation of the formula 2. Composition according to claim 1, characterized in that that the compound ethyl-NN-di-n-propyl-thiolcarb- / ^ 2 5 amate, ethyl- ^ N-di-n-butylthiolcarbamate, n-propyl S C N N. N-di-n-propylthiolcarbamate.n-propyl-N ^ N-di-n- butylthiol carbamate or n-amyl-N.N-isopropylthiol- "Κ. carbamate is. ίο Publications considered: where R _{1 is} a lower alkenyl or alkyl radical and German Patent No. 858 352.