DE2225718A1 - 2-chloroallyl cis and 2-chloroallyl trans-2,5-dimethyl-1-pyrrolidine carbodithioate, process for their preparation and herbicidal compositions containing these compounds - Google Patents

Description

¹¹ 2-chloroallyl-cis- and 2-chloroallyl-trans-2,5-dimethyl-1-pyrrolidinecarbodithioate, process for their preparation and herbicidal compositions containing these compounds "

Priority: May 28, 1971, V.St.A., no.148 159 March 9, 1972, VoSt.A., Ir. 233 295

U.S. Patent 3,078,153 discloses the use of 2-chloroallyl-1-pyrrolidinecarbodithioate described as a specific pre-emergence herbicide against grasses. In the aforementioned patent although the production of 2,5-dimethylpyrrolidincarbdithioaten suggested; However, "no information regarding the production, the physical properties and use of these prebondings. Furthermore, neither is the ice nor that tranB isomers mentioned or described.

The object of the invention was to find new compounds with excellent

ORIGINAL 2098 A9 / .1 196

herbicidal effects available to control broadleaf and grassy weeds can be used and are more effective against grassy weeds than 2-chloroallyl-1-pyrrolidinecarbodithioate. This object is achieved by the invention.

The invention thus relates to 2-chloroallyl-cis and 2-chloroallyl-trans-2,5-dimethyl-1-pyrrolidinecarboethioate der Formula I and II

CH ₃

Cl

(D

H ₂ C = C-CII ₂ Cl

(ID

The invention further relates to a process for the preparation of the compounds according to the invention, which is characterized in that that one cis or trans-2,5-dimethylpyrrolidine in alkaline Solution with carbon disulfide in the corresponding alkali metal salt of cis or trans-2,5-dimethyl-1-pyrrolidine carbodithioate transferred and the compound thus obtained with 2,3-dichloro

- - -209849/4196

propeti- (1) implements.

Sodium hydroxide is preferably used to prepare the alkaline solution used, the sodium salt of the cis or »trans-2,5-dimethyl-1-pyrrolidincarbodithioats is received »

The preparation according to the invention of 2-chloroallyl-cis-2,5-dimethyl-1-pyrrolidinecarbodithioate can be seen from the reaction scheme below.

H-

KaOH

S u

NaS-C—

B ₂ O CS ₂

CH ₂ = C-CH ₂ Cl Cl

CH ₂ = C-CH ₂ -

• s — c—

Di.e preparation of 2-chloroallyl-trans-2,5-dimethyl-1-pyrrolidinecarbodithioate takes place in an analogous manner, with trans-2,5-dimethylpyrrolidine being used instead of cis-2,5-dimethylpyrrolidine will.

The compounds according to the invention have an excellent one herbicidal effect against broad-leaved and grassy weeds

2098A9 / 1

and are the well-known 2-chloroallyl-1-pyrrolidinecarbodithioate think; this applies in particular to the cis isomer.

The invention thus further relates to herbicidal compositions which contain at least one of the compounds according to the invention in effective The herbicidal compositions contained in amounts can contain mixtures of the Be compounds with solid or liquid diluents or with solvents. The inventive Compounds can be used both in undiluted form and also herbicidal agents according to those in US Pat 3,419,626 "method using the methods described therein" Thinners can be processed. The herbicidal agents can also contain surface active agents, other pesticides or growth regulators, fertilizers, spray oils, adhesives, Contain carriers and / or other diluents. The herbicidal compositions can be from about 0.01 to about 99 percent by weight contain at least one of the compounds according to the invention as an active ingredient.

By applying a phytotoxic amount of one of the .gemässen according to the invention Compounds at the site of unwanted plant growth can include both grassy and broad-leaved weeds are combated »The effect of the cis isomer is the same as that of the well-known 2-chloroallyl-1-pyrrolidinecarbodithioate in the -Canipulation of grass-like weeds-superior »One of the -invention Compounds or a herbicidal agent prepared therefrom can, when used as a pre-emergence herbicide, directly on the Soil are applied. It can also be a mixture of the two

209849/1196

Isomers are used »The compounds according to the invention can in the form of spraying agents, impregnating agents, dusts, Emulsions, dispersions, suspensions or solutions or in other suitable forms are used o The inventive Compounds are effective as herbicides when applied to the soil in amounts from 448 g to 4.48 kg / ha. The inventive Compounds are particularly suitable for combating broad-leaved weeds such as Indian mallow, Foxtail, velvet poplar and purslane, grass-like weeds such as aleppo beet, green millet, chicken millet, Japanese millet, bluegrass and fingergrass, and sedges, such as purple cypefgrass. When using such amounts according to the invention Compounds that are needed to control the aforementioned weeds are useful plants, such as cabbage, grain, Cotton, peanut, green bean, and soybean, not harmed.

The examples illustrate the invention. Percentages, quantities, parts and proportions relate to weight, if not otherwise specified.

example 1

Preparation of 2-chloroallyl-cis-2,5-'dimethyl-1-pyrrolidiacarbodithioate

A reactor is charged with 40.0 g (1.0 mol) of sodium hydroxide pellets and 175 ml of water. The mixture is stirred until the cookies are dissolved. The solution is ^{cooled to 2 0} C and

209849 / 119-6

with 99.0 g (1.0 mol) of cis-2,5-dimethylpyrrolidine (bp. 105 to 106 ⁰ Ci n _D ⁵ ' ⁵ = 1.4240} phenylurea derivative: M. 116 to 117 ⁰ C) and then with stirring 76.1 g (1.0 mol) of carbon disulfide are added dropwise and cooling at 0 to 9 ^° C. After the addition is complete, the mixture is stirred for ^{45 minutes at 0 to 5 ° C. while cooling.} The mixture is then diluted with 250 ml of acetone and filtered. 60.0 g of crude product are obtained. Further crude product is obtained by evaporating the piltrate. The combined crude product is recrystallized from 1500 ml of ethyl acetate. 211.7 g of sodium cis-2,5-dimethyl-1-pyrrolidinecarbodithioate trihydrate are obtained. Analysis: C ₇ H ₁₂ NS ₂ Na.3H ₂ O:

CHN

calculated: 35.6 7.2 5.6 percent found: 33.6 6.4 5.4 percent

25.1 g (0.1 mol) of sodium cis-2,5-dimethyl-T-pyrrolidinecarbodithioate trihydrate and 250 ml of acetone are charged into the reactor. The mixture is stirred until the sodium salt is dissolved. The solution is ^{warmed to 37 °} C. and, while stirring, a solution of 11.1 g (0.1 mol) of 2,3-dichloropropene (1) in 50 ml of acetone is added dropwise. When the addition is complete, the mixture is refluxed for 4 hours. The reaction mixture is then diluted with 1 liter of ice water and then extracted twice with diethyl ether. The combined diethyl ether extracts are dried over anhydrous sodium sulfate and evaporated. 22.4 g of a yellow oil are obtained, which is distilled under reduced pressure. This gives 18.6 g

209849/1196

2-chloroallyl-cis-2,5-dimethyl-1-pyrrolidinecarbodithioate vom Bp H9 "to 152 ° C / 0.8 torr.

Analysis: C ₁₀ H ₁

• "calculated : 48 C. 6th H 5 N percent found : 48 ,1 6th , 5 VJl , 6 percent , 2 , 3 , 5

Example 2

Preparation of 2-chloroallyl-trans-2,5-dimethylpyrrolidinecarbodithioate

A reactor is charged with 6.1 g (0.151 mol) of sodium hydroxide pellets and 75 ml of water. The mixture is stirred until the cookies are dissolved. The solution is cooled to 10 ⁰ C and with stirring and cooling at 10 to 15 ⁰ C with 15.0 g (0.151 mol) of trans-2,5-dimethylpyrrolidine (Kp 108 to 1o9 ° C; n ^ ^{5 '5} = 1.4265; Phonylharnstoffderivat: P. 143 to 145 ° C) and then under stirring and cooling at 0 to 5 ⁰ C was added dropwise 11.5 g (0.151 mol) of carbon disulfide staggered After complete addition, the mixture is allowed to warm to 25 ⁰ C. »The reaction mixture is diluted with 50 ml of acetone, and the diluted mixture is then ^{stirred for 1 hour at 25 °} C. and then evaporated.» The solid reaction product obtained is suspended in diethyl ether, filtered and dried. 32.7 g of sodium trans-2,5-dimethyl-1-pyrrolidinecarbodithioate trihydrate are obtained.

Analysis: C ₇ H ₁₂ ^NS 2 ^Na ° 3 ^ 2 ^0:

CHN

calculated: 33.6_7.2_ 5_.6 percent found: '32.7 6.6 5.4 percent

2 0 9 8 4 9/1 196

A reactor is charged with 30.0 g (0.12 mol) of sodium trans-2,5-dimethyl-1-pyrrolidinecarbodithioate tr'ihydrate and 400 ml of acetone. The mixture is stirred until the sodium salt is dissolved. The solution is stirred and heated under reflux and treated dropwise with a solution of 13.3 g (0.12 mol) 2,3-dichloro-propene (1) in 50 ml acetone. After the addition is complete, the mixture is refluxed for 90 minutes heated »The reaction mixture is then diluted with 1 liter of ice water and extracted twice with diethyl ether. The combined diethyl ether extracts are dried over anhydrous sodium sulfate and evaporated. 27 g of a viscous oil are obtained, which is distilled under reduced pressure. Here, HO are 22.9 g of 2-chloroallyl-Straus-2,5-dimethyl-1-pyrrolidincarbodithioat from Kp. To 142 ⁰ C get / 0.2 Torr.

Analysis: C

calculates j found:

C. 6th H 5 N percent 48 ,1 6th , 5 5 -.6 percent 48 , 3 , 5 , 6

Example 3

Preparation of 2-chloroallyl-1-pyrrolidinecarbodithioate (comparison compound)

A reactor is charged with 8.0 g (0.2 mol) of sodium hydroxide pellets and 24 ml of water. After the cookies are loosened, the solution with 160 ml of water and 14.2 g (0.2 mol) of pyrrolidine offset. The solution thus obtained is then added dropwise at 19 to 25 ° C. with 15.2 g over a period of 10 minutes with stirring

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(0.2 mol) carbon disulfide added. After the addition is complete, the mixture is stirred at 25 ° C. for 1 hour. Then 22.2 g (0.2 mol) of 2,3-dichloropropene (1) are added to the mixture in one pour. The resulting mixture is heated to 40 to 60 ° C for 3 hours and then cooled to 25 ° C. On cooling, a solid precipitate separates out, which is filtered off and dried. After recrystallization of the precipitate from 400 ml of hexane, 30.3 g of 2-chloroallyl-1-pyrrolidinecarbodithioate with a melting point of 49 to 50.5 ° C. are obtained. In US Pat. No. 3,078,153 an F. of 45 to 46 ^° C. is given for the aforementioned compound.

Example 4

Pre-emergence tests are carried out on the compounds according to the invention, which are hereinafter referred to as cis _T or trans-isomer, on weeds. ^{u11 (} carried out in useful plants. "2-Chlorally1-1-pyrrolidiucarbodithioate" is used as a comparative verb. The experiments are carried out as described below.

In a field from which all weeds are removed before the attempt seeds of the weeds and crops listed below are sown:

0 9 8 4 9/1 1 0 6

Weeds

1) Indian Mallow - ATmtilon theophrasti Medic.

2) wire-haired foxtail - Amaranthus retroflexus L.

3) Velvet poplar - Sida- spinosa L.

4) Sunflower - Helianthus annuus L.

5) Buckwheat - Fagopyrum esculent um Moench.

6) Morning Glory - Ipomoea spp. L.

7) Aleppo millet - Sorghum halepense (L.) Pers.

8) green millet - Setaria viridis (L.) Beauv.

9) Chicken millet - Echinochloa crusgalli (L.) Beauv. 10) Japanese millet - Echinochloa frumentaeea (Boxb.)

Plant hat

1) Grain - Zea mays L.

2) Soybean - Glycine max. (L.)

3) green bean - Phaseolus vulgaris L.

4) Heis - Oryza sativa L.

5) Peanut - Arachis hypogaea L.

6) Cabbage - Brassica oleracea L.

7) Sorghum - Sorghum vulgare var. Saccharatum (L.)

8) Tomato - Lycopersicon esculentum Mill.

9) Cotton - Gossypium hirsutum L. 10) Alfalfa - Medicago sativa L.

19ö

In the experiments in which results obtained with common purslane (Portulaca oleracea L ₀ ), bluegrass (Eleusine indica (L ») Gaertn») and purple cypergrass (Cyperus rotundus Lo) are given, these weeds are also sown »After sowing the field is loaded with aqueous dispersions

"is the one containing 120 g of test compound / liter emulsifiable concentrates were produced »The aqueous dispersions are applied to the soil in such quantities the 4.48, 2.24, 1.12, 0.56 and 0.28 kg of test compound per hectare correspond. The total amount of rain that fell during the tests is measured.

6 weeks after the treatment, the degree of damage to the weeds is determined by determining the minimum lethal dose (LDq-.) Required to destroy 90 to 100 percent of the broad-leaved and grass-like weeds and the sedge. The LDq _n values ί are average values obtained from 3 tests in each case and are expressed as the minimum required amount (kg / ha) of the respective compound with which 90 to 100 percent destruction of the weeds in question is obtained ο In Table I the minimum LDq _n values for the individual weeds compiled "

A security test is also carried out in which the maximum Amount of animal compounds according to the invention (kg / ha) determined which does not cause damage to the crops concerned » Each value is a mean value determined from 3 tests »

The results of this experiment are summarized in Table II » 209849/1196

Ta-fr hurry I weed control, L ·!) 90 (kg / ha)

! Experiment 1 Broad-leaved weeds Fox
tail velvet
poplar Portu
lak Grasses Aleppo
millet green
Bristles
millet Chicken
millet. Yep
niche
millet * - t Panicles
grass sedge ■ Rainfall:
2.29 cm indiani
sch
mallow
« purple
colored
Cyper;
grass cis isomer
Comparison verb
Attempt 2 mm Rainfall:
33.02 cm 1.5
3.3 1.3
2.0 1.6
4.0 - 1.0
> 4.0 2.0
3.3 1.3
3.3 2.0
4.0 cis isomer
trans isomer
Comparison verb
Attempt 3 2.6
3.3 4.0 y
4.0 y Rainfall:
45.72 cm 0.4
0.7
2.0 0.7
1, ⁷
3.2 - 0.8
0.7
2.6 2.7
3.3
3.3 2.0
0.8
3.3 1.0
1.0
3.3 ; cis isomer
trans isomer
Attempt 4 2.3
4.0
> 4.0 1.0!
> 4.0 y
> 4.0!
I. Rainfall:
16.67 cm 3.3
4.0 - 0.8
1.1 1.8
> 4.0 1.3
1.3 cis isomer
trans isomer
Comparison
link 1.3
1.7
3.3 2.7
2.7
> 4.0 - 2.0
1.0
2.7 2.0
2.0
2.7 2.0
1.5
3.0 · - - -

3! at e lie II security test. Maximum amount (kg / ha)

O CJD OO

Attempt 1 Crops grain soy
Bean green
Bean rice Earth
nut Cabbage Sorghum tomato tree
wool alfalfa Rainfall:
2.29 cm I. cis isomer
Attempt 2 'Rainfall:'
33.02 cm > 4, Ό > 4.0 > 4.0 5.0 > 4.0 > 4.0. > 4.0 > 4.0 > 4.0 - cis isomer
trans isomer
Attempt 3 t Rainfall:
45.72 cm 3.0
5.5 > 4.0
> 4.0 ^: 1.0
0.8 H ₉ Ο
■ 5.0 "- ■ 0.8
1.0 0.7
0.7 - 2.0
1.0. cis isomer
trans isomer
Attempt 4
Amount of rain!
16.67 cm cis isomer
trans isomer mm H, 0
> 4.0 1.0
1.7 H, 0
> 4.0 - 2.7
1.7 - H, O
> 4.0 - ' > 4.0
5.5 5.5
A, 0 > 4.0
'H, 0 5.5
> 4.0 H, O
> 4.0 - 5.5
1.5 > 4.0
5.5
• > 4.0
^ 4.9 5.5 ·
2.7

ro ro ro cn

-H-

The values compiled in Table I show that the inventive Compounds in addition to their effectiveness against grassy weeds have a broad spectrum of herbicidal effectiveness in combating broad-leaved weeds. Furthermore, the cis isomer of the comparative compound is in the - Superior control of grassy weeds. The values compiled in Table I and Table II show that the amounts of the amounts according to the invention required for combating weeds Compounds in no case cabbage, grain, cotton, peanut, green bean and soybean are harmed.

Example 5

Bluegrass (Eleusine indica (L.) Gaertn.) And Pingergrass (Digitaria spp.) Sown.

The field is then treated with aqueous dispersions made from emulsifiable concentrates containing 120 g test compound / liter of the cis and trans isomers. The aqueous dispersions are applied to the soil in such amounts as the 6.72, 3.36, 1.68 and 0.84 kg of the test compounds per hectare. The amount of rain that fell during the tests is measured.

6 weeks after treatment, the degree of damage is using on a scale ranging from 0 to 100, with the Value 0 a perfectly normal plant and value 100 die

Means annihilation. The results of these experiments

209849/1196

- 15 are compiled below:

Amount applied, kg / ha 6.72 3.36 1.68 x 0.84

Rainfall: 5.33 cm ■ 90 93 80 • cis isomer 83 87 ^53:; 71 trans isomer 'S "

These results show that the compounds of the invention have an excellent herbicidal effect, this effect being higher for the cis isomer than for the trans isomer.

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Claims (4)

Claims 2-chloroallyl-cis- and 2-chloroallyl-trans-2,5-dimethyl-1 pyrrolidine carbodithioate of the formula I and II S Il H2C = C-CH2-S-C-Cl (D H ₂ CC-CH ₂ -SC (II) 2. Process for the preparation of the compounds according to claim 1, characterized in that one cis- or trans-2,5-dimethylpyrrolidine in alkaline solution with carbon disulfide in. the corresponding alkali metal salt of cis or ο trans - 2,5-dimethyl-1-pyrrolidinecarbodithioateB and the compound thus obtained is reacted with 2,3-dichloropropene- (1). 209849/1196 3. The method according to claim 2, characterized in that one cis or trans-2,5-dimethylpyrrolidine in sodium hydroxide solution with Carbon disulfide into the corresponding sodium salt of cis or trans-S ^ -Diniethyl-l-pyrrolidincarbodithioats transferred and the compound thus obtained with 2, J-dichloropropene (l) implements. 4. Herbicidal agents, consisting of a) about 0.1 to about 15 percent by weight of a surfactant By means of, b) about 0.1 to about 99 percent by weight of at least one A compound according to claims 1 to J and c) usual additives and inert carriers as remainder * 209849/1 196