NO145437B - ANALOGY PROCEDURE FOR PREPARING A PHYSIOLOGY ACTIVE P-BIFENYLESTER OF A PROSTAGLANDIN ANALOGUE OF THE E OR F SERIES. - Google Patents

Description

Means for combating plant parasitic nematodes.

The present invention relates to a new agent for combating plant parasitic nematodes, with new carbamic acid derivatives as active substances.

In the fight against nematodes, only such compounds have achieved a practical significance which either act in the gas phase, as e.g.

1,2-dibromo-3-chloropropene and the mixture of dichloropropane and dichloropropene, or those that are subject to a rapid decomposition in the soil, such as e.g. sodium salt of monomethyldithiocarbamic acid or 3,5-dimethyl-tetrahydro-1,3,5-thiadiazine-2-thione.

It has now been found that compounds with the general formula

where X-p Xg and X2 independently of each other mean oxygen or sulphur, and R2 independently of each other hydrogen or an alkyl residue with 1 - 4' carbon atoms, and A a straight-chain or branched alkyl residue with 2-4 carbon atoms of which in the case of a branched chain 2

C atoms in the direct chain between X-^ and X2?

are excellently suited as active substances for combating plant parasitic nematodes.

The compounds with the above-mentioned formula I are particularly effective

where the symbol A stands for a straight-chain alkyl residue with 2 or 3 carbon atoms, i.e. A denotes -CHg-CH^- and -Ch^-CH^-Ch^-•

The compounds in the above-mentioned formula have great advantages, particularly with regard to their durability against the hitherto known and used nematocides. The sodium salt of monomethyldithiocarbamic acid mentioned at the beginning is only storable as a solution of a certain concentration and as such only has the duration necessary for the application, whereby e.g. the highly desired use as a power source is ruled out.

Furthermore, the toxicity, the irritating effect and the unpleasant smell of the compounds used according to the invention are significantly less than wood

the hitherto used nematocides.

Compared to the nematicidally active N-dimethyl-dithiocarbamic acid methyl esters, respectively N-monomethyl-thiolcarbamic acid n-butyl ester and N-dimethyl-thiolcarbamic acid n-butyl ester described in German patent no. 742,185 and in DAS no. 1052159, they excel according to the invention usable active substances by a better nematocidal effect.

The most preferred and most effective compounds of the general formula I are those where both residues X o °9 ^3 mean sulfur (dithio-carbamic acid derivative). Preferably, one of the residues R and R 2 means hydrogen, while the other is a low molecular weight alkyl group, especially a methyl or ethyl group.

The new compounds of formula I can be obtained by reacting a compound of the formula

with a connection with the formula

where X-^, Xg j Rj_) R2°9 A have the aforementioned meanings

and of the residues Y and Z, one means a movable,

in the reaction as anion exiting residue, and the other group -X2Q, where Q is a mobile, in the reaction as cation exiting residue.

The residue emerging as an anion is preferably a halogen atom, which e.g. chlorine or bromine. The residue Q emerging as a cation is hydrogen, a metal atom, preferably an alkali metal atom or the equivalent of an alkaline earth metal atom or the ammonium group. According to a variation for the method, instead of the reactive, functional derivatives of acids with formula II, phosgene, resp. thiophosgene and the corresponding alkyl and dialkyl amines or the corresponding alkyl isocyanates or alkyl isothiocyanates with compounds of the general formula II are reacted, where Y means a hydroxyl or mercapto group.

Following a further method for preparing compounds of formula I, a compound of formula is reacted

where X-p X^, A, R-^ and R 2 have the above meaning, with acrylonitrile. This reaction is optionally carried out in the presence of a base and/or a solvent.

The new compounds can be used in solid form to combat nematodes, for example as a finely powdered stromal agent or as granules, and also in liquid form as an emulsion, suspension or solution. The choice of forms of application is based on the established method of application, which in turn particularly depends on the species of nematodes to be combated, plant cultures to be protected, climate and soil conditions, as well as the working technical conditions. The most advantageous is a distribution of the active substance as evenly as possible over a 15 - 25 cm deep soil layer, as the consumption of active agents is generally 50 - 250 kg/ha. j An intentional, limited use is, however, also possible, e.g. on planting holes or sowing furrows, which possibly provides an outstanding protective effect with reduced consumption of active agents.

Dusting agent can be produced on the one hand by mixing or

joint grinding of the active substance with a solid, powdered water-insoluble or heavily soluble carrier._ As such Jean'

e.g., used: talc, diatomaceous earth, k a c 1 i n, betonite, calcium carbonate boric acid or tricalcium phosphate. On the other hand, the active substance can also be distributed on the carrier substance with the help of a volatile solvent. For the production of stromal agents, one can either use coarse-grained and/or particularly heavier carriers, such as e.g. coarser ground limestone, sand and loess, or simply granulated mixtures of the active substance with finer-grained, possibly porous carriers.

Furthermore, starch as a carrier in the coarse grain, possibly in granulated form, can also contain solid substances of greater water or citrate solubility, e.g. artificial fertiliser, which contains calcium phosphate or other calcium, potassium or ammonium salts, waste, phosphate or nitrate.

Emulsions according to the invention can be used both on unpaved fields and in plant cultures due to their penetration ability.

They are prepared, for example, by dissolving the active substance in an organic solvent, such as xyleh,, and emulsifies this solution in water containing a surface-active substance. For the use of emulsions in practice, it is most advantageous, first and foremost, in combinations of active substance with inert organic solvent and/or surface-active substances (emulsifiers) to produce concentrates, which in turn produce single or multi-phase systems and can be processed with water into emulsions, ready for use. As surface-active substances (emulsifiers) come both cation-active substances, such as, for example, quaternary ammonium salts, anionic substances, such as salts of aliphatic, long-chain sulfuric acid monoesters, and as non-ionic surfactants 'f .e.g. polyethylene glycol ether of fatty alcohols or of dialkyl phenols and polycondensation products of ethylene oxides, as well as amphoteric surfactants in consideration. Suitable solvents for the production of emulsion concentrates are, for example, cyclic hydrocarbons, such as benzene, toluene or xylene, in addition to ketones, alcohols and additional solvents such as ethyl acetate, dioxane, acetonglycerol or diacetonalcohol.

Suspensions can be obtained by directly suspending the moist active substance in water, which possibly contains a surface-active substance, or by suspending fertile powders, which in turn are produced by mixing solid active substances' with surface-active substances or with solid powdered carriers and surfactants.

Halogen hydrocarbons with their own nematocidal effect come into consideration as solvents for the aforementioned active substance, e.g. 1,2-dibromo-3-chloro-propene, dichloro-butene or dichloropropane, dichloropropene mixtures, whose immediate nematicidal action is complemented in a valuable way by the sustained action of the active

fabric.

The aforementioned active substances can be used to combat a wide variety of nematodes, such as e.g. Meloidogyne arenaria, Pratylenchus sp., Ditylenchys dipseci, etc. The compounds are not phytotoxic in the practical amounts of use that come into question, so that harmful effects on plant growth are excluded. If desired, the biological activity of the agent according to the invention can be supplemented by the addition of fungicides, herbicides or insecticides or additional nematocidal active substances.

As active substances with the general formula I can e.g. the following connection is used:

(3-((3-cyanoethylmercapto)-ethyl-N-methyldithiocarbamate,

m.p. 69.5 - 72.5°. p-(B-cyanoethyloxy)-ethyl-N,N-dimethyl-dithiocarbimate,

kp. q 2 188°.

(3-((3-cyanoethyloxy)-ethyl-N-methyldithiocarbamate.

(3-(B-cyanoethylmercapto)-ethyl-N,N-dimethyl-thiolcarbamate,

kp. 03 167.5 - 168.5°. N-(|3-cyanoethyloxy)-propyl-N,N-dimethyldithiocarbamate,

kp. O53 156°.

γ-(β-cyanoethyloxy)-butyl-N,N-dimethyl-dithiocarbamate. V-(β-cyanoethyloxy)-propyl-N-methyldithiocarbamate. 6-((3-cyanoethyloxy)-butyl-N-methyl-dithiocarbamate.

(3-((3-cyanoethyloxy)-propyl-N-methyl-dithiocarbamate.

(3-((3-cyanoethylmercapto)-ethyl-N,N-dimethyl-carbamate,

kP- 0.001 115 - li8°-

Of the aforementioned compounds, the former in particular (3-((3-cyano-ethylmercapto)-ethyl-N-methyl-dithiocarbamate) has the strongest nematocidal effect.

In the following examples, the test methods used for determining the activity are stated, as well as some typical forms of preparation of the new active substance for nematocidal agents, as well as the results obtained with the active substances in nematode control. Parts always mean parts by weight.

EXAMPLE 1

To achieve the desired concentration of the required amount of active substance (consumption amount), (3-([3-cyanoethylmercapto)-ethyl-N-methyldithiocarbamate) is mixed intimately with 20 ml of washed*, dried sand and the mixture is mixed with 1 liter of watery soil that is infected with Meloidogyne arenaria. After a withdrawal period of 7 days, the soil is divided into three flower pots., and two tomato cuttings are planted in each of them. After 9 weeks, the root nodules that had formed on the roots of the plants were counted and the weight of the plant was determined. The count of the root nodules produce at 50 ppm (ppm = parts active substance versus 10^ parts diluent) a more than 90% effect, at 100 ppm is practically complete effect.The substance shows no phytotoxic properties.

EXAMPLE 2

20 parts active substance, e.g. NC-CH2-CH2-S-CH2-CH2-S-CS-NHCH3 and 80 parts of talc are ground in a ball mill to great fineness. The resulting mixture serves as a standard.

EXAMPLE 3

20 parts active substance, e.g. NC-CH2-CH2-0-CH2-CH2-S-CS-NHCH3 is dissolved in a mixture of 48 parts of diacetone alcohol, 16 parts of xylene and 26 parts of an anhydrous, high-molecular condensation product of ethylene oxide with higher fatty acids. This concentrate can be diluted with water to emulsions of any desired concentration.

EXAMPLE 4

80 parts active substance, e.g. NC(CH2)2~0-(CH2)3-S-CS-NHCH3 is mixed with 2-4 parts of one wetting agent, e.g. sodium salt of an alkyl polyglycol ether monosulphate, 1-3 parts of a protective colloid, e.g. sulphite liquor and 15 parts of an inert, solid carrier material such as e.g. kaolin, bentonite, chalk or diatomaceous earth and then finely ground in a suitable mold. The resulting wettable powder can be mixed with water and gives very constant suspensions.

EXAMPLE 5'

5 parts by weight active substance, e.g. NC(CH2)2~S-(CH2)2-S-C0-N(CH3)2 is mixed and ground with 95 parts by weight of calcium carbonate {- ground limestone). The product can be used as a ironing tool.

EXAMPLE 6

5 parts by weight active substance, e.g. NC(CH2)2~<0->(CH2)4-S-CS-NHCH3 is mixed with 95 parts of a powdered carrier material, e.g. sand or calcium carbonate and moistened with 1-5 parts by weight of water or isopropanol. The mixture is then granulated.

For the granulation to take place, the above or a mixture containing more active substance, e.g. of 10 parts active substance and 90 parts calcium carbonate, a multiple amount e.g. 100 - 900 parts of any water-soluble artificial fertiliser, such as e.g. ammoniuTnsulf at, mixed to.

EXAMPLE 7

By mixing 50 parts of the compound NC(CH2)2-0-(CH2)3~S-CS-INHCHg, 45 parts of xylene, 2.5 parts of an ethylene oxide condensation product of an alkylphenol and 2.5 parts of a mixture sodium urn-saltex of dodecyloxyethylsulphuric acid and dodecylethoxyethoxyethoxysulphuric acid rnan obtains a solution that can be emulsified in var.n.

EXAMPLE 8

In a field study, (3-((3-cyanoethyl-thio)-ethyl-N-methyldithiocarbamate) in the form of a stromal agent was tested with respect to its nematocidal activity against Meloidogyne sp., Pratylenchus sp. and other parasitic nematodes. As research plants were used tomatoes, bush beans and melons.The effect was determined by soil analysis which was carried out approximately 4 weeks after the treatment and by determining the yield weight.

The soil analysis gave the values summarized in the following table, which indicate the percentage killing, 20 cm 3 of soil from a 500 cm fertile soil sample was tested.

The increase in productivity was 60 - 100% for tomatoes, beans and melons compared to the control plants.

EXAMPLE 9

The nematicidal effect of the following compounds is determined and compared: I (3- ((3-cyanoethylmercapto)-ethyl-N-methyldithiocarbamate

(according to the present application)

II sodium salt »y monomethyldithiocarbamic acid

(according to US patent 2,791,605)

Method.

The active substance to be examined is sprinkled in a concentration of 30 g per m 2 on o a 5 m 2 plot of land that is infected with Meloidogyne sp., Pratylenchus sp., Rotylenchus and Tylenchorhynchus and is incorporated using a tiller for approx. 20 cm depth. Soil samples were taken at 28, 82 and 130 days after the soil treatment.

■i

Results.

The results for the plots in 2 fields are given in % of the attack on the control plot on the 28th day from the treatment date.

Follow-up conclusion.

From the above table it is clear that the compound I which can be used according to the invention has a stronger nematocidal effect than the known compound II.

EXAMPLE 10

The nematicidal effect of the following compounds is determined and compared: I (3-((3-cyanoethyloxy)-ethyl-N-methyldithiocarbamate

(according to the present application)

II (3-((3-cyanoethylmercapto)-ethyl-N-methyldithiocarbamate

(according to the present application)

III N,N-dimethyl-dithiocarbamic acid methyl ester

(according to German patent 742,185)

IV N-monomethyl-thiolcarbamic acid-n-butyl ester

(according to "DAS" 1,052,159)

V N,N-dimethyl-thiolcarbamic acid n-butyl ester

(according to "DAS" 1,052,159)

Method.

The amount of active substance required for the determined concentration is mixed with washed sand, added to 100 ml of soil, the whole is rinsed in broken glass and kept closed for the days specified below.

To increase the effect of the gas, the aforementioned glass shards are further added to a one-sided open glass tube containing 20 ml of sample soil infected with Meloidogyne larvae, in such a way that no direct contact is possible between the contents of the glass shard and the contents of the glass tube. To check the effect of the gas, the 20 ml of soil in the glass tube is examined separately for surviving nematodes. Here means: o no reduction of live nematodes

+ 90% kill of Meloidogyne

++ 100% kill of Meloidogyne

+++ 100% Meloidogyne kill and 100%

killing saprozoic nematodes.

ppm means parts of active substance per million parts of soil.

Results.

Fdlqe conclusion:

From the above table it appears that the compounds I and II used according to the invention show a full effect after 14 and 20 days, respectively, while the known compounds III - V after 20 - 26 days only effect a 90% killing of Meloidogyne.

Claims (3)

1. Means for combating plant parasitic nematodes, characterized in that it consists of or as an active ingredient contains at least one carbamic acid derivative with the general formula where X-^, X2 and' X3 independently of each other mean oxygen or sulphur, A a straight-chain or branched alkylene residue with 2-4 carbon atoms, of which with a branched chain at least 2 carbon atoms are in the direct chain between X-^ and X2, and and R 2 independently of each other hydrogen or an alkyl residue with 1-4 carbon atoms. 2. Agent according to claim 1, characterized in that it consists of or as an active ingredient contains at least one carbamic acid derivative with the general formula , where n means 2 or 3, and X^, X2, Xg, R-^ and R2 have the meaning stated in claim 1. 3. Agent according to claim 2, characterized in that it consists of or contains as an active ingredient B-(B-cyanethylmercapto)-ethyl-N-methyl-dithiocarbamate.