DE2321522C2 - Insecticidal agent for combating caterpillar feeding on leaves - Google Patents

Description

This sequence of process steps is the lactam (1-substituted 2-piperidone) with a dialkyl sulfate (R ₂ SO ₁ ) or a trialkyloxonium _{fluorate (BF 4} ORi) and then with an alkoxide (alcoholate) to the corresponding lactam acetal (1-substituted test, 2 -Di (RO) pyrrolidine) reacted, which is then converted into the desired N-substituted 2- (nitromethyiene) pyrrolidine with nitromethane or a suitable substituted nitromethane or with an I-nitroalkane.

Some of the 1-substituted 2-piperidones are known Links. Others are according to one of the in Houben-Weyl, "Methods οΓ Organic Chemistry", Vol. 11, Tell II. Pages 5II-S87 (1958) summarized methods.

The compounds provided as active ingredients according to the invention can have two geometric isomers, depending on the position of the substituents. H. they exist as clstrans isomers.

It has been $ *; * i. that these connections are special are effective against caterpillars that stand out from the foliage nourish the plants. Among the leaf-eating, sexually immature insect larvae of this species are the most important the caterpillars of the order butterflies (Lepldoptera).

Some of the compounds provided as active ingredient according to the invention have systemic activity, ie, when they are applied to the root system of plants, they rise up in the plant and act on the insects that feed on the plant seeds or on the foliage. UIE new RaupenvertllgungsmlUel have little or n'cht pH'otoxlsch and virtually completely harmless f Gr plants in the doses in which they w insects on plants. Combat sam ^'1. This Raupenvertilgungsmittel also be included in the plant or absorbed when Non-leaf-eating beneficial insects such as bees are not attacked.

Compared to the larvae of Heliothis vlrescens, the new active ingredients were found to be z. T. several times more effective than dlazinone. You continue to stand out due to their low mammalian toxicity. the essential lower than that of dlazinon. and can hence it can be handled fairly safely.

The caterpillars according to the invention are used in the catfish customary for insecticides, such as these are described, for example, in US Pat. No. 3,116,201 It can be the compound either sprayed or otherwise in the form of a solution or dispersion 'Or it is absorbed with an inert, finely divided carrier material and used as dust applied. Useful solutions for spraying. Brushing or dipping can be done with the help of any Im Horticultural produced inert liquid carrier commonly used, for example with neutral hydrocarbons such as kerosene and other light petroleum distillates of moderate viscosity and volatility.

The solution can contain further auxiliaries such as spreading agents or wetting agents, examples of which are fatty acid elves, resin elves, saponins, gelatine, Casein, long-chain fatty alcohols, long-chain alkyl sulfonates, phenol-ethylene oxide condensation products or Ammonium salts. These solutions can be used as such; preferably they are in water dispersed or emulsified and the resulting aqueous dispersion or emulsion used as a spray. Solid carriers are inter alia. Talc, bentonite, lime, Plaster of paris, and the like. Inert solid diluents. If necessary, the active ingredients can also be used as an aerosol by using a compressed

Gas can be dispersed into the atmosphere.

The concentration of the active ingredients in connection with the above-mentioned carriers will depend on numerous factors including the carrier used, the method and the conditions of application

ίο and the species of insect to be controlled; the assessment of these factors and the coordination is familiar to those skilled in the art of insecticides. In general it can be said that the active ingredients in a concentration of only 0.01 to 0.5%

ti act on the total weight of the agent; in some circumstances only about 0.001% or es will suffice about 2% or more of the active ingredient must be able to be used. Commercially suitable concentrates that can be diluted in the field and / or for spraying hen intended to be ultra-low volume can even contain 25 to 50% by weight or more of the insecticide. The active ingredients according to the invention are either as only active ingredients or used in conjunction with other insecticidally active substances. examples for other insecticides are the naturally occurring insecticides like pyrethrum. Rotenon or Sabadllla as well the numerous synthetic insecticides including Benzolhexachlorld, Thiodlphenylamln, Cyanide, Tetraäthylphyrophosphat, Dlihyl-p-nitrophenyl-thriophos-

w phat, Dimethyl ^^ - dichlorviiiylphosphat, 1,2-Dlbromo-2,2-dlchloräthyl-dlrtv; 'iiylphosphat, azobenzene and the numerous arsenic, lead and / or fluorine compounds.

The invention is illustrated in the following examples explain in more detail. In examples I to 3 and 5 to 11

I) is the preparation and in Examples 4, 12 and 13 the testing of the effectiveness against certain larvae of typical representatives of the active ingredients provided according to the invention is described. The identity of the compounds was determined in all cases by elemental analysis

• to and spectral analysis confirmed.

example 1 2- (nitromethylene) pyrrolidln (I)

This compound was obtained as an orange-yellow solid ^4> with a melting point of 10 5 to 107 ° C. according to Example I of US Pat. No. 3,560,523

Example 2 2- (bromonltromethylene) pyrrolledln (II)

4.0 g (0.025 mol) of bromine were added dropwise and with tubes to a solution of 3.2 g (0.025 mol) of 2- (n-tromethylene) piperldln in 50 cm of water at ⁰ ° C. The precipitate formed was filtered off: obtained 1.8 g of a cream-colored powder with a melting point of 149 to 150.5 ° C. (decomposition) were obtained. A further 0.3 g precipitated out on cooling the filtrate. 0.8 g of the first crop were recrystallized from ethanol; Yield 0.7 g of 2- (bromonltromethylene) pyrrole thin in the form of pale yellow

Needles with a melting point of 158 to 159 ° C (decomposition)

Example 3 3-methyl-2- (n-tromethylene) pyrroll thin (111)

The ethyl methylate of 3-methyl-2-pyrrolldon was from the known 3-methyl-2-pyrrolldon according to GB-PS 12 36 842 prepared.

A solution of 12.7 g (0.10 mol) of ethyl methylate of 3-methyl-2-pyrrolldone in 30 cm of methyl methane was 4

-Day kept under reflux and occasionally ethanol distilled off as a by-product to the reflux temperature bring it back to 100 ° C. Excess nitromethane and existing ethanol were then taken under stripped under reduced pressure; there is a darker behind oily residue. This residue was dissolved in ethyl acetate and passed through a FlorisII *) column. The filtrate was evaporated; a crystalline residue remained which was recrystallized from ether became. Yield 4.6 g of white 3-methyl-2- (nitromethy- to Ien) pyrrolidine with a melting point of 47-47.5 ° C.

Example 4

The activity or effectiveness was determined with the aid of suitable test methods to determine the LC _S o dosage (dose in grams of test compound per 100 cm ^{1 of} solvent which is required in the solution or suspension used as a spray to kill 50% of the test larvae). 2- (Nltromethylene) pyrrolidines were tested with regard to larvae of various insect species. The liquid carrier used to prepare the solution or suspension was composed of 2 parts by volume of acetone, 8 parts by volume of water and 0.05 parts by volume of Atlox, a wetting agent. The results are summarized in Table 1 below.

Table 1

LC »Dose of test compound for the specified insect (% active ingredient present)

30th

link
No.

Grain beetle

black earthworm

Cabbage caterpillar

35

40

I 0.0142 0.015 0.02

II 0.035 0.012 0.02

III 0.025 0.008 0.02

Example 5 l-ethyl-2- (nltromethylene) pyrrolldin (VI)

I-Ethyl-2- (tromethylene) pyrrole-dine turned pale yellow in color Solid with a melting point of 129.5 to 131 ° C from 1-EthyI-2-pyrrolidon according to Example Ib with the GB-PS 12 36 842 produced.

Examples 6, 7 and 8

Using the same process, the following were produced:

l-methyl-2- (n! tromethylene) pyrrolldine (VII),

yellow solid, mp 129.5-131 ° C 1 - (n-Propyl) -2- (nltromethy! En) pyrrolldln (VIII),

pale yellow solid, m.p. 88 to 90 ° C and 1- (2-propynyl) -2- (n-tromethylene) plperldln (IX), pale yellow solid. Mp 144-145 ° C (dec.).

Example 9
3-bromo-1-methyl-2- (n-tromethylene) pyrrolledln (X)

5.4 g of 1-methyl-2- (n-tromethylene) pyrroline, 8.0 g of N-bromosuccinic oil and a trace of benzoyl peroxide were ^{mixed with 75 cm 1 of} carbon tetrachloride and the mixture was left to stand overnight. The solvent was then poured off, water was added to the solid residue and the mixture was extracted with chloroform.

·) Magnesium silicate gel, highly selective adsorbent for chromatography

50

5 '

60

65 gen. This extract was washed with water, dried over magnesium sulfate and the solvent evaporated. Yield 4.8 g ^ of a solid substance with a melting point of 95 to 100 ° C (decomp.). After recrystallization from ethanol, 1.2 g of 3-bromo-1-methyl-2- (nitromethylene) pyrrolldine were obtained as a yellow powder with a melting point of 126 to 130 ° C. (decomposition).

Example 10
1,3-dimethyl-2- (n-tromethylene) pyrrolidine (XI)

This compound was derived from the well-known 1,3-DImethyl-2-pyrrole idon prepared in the sense of GB-PS! 2 36 842 and the reaction product, as described there, worked up. 2.7 g of substance were obtained, which was recrystallized from ethanol (pentane). yield 1.2 g of 1,3-dimethyl-2- (nitromethylene) pyrrolidIn In the form of pale yellow platelets with a melting point of 88 to 89 ° C.

Example Il
l-AcetyI-2- (nitromethylene) pyrrolidine (XII)

8.5 cm ¹ (0.12 mol) of (acetyl chloride) were added dropwise over a period of 16 minutes with a stirrer to a solution of 12.8 g (0.1 mol) of 2- (Nltromethylene) pyrrolldIn in 150 cm ^{1 of} methylene chloride. At the beginning of the addition, the temperature of the solution was 10 ° C., after the addition was complete it was 3 ° C. The mixture was then left overnight at room temperature. It was then filtered and the filtrate was dissolved in a mixture of ether and methylene chloride , the solution filtered through kieselguhr, the solvent evaporated and the solid residue recrystallized from carbon tetrachloride. Yield 3.5 g of 1-acetyl-2- (tromethylene) pyrrolide in the form of a colorless solid substance with a melting point of 62 to 64 ° C.

Example 12

The activity or effectiveness was determined with the aid of suitable tests in which the LC _{! O} dose (in grams of test compound per 100 cm of solvent that is required in the sprayed solution or suspension to kill 50% of the test larvae) was determined; N-substituted 2- (nitromethylene) pyrro-Hdine were tested with reference to larvae of various insect species. The liquid carrier used to prepare the solution or suspension was composed of 2 parts by volume of acetone, 8 parts by volume of water and 0.05 part by weight of wetting agent. The results are summarized in Table 2 below.

Table 2

LC50 dose of test compound for the given Insect (% active ingredient present)

Connection

Grain beetle

black
trdraupe

Kohlspannerrauoe

VI 0.06 VII 0.0096 VIII 0.115 IX 0.073 X 0.05 XI 0.04 XII 0.033 - = no attempt

0.0065

0.016

> 0.02
0.024

> 0.02

Example 13

The systematic activity of the compounds I and VII was examined on broad bean plants (vlcla faba). The plant roots were in aqueous solutions immersed, the Tesl connections in different Concentration contained; then larvae (3rd stage of development) of the grain weevil or grain weevil were placed on the foliage and the mortality of the caterpillars was determined 48 hours later. The results are In the following table 3 summarized. Specified

the concentration of the test compound in the Solution (ppm Wlrksloff in the solution), which was necessary to 5O '\. kill the insects.

Table 3

link

LC ₅₀

25 37

Claims (2)

Patent claims: 1. Insecticidal agent for combating caterpillar feeding on leaves, characterized by a Active ingredient of the general formula The invention relates to an insecticidal agent for Combating caterpillar feeding by leaves, which contains an optionally N-substituted 2- (Nltromethylene) pyrrole as an active ingredient. The active ingredient corresponds to the general formula in which X and Y are identical or different and in each case for a hydrogen or halogen atom or for one Alkyl group with up to 6 carbon atoms and R is a hydrogen atom or an alkyl, alkenyl or Alklnyl group with up to 6 carbon atoms, one Phenyl group or an alkylcarbonyl group with up to 7 Carbon atoms is. He gets along with usual Support and carrier materials used. Preferred means are the subject of claim 2. The insecticidal agent for combating caterpillar damage by leaves is applied to the leaf or the Applied roots of the plants. Preferred catfish contain the alkyl, alkenyl or Alkyl groups no more than 4 carbon atoms. she can be either straight-chain or branched. A class of compounds which are used in the agents according to the invention are the compounds of the general formula in which R is hydrogen stands. The compounds in which X is a hydrogen atom are preferred and the compounds in which Y is a hydrogen, bromine or chlorine atom or a Ci-CVAIkylgruppe show the highest activity. 2- (Nltromethylene) pyrrolledln and 2- (bromonltromethylene) pyrrolled are particularly preferred in which X and Y are identical or different and each represents a hydrogen or halogen atom or stand for an alkyl group with up to 6 carbon atoms and R is a hydrogen atom or an alkyl, Alkenyl or alkylnyl group with up to 6 carbon atoms, a phenyl group or an alkylcarbonyl group with up to 7 carbon atoms, together with the usual auxiliary and carrier materials. 2. Composition according to claim I, characterized in that in the formula given for the active ingredient X and Y and each represent a hydrogen atom and R represents a hydrogen atom or an alkyl group having up to 4 carbon atoms. din. Another preferred compound of the class of compounds in which R is hydrogen is 3-methyl-2- (n-tromethylene) pyrrolidine. Further typical examples for this class of active ingredients provided according to the invention are: 2-i-chloromethylene) pyrrolidln 2- (N-tromethylene) -3-bromopyrrolline 2- (Nltromethylene) -3-chloropyrrole-din 2- (1-nitroethylidene) pyrrolidine 3-Ch! Or-2- (tromethylene) pyrolledln 3-ethyl-2- (nitromethylene) pyrrole thin 3-fluoro-2- (n-tromethylene) pyrrolldin 4-methyl-2- (nitromethylene) pyrrolldIn 2- (Bromonllromethylene) pyrroll thin 2- (Fluornltromethylene) pyrrole thin 2- (Bromonitromethylene) -3-bromopyrroll thin Those according to the invention as active ingredients Compounds in which R is hydrogen, can NEN analogous to the process described in US-PS 35 60 523 for the production of 2- (nltromethylene) -pyrrolldinen are produced. In this sequence of process steps, butyrolactam (2-pyrroleic diminone) is treated with a dialkyl sulfate (RiSO ₄ ) or a trialkyloxone umfluoborat (BF ₄ ORi) and then treated with a base; the corresponding 2- (RO) -J ¹ -pyrrolidine is then treated with nitromethane or with a suitable substituted nitromelhan or with a 1-nitroalkane and the desired 2- (nitromethylene) pyrrolidine is obtained th. Some of the butyrolactams are known compounds; others are produced using conventional methods, such as in Houben-Weyl. "Methods of Organic Chemistry". Vol. 11. Tell II, rare 511-587 (1958) are summarized. Another class of compounds used in the Agents according to the invention are used are the compounds in which R has a meaning other than Has hydrogen. •) 0 As a result of its effectiveness against caterpillars is a preferred subclass of this type of compound is that in which X is a hydrogen atom. the highest activity In this subclass, the compounds show in which Y stands for a hydrogen, chlorine or bromalom or a C -C alkyl group, in particular represents a hydrogen atom and R is a C -C alkyl group, in particular a straight-chain C -C alkyl group. Particularly preferred compounds of these Great. In which R has a different meaning than what hydrogen. are l-ethyl-2- (nitrometiylen) pyrrolidln, I- Methyl 2- (n-tromethylene) pyrroll thin, 1- (n-propyl) -2- (ntxr_methylene) pyroll thin. 3-Bromo-1-methyl-2- (n-tromethylene-pyrrolidine, 1,3-dimethyl-2- (nitromethylene) pyrroline and I-acetyl-2- (nltromelhylen) pyrrolldln Other examples of this class of compounds are: 1- (2-butenyl) -2- (n-tromethylene) pyrrole thin 1- (2-butyl) -2- (n-tromethylene) pyrrole thin l-Allyl-2- (n-tromethylene) pyrrole thin 2- (Bromonltromethylene) -l-methylpyrrolidln 1-methyl-2- (bromine-tromethylene) pyrrolled! n 1-methyl-2- (bromonitromethylene) -3-bromopyrrolledln 1-methyl-2- (n-tromethylene) -3-bromopyrrolledln These compounds according to the invention in which R does not represent hydrogen, can be prepared analogously to the process described in GB-PS 12 36 842 for the preparation of 2- (Nltromethylenlpyrrolldinen