IL25546A - 7-coumaranyl-n-methyl-n-acetyl carbamates and their use as insecticidal and acaricidal agents - Google Patents

Description

ni'ipKi is*p-»n » elpa ana ¾n&>»ni 7-Oo iaaFanyl-H-aetlifl--ii-aoetyl earbamates and their use as iaseetieidal and acaricidal FABBBSTORIKIH BATES ABPIfillSESBiLSCHAPT C: 2431 2 -* — the present invention concerns new S-acyl-K- methyl-earbamic acid esters of 7-hydroxycoumarane which have lnseetieidal and aearicidal properties, their preparation, and their use as insecticid&l and acaricidal agents.

It is known that R-acyl-N-methyl-carbamic acid esters, especially the 2-isopropoxy-phenyl-N~acetyl- -metiiyl-carbasiic acid ester, have an lnseetieidal activity (cf.

British Patent Specification Ho* 982,235)· Like almost all carhsimic acid esters, however, these compounds have the disadvantage of being very rapidly hydrolysed in an alkaline medium. I!hey have, therefor , relatively short period of effectiveness on substrates , especially limed substrates. also known that co aaranyl-B-iae h l-carbamic acid esters, especially 2^ethyl«7-e0Uiiiaranyl-lSi-→riethyl-»carbamie acid ester, have a strong lnseetieidal activity and a very good stability on a freshly limed substrate (ef. Belgian Patent Specification No. 649»2βΟ).

This invention consists in ew coumaranyl-li-acetyl-E-methyl-c&rbaaiie acid esters of the general formula:- ί 3 wherein K stands for a lower aliphatic hydrocarbon radical and t R«» S* and it, , which may be the same or different, stand for hydrogen atoms or lower alkyl radicals, have strong insecticidal and acaricidal properties.

The new coumaranyl-carbamic acid esters of general formula (I) are obtained, in a particularly advantageous manner, hen coumaranyl-carbamic acid esters of the general formul :- wherein , Eg» ^3 ^4 have the same meanings as above , are reacted with the acid anhydrides of the general formula:- (R00)20 (III) wherein R has the same meaning as above.

The new compounds according to the present invention can also be obtained by other methods, for example: (a) by reacting the coumaranyl-carbamic acid esters of general formula (II) with appropriate acid halides; (b) by reacting appropriate coumaranyl-chloroformic acid esters with appropriate acylamines; and (c) by reacting appropriate hydrox coumaranes with appropriate N-methyl-N-acyl-carbamic acid chlorides.

Compared with the known insecticides of the N-acyl - - carbamate type, the active compounds according to the present invention, surprisingly, exhibit a higher inseeticidal power (of. Sx&aple 1 ) or a longer-lasting effect on limed and non-limed substrates (of. Examples 2 and 3). At the same time , the active compounds according to the present invention, surprisingly, exhibit a more rapid inseeticidal effect (of. Example 2) and a lower toxicity towards warm-blooded animals (c . Example 2), than the known coumaranyl-fl-methyl-carbamic acid estera.

There ore , the active compounds according to the present invention-constitute a valuable addition to the art.

The course of the reaction of a compound of fortrsula (II) with a compound of formula (III) in the preferred method of preparing the compounds according to the present invention is illustrated by the following specific ease H5 (IV) general .Preferred are those compounds of the/formula (II) in which the symbols , R2, and stand for hydrogen atoms and/or aliyl radicals containing 1 - 5 carbon atoms, and those compounds of the general formula (III) in which the symbol R stands for hydrogen or an alkyl radical containing 1 - 4 carbon atoms. ihe reaction with the acid anhydride is expediently carried out in the presence of a fairly large excess of the acid anhydride but inter organic solvents may be present at the same time* It is expedient to add acidic catalysts, especially concentrated sulphuric. acid or p.-toluene-sulphonic acid, in order to accelerate the reaction.

The reactions may be carried out within a fairly wide temperature range. In general, the operation is carried out between 70 and 170°0. , preferably at the boiling temperature of the reaction mixture.

The process is carried out in the usual manner. It is expedient to use an excess of anhydride and to add about 0.1 - 5#» referred to the carbamic acid ester, of an acidic catalyst. Working up is performed in the usual manner, for example, by fractional distillation.

The production of two new compounds according to the present invention is illustrated by the following Examples :-Example A .7 grams (o.l mol) 2-methyl-7-coumaranyl-N-methyl carbamate are dissolved in 120 ml. acetic anhydride, to which 3 drops of concentrated sulphuric acid have been added, and the solution is boiled under reflux for 30 minutes. After cooling, 1,5 g. sodium acetate are added and excess acetic anhydride is removed at water pump vacuum. The residue is taken up with benzene and the solution extracted several times by shaking with water. The benzene is removed in a vacuum and the residue distilled.

Yield: 20 g. 2-methyl-7-coumaranyl-N-acetyl-W-methyl carbamate Boiling point: 135 - 136°C./0.45 mm. Hg.

Example B 21.2 grams of this acetyl compound are obtained from 22.1 g. (0.1 mol) 2-dimethyl-7-coumaranyl-N-methyl carbamat by the same method as described in Example A.

Boiling point: 140 - 142°C./0.75 mm. Hg.

Example C 21.9 grams of this acetyl compound are obtained from 22.1 g. (0.1 mol) 2, 3-dimethyl-7-coumaranyl-N-methyl carbamate by the same method as described in Example A.

Boiling point: 165 - 166°C./1 mm. Hg.

Example D By acetylating 23,5 grams (0.1 mol) 2,3,3-trimethyl-7-coumaranyl-N-methyl carbamate, 24 g.. 2,3,3-trimethyl-7-coumaranyl-N-methyl-N-acetyl carbamate are obtained.

Boiling point: 167 - 168°C / 1.7 mm. Hg.

Le A 9438 - 7 - The active compounds according to the present invention have strong insecticidal and acaricidal effects but a low toxicity towards warm-blooded animals and a low phytotoxicity .

The effects appear rapidly and are long lasting. The active compounds can, therefore, be used with good results for combating noxious sucking and biting insects and Diptera, as well as mites (Acarina) .

The sucking insects essentially include aphids, such as the peach aphid (Myzus persicae) , the black bean aphid (Doralis fabae) ; coccids, such as Aspidiotus hederse. Lecanium hegperidum and Pseudococcus maritimus ; Thvsanoptera. such as Eercinothrips femoralis ; and bugs, such as the beet bug (Piesma quadrata) and the bed bug (Cimex lectularius) .

The biting insects essentially include butterfly larvae, such as Plutella maculipennis and Lymantria dispar: beetles, such as grain weevils (Sitophilus granarius) , the Colorado beetle (Leptinotarsa decemlineate) and also species living in the soil, such as wire worms (Agriotes SP.) and cockchafer larvae (Melolontha melolontha) : cockroaches, such as the German cockroach (Blatella germanica) ; Orthoptera. such as the cricket ( Gryllus domesticus) ; termites, such as i tioulitermes, : and Hymenoptera. such as ants.

The Diptera essentially comprise the flies, such as the fruit fly (Drosophila melanomaster) , the Mediterranean fruit fly (Ceratitis capitata) ♦ the house fly (Musca domestica) and gnats, such as the mosquito (Aedes ae&ypti) .

Especially important mites are the spider mites (Tetran chidae) , such as the common spider mite (Tetranychus urticae) , the fruit tree spider mite (Paratetranvchus pilosus) ; gall mites, such as the red currant gall mite (Eriophyes ribis) , and Tersonemides . such as Tarsonemus pallidus ; and also ticks.

The active compounds according to the present invention are equally suitable as insecticides and acaricides in plant protection and also for combating hygiene pests, for example in homes, stables and store rooms.

The active compounds according to the present invention can be converted into the usual formulations, such as solutions, emulsions, suspensions, powders, pastes and granulates. These are produced in known manner, for example, by mixing the active compounds with extenders, i.e. liquid and solid diluents and carriers, optionally with the use of surface-active agents, i.e. emulsifying agents and/or dispersing agents. In the case of the use of water as an extender, organic solvents can, for example, be used as auxiliary solvents.

As liquid diluents or carriers, there are preferably used aromatic hydrocarbons, such as xylenes or benzene, chlorinated aromatic hydrocarbons, such as chlorobenzenes , paraffins, such as mineral oil fractions, alcohols such as methanol or butanol, and strongly polar solvents, such as dimethyl sulphoxide or dimethyl formamide, as well as water.

As solid diluents or carriers, there are preferably used ground natural minerals, such as kaolins, clays talc or chalk, and ground synthetic minerals such as highly-dispersed silicic acid or silicates.

Preferred examples of emulsifying agents include non-ionic and anionic emulsifiers, such as polyoxyethylene-fatty acid esters polyoxyethylene-fatty alcohol ethers, for example, alkyl-aryl-polyglycol ethers alkyl sulphonates and aryl sulphonates; and preferred examples of dispersing agents include lignin, sulphite waste liquors and methyl cellulose.

The compounds according to the present invention can be present in the formulations in admixture with known active ingredients.

The formulations generally contain between 0.1 and 95 , preferably between 0.5 and 90, per cent by weight of active compound.

The active compounds can be used as such, in the form of their formulations or of the preparations made therefrom for application, such as solutions, emulsions, suspensions, powders, pastes and granules ready for use. Application is carried out in the usual manner, for example, by spraying, sprinkling, watering, scattering and dusting.

The concentration of the active compound can be varied within a fairly wide range. In general, concentrations of 0.00001S& - 20 , preferably 0.01 to 10$, are used.

The following Examples are given in order to illustrate the utility of the new compounds according to the present invention:-Example 1 Lymantria test Solvent: 3 parts by weight acetone Emulsifier: 1 part by weight alkyl aryl polyglycol ether.

To produce a suitable preparation of active compound, 1 part by weight of the active compound is mixed with the stated amount of solvent containing the stated amount of emulsifier, and the concentrate is diluted with water to the desired concentration.

Branches of the white hawthorn (Crataegus monogyna) are sprayed with the preparation of the active compound until dew moist and infested with caterpillars of the gipsy moth (Lymantria dispar) · After the speoified periods of time, the degree of destruction is determined as a percentage. 100 means that all the caterpillars are killed, whereas 0% indicates that none are killed.

The active compounds, their concentrations, the evaluation times and the results obtained can be seen from the following Table: a l e (Plant damaging insects) Active compound Concentration Degree of Destruction of active comp, after 3 days (known) Example 2 Residual test on clay and plywood Test animals: house flies (Musca domestica) Wettable powder base consisting of: > sodium di-isobutyl-naphthalene-l-sulphonate 6?e sulphite waste liquor partially condensed with aniline 0 highly-dispersed silicic acid containing calcium oxide 51$ colloidal kaolin.

To produce a suitable preparation of the active compound, 1 part by weight of the active compound is intimately mixed with 9 parts by weight of the wettable powder base. The spray powder thus obtained is suspended in 90 parts by weight of water.

The suspension of the active compound is sprayed, in an amount of 1 g. of active compound per square metre, on to various substrates.

The sprayed coatings are tested at definite time intervals for their biological activity.

For this purpose, the test animals are plcaed on the treated substrates. The test- animals are covered with a squat cylinder, the upper end of which is closed with a wire mesh, in order to prevent the animals from escaping. Within a residence time of 6 hours on the substrate, the period of time is determined which is required for a 100 knock down effect.

The active compounds, the type of substrate and the results obtained can be seen from the following Table: a l e Residual test Test animal: M sca domestica 100$ knock down effect on t Age of residual coatings in Active compound 1 D 1 W 2 W 3 0 Le A 9438 - 14 - Residual test Test animal: Musca domestica 100 knock down effect o Age of residual coatings Active compound Substrate 1 D 1 W 2 W Le A 9438 - 15 - Example 5 Residual test on limed clay Test animals: Oriental cockroaches (Blatta orientalis) (males) Vettable powder base consisting of: yfo sodium di-isobutyl-naphthalene-l-sulphonate 6$ sulphite waste liquor partially condensed with aniline 0# highly-dispersed silicic acid containing calcium oxide 51$ colloidal kaolin.

To produce a suitable preparation of the active compound, 1 part by weight of the active compound is intimately mixed with 9 parts by weight of the wettable powder base. The spray powder thus obtained is suspended in 90 parts by weight of water.

The suspension of the active compound is sprayed, in an amouht of 1 g. of active compound per square metre, on to a clay substrate which had been freshly limed 24 hours before.

The sprayed coating is tested at definite time intervals for its biological activity.

For this purpose,, the test animals are placed on the treated substrate. The test animals are covered with a squat cylinder, the upper end of which is closed with a wire mesh, in order to prevent the animals from escaping. Within a residence time of 6 hours on the substrate, the period of time is determined, which is required for a 100 knock down effect.

The active compounds, the type of substrate and the results obtained can be seen from the following Table: Residual test Test animal: Blatta orientalis (oo) 100$ known down effect o Age of residual coatings Active compound Substrate 1 D limed clay 360' ( (known) limed clay 105' Le A Q4 8 - 17 - Example 4 Phaedon Test 1 Solvent : 3 parts by weight acetone Enmlsifier: 1 part by weight alkyl aryl polyglycol etitier.

To produce a suitable preparation of active compound, 1 part by weight of the active compound is mixed with the stated amount of solvent containing the stated amount of enmlsifier and the concentrate is diluted with water to the desired concentration.

Horse-radish leaves (Oochlearia armoratia) are sprayed with the preparation of the active compound until dripping wet and then infested with horse-radish beetles (Phaedon cochleariae) .

After specified periods of time, the degree of destruction is determined as a percentage: 100 # means that all the beetles are killed whereas 0# means that none are killed.

The active compounds, their concentrations, the times of evaluation and the results obtained can be seen from the following Table: a b l e (Plant damaging insects) (Plant damaging insects) Active compound Concentration Degree of Destruction of active comp. after 3 days 0 Le A 9438 - 19 -

Claims (1)

1. acid esters of the general formulas wherein R stands for a lower aliphatic hydrocarbon radical and and which may or stand hydrogen atoms or lower compound of the compound of the Process for the preparation of acid esters of the general formula given in claim wherein a compound of the general formula in which as in claim is an reacted acid anhydride of the general in which R has the same meaning as in claim Process according to claim wherein the reaction is carried out with the use of an excess of the acid Process according to claim 4 or wherein the reaction is carried out with the use an acidic Process according to claim wherein the acidic catalyst Process according to any of claims 4 wherein the reaction is carried out at a temperature of 70 Process for the preparation of compounds of the general formula given in claim substantially as hereinbefore described and Compounds of the general formula given in claim whenever prepared by the nrocess according to any of claims 4 Insecticidal and acaricidal compositions comprising a compound of the general formula given in claim 1 and a solid or liquid diluent or Method of combating insects or which comprises applying to an insect or acarid habitat a compound of the general formula given in claim alone or in admixture with a solid or liquid diluent or Dated this 6th day of 1966 insufficientOCRQuality