DE1543603C - 8-Chromanylcarbamates and processes for their preparation and their use as pesticides - Google Patents

Description

R ₄

IO

in which R ₁ and R ₂ each represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ₃ a hydrogen atom, an alkyl, alkenyl or alkynyl group having 1 to 3 carbon atoms, R ₄ a hydrogen atom or the methyl group and Y a hydrogen atom or in the 5- or 6-position is a chlorine atom or an alkyl group with at most 4 carbon atoms.

2. Process for the preparation of 8-chromanyl carbamates of the general formula given in claim 1, characterized in that one an 8-chromanol of the general formula

γ; ■

OH

in which R ₁ , R ₂ and Y have the meaning given in claim 1, is reacted in a manner known per se with an equivalent amount of a corresponding isocyanate or with phosgene and then with a corresponding amine.

3. Use of the 8-chromanyl carbamates according to claim 1 as pesticides.

The invention relates to 8-chromanyl carbamates of the general formula

C-N

R ₄

35

40

in which R ₁ and R ₂ each represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ₃ a hydrogen atom, an alkyl, alkenyl or alkynyl group having 1 to 3 carbon atoms, R ₄ a hydrogen atom or the methyl group and Y a hydrogen atom or in the 5- or 6-position is a chlorine atom or an alkyl group having at most 4 carbon atoms, and a process for their preparation and their use as pesticides. - : ./^'-\-:: ^r V-; : .. ■■ '■.: ■ ; - ^: - ■. ■. · ■■■ ·; :. :: "- '. *

The 8-chromanyl carbamates of the general formula given above have excellent pesticidal properties Effects, including against Arthropoda, such as Coleoptera (beetles), Hemiptera (real Bugs), Homoptera (aphids), Acarina (mites), Diptera (flies and wasps), Blattaria (cockroaches). ' and Lepidoptera (moths and butterflies). In addition, several of these compounds are special effective in controlling nematodes.

In the following experiments, the effect against known carbamic acid esters was tested, and thereby the indicated results were obtained.

Attempt I.

The 2,2 - dimethyl - 8 - chromanylmethyl carbamate (compound A = example 1) was compared to the from the French patent 1 403 952 known 2-methyl-coumaran-7-N-methylcarbamate (Compound B), the 1-naphthylmethyl carbamate known from U.S. Patent 2,903,478 (Compound C) and with respect to the 2-isopropoxyphenylmethyl carbamate known from US Pat. No. 3,111,539 tested for action on various pests. .

The compound to be tested (0.5 g) was dissolved in 40 ml of acetone and the solution was dissolved in 360 ml Water dispersed, the one drop of Triton X-IOO (Isooctylphenylpolyäthoxyäthanol, a surface-active Means) contained; Equal parts of these solutions were diluted with water to form solutions which contained 1250, 156, 78 and 39 ppm of the active ingredient. The test insects and -Procedures were as follows: The activities against spotted ladybird (Epilachna varivestis MuIs.) and cotton caterpillar (Südl. Heerwurm) (Prodenia eridania [Cran.]) was determined by the leaves of spotted field bean plants were immersed in the test solution and · by the leaves with the Insect larvae became infected as soon as they dried; the activity against spotted spider mite (Tetranychus telarius [L.]) was determined on spotted field bean plants, their leaves immersed after infection with adult mites; the activity against pea aphid (Macrosiphum pisi [Harris]) was determined on broad-leaved bean plants, the leaves of which before infection with adult aphids were immersed, and the activities opposite Silkworm beetle (Oncopeltus fasciatus [Dallas]) and, opposite, plum weevil (Conotrachelus nenuphar [Herbst]) was determined by spraying the test solutions onto glass dishes which which contained adult insects. All insects in the experiment were at 26.7 ° C and 50% relative humidity for a period of 48 hours

kept in a chamber. After this time, the number of insects killed and alive counted and the percentage kill calculated.

The following table summarizes the values found, which are an average of two Repetitions are.

Percent kill at 156 ppm

Connection A Connection B Compound C Connection D Example . ... known , known known 100 *) r ■ ':' ·. loo V; 100 :. ^: Λν 100. ^: 100 '" ■ Λ · :. '72 100 ^: .v- ■ ο.; 98 ■ λ · · '·· ■ '85 ■ -. 4 .- 37 100 *) 100 95 100 *) ': loo ■■ ;. ^: 100 ^: ν ^: 100 90, '■; 55. 0 **) 60

Test insect

Spotted ladybug

Cotton caterpillar (southern army worm) Two-spotted leaf spider mite
Pea aphid ..... '.;'....; .....

Silkworm beetle

Plum weevil

*) At 78 ppm. **) At 1250 ppm.

From these values in the table it can be seen that the compound A corresponds to the known compounds B, C and D is superior in effect overall and has a wider spectrum of activity. ,

Experiment II

It became the effect of some of the compounds according to the invention against the known carbamate esters B, C and D tested for their effect on the pea aphid and the plum weevil. The method used here corresponds to that of experiment I.

In the following table are the results obtained The values reported are an average of two replicates are.

Percent kill at 156 ppm

spotted
Ladybug

Pea aphid

Plum weevil

1. 8-Chromanylmethylcarbamate ... '..

2.2> trimethyl-8-chromanylmethyl carbamate

3. 2,2-dimethyl-8-chromanyl dimethyl carbamate

4. 2,2-Dimethyl-8-chromanylaIlyl-

5. ^^ - dimethyl-β-chromanyl-; propargyl carbamate ...... 1 .......

6. 1-methyl-coumaran-T-N-methylcarbamate (Connection B) '.........

7. 1-naphthylmethyl carbamate
(Compound C)

8. 2-isopropoxyphenylmethyl carbamate (Connection D) ..; ..: ......

*) At 39 ppm: i; '***) At 1250 ppni.

(Example 2) (Example 5) (Example 10) (Example 12) (Example'13)

(known from French patent specification, 1043 952) - \ .. ..; ■ -;

(known from the -;., ϊ : U.S. Patent ν

2 903 478) ": ■ ■■■ ··;: - ':

(known from the USA patent, 3111539); ·:, ■ 100 *)
100

100
100 *)

: 100 (80 *)

aoo-

100

100 *)

100

100 *)

100 (80 *)

55

60

. Not even the ^ in the previous experiments tested compounds according to the invention have similar insecticidal properties.

The nematocidal activity of 2,2-dimethyl-8-chromanylmethyl carbamate can be seen from the following experiment: One infested with nematodes Soil was made by mixing about 1000 larvae of the root-knot nematode (Meloidogyne incognita) made in 11 clay-sand-earth. Such an amount of 2,2-dimethyl-8-chromanylmethyl carbamate became in this infected soil in the form of a 5% dust mixed in on attapulgite clay that concentrations of 100 and 25 ppm were found. These mixtures were kept in the greenhouse for 4 days kept in a moist state, then young tomato plants were planted in the ground and 5 weeks

let grow. After this time, the roots of the tomato plants were washed free from the earth, and the extent of infection was determined in comparison with a plant in one with Nematode-infected soil that had not undergone any chemical treatment. The received The results are summarized in the table below. . ■ '. ■

.... nematocidal activity.

Concentration ■
in ppm Root node
,. index*) degree of
Nematode control 100
25th
Untreated 0
0
4th excellent
excellent
none

*) Root node index:

4 = very strong occurrence of nodules, as with untreated

Plant.
3 = strong occurrence of lumps, but less than at

untreated plants.
2 = moderate occurrence of nodules. 1 = low occurrence of nodules. 0 = no occurrence of knots, complete control.

The 8-Chromanylcarbamate according to invention can in the _; In the form of customary formulations, for example as sprays, in the form of dust or as solutions, can be used. .

The 8-chromanyl carbamates of the general formula given above are prepared by one an 8-chromanol of the general formula

γ y

R-

in which R ₁ , R ₂ and Y have the meanings given above, is reacted in a manner known per se with an equivalent amount of a corresponding isocyanate or with phosgene and then with a corresponding amine. .

The 8-chromanol to be used as starting material can be obtained from a corresponding chroman, z. B. by conversion into the corresponding 8-lithium compound according to that of Hallet and Hüls in the Bulletin Societe Chimique Beige, 61, 33 (1952), described method, which then oxidizes and then hydrolyzed to the 8-chromanol in question, or by bromination of a corresponding one Chromans to the 8-bromine compound and convert it into the 8-hydroxy compound or also by nitration of a corresponding chroman to the 8-nitro compound, reduction of the same corresponding to the 8-amino compound with subsequent diazotization and hydrolysis of the diazonium salt 8-Chromaol can be produced. Furthermore, from a corresponding 8-methoxychroman the 8-chromanol in question can be obtained by conventional ether cleavage. Furthermore, the relevant 8-chromanols prepared from appropriate reaction components by customary ring closure methods will.·

example 1
2,2-dimethyl-8-chromanylmethyl carbamate

1.0 g of 2,2-dimethyl-8-chromaol, which, according to that of Hallet and Hüls in the Bulletin Societe Chimique Beige ”, Vol. 61, pp. 33 to 43 (1952), was prepared in 10 ml of ether dissolved and treated with 2 drops of triethylamine, and 0.5 g of methyl isocyanate was added to this solution. The mixture was then under for 24 hours Heated to reflux, then cooled and filtered. The white crystals obtained were washed with ether and washed with pentane. 0.9 g of 2,2-dimethyl-8-chromanylmethyl carbamate were obtained obtained from the mp 147 ° C.

Example 2
8-chromanyl methyl carbamate

A mixture of 2.5 g of 8-chromanol, 1.5 g of methyl isocyanate, 10 ml of ether and 2 drops of triethylamine was diluted with pentane and filtered after standing overnight. There were 3 g of 8-chromanyl methyl carbamate obtained from the m.p. 158 ° C.

The 8-chromanol used as starting material above was prepared as follows: 450g Brerizcatechol were dissolved in a hot solution of 220 g of sodium hydroxide in about 200 ml of water. To this solution were added dropwise 360 g of 3-chloropropionic acid, which was dissolved in a solution of 230 g of potassium carbonate were dissolved in a minimum amount of water. The whole thing was then 10 minutes heated to reflux, then cooled in an ice bath and washed with dilute hydrochloric acid adjusted to a pH of 2. The aqueous solution was extracted with ether. The ether extract was washed, dried over magnesium sulfate and concentrated to give 3- (o-hydroxyphenoxy) propionic acid was obtained as an oil. About 900 ml of acetic anhydride were then added to this oil, and the solution was refluxed overnight. The excess acetic anhydride was now distilled off, and the residue was washed with water. The organic layer was separated and dried over magnesium sulfate. The obtained crude 3- (o-acetoxyphenoxy) propionic acid became Given 1.51 polyphosphoric acid at 45 ° C and stirred at this temperature for 2 hours. The reaction, mixture was then cooled to room temperature, diluted with water and extracted with ether. The ether extract was washed with an aqueous sodium bicarbonate solution, dried and concentrated. Solid 8-hydroxychroman-4-one became the residue obtained, which melted after recrystallization from ethyl acetate at 169 to 170 ° C. '

5.0 g of this S-hydroxychroman- ^ one were with zinc amalgam, which had been obtained by adding 20 g of washed zinc dust to a solution of 4 g of mercury (II) chloride in 2.0 ml of concentrated hydrochloric acid, and 30 ml more concentrated Hydrochloric acid was stirred under reflux for 1 hour. The mixture was then cooled and extracted with ether, the ether layer treated with sodium bicarbonate, dried over magnesium sulfate and evaporated. There were obtained 5.0 g of crude 8-chromanol from Kp. _Oo7 61 to 64 ⁰ C.

Example 3
2,2-diethyl-8 * -chromanylmethyl carbamate

A mixture of 3 g of 2,2-diethyl-8-chromanol, 10 ml of ether, 3 drops of triethylamine and 1.2 g of methyl isocyanate was reacted according to Example 2 and worked up. 3.0 g of 2,2-diethyl-8-chrome-.anylmethylcarbamat mp 68 to 70 ⁰ C obtained.

The 2,2-diethyl-8-chloro-ethanol used as starting material above has been prepared as follows: 101 g; 3-Ethyl-l- (o-hydroxyphenyl) -3-pentanol, as described by L · I. S mith and PM R u ο ff in the "Journal of American Chemical Society", vol. 62, p. 146 (1940) , ■ described, prepared: were dissolved in 150 ml of glacial acetic acid and treated dropwise with 100 ml of sulfuric acid. The mixture was refluxed for about 2 hours, then left to stand overnight at room temperature: the mixture was then poured onto ice / water and extracted again with ether. The combined ether extraction \ ,. were NEN dried over magnesium sulfate and filtered y the ether was removed and the residual oil distilled under reduced pressure to obtain '77, 5 g of 2,2-Diäthylchroman from Kp. _OO0 8 were obtained 57 to 60 ° C.

40 g of the above 2,2-diethylchroman was added to a solution consisting of 150 ml of ethyl ether and 137 ml of hexane containing 14 g of n-butyllithium which had been purged with nitrogen, and the mixture was refluxed for 20 hours. The mixture was then in one. Ice-water bath cooled and oxygen under. Stirring iri. the mixture initiated. After the oxygen absorption ceased, the mixture was acidified with cold aqueous sulfuric acid. The ether-hexane phase was separated off, washed with water and dried over magnesium sulfate and the solvent was evaporated. Then the back - ..: ■■ was with decolorizing activated charcoal in dry ether.,: Treated and the --ether solution was distilled. After the removal of unreacted 2,2-Diäthylchromari (Kp. _Ol 65 to 73 ° C) 3.8 ^ ^ l-diethyl-S-chromanol were obtained from Kp.0,015 78 to 80 ⁰ C. , ^v

'Example 4 x ¹ ;: .-; : ν

o-ethyl ^^ - dimethyl-S-chromanylmethyl carbamate _;

A mixture of 10 g of 6-ethyl-2,2-dimethyl-8-chromanoL 5 g of methyl isocyanate and 5 drops of triethylamine in ethyl ether were prepared as in Example 3 implemented and processed. 5.5 g of 6-ethyl-2,2-dimethyl-8-chromanylmethyl carbamate were obtained obtained from bp 114 to 115 ° C.

Example 5
2,2,5-trimethyl-8-chromanylmethyl carbamate

1.5 g of 2,2,5-trimethyl-8-chromanol were reacted with methyl isocyanate as in Example 3 and worked up. There were 1.2 g of 2,2,5-trimethyl-8-chromanylmethylcarbamate from 132.5 to 133.5 ° C after Obtained recrystallization from hexane. Examples 5-chloro-2,2-dimethyl-8-chromanylmethyl carbamate

5 8.5 g of S-chlorine ^^ - dimethyl-S-chromanoJ were reacted with - .. ·· 2.4 g of methyl isocyanate according to the method described in Example 1, with 5.3 g of 5-chloro-2,2- dimethyl-8-chromanylmethylcarbamat, mp 128-129 ⁰ C were obtained.

Example 7

2,2-dipropyl-8-chromanylmethyl carbamate,

By reaction of 2,2-dipropyl-8-chromanol _I5 with methyl isocyanate according to the procedure of Example 3 was ^^ - dipropyl-S-chromanylmethylcarb- AMAT, mp 99 to 100 ⁰ C obtained. ■ ">'■

>: ':. -V; ν Example 8; ... r ν

6-sec-butyl-2,2-dimethyl-8-chromanylmethyl- ". Carbamate ·

The 6-sec-butyl-2,2-dimethyl-8-chromanol was

with methyl isocyanate according to the method of

'25 game 1 implemented, with 6-sec-butyl-2,2-dimethyl-

8-chromanylmethylcarbamat mp 169 to 17O ⁰ C

was obtained. ^!

-.Example'9, 2,2,7-trimethyl-8-chromanylmethyl carbamate

The 2,2,7-trimethyl-8-chromanol was reacted with methyl isocyanate - as in Example 1, wherein 2,2,7-trimethyl-8-chromanylmethylcarbamate with a melting point of 35 115 to 116 ° C (hexane) was obtained.

Example 10 '^ ·

2,2-dimethyl-8-chromanyl dimethyl carbamate

40 26.7 g ^^ - dimethyl-S-chromanol, which had been prepared as in Example -..-, 'game 1, were added dropwise at room temperature to a solution of sodium methylate, which was obtained by dissolving 3, 45 g of sodium had been prepared in 50 ml of methanol. The mixture was ^{heated at 50 °} C. for 1 hour, and the methanol was removed by distillation: under reduced pressure. The sticky solid that remained was triturated with hexane, '.;.;".'""Filtered to give a white powder. To a solution of 13.5 g of this sodium salt in 75 ml of dioxane was added dropwise 7.5 g of dimethylcarbamoyl chloride. After the exothermic reaction subsided, the slurry was heated to 75 ° C for 2 hours. The slurry was concentrated under reduced pressure and the residue became diluted with lOOmlÄther The ether solution was washed with water, dried and distilled to give 7.1 g ^^ -. S-dimethyl-chromanyldimethylcarbamat from Kp _ool 101-102 ⁰ C. "" ■ '* ■ ..' V... ■. '". 60 '■■■■ r - \ -;:.: U ^ ■■:; ■: ■: .. ·' ... ■: · ,: ■: ... yf>! - hv ..- , [ '. Example 11. · _■:; .; ^; · _; V ' ^:: . ^: . '■:' ■■ <. '.

2,2-dimethyl-8-chromanylpropyl carbamate.

To a solution of 11.75 g of 2,2-dimethyl-8-chromium

65 anol and 0.2 g 1,4-diazabicyclo- (2,2,2) -octane in 75 ml

Ethyl ether was added dropwise with stirring 6.0 g of propyl isocyanate. The mixture was at Stirred at room temperature overnight. The ether

309 612/175

and excess propyl isocyanate were removed by distillation and the residue was with Diluted petroleum ether. The solid was separated and there was found 7.0 g of 2,2-dimethyl-8-chromanylpropyl carbamate obtained from the mp 71 to 72 ° C (hexane).

- · '. Example 12 '■: ■ /; J

^^ - Dimethyl S-chromanylallyl carbamate. ■, · -...; ■

16.2 g of 2,2-dimethyl-8-chromahol were reacted with 6.0 g of allyl isocyanate in 50 ml of benzene according to Example 11, with 8.5 g of 2,2-dimethyl-8-chromanylallyl carbamate after recrystallization from hexane from 70 to 71 ° C.
"■■ '·.' .. · '''_' _ ■ .- "■; ■ '' ■ ^'■': - · ■ ^·":.... V ■■ ". ' ! 5 Example 13

2,2-dimethyl-8-chro'manyl-propargylcarbamate

11 ml of liquid phosgene were added at 0 ° C. to a solution of 25 g of 2,2-dimethyl-8-chromanol in 10.0 ml of benzene. While the temperature was kept at 4 to 7 ^° C., 14.2 g of triethylamine were added dropwise. The mixture was stirred for 1 hour at 5 ° C then 2 hours at 25 ° C / The slurry was diluted with 150 ml of cold water. The benzene layer was separated, dried and concentrated to leave 32.5 g of the yellow oily 2,2-dimethyl-8-chrömanylchloroformate which was used without further purification. A solution of 16.2 g of this 'raw' ^^ - dimethyl-S-chrömanylchlorformate in 50 ml of benzene was added dropwise with stirring to a solution of 3.7 g of propargylamine and 6.8 g of triethylamine in 25 ml of benzene. The slurry was stirred for 3 hours at 50 to 6O ⁰ C, then cooled to 20 ° C and filtered. The filtrate was washed with cold water, dried and concentrated by evaporation. The _s residual oil was diluted with hexane, and the precipitated white solid was isolated by filtration to give 8.0 g of 2,2-dimethyl-8-chromanyl-propafgylcarbamat. were obtained. By recrystallization from hexane, 7.0 g of the compound in platelet form with a melting point of 95 to 95.5 ° C. were obtained.

Claims (1)

Patent claims: 1. 8-Chromanylcarbamate of the general formula R ₁ .γ O — C —N Il ^N ο Ki