DE1618954C - Alpha-cyanoethyl-N-phenylcarbamates, process for their preparation and fungicidal agents - Google Patents

Description

CN

The compounds of the general formula I can according to the invention either by customary methods by condensation of substituted anilines of the general formula *

(H)

(I)

in which X is a chlorine atom and / or a methyl group and η is an integer from 1 to 5. 2. Process for the preparation of the compounds according to claim 1, characterized in that one by conventional methods either

a) a substituted aniline of the general formula

NH ₂ (II)

with a-cyanoethyl chloroformate or

b) a substituted N-phenylcarbamoyl chloride the general formula

Il

NH-C-Cl

(XII)

or a substituted phenyl isocyanate of the general formula

NCO

in which X and η have the meaning given in claim 1, reacts with α-cyanoethyl alcohol.

3. Fungicidal agents, characterized by a content of at least one compound according to Claim 1 as an active ingredient and customary carriers, diluents and / or auxiliaries.

The invention relates to α-cyanoethyl-N-phenylcarbamates of the general formula

55

NH-CO-CH-CH ₃

in which X is a chlorine atom and / or a methyl group and η is an integer from 1 to 5.

ίο in which X and η have the above meaning, with a-cyanoethyl chloroformate of the formula

CN O

I Il

CH ₃ CHOCCl

or of substituted N-phenylcarbamoyl chlorides the general formula

20th

Il

NH-C-Cl

(IH)

in which X and η have the above meaning, with a-cyanoethyl alcohol of the formula

CH

- I.

CH ₃ -CHOH

or by reacting substituted phenyl isocyanates the general formula

NCO

(IV)

in which X and η have the above meaning, are prepared with α-cyanoethyl alcohol.

The compounds of general formula I are valuable fungicides.

Fungicides of the organomercury type, which have hitherto been used in general as fungicides for agriculture have been used, show a very good effect on the various phytopathogenic fungi, z. B. against the causative agent of the Brusone disease Piricularia oryzae, such as Cochliobolus miyabeanus Drech. (S. Ito et Kurib.) And Helminthosporium sigmoideum Cav. However, these organomercury compounds have high toxicity to mammals and fishing.

It has been found that the compounds of general formula I are less toxic and one fungicidal effect z. B. opposite Piricularia oryzae Cav., Cochliobolus miyabeanus Drech. (S. Ito et Kurib.), Gibberella fujikuroi (Saw.) WoIl., Helminthosporium sigmoideum Cav., Hormodendrum sp. and Alternaria kikuchiana Tanaka.

Accordingly, the invention also relates to fungicidal agents which contain at least one compound of the general formula I as active ingredient and customary carriers, diluents and / or auxiliaries contain.

Particularly preferred compounds of the general formula I are given in Table I.

Table I Examples of the new compounds

Structure designation

Il

NH-C-O-CH-CH,

Cl

Cl
Cl

Cl

Cl

NH-CO-CH-CH ₃

Il

NH-CO-CH-CH ₃ CN

Cl

Cl

Cl

Cl

■ Cl

Cl

Cl Cl Cl

Il

NH-CO-CH-CH ₃

NH-CO-CH-CH ₃

. . ' ^CN

Il

NH-CO-CH-CH ₃ CN

Cl

Il

NH-CO-CH-CH ₃

Cl Cl

CH

-CO-CH-CH ₃

CN O

Il '^;

NH-CO-CH-CH ₃

CH, CH,

α-cyanoethyl-N-2-chlorophenylcarbamate; M.p. 94 to 95.5 ° C

α-cyanoethyl-N - ^ - dichlorophenyl carbamate; M.p. 125.5 to 126.5 ° C

α-cyanoethyl-N-2,5-dichlorophenyl carbamate; F. 116 to 118 ° C

α-cyanoethyl-N-SjS-dichlorophenyl carbamate; 109-111.5 ° C

α-cyanoethyl-N- ^ Ao-trichlorophenyl carbamate; M.p. 74 to 76 ° C

α-cyanoethyl-N ^ AS-trichlorophenylcarbamate; Mp 137-139 ° C

α-cyanoethyl-N ^^ ASjo-pentachlorophenylcarbamate; 163 to 166 ° C

α-cyanoethyl-N-3-methylphenyl-carbamate; M.p. 70 to 71 ° C

α-cyanoethyl-N-2,3-dimethylphenylcarbamate; M.p. 81 to 83 ° C

continuation

Structure designation

H ₃ C

γ x ^ _ -NTtr r <r \ nxJt

NH-C-O-CH-CH ₃

CH,

CH

Il

NH-C-O-CH-CH ₃

CN

Il

NH-CO-CH-CH ₃

CN

CH

NH-CO-CH-CH ₃

CN

Cl

Il

NH-CO-CH-CH ₃

CN α-cyanoethyl-N ^^ dimethylphenylcarbamate; 80 to 83 ° C

a-cyanoethyl-N ^ o-dimethylphenyl-. carbamate; M.p. 58 to 62 ° C

α-cyanoethyl-N-S ^ -dimethylphenylcarbamate; M.p. 43 to 47 ° C

α-cyanoethyl-N-S ^ dimethylphenylcarbamate; M.p. 82 to 84 ° C

α-cyanoethyl-N- ^ S-dimethylphenylcarbamate; M.p. 51 to 54 ° C

o-cyanoethyl-N-S-methyl ^^ ö -trichlorophenyl carbamate; M.p. 145 to 148 ° C

The effect of the above compounds was tested on the following phytopathogenic fungi:

(a) Piricularia oryzae Cav. (abbreviated P. o.), _6o

(b) Cochlibolus miyabeanus Drech. (S. Ito et Kurib.) (abbreviated C. m.),

(c) Gibberella fujikuroi (Saw.) WoIl. (abbreviated G. f.),

(d) Helminthosphorium sigmoideum Cav. (abbreviated _fi H. s.), ⁵

(e) Hormodendrum sp. (abbreviated hormone),

(f) Alternaria kikuchiana Tanaka (abbreviated A. k.).

Using a potato juice agar containing 2% glucose, solutions were made with different concentrations of each test compound in acetone individually diluted 20-fold. 20 ml Each diluted solution was placed in a petri dish of 10 cm inside diameter to form a plate poured. Spores of the fungi were spread individually on the plate. 7 days after inoculation the minimum inhibitory concentration (mcg / ml) for the mycelial growth of each test solution was determined. The results are shown in Table II.

Table II

Test connection P.o. Cm. Minimum inhibitory concentration, γ / τηΐ H. s. Hormone A.k. No. 500 1500 G. f. 500 1250 1500 1 150 1500 1250 1000 1000 1500 2 300 500 1250 500 500 300 3 125 40 1000 125 125 50 4th 300 100 500 125 125 50 5 300 100 1000 125 125 100 6th 125 100 500 500 50 100 7th 500 1000 300 500 1500 1000 8th 150 2000 1500 1000 1000 1500 9 300 200 1000 200 200 300 10 300 100 500 1500 1500 1500 11th 200 50 1000 1000 500 100 12th 500 200 100 200 200 1000 13th 1500 1500 1000 500 500 500 14th 100 100 200 100 100 100 15th 500

As can be seen from Table II, the compounds are pathogenic to various plants Mushrooms effective. Not all of the compounds have high germination inhibition activity from Conidia from Cochliobolus miyabeanus Drech. (S. Ito et Kurib.), But they can prevent mycephalic growth strongly inhibit, and they show a long lasting effect. Furthermore, most of the connections show a considerably high protective and healing effect against Helminthosporium sigmoideum Cav.

The compounds of the invention can be used in the form of conventional preparations, for example as emulsifiable concentrates, wettable powders, granules, dusts and tablets, being more active Component of at least one compound of general formula I is used. Fungicides in the form of powders or solids, e.g. wettable powders, dusts, granulates and tablets, can be used as a carrier or extender z. B. clay, talc, kaolin and diatomaceous earth, Contain carbon, gypsum or calcium carbide or starch or carboxymethyl cellulose. In case of Emulsifiable concentrates can contain the usual cyclic or straight-chain hydrocarbons or Alcohols, ketones, esters and ethers derived therefrom can be used as solvents. Nonionic surfactants and if necessary anionic or cationic surfactants, lignosulfonates or polyvinyl alcohols can be used as an aid.

Experimental example 1

Rice plants (Norin No. 2, three-leaf seedlings) grown in pots were individually sprayed with an emulsion obtained by diluting an emulsifiable concentrate with water to an active ingredient concentration of 500 ppm was. The emulsifiable concentrate was made up of 40 parts of the compound under investigation, 40 parts of xylene and 20 parts of a nonionic wetting agent hcigestelll. The next day the seedlings became with spores of Piricularia oryzae Cav. bcimplt. and 6 days later the number of the disease spots per leaf counted by the ratio (percentage of the number of disease spot reduction in de: treated areas versus the number of disease spots in the untreated plant: to calculate. The calculated ratios were given as the inhibition ratio. The results are fine Table III compiled.

Table III

Test connection concentration Inhibition ratio No. ppm % 1 500 10.7 2 500 37.2 3 500 49.0 4th 500 75.2 7th 500 71.4 8th 500 9.8 12th 500 63.0 5 500 53.6 15th 500 48.8 Not treated . . 0

Experimental example 2

The same rice plants as in the experimental example were individually with 150 mg of a dust pr. Pot treated.

The dust was created by mixing 2 or 3 parts of the compound under investigation, 7 parts finely powdered mixture of clay and talc and 1 part powdery calcium clearate and connect Dilute with 90 parts of the mixture made from clay and talc. The next day were di Rice plants inoculated with spores of Piricularia oryzae Cabe. 6 days later, the inhibition ratio became calculated in the same way as in the experimental example. The results are in Table I. compiled.

209 521/4

Table IV

* Applied Inhib sample 2% dust of the crowd ratio Connection No. 4 ... mg / pot % 3% dust of the Connection No. 8 ... 150 81.3 Untreated 150 31.0 - 0

Day the rice plants were covered with spores of Cochliobolus miyabeanus Drech. (S. Ito et Kurib.) Inoculated. 6 days later, the number of disease spots per leaf was counted. -The results are in the table V compiled. " · '"·';

♦ ■ · "* ■ ' Table V' ^:

IO

Experimental example 3

Rice plants (Norin No. 21, seedlings in the four-leaf stage) that have been grown in pots were individually sprayed with a solution obtained by dissolving a wettable powder in Water was made to an active ingredient concentration of 500 ppm. The wettable powder was made by mixing the test compound with a mixture Clay and talc and 3 percent by weight of a non-ionic wetting agent. The next

Test connection Triazine concentration number of
Disease spots No. Phenylmercuric ppm per sheet 1 silver iodide 500 46.9 2 Untreated 500 20.5 3 500 7.0 4th 500 5.7 6th 500 9.2 11th 500 13.5 13th 500 31.0 500 6.2 20th 5.3 than mercury - 50.6

Experimental example 4

The compounds to be investigated were in the form of wettable powders. These preparations were diluted with water and applied to white bean seedlings at a dose of 7 ml each, which were grown to the two-leaf stage in flower pots with a diameter of 15 cm. 1 day later the leaves were infected with the mycelium (about 6 mm in diameter) from Sclerotinia sclerotiorum. Four days later, the extent of the infection was observed. The results are summarized in Table VI. The degree of damage was calculated using the following equation:

Degree of damage = Σ (infection index x number of leaves)
(Total number of leaves observed x 5)

100.

The infection index (infected leaf area) was determined using the following rating scale:

Test connection

Infection index

40

Infected leaf area

no infection

less than Vs of total leaf area

Vs or more, but less than _^2/5 of the total leaf area

² / s or more, but less than _^3/5 of the total leaf area

_^3/5 or more, but less than _^4/5 of the total leaf area

_^4/5 or more than the total leaf area

Table VI

55

Test connection Conc
tration
ppm Damaging
gearing
Degree connection
number 1 250 21.3 No. 3 250
250 9.7
0 No. 4 250
250 6.5
24.1 No. 6 No. 7

NHCOCH ₂ CH ₂ CN
0

60

65 concentration ppm

250 250 250 250 250 250

250

250

Degree of damage

CNA ² ).

Not treated ...

annotation

') Described in US patent specification 3036 112. ² ) Commercially available fungicide with 50% 2,6-dichloro-4-nitroaniline as active ingredient.

It can be seen from the table that the compounds according to the invention are excellent fungicides and are superior to the known fungicides.

Claims (1)

Patent claims:
1. a-Cyanoethyl-N-phenylcarbamate of the general 'my formula NH Il CO-CH-CH ₃