DE1168697B - Agent for combating unwanted vegetation - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Boarding school KI .: AOIn

German class: 4SI -19/02

Number:
File number:
Registration date:
Display day:

B 59521IV a / 451
September 24, 1960
April 23, 1964

It is known to use esters of chlorinated aliphatic acids as herbicides. Have these esters However, compared to the alkali salts of chlorinated aliphatic acids, it is not a better herbicide Effect.

It is also known to use chlorinated carboxylic acids as weed control agents. The selective one However, the effect of these acids in the control of wild oats is very unsatisfactory.

It has now been found that compounds of the formula

R - COO- / CH \ - X

in which R denotes the trichloromethyl, "," - dichloropropyl or "," - dichloroethyl radical, X halogen or the cyano group, R 'denotes hydrogen, alkyl or alkoxyalkyl and η denotes the integers from 1 to 4, for selective control of monocotyledonous weeds in dicotyledon seeds are suitable, preferably for controlling wild oats in beets.

The esters to be used according to the invention can be prepared by customary methods, e.g. B. by converting the acid chlorides of trichloroacetic acid, «, Λ-dichloropropionic acid or«, «- dichlorobutyric acid with the substituted alcohols or by esterification of the free acids with the Alcohols in the presence of a catalyst, e.g. B. sulfuric acid or p-toluenesulfonic acid, and in counter-3 <> wart an azeotropically distillable hydrocarbon with water, e.g. B. benzene, toluene or ethylene chloride. Halogenated or aliphatic ones substituted by the cyano group can be used as alcohol components Alcohols e.g. B. ethylene chlorohydrin, propylene chlorohydrin, 3-chloropropanol, 4-chlorobutanol, glycolonitrile, / S-cyanoethyl alcohol or / J-hydroxy-y-methoxybutyronitrile be used. The production can, for example, according to the following procedures be made.

a) To a solution of 90 parts (parts by weight) of trichloroacetyl chloride in 500 parts of toluene, a mixture of 65 parts of triethylamine and 44 parts Äthylencyanhydrin dropwise at 0 to 20 ⁰ C with stirring. After completion of the addition a further 2 hours at room temperature and then for 2 hours at 5O ⁰ C is stirred. The toluene solution is then washed with water and 2N hydrochloric acid, dried with sodium sulfate and the toluene is evaporated off in vacuo. This gives 79 parts of trichloroacetic acid-.beta.-cyanoäthylester that at 0.8 mm pressure at 110 ⁰ C boiling. Its refractive index nf = 1.4759.

Means to combat unwanted
Vegetation

Applicant:

Aniline & Soda Factory in Baden

Aktiengesellschaft, Ludwigshafen / Rhein

Named as inventor:

Dr. Günter Scheuerer,

Dr. Horst Pommer, Ludwigshafen / Rhine,

Dr. Herbert Stummeyer, Limburgerhof (Palatinate),

Dr. Adolf Fischer, mother city

As described above, from 44 parts of ethylene cyanohydrin and

a) 80 parts of α, α-dichloropropionyl chloride 68 parts "" dichloropropionic acid-.beta.-cyanoäthylester of boiling point 82 to 84 ⁰ C at 0.2 mm pressure and the refractive index "ff = 1.4607;

b) 87 parts "" - Dichlorbuttersäurechlorid 74 parts a, "- Dichlorbuttersäure- / 3 cyanoäthylester of boiling point 112 to 115 ⁰ C at 0.4 mm pressure and the refractive index nf = 1.4626.

As described above, 90 parts of trichloroacetyl chloride are reacted with 70 parts of jö-hydroxy-γ-methoxybutyronitrile in 500 parts of toluene and in the presence of 65 parts of triethylamine. This gives 93 parts of trichloroacetic acid (a) -methoxymethyl - /? - cyano) ethyl esters, of 0.1 mm pressure at 100 to 102 ⁰ C boiling.

b) Another method for the preparation of the esters is described in the following procedure:

Parts «, oc-dichloropropionic acid, 176 parts of ethylene chlorohydrin, 0.5 parts of p-toluenesulfonic acid and parts of benzene are heated to the boil, with off The resulting water is continuously separated from the distillate and the benzene is continuously fed into the circuit is returned. In this way, 36 parts of water are separated off from the distillate within 4 hours. The benzene solution of the ester in the reaction vessel is washed with water and fractionated distilled. 390 parts of α, α-dichloropropionic acid jS-chloroethyl ester are obtained in this way. which boils at 94 ° C at 13 mm pressure and the refractive index «F? = 1.4625 has.

Correspondingly, α, α-dichlorobutyric acid is obtained from 314 parts with ethylene chlorohydrin 373 parts «,« - dichlorobutyric acid-jS-chloroethyl ester, which at 12mm

409 560/419

Pressure boils at 10O ⁰ C and has the refractive index "f = 1.4647.

It is known to use chlorinated carboxylic acids with polyglycols or to esterify alcohols substituted by phenoxy groups and the esters thus obtained to be used as a plant protection product. In contrast, the compounds to be used according to the invention are Esters of chlorinated carboxylic acids with monovalent, halogen or cyano groups substituted alcohols. The active ingredients according to the invention do not contain any phenoxy groups. the Agents according to the invention are distinguished from the known agents by a better selectivity, especially against sugar beets. When they are used, the crops become fewer damaged than when using the known means.

The esters can in a conventional manner, for. B. in the form of dispersions or emulsions, as a spray applied and mixed with other known herbicides.

The following examples show the use of the agents according to the invention.

example 1

Wild oat (Avena fatua), mustard (Sinapis alba) and burdock (Galium aparine) seeds are found in Sown sandy soil and then aqueous emulsions of trichloroacetic acid - /? - cyanoethyl ester and trichloroacetic acid ß-chloroethyl ester in amounts corresponding to the application of 101 active ingredient in 10001 water, sprayed evenly on the ground per hectare. After about 5 weeks they are Mustard (Sinapis alba) and burdock plants (Galium aparine) are strongly inhibited in their growth. After the same time, the Avena fatua plants have almost completely died.

The following esters are correspondingly effective:

^, A-dichloropropionic acid-ß-cyanoethyl ester, Λ, χ-dichloropropionic acid-jS-chloroethyl ester,
^ .Ä-dichlorobutyric acid-jS-cyanoethyl ester,
• ^ Tc-dichlorobutyric acid jS-chloroethyl ester

when used in amounts of 5 to 101 active ingredient per hectare.

Example 2

In the greenhouse, young plants of peas (Pisum sativum), beets (Beta vulgaris), onions are grown (Allium cepa), mustard (Sinapis alba) and wild oats (Avenna fatua), which develops one to three leaves have, with ß-cyanoethyl trichloroacetate in an amount corresponding to the application of 81 active ingredient, dispersed in 10001 of water, each Acres sprayed. The plants initially grow normally compared to control plants that have not been sprayed Further. After about 14 days you can recognize the mustard (Sinapis alba) and wild oat plants (Avena fatua) chlorotic lightening, especially at the leaf tip and the leaf margins. The pea (Pisum sativum), beet (Beta vulgaris) and bulb plants (Allium cepa) show only minor changes. After a further 2 weeks, the wild oat plants (Avena fatua) are clearly inhibited in their growth. The pea (Pisum sativum), onion (Allium cepa) and mustard plants (Sinapis alba) only show slight growth inhibition, while the beet plants (Beta vulgaris) completely after this time look normal.

Example 3

An aqueous emulsion of ß-chloroethyl trichloroacetate is dispersed in amounts corresponding to the application of 30 to 40 liters of active ingredient in 10001 water, per hectare on cypergrass (Cyperus rotundus) and common couch grass (Agropyrum repens) sprayed. The plants begin to wither after a few days and are almost perfect after 6 weeks dead.

Example 4

Beets (Beta vulgaris) are sown in 2 m ^{2 large plots on light sandy soil.} After the plants emerge, i.e. in the cotyledon stage of the beets (Beta vulgaris), trichloroacetic acid - /? - cyanoethyl ester (I), trichloroacetic acid ß-chloroethyl ester (II) and trichloroacetic acid sodium (III) in amounts corresponding to the application of 5, 10 or 151 of the individual esters or 5, 10 or 15 kg of the sodium salt, dispersed or dissolved in 1000 l of water each, sprayed onto the plants per hectare. After 5 weeks it was found that the wild oat plants (Avena fatua) and annual panicle grasses (Poa annua) which had risen from the ground were well controlled by all three agents when using 10 and 151 or kg of active ingredient per hectare corresponding amounts. The beet plants (Beta vulgaris), on the other hand, showed normal growth in comparison with untreated plants only when the active ingredients I and II were used in amounts corresponding to 5, 10 and 15 liters of active ingredient per hectare. When using active ingredient III, especially when using an amount corresponding to the use of 10 or 15 kg of active ingredient per hectare, there was a marked inhibition in the growth of the beet plants (Beta vulgaris).

Example 5

The-methyl- / 3-chloroethyl ester is found on soil contaminated with wild oats of dichlorobutyric acid per hectare in active ingredient amounts of 5 to 10 kg with the help of a Emulsifier (sodium lignosulfonate) in 10001 water, emulsified, sprayed. Then the sprayed on Substance evenly worked into the top 5 cm of the soil. Then the sowing takes place of beets (Beta vulgaris) in the top 2 cm of this soil. The effect is checked 4 weeks later:

In comparison to the plants grown on untreated soil, the beet plants show none Growth differences. The wild oat plants have a height on the untreated control plots of 12 cm, while in the treated with the Λ-methyl-jo-chloroethyl ester of dichlorobutyric acid Most of the parcels have no wild oat plants at all or if they have emerged have accumulated, stopped just above the ground in a strongly inhibited state in growth are. After a further 2 weeks, these wild oat plant remains are also there completely dead in the treated plots.

Claims (1)

Claim: Means for combating unwanted vegetation, marked by a Content of cyanoalkyl or chloroalkyl esters of trichloroacetic, dichloropropionic or dichlorobutyric acid the formula R -COO- / CH \ -X \ R ' In in which R is the trichloromethyl, "," - dichloropropyl or ", iv-dichloroethyl radical, X is halogen or the cyano group, R 'is hydrogen, alkyl or alkoxyalkyl and η is the integer from 1 to 4, as active ingredients. Considered publications:
German Patent No. 1,010,314;
German regulations no. 1 022 414, 1 035 636, 057 381, 1 107 239.
British Patent Nos. 807 599, 807 327. 409 560/419 4.64 © Bundesdruckerei Berlin