CH644358A5 - SUBSTITUTED 4-ALKYLTHIOALKANESULPHONANILIDE. - Google Patents

Description

The invention relates to halogen-substituted 4-alkylthio-alkanesulfonanilides which are substituted in the p-position by alkylthio, alkylsulfinyl or alkylsulfonyl groups and their salts which are compatible with agriculture. The compounds according to the invention are effective herbicidal agents and plant growth regulators. The invention also relates to herbicidal compositions containing the new compounds and to a method for regulating the growth of higher plants using the new compounds.

The compounds according to the invention have the following formula:

HNS02-R

i "ïç)

(I)

S (0) nR '

in which R is a monohalomethyl group, namely chloromethyl, bromomethyl, iodomethyl or fluoromethyl group, R 'is an alkyl group having 1 to 4 carbon atoms, 4 is a halogen atom, B is a hydrogen or a halogen atom and n is 0 to 2.

The compounds according to the invention can be present as salts which are suitable for agriculture. General formula I is not intended to include 2-fluoro-4-methanesulfonylchloromethanesulfonanilide. This compound was described in EP-A-0 010 249 (Bayer) on page 9 (twelfth compound) and also in EP-A-0 010 250 (Bayer) on page 9 (tenth compound). This connection was also listed on page 16 of OS 2 845 997 (Bayer).

The agent according to the invention for regulating the growth of taller plants is characterized in that it contains at least one compound of the formula I as active ingredient component, apart from 2-fluoro-4-methanesulfonylchloromethanesulfonanilide, or a salt thereof which is acceptable for agriculture.

In the process for regulating the plant growth of higher plants, the plants are brought into contact with at least one compound of the formula I, apart from 2-fluoro-4-methanesulfonylchloromethanesulfonanilide, or a corresponding salt thereof.

The active substances can be dispersed in a carrier in the agents according to the invention. The compounds according to the invention are particularly suitable for use in the field of selective herbicides for controlling specific plant species in the presence of special crop plants (with little or no destruction of the crop plants occurring), for example. B. to control weeds, such as rhizomatous Johnson grass, annual grasses, yellow cypress grass and / or purple cypress grass in crops such as cotton or soybeans.

The compounds of the formula I, in which R is the —CH2C1 group and A is a chlorine or bromine atom, represent a preferred group of compounds on account of their high activity.

The compounds of formula I can form salts, i.e. Compounds of the formula given above, in which H is replaced by a cation suitable for agriculture. These salts are generally metal, ammonium and organic amine salts and can be prepared by treating a compound in the acid form with an appropriate base under mild conditions. To

3rd

The preferred metal salts according to the invention include the alkali metal salts (for example lithium, sodium and potassium salts) and alkaline earth metal salts (for example barium, calcium and magnesium salts) and the heavy metal salts (for example zinc and iron salts) and other metal salts such as aluminum - 5 salts. Suitable bases for the production of the metal salts according to the invention are the metal oxides, hydroxides, carbonates, bicarbonates and alkoxides (alcoholates). Some salts can also be prepared by ion exchange (by reacting a salt according to the invention with an organic or inorganic salt in a cation exchange reaction). The organic amine salts include in particular the salts of aliphatic (e.g. alkyl), aromatic and heterocyclic amines as well as those with mixed structures of this type. The amines used for the preferred preparation of the salts according to the invention can be primary, secondary or tertiary and preferably contain no more than 20 carbon atoms. Such amines are e.g. Morpholine, methylcyclohexylamine, glucosamine, amines derived from fatty acids, etc. 20

NHS02R

<r

S (0) nR *

Reaction stage (1) comprises the formation of the substituted 4-thiocyanoanilines from the correspondingly substituted anilines (the compounds are known or processes for their preparation are known) by generally customary processes.

Reaction stage (2) comprises the formation of the substituted 4-alkylhioanilines directly from the corresponding 4-thiocyanoanilines. This reaction can be carried out using various customary methods. E.g.

the thiocyano group can be alkylated in alcoholic sodium cyanide solution. The alcohol preferably has the same hydrocarbon radical as the desired alkyl group. Optionally, a sodium mercaptide can first be formed from the thiocyano group and this can then be alkylated using an alkylating agent such as an alkyl halide (methyl iodide).

Step (2) can also be carried out by first converting the sodium mercaptide into the 60 free mercaptan by acidification. The mercaptan is then usually reacted with an alkylating agent such as an alkyl halide (methyl iodide) in the presence of an organic base. Suitable organic bases are tertiary amines such as triethylamine, dimethylcyclohexylamine, pyridine and the like. The reaction is usually preferred when the alkyl halide is a tert-butyl halide (tert-butyl bromide)

is.

644 358

The amine and ammonium salts can be prepared by reacting the acid form with an appropriate organic base or ammonium hydroxide. The salts listed above are compatible with agriculture, and the specially selected salt depends on the specific intended application and economic considerations. The alkali, alkaline earth, ammonium and amine salts are particularly suitable.

The salts according to the invention can often be formed by reacting the precursors or intermediate products in aqueous solution. This solution can be evaporated to give the salt of the corresponding compound, usually to a dry powder. In some cases it may be more convenient to use a non-aqueous solvent such as alcohols, acetone, etc. The resulting solution can then be used to remove the solvent, for. B. evaporated under reduced pressure.

The compounds according to the invention can be prepared according to the following reaction scheme:

<3> j

The reaction of step (3) is the halomethanesulfonylation of the product of step (2) with two or more equivalents of halomethanesulfonyl chloride in the presence of a base. If 1 to 2 equivalents of the sulfonyl chloride are used, a mixture of the mono- and bi (sulfonylated) product can be obtained, which can be used in step (4). If two or more equivalents of the chloride are reacted, the bi (sulfonylated) product is preferred. Suitable bases for the implementation of stage (3) are organic and inorganic bases, such as pyridine, triethylamine, N, N-dimethylaniline and substituted pyridines and the like. Excess liquid bases can be used instead of a solvent. Stronger bases favor the formation of the bi (sulfonylated) product over the mono (sulfonylated) product.

Step (4) is a partial hydrolysis of the bis compounds which occur as an intermediate. This basic hydrolysis preferably proceeds in high yield using a strong base such as potassium hydroxide in methanol. Optionally, the step (3) starting compound can be converted directly to the step (4) product using a mono (sulfonylation) reaction using one or more equivalents of the base. This reaction is favored by a weaker base than pyridine, such as 3-bromopyridine.

Step (5) can be carried out using conventional oxidation processes,

(1)

(5)

O

SR '

644 358

4th

e.g. B. with hydrogen peroxide in acetic acid, sodium meta-iodate and the like. The sulfoxide compound (n = 1) is e.g. formed when equimolar amounts of the oxidizing agent and the reactant are used, while the sulfone (n = 2) can be formed directly using two moles (or a slight excess) of the oxidizing agent per mole of reactant.

The herbicidal activity of the compounds according to the invention was determined by tests on greenhouse plants. Both pre-emergence and post-emergence activity were determined in a direct study against a selected group of weeds and grasses. The following weeds are examples used for these experiments.

Grasses:

Giant Foxtail (Setaria faberi)

Chicken millet (Echinochloa crus-galli)

Cinquefoil (Digitaria ischaemum)

common grasshopper (Agropyron repens)

yellow cypergrass (Cyperus esculentus)

broad-leaved plants:

bent back foxtail (Amaranthus retro-flexus)

Purslane (Portulaca oleracea)

wild mustard (Brassica kaber)

Field Bindweed (Convalvulus arvensis)

The compounds to be tested were dissolved in a small amount of acetone or other suitable solvent and then diluted with water to a concentration of 2000 ppm. The same proportions were diluted to a final concentration of 500 ppm. 80 ml of this solution were added to a 15 cm pot containing the weed seeds, corresponding to a concentration of 22.4 kg / ha. The use of 20 ml of the solution corresponds to a concentration of 5.6 kg / ha. All of the following irrigations were carried out from the ground. Two pots were used per treatment. Two to three weeks after the treatment, the values were determined and recorded as a percentage of the kill of the species in question before emergence compared to untreated control plants.

To determine post-emergence activity,

The same weed mixtures were grown for two to three weeks until the grasses reached a height of approximately 2.5 to 7.6 cm and the broad-leaved weeds reached a height of approximately 2.5 to 3.8 cm. They were approximately 10 s. or sprayed with the above-mentioned solution containing 2000 ppm until the leaf surface was thoroughly wetted.

The values were determined two to three weeks after the treatment and recorded as a percentage kill of the species in question, compared to untreated control plants.

The compounds according to the invention are herbicides with a broad spectrum of activity. The mechanism by which this herbicidal activity is brought about has not yet been fully elucidated. However, the compounds according to the invention also show various effects for modifying plant growth. A modification of plant growth as given here consists in all deviations from natural development, e.g. defoliation, stimulation, developmental inhibition, delay, dehydration, occurrence of giant or dwarf growth, control, etc. The activity for controlling plant growth is generally observed when the compounds according to the invention interact with certain processes within the plant. If these processes are essential, the plant will die * if treated with a sufficient amount of the compound. However, the way plant growth is modified varies with the different plants.

For application to the plants, the compounds can be finely divided and suspended in any conventional aqueous medium. Spreading aids, wetting agents, tackifiers and other auxiliaries may also be added, if necessary. Dry powders can be used as such or diluted with inert substances, such as diatomaceous earth as dusts.

The agents according to the invention are usually applied to the plants or the soil is covered with them if regulation before emergence is desired. The application can be carried out with the aid of conventional spraying devices, dusting devices and the like. The amount applied is generally 0.56 to

22.4 kg / ha, however, depending on the circumstances, the application may also be above or below.

The compounds according to the invention can advantageously be used together with other known herbicides in order to expand the spectrum of those weeds which are combated by the herbicides according to the invention, or for better combating a weed which is not adequately controlled by special individual compounds according to the invention. Known herbicides include phenoxy herbicides, e.g. B. 2,4-D, 2,4,5-T, Silvex and the like, carbamate herbicides, thiocarbamate and dithiocarbamate herbicides, substituted ureas, e.g. Diuron, monuron and the like, triazines, e.g. Simazine and atrazine, chloroacetamide and chlorinated aliphatic acids, chlorinated benzoic acid and phenylacetic acid, paraquat, nitralin and the like. In addition, herbicidal compositions comprising compounds according to the invention can additionally contain nematicides, fungicides, insecticides, fertilizers, trace elements, agents for improving the soil and other plant growth regulators and the like.

The invention is illustrated by the following examples. Unless otherwise stated, parts are always parts by weight.

Preparation 1 2-bromo-4-thiocyanoaniline

To a cold (0 to 5 ° C) solution of 20.6 g (0.12 mol) of o-bromoaniline and 29.2 g (0.36 mol) of sodium thiocyanate in 300 ml of methanol was a solution of

19.5 g (0.122 mol) of bromine in 75 ml of methanol which was saturated with sodium bromide were added dropwise. The solution was stirred 1 h after the bromine was added and then poured into water and neutralized with sodium carbonate. The resulting solid was filtered off, washed with water and dried, mp 74 to 79 ° C.

The following compounds were made by the same general procedure:

2-chloro-4-thiocyanoaniline, mp 63 to 65 ° C 2-fluoro-4-thiocyanoaniline, mp 34 to 35 ° C 2,5-dichloro-4-thiocyanoaniline, mp 111 to 115 ° C 2,3-dichloro 4-thiocyanoaniline, mp 132-137 ° C 2-iodo-4-thiocyanoaniline, mp 92-93 ° C

Preparation 2 2-bromo-4-methylthioaniline

A solution of 11.5 g (0.05 mol) of 2-bromo-4-thiocyanoaniline and 1.23 g (0.025 mol) of sodium cyanide in 100 ml of methanol was stirred at room temperature overnight.

Then 0.025 mol of sodium cyanide was added and that

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The reaction mixture was heated and kept at the reflux temperature for 2 h and then cooled to 0 to 5 ° C. Methyl iodide was added and stirring continued. Thin layer chromatography showed one product point. The product was isolated by extraction with methylene chloride. 8.4 g were obtained.

The following other compounds were prepared by the same general procedure: 2-chloro-4-methylthioaniline (oil) 2,3-dichloro-4-methylthioaniline (solid)

Preparation 3 2-chloro-4-ethylthioaniline A solution of 40 g (0.22 mol) of 2-chloro-4-thiocyanoaniline in 250 ml of ethanol was stirred with a solution of 58.5 g (0.22 mol) Sodium sulfide nonahydrate added to 110 ml of water and the mixture heated to 50 ° C for 45 min. Then 36.6 g (0.22 mol) of ethyl iodide were added and the mixture was stirred at 50 ° C. for a further 2 h and then at room temperature overnight. The reaction mixture was poured into 31 water and the product extracted with ether. The combined organic extracts were washed with water and dried over CaS04. After removal of the drying agent and solvent, 2-chloro-4-ethylthioaniline was obtained as an oil.

The following other compounds were prepared by the same general procedure: 2-bromo-4-ethylthioaniline (oil)

2-fluoro-4-ethylthioaniline (oil)

2-chloro-4-isopropylthioaniline (oil) 2,5-dichloro-4-ethylthioaniline (oil) 2,3-dichloro-4-methylthioaniline (oil)

2-iodo-4-ethylthioaniline (oil)

Preparation 4 2-chloro-4-tert-butylthioaniline A solution of 36.9 g (0.20 mol) of 2-chloro-4-thiocyano-aniline in 100 to 200 ml of ethanol became a solution of 48.04 with stirring g (0.20 mol) of sodium sulfide nonahydrate are added to 100 ml of water and the mixture is heated to 50 ° C. for 90 minutes. The cooled reaction mixture was poured into 11 water and dilute hydrochloric acid was added to a pH of 6.0 to 6.5. The product was extracted with ether, the ether washed with water and then dried. After removing the drying agent and ether, 2-chloro-4-mercaptoaniline was obtained as a yellow oil.

22.86 g (0.18 mol) of dimethylcyclohexylamine in 125 ml of methylene chloride were stirred with a solution of 27.0 g (0.17 mol) of 2-chloro-4-mercaptoaniline and 22.86 g (0.18 mol) Tert-butyl bromide in 125 ml of methylene chloride was added dropwise and the mixture was stirred at room temperature for about 68 h. Then a further 2.3 g of dimethylcyclohexylamine and 2.5 g (0.018 mol) of tert-butyl bromide were added and stirring was continued overnight. The reaction mixture was poured into water and the product extracted with methylene chloride. The combined extracts were washed with dilute hydrochloric acid and water and dried. After removal of the drying agent and methylene chloride, impure 2-chloro-4-tert-butylaniline was obtained as a beige solid.

example 1

2-Bromo-4-methylthiochloromethanesulfonanilide 0.03 mol chloromethanesulfonyl chloride was added dropwise with stirring to a cold (0-5 ° C) solution of 6.2 g (0.028 mol) o-2-bromo-4-methylthioaniline in 20 ml pyridine. The solution was stirred overnight at room temperature, poured into ice water and poured into 12N hydrochloric acid with stirring, 2-bromo-4-methylthiochloromethanesulfonanilide being formed as an oil. A methylene chloride solution of the oil was washed with water and dried. After removing the desiccant and methylene chloride, a red oil was obtained. Crystallization from methylene chloride-hexane gave a red-tan solid, mp 72 to 85 ° C.

Analysis:

Ber. for C8H9BrClN02S2: C 29.0 H 2.7 N 4.2% Found: C 29.6 H 2.8 N 4.3%

The following compounds were prepared by the same general procedure: 2-chloro-4-methylthiochloromethanesulfonanilide,

Mp 79 to 82 ° C

2,3-dichloro-4-methylthiochloromethanesulfonanilide,

Mp 119 to 123 ° C

Example 2

2-Chloro-4-ethylthiochloromethanesulfonanilide 4.0 g (0.027 mol) of chloromethanesulfonyl chloride became with stirring a solution of 5.0 g (0.027 mol) of 2-chloro-4-ethylthioaniline in 6.4 g (0.041 mol) of 3-bromopyridine added dropwise and the mixture was stirred at room temperature overnight. The reaction mixture was taken up in 200 ml of methylene chloride and 200 ml of 20 percent dilute hydrochloric acid were added, the layers were separated and the methylene chloride solution was washed three times with 200 ml of 10 percent dilute hydrochloric acid and then dried over CaSO 4. After removing the drying agent and the solvent, the product was obtained as a reddish oil. This was taken up in hexane and cooled. This gave 2-chloro-4-ethylthiochloromethanesulfonanilide, mp 70 to 72 ° C.

Analysis:

Ber.fûrC9HnCl2N02S2: C 36.0 H 3.7 N 4.7% Found: C 36.3 H 3.5 N 4.7%

Other compounds prepared by the same general procedure are: 2-bromo-4-ethylthiochloromethanesulfonanilide,

Mp 63 to 65 ° C 2-chloro-4-isopropylthiochloromethanesulfonanilide,

Mp 50 to 53 ° C. 2-fluoro-4-ethylthiochloromethanesulfonanilide,

Mp 78 to 81 ° C. 2-fluoro-4-methylthiochloromethanesulfonanilide,

Mp 88 to 90 ° C. 2-fluoro-4-isopropylthiochloromethanesulfonanilide (oil) 2-bromo-4-tert-butylthiochloromethanesulfonanilide,

Mp 100 to 102 ° C 2-iodo-4-ethylthiochloromethanesulfonanilide,

Mp 74 to 76 ° C 2,5-dichloro-4-ethylthiochloromethanesulfonanilide,

Mp 132.5 to 134 ° C 2,5-dibromo-4-ethylthiochloromethanesulfonanilide,

Mp 189 to 195 ° C 2,5-dibromo-4-isopropylthiochloromethanesulfonanilide,

Mp 132 to 133 ° C 2,3-dichloro-4-ethylthiochloromethanesulfonanilide,

Mp 92-94 ° C 2-bromo-4-isopropylthiochloromethanesulfonanilide,

Mp 56-59 ° C.

Example 3

N-chloromethylsulfonyl-2-chloro-4-ethylthiochloromethane sulfonanilide

60 g (0.4 mol) of chloromethanesulfonyl chloride were added dropwise with stirring to a cold (0 to 5 ° C.) solution of 15.1 g (0.081 mol) of 2-chloro-4-ethylthioaniline in 104 ml of pyridine.

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The solution was stirred at room temperature and poured into ice water and 12N hydrochloric acid with stirring. The product was extracted into CH2C12, washed with water and dried. After removing the drying agent and the solvent, the crude product was obtained. Chromatography on silica gel with methylene chloride as the eluent gave the pure product as an oil.

Example 4

2-Chloro-4-ethylthiochloromethanesulfonanilide A solution of 7.2 g (0.017 mol) of N-chloromethylsulfonyl-2-chloro-4-ethylthiochloromethanesulfonanilide and 2.9 g of 85 percent potassium hydroxide in methanol was stirred at room temperature for about 3 days. The solvent was evaporated, the residue was taken up in hot water, filtered and the filtrate acidified with 12N hydrochloric acid. The product was filtered off and air dried.

Example 5

2-Chloro-4-methanesulfinylchloromethanesulfonanilide To a solution of 1.8 g (0.0061 mol) of 2-chloro-4-methylthiochloromethanesulfonanilide in 20 ml glacial acetic acid was added 0.0061 mol of 30 percent hydrogen peroxide. The solution was stirred at room temperature overnight, immediately heated to reflux and treated with water. The aqueous mixture was extracted with methylene chloride, washed with water and dried. After removing the desiccant and the solvent, a yellow oil was obtained. This crystallized from hexane to a white solid, mp 99 to 110 ° C. Analysis:

Ber. for C8H9C12N03S2: C 31.8 H 3.0 N 4.6% found: C 31.8 H 3.0 N 4.7%

The following compounds were made by the same general procedure. 2-bromo-4-methanesulfinylchloromethanesulfonanilide,

Mp 108-116 ° C 2-bromo-4-ethanesulfinylchloromethanesulfonanilide,

Mp 157 to 159 ° C 2,3-dichloro-4-methanesulfinylchloromethanesulfonanilide,

Mp 153-163 ° C 2-fluoro-4-methanesulfinylchloromethanesulfonanilide, mp 118-122 ° C

2-fluoro-4-isopropylsulfinylchloromethanesulfonanilide,

Mp 118 to 121 ° C

2-bromo-4-tert-butylsulfinylchloromethanesulfonanilide,

Mp 112-115 ° C 2-iodo-4-ethanesulfinylchloromethanesulfonanilide,

Mp 165 to 167 ° C. 2,5-dichloro-4-ethanesulfinylchloromethanesulfonanilide,

Mp 151 to 154 ° C 2,3-dichloro-4-ethanesulfinylchloromethanesulfonanilide,

Mp 118 to 121 ° C. 2-chloro-4-tert-butylthiochloromethanesulfonanilide,

Mp 89 to 90 ° C.

Example 6

2-Chloro-4-methanesulfonylchloromethanesulfonanilide To a solution of 3.0 g (0.0101 mol) of 2-chloro-4-methylthiochloromethanesulfonanilide in glacial acetic acid (30 ml) was added 0.0405 mol of 30 percent hydrogen peroxide with stirring. The solution was heated under reflux for 2.5 h, water was added and the mixture was cooled. The resulting precipitate was filtered off, washed with water and dried. A white solid was obtained, mp 172 ° to 180 ° C.

Analysis:

Ber. for C8H9C12N04S2: C 30.2 H 2.8 N 4.4% Found: C 30.2 H 2.8 N 4.4%

Other compounds prepared by the same general procedure are: 2-bromo-4-methanesulfonylchloromethanesulfonanilide,

Mp 156 to 168 ° C. 2-bromo-4-ethanesulfonylchloromethanesulfonanilide,

Mp 120 to 122 ° C 2-chloro-4-ethanesulfonylchloromethanesulfonanilide,

Mp 146 to 148 ° C 2-chloro-4-isopropylsulfonylchloromethanesulfonanilide,

Mp 146 to 149 ° C 2-fluoro-4-ethanesulfonylchloromethanesulfonanilide,

Mp 143 to 144 ° C 2-fluoro-4-isopropylsulfonylchloromethanesulfonanilide,

Mp 140 to 142 ° C. 2-bromo-4-tert-butylsulfonylchloromethanesulfonanilide,

Mp 169 to 170 ° C 2,5-dichloro-4-ethanesulfonylchloromethanesulfonanilide,

Mp 182 to 183 ° C. 2,3-dichloro-4-ethanesulfonylchloromethanesulfonanilide,

Mp 164 to 166 ° C 2-iodo-4-ethanesulfonylchloromethanesulfonanilide,

Mp 130 to 132 ° C.

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Claims (7)

644 358 2nd PATENT CLAIMS 1. Substituted 4-alkylthioalkanesulfonanilides of the general formula (I) HNSOnR vV B-O V " (I) S {0) nRI in which R is a monohalomethyl group, R 'is an alkyl group having 1 to 4 carbon atoms, A is a halogen atom, B is a hydrogen or halogen atom and n = 0 to 2 and their salts which are suitable for agriculture, except 2 -Fluoro-4-methanesulfonylchloromethanesulfonanilide. 2. 2-bromo-4-ethanesulfinylchloromethanesulfonanilide according to claim 1. 3.2-bromo-4-ethanesulfonylchloromethanesulfonanilide according to claim 1. 4. 2-chloro-4-methanesulfinylchloromethanesulfonaniIid according to claim 1. 5. 2-chloro-4-methanesulfonylchloromethanesulfonanilide according to claim 1. 6.2-chloro-4-ethanesulfmylchloromethanesulfonanilide according to claim 1. 7. 2-chloro-4-ethanesulfonylchloromethanesulfonanilide according to claim 1. 8. Agent for regulating the growth of higher plants, characterized in that it contains at least one compound of the formula I as active ingredient HNS02R 10th 15 20th 25th 35 (I) S (0) nR * 40 in which R is a monohalomethyl group, R 'is an alkyl group having 1 to 4 carbon atoms, A is a halogen atom, B is a hydrogen or halogen atom and n = 0 to 2 or their agricultural salts, with the exception of 2-fluoro-4- contains methanesulfonylchloromethanesulfonylanilide. 9. A method for regulating the plant growth of higher plants, characterized in that the plants with an effective amount of a compound of formula I. 50 HNS02R (I) S (0) nR ' in which R is a monohalomethyl group, R 'is an alkyl group having 1 to 4 carbon atoms, A is a halogen atom, B is a hydrogen or halogen atom and n = 0 to 2 or their agricultural salts, with the exception of 2-fluoro-4- methanesulfonylchloromethanesulfonylanilide. 60