JPS5934180B2 - Novel 4-methyl/2-trifluoromethyl methanesulfonanilide - Google Patents

Description

Detailed Description of the Invention The present invention provides 2-(trifluoromethyl)-methanesulfonanilide substituted at the para position with a methylthio group, methylsulfinyl group or methylsulfonyl group, salts thereof usable for horticulture, and Relates to compositions containing the compound.

The compounds of the invention are active herbicides or plant growth regulators. The invention also relates to herbicidal formulations containing said compounds and to the use of said compounds to regulate and control high growth. The process for making this compound and the intermediates obtained in this process are also encompassed by the present invention. Several types of haloalkylsulfonamide-substituted aromatic compounds are known in the art that have certain uses for these compounds. For example, US Pat. No. 3,639,474 discloses that trifluoromethanesulfonanilides having trifluoromethyl, methylthio, methylsulfinyl, and methylsulfonyl substituents are useful as herbicides. French Patent No. 1,188,591 discloses two types of compounds: haloalkylsulfonanilides and haloalkyls in which the benzene rings are linked directly or by various groups including sulfonyl, sulfinyl, and thio groups. sulfonamide diphenyl compounds are disclosed. The scope of use disclosed in this French patent is the antiparasitic, antibacterial and antifungal activity of textile materials. However, herbicidal activity is not disclosed in this patent.
GB 971,219 discloses alkanesulfonanilides containing chlorine and nitro ring substituents which have herbicidal activity. The compound of the present invention is applied to JOhnsOnGrass (SOrg) with established rhizomes.
It is particularly effective for controlling humhalepense (L.Pers).

Although various commercially available herbicides can be used on the grass seedlings, this removal is important because the rhizomes of the grass cannot be removed at the rate of use of commercial herbicides used on agricultural crops. It has been unexpectedly discovered that the compounds of the present invention are effective for the effective removal of rhizomatous colonized grass. The compounds of the present invention can also be used in plants of the genus Carex (e.g. Cyperusesc
ulentus). The present invention relates to a compound of the formula (where ?]n1 is O, 1 or 2) and salts of this compound for use in agriculture.

The acid form of the compounds of the invention is acidic, ie the hydrogen of the amide group is acidic.

These compounds are therefore salts, ie compounds of the above formula in which the hydrogen is replaced by a cation used in agriculture. These salts are generally metal salts, ammonium salts and organic amine salts. In particular, the metal salts of the invention include alkali metal (e.g. lithium, sodium and potassium) salts, alkaline earth metal (e.g. barium, calcium and magnesium) salts,
heavy metal (eg zinc and iron) salts and other metal salts such as aluminum. Suitable bases used to make metal salts are metal oxides, metal hydroxides, metal carbonates, metal bicarbonates and metal alkoxides. Certain salts are also made by cation exchange reactions (reacting the salts of the invention with organic or inorganic salts in a cation exchange reaction). Organic amine salts are aliphatic (eg, alkyl) amine salts, aromatic amine salts, heterocyclic amine salts, and amine salts having mixtures of these chemical structures. Amines useful in making the salts of this invention are primary, secondary or tertiary amines, preferably containing up to 20 carbon atoms. Such amines are, for example, morpholine, methylcyclohexylamine, glucosamine, amines derived from fatty acids, and the like. The amine and ammonium salts can be made by reacting the acid form of the compound with a suitable organic base or ammonium hydroxide. Any of the above types of salt can be used in agriculture, the choice being made depending on the particular application and economic considerations. Particularly useful salts are alkali metal salts, alkaline earth salts, ammonium salts and amine salts. The salts of the present invention are usually produced by reacting precursors in an aqueous solution.

The solution is evaporated to yield the salt of the compound, usually as a dry powder. In some cases, it may be advantageous to use non-aqueous solutions such as alcohol, acetone, etc. The resulting solution is then freed of solvent, for example by evaporation under reduced pressure. Since many salts are water soluble, these salts are often used in aqueous solutions. Compounds of the invention can be made by sequential reactions outlined below.

The first step reaction is carried out by heating 5-chloro-2-nitrobenzotrifluoride and a slight excess of methanethiol in the presence of a suitable amount of base in a suitable inert solvent.

The inert solvent is a solvent such as a lower alkanol in which the reactants are readily soluble, such as ethanol. The base is a strong organic or inorganic base. Suitable organic bases are tertiary amines such as N-N-dimethylaniline, triethylamine, pyridine or alkoxides such as sodium ethoxide. Suitable inorganic bases are alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, or calcium hydride. This product is isolated in a conventional manner. The second step reaction is the reduction of the nitro group of the novel intermediate, 2-nitro-5-methylthiobenzotrifluoride ().

Good results are obtained using well known chemical or catalytic methods. Raney nickel is one suitable reduction catalyst. This product is isolated in a conventional manner. The third step reaction is bis(methylsulfonylation) by adding 2 moles or more of methanesulfonyl chloride to the new intermediate, 4-methylthio-2-trifluoromethylaniline (), in the presence of excess base. .

The resulting product is a novel intermediate (). Alternative method 3
Step a is mono(methylsulfonyl) formation in which 1 equivalent of methanesulfonyl chloride is added to the compound in the presence of 1 equivalent of base in an inert solvent. Suitable bases for the reactions in step 3 and step 3a are organic or inorganic bases, such as pyridine, triethylamine, N-N-dimethylaniline and substituted pyridines. The fourth step is a new intermediate ()
This is the partial hydrolysis of

This is a base hydrolysis reaction using a strong base, such as potassium hydroxide, in methanol. Both the fifth and sixth steps involve conventional oxidation methods, such as hydrogen peroxide in acetic acid;
It is carried out using sodium metaperiodate, etc. Fifth
The steps require equimolar amounts of peroxide and reactants, but the sixth step requires 2 moles per mole of reactants (or a slight excess).
oxidizing agent. The herbicidal activity of the compounds of the invention was determined using a screening test on greenhouse plants.

The activity of selected weeds before and after emergence was measured by direct screen. For use in plants, the compound is ground and suspended in a conventional aqueous medium.

Also, spreading agents, wetting agents, adhesives or other auxiliary agents can be added as required. The dry powder may be used as such or mixed with an inert material such as diatomaceous earth. The usage ratio is generally 0.225-9k9/ega, but can be increased or decreased depending on the situation. The compounds of the present invention are particularly effective against John's grass, thereby extending or maximizing the range of weeds controlled by the herbicidal components of the present invention, and thus weeds not adequately controlled by the compounds of the present invention. It is particularly advantageous to incorporate other known herbicides with the compounds according to the invention in order to achieve even better control of herbicides.

Among these other known herbicides, the main ones are phenoxy herbicides, such as 2,4-D:2,4,5-T, Silvex (trade name), carbamate ester herbicides, Thiocarbamate herbicides, dithiocarbamate herbicides, urea herbicides such as DiurOn, MOnu
triazine herbicides, such as simazine (Si
mazine) and atrazine, chloracetamide herbicides and chlorinated fatty acid herbicides, chlorinated benzoic acid herbicides and phenylacetic acid herbicides such as Chloramben, trifluralin (
Trifluralin), Paraquat (Paraqu
at), other herbicides such as Nitralin, etc. Additionally, herbicide compositions containing the compounds of the present invention may also contain nematicides, fungicides, insecticides, fertilizers, trace metals,
A soil conditioner, other plant growth regulators, etc. may be added.
The following examples are illustrative of the operating procedures of the invention but are not intended to limit the scope of the invention.

Example 1 The sodium salt of 2-nitro-5-methylthiobenzotrifluoride methanethiol was mixed with methanethiol (10
07, in slight excess of 2.0 mol), sodium hydroxide (807, 2.0 mol) and ethanol (21) by stirring for 1 hour at O-5°C under nitrogen gas. .

To this solution is rapidly added 5-chloro-2-nitrobenzotrifluoride (451.27, 2.0 mol). The solution is left at room temperature overnight, then refluxed for 4 hours, cooled, filtered and the solvent is evaporated under reduced pressure. The resulting oil is poured into cold water (11), extracted with methylene chloride, dried over magnesium sulphate and then the solvent is evaporated under reduced pressure to give a yellow solid. This solid was recrystallized from hexane and
This yields a product with a melting point of 47-50°C. Analysis: C
Calculated value of 8H6F3NO2S: C4O. 5%; H2.5
%; N5.9%; Actual value: C4O. 4%; H2.5%;
N5.6%.

Example 2 4-Methylthio-2-trifluoromethylaniline 2-nitro-5-methylthiobenzotrifluoride (1907, 0.85 mol) in ethanol (11) was dissolved in about 45
Reduce with Raney Nickel in hydrogen gas at psi.

After complete absorption of hydrogen, the catalyst is deactivated with sulfur, the mixture is filtered and then the liquid ▲ is evaporated under reduced pressure to yield the desired product as an oil. Infrared absorption spectrum 2.9μ
(Strong NH band) Example 3 N-methylsulfonyl-4-methylthio-2trifluoromethyl-methanesulfonanilide Methanesulfonyl chloride (21.87, 0.19 mol) was
Example 2 (1) dissolved in pyridine (487, 0.61 mol)
5.87, 0.076 mol) of 4-methylthio-2-trifluoro-methylaniline in a cold (0-10° C.) stirred solution.

The solution was stirred overnight at room temperature, poured into a mixture of ice water (80 ml) and concentrated hydrochloric acid (20 ml), dried over magnesium sulfate and the solvent evaporated under reduced pressure. Recrystallized from methylene mixture, melting point 1
Produces a white solid at 45-154°C. Analysis: ClOHl
Calculated value of 2F3NO4S3: C33. l%; H3.3%
;N3.9%;Actual value:C32.9%:H3.3%:N
3.8%. Example 4 4-Methylthio-2-trifluoromethylmethanesulfonanilide N-methylsulfonyl-4-methylthio-2
Trifluoromethyl methanesulfonanilide (5457
, 1.5 mol), 85% potassium hydroxide (297y)
4.5 mol) and methanol (21) is stirred at room temperature overnight.

The solvent is evaporated under reduced pressure and the resulting solid is dissolved in hot water. The solution is filtered and the filtrate is made acidic with dilute hydrochloric acid. The product is isolated by extraction with methylene chloride, dried over magnesium sulfate, and then evaporated under reduced pressure to yield a beige solid with a melting point of 82-85°C.

Analysis: Calculated value of C9HlOF3NO2S2: C37.9
%: H3.5%; N4.9%; Actual value: C38. O%
; H 3.7%: N 4.9% o Example 5 4-Methylsulfinyl-2-trifluoromethylmethanesulfonanilide 4-Methylthio-2-trifluoromethylmethanesulfonanilide (118.0%) in glacial acetic acid (470ml). 5V, .0.42mol) low temperature (0-5℃
) 30% hydrogen peroxide (47.3V, 0.4
2 mol) is added.

The solution is stirred at 0-5° C. for 6 hours, left overnight at room temperature, diluted with water (1000 ml) and extracted with methylene chloride. The extract was further washed with water, dried over magnesium sulfate, and the product was precipitated with hexane to a melting point of 1.
A white solid is obtained at 23-125°C.

Analysis: Calculated value of C9H, OF3NO3S2: C35.9
%; H3.3%: N4.7%: Actual value: C35.9%;
H 3.4%; N 4.6%o Example 6 4-Methylsulfonyl-2-trifluoromethylmethanesulfonanilide 4-Methylthio-2-trifluoromethanesulfonanilide (10
Add 30% hydrogen peroxide (170 V, 1.49 mol) to a hot (60° C.) stirred solution of 5.6 V, 0.37 mol) while maintaining reflux with or without external heating.
Add dropwise.

The solution was heated at reflux for a further 2 hours and was mixed with water (250
m1) is added and the mixture is then cooled.

The mixture is filtered to collect the precipitate, which is washed with water and then dried to yield a white solid with a melting point of 177-181°C.

Analysis: Calculated value for C9HlOF3NO4S2: C34. l
%, H3.2%, N4.4%: Actual value: C34. l%,
H3.2%: N4.4%.

Claims (1)

[Claims] 1. A compound of the general formula ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (in the formula, n represents 0, 1 or 2). 2. The compound according to claim 1, which is 4-methylthio-2-trifluoromethyl-methanesulfonanilide. 3. The compound according to claim 1, which is 4-methylsulfinyl-2-trifluoromethylmethanesulfonanilide. 4. The compound according to claim 1, which is 4-methylsulfonyl-2-trifluoromethylmethanesulfonanilide.