CS257773B2 - Acaricide,herbicide and growth regulating agent and method of its active component production - Google Patents

Abstract

2-Trifluoromethyl-4,6-dinitro-phenol compounds of formula (I> <IMAGE> wherein X stands for hydrogen, alkali metal, alkaline earth metal, C1-10 alkyl, alkylcarbonyl, alkenylcarbonyl, phenylcarbonyl, halogen-substituted phenylcarbonyl or halophenyl or a group of the general formula (a> <IMAGE> wherein R1, R2 and R3 are the same or different and can stand for hydrogen, alkyl, alkoxyalkyl, alkenyl hydroxyalkyl, cycloalkyl, phenyl or substituted phenyl, have herbicidal, acaricidal or crop regulating properties.

Description

The process of the invention provides compounds of formula I wherein X is an alkali or alkaline earth metal by hydrolyzing 2-chloro-3,5-dinitrobenzotrifluoride in an aqueous medium by treatment with an alkali or alkaline earth metal hydroxide.

The phenolates obtained can optionally be converted into another compound of the formula I in a known manner.

It is known that 2-methyl-4,6-dinitrophenyl (dinitro-ortho-cresol, DNOC) and its alkali salts, which are structurally similar to the compounds of formula I according to the invention, exhibit herbicidal and acaricidal activity. Formulations containing these agents are, for example, Novenda and Cresonite. Also known herbicide is 2-sec-butyl-4,6-dinitrophenol (DNBP), a derivative of dinitro-ortho-cresol, which can be used in small doses as a biostimulator in maize cultures [Ohlrogge AJ: The Development of DNBP (Dinoseb) Inc. and Biostimulant for Corn in Plant Growth Regulators; Editor: Stutte C.A. 79-87 pages Advances in chemistry series; 159. American Chemical Society, Washington, 1977].

So far, only processes for the preparation of compounds similar in structure to the compounds of formula I are known. The preparation of the compounds of formula I and their biological properties are not described in the literature. It is known from British Patent No. 1,378,994 to prepare 2,4-bis (trifluoromethyl) -6-nitrophenol and its derivatives. U.S. Pat. No. 3,813,446 discloses the preparation of 2,6-dinitro-4-trifluoromethylphenol. These known processes are carried out in organic solvents, optionally in the presence of phase transfer catalysts. Undesirable side reactions, for example the formation of ether derivatives in methanolic medium, or the hydrolysis of the trifluoromethyl group to the carboxyl group, also take place. These side reactions do not occur in the process of the invention.

We have found a chemical process for the preparation of compounds of the formula I which is also economical on a technical scale and leads to products of satisfactory purity. As further experiments have shown, the novel compounds of the formula (I) obtained exhibit significant biological activity.

The compounds of formula (I) obtained by the process of the invention were tested in the form of various compositions by a series of tests for their biological activity. The experiments have been successful and have shown that the number of pesticidal compositions can be enriched with novel herbicidal, acaricidal and growth-regulating compositions containing a compound of formula (I).

Compounds of formula (I)

where

X is hydrogen, an alkali or alkaline earth metal, an alkyl or alkenylcarbonyl group having 1 to 10 carbon atoms, an optionally substituted phenylcarbonyl group, or a group of formula (a)

HNR 1 R 2 R 3 (a) wherein R 1, R 2 and R 3 independently of one another are hydrogen, alkyl, alkoxyalkyl, alkenyl, hydroxyalkyl, cycloalkyl or optionally substituted phenyl, are prepared by preparing in the first step from 2-chloro-3,5- of dinitro-benzotrifluoride by reaction with an alkali or alkaline earth metal hydroxide corresponding to the alkali or alkaline earth metal phenolate. The reaction is carried out without catalyst in an aqueous medium at 20 to 100 ° C, preferably 60 to 80 ° C, and at a base concentration of 5 to 20% by weight, preferably 10 to 15% by weight. The phenolate obtained by hydrolysis can be converted into a phenol derivative in a known manner. If desired, another compound of formula I can be obtained from the phenol obtained (X = H) by reaction with the corresponding base.

The compounds of formula I are isolated from the reaction mixture and can be used as pesticides. Conventional carriers, additives and auxiliaries are used for this purpose. The formulations are chosen according to the purpose for which they are to be used. Depending on the method of use and the type of composition, the compositions contain from 0.1 to 80% by weight of active ingredient. The compositions are used in plant cultures to control weeds or to control plant growth.

The novel compounds of formula I enrich the selection of compounds of similar activity. They therefore represent an enrichment of the state of the art. The process of the invention provides these compounds in an economical, simple and easily reproducible manner. It is further preferred that the reaction is carried out in an aqueous medium, without catalyst, during the hydrolysis, no undesirable side reactions occur.

б

The invention is illustrated by the following non-limiting examples.

Preparation of compounds of formula I

Example 1

Up to 1000 cm ³ flasks equipped with stirrer, dropping funnel, reflux condenser and thermometer. 300 g of a 10% sodium hydroxide solution (0.75 mol of NaOH) are added. 81.3 g of 95% pure (= 0.3 mol) 2-chloro-3,5-dimethylbenzotrifluoride are added to the hydroxide with stirring. The mixture was heated to 60 ° C and stirred for 4 hours at 60-65 ^C C. is created from the aqueous suspension and emulsion.

The reaction mixture was cooled to room temperature with stirring and 37% hydrochloric acid corresponding to 0.82 mol of HCl was added over one hour. The mixture is stirred vigorously during uniform dosing. The precipitate formed is filtered off, washed with water and dried to constant weight at room temperature. 68.1 g of 94% pure 2-trifluoromethyl-4,6-dinitrophenol (determined by mass spectrometer with gas chromatograph attached) are obtained. Yield 90%.

Example 2

60 kg of water was charged to an enamelled 250 liter reactor equipped with a stirrer and reflux condenser. 32.5 kg of 2-chloro-3,5-dinitrobenzotrifluoride are added to the water with stirring. The reaction mixture was heated to 75 ^° C. 65 kg of 20% sodium hydroxide was added to the reactor at a constant rate through a metering pump, maintaining the temperature at 75-80 ° C. The reaction mixture was further stirred at this temperature for 3.5 hours and then cooled to room temperature. 9.5 kg of concentrated hydrochloric acid are added at a uniform rate over one hour. The precipitate formed is centrifuged, washed with water and air-dried to constant weight. 28 kg of 2-trifluoromethyl-4,6-dinitrophenol of purity are obtained

94.3%. Yield 92.4%.

Production of resources

Example 1 a d 3

Emulsion concentrate containing 00% by weight (ЕС 60)

433 g of 2-trifluoromethyl-4,0 dinitrophenol (97%) was dissolved at 40 ° C in a mixture of 200 g of isophorone and 25 g of xylene. The solution was cooled to room temperature and filtered through a 0.1 µm GAF filter. 36 g of Tensiofix V 7425 and 6 g of Tensiofix LS are added to the filtrate as an emulsifier with stirring.

Example 4

Emulsion concentrate containing 60% by weight (ЕС 60)

The procedure is as described in Example 3, but the isophorone is replaced by cyclohexa pentane and xylene by the solvent Aromatol. The substances listed in the following table are used as emulsifiers.

Emulsifier in g:

Tensiofix AS

Tensiofix LS

Emuiso ^ en EL

Sapogenat T 180

Sapogenat T 500

Example 1 and d 5

Water-soluble concentrate containing 20% by weight (WSC 20)

To 300 g of a 30% aqueous solution of sodium 2-trifluoromethyl-4,6-dinitrophenolate 50 g of ethylene glycol and 4 g of Tensiofix CG-21 are added as emulsifiers. Make up to 450 g with deionized water.

Example 6

An oily paste containing 20% by weight

620 g of 2-trifluoromethyl-4,6-dinitrophenol are dissolved in 500 g of cyclohexanone and 120 g of cosmetic vaseline are added thereto.

ABC —10 —— - 1225 - 10— - 207 oil. The resulting solution is emulsified with a 10% Tensiofix PO-132 emulsifier solution using an ultra high speed stirrer while maintaining the temperature at 30 ° C. The mixture was cooled to 15 ° C. A 0.2% solution of Kelsan S in ethylene glycol (50 g) was added over one hour with slow stirring.

Efficacy tests

Example 7

Testing of herbicidal activity in a greenhouse

Seeds of white mustard, bent-grass, gooseberry, Italian millet, winter wheat and maize are planted in pots.

After germination, plants in the 2-4 leaf stage are sprayed with 0.2 spray slurry (prepared by diluting with 10% ЕС- and WSC-formulation containing the test substance), each compound tested at 2, 5.5 and 10 kg / ha. On the 14th day after treatment, the% damage was evaluated. The results are summarized in Table 1.

TABLE 1

compound dose kg / ha mustard Pigweed lebeda millet wheat maize 2-trifluoromethyl- 4,6-dinitrophenol 1,25 45 50 75 0 0 0 2.55 75 85 90 10 5 5 5.0 95 100 ALIGN! 100 ALIGN! 30 10 15 Dec 2-Trifluoromethyl- 1,25 40 50 70 0 0 0 4,6-dinitrophenol- 2.5 60 60 75 -. - - diethanolamine 5.0 80 85 80 10 10 10 2-trifluoromethyl- 1,25 45 50 70 0 0 0 4,6-dinitrophenyl- 2.5 55 65 75 0 0 0 dimethylamine 5.0 75 80 85 20 May 10 10 2-trifluoromethyl- 1,25 50 60 70 0 0 0 4,6-dinitrophenolate 2.5 80 85 90 10 0 10 sodium 5.0 100 ALIGN! 100 ALIGN! 100 ALIGN! 15 Dec 15 Dec 15 Dec 2-trifluoromethyl- 1,25 65 45 70 0 0 0 4,6-dinitrophenolate 2.5 75 85 90 10 0 10 Potassium 5.0 90 100 ALIGN! 100 ALIGN! 15 Dec 15 Dec 15 Dec 2-Trifluoromethyl- 1,25 40 50 70 0 0 0 4,6-dinitrophenol- «2,5 70 80 90 10 0 0 methylcarbonyl 5.0 90 95 100 ALIGN! 20 May 10 10 2-trifluoromethyl- 1,25 40 40 60 0 0 0 4,6-dinitrophenol- 2.5 50 60 70 0 0 0 ethylcarbonyl 5.0 80 80 80 10 10 10

Example 8 ’

Determination of inhibition of Hill reaction

The method of Arnon et al. chloroplasts are isolated from spinach. 6 ml of 0.35 µM sodium chloride solution and 0.6 ml of 0.2 M TRIS buffer are added to one gram of vein-free spinach leaves. The mixture is ground, filtered through several layers of gauze, and then centrifuged at 2000 rpm for 5 minutes. The chloroplast residue is suspended in 0.035 M sodium chloride solution, homogenized in a Potter tube, and the chloroplast suspension obtained is stored at 0 ° C.

A mixture is prepared from a suspension of chloroplasts and K3Fe (CN) 6, K2HPO1, TRIS.HCl-buffer and MgCl2. To this are added solutions of the compounds of formula I (as stabilizers). These compounds are used in an amount of 10 ^-10 to 10 ^-3 moles, optionally standard substances - solutions of N- (3,4-dichlorophenyl) -N ', N'-dimethylcarbamide (DCMU) and dinitro-ortho-cresol (DNOC). The resulting mixtures are left for 20 minutes under 5,000 lux illumination. The reaction was then quenched by the addition of 25% trichloroacetic acid (TCA). The precipitate is centrifuged and the extinction of the solution is determined at 420 nm with a Spectronom 204 photometer. The set of measurements is repeated with dark experiments. Hill response inhibition was determined by the difference in the extinction of light and dark experiments, and a calibration curve was determined in <µg / ml potassium ferrocyanide (percent inhibition was taken as a function of concentration and the corresponding concentrations for 50% braking were subtracted from the curve). - I50).

The results are summarized in Table 2. TABLE 2

Compound (micromol / dm ³ )

I50

2-trifluoromethyl-4,6-dinitrophenol 0.21

2-Trifluoromethyl-4,6-dinitrophenoldiethanolamine 0.57

2-Trifluoromethyl-4,6-dinitrophenol dimethylamine 0.52

2-Trifluoroethyl-4,6-dinitrophenol-NH10.25

2-Trifluoromethyl-4,6-dinitrophenol-Na0.20

2-trifluoromethyl-4,6-dinitrophenol-K '0.31

Comparative substances:

dinitro-ortho-cresol-Na0.86

N- (3,4-dichlorophenyl) -N ^', N'-dimethylkarbamid0,071

It is apparent from the above data that 2-trifluoromethyl-4,6-dinitrophenol and its salts, like N- (3,4-dichlorophenyl) -N ', N'-dimethylcarbamide, are inhibitors of the secondary photochemical system and are approximately N - (3,4-dichlorophenyl) -N ', N'-dimethylcarbamide and dinitro-ortho-creso257773 f. Of the compounds of the invention, the amine salt has less potency in this test than the alkali metal and ammonium salts.

Example 9

Tests on herbicidal activity on maize (wild)

The experiments were carried out with 2-trifluoromethyl-4,6-dinitrophenol-Na WSC 20 prepared according to Example 5, or with 2-trifluoromethyl-4,6-dimetrophenol EC 60 prepared according to Example 3. 25-26 April was sown. 8 to 10 cm deep into brown forest soil containing 1.8% of organic matter, Pioneer 3950 maize grains at 73,000 / ha. On May 30, 300 liters / ha were sprayed (Tee-Jet 11,002, 1.5 atm) at which time most maize plants had 3-4 leaves, most weeds 2-4 leaves. Each formulation was tested in four At the time of treatment, the area was covered at 87.5 ° / op levels, consisting of 58% of amaranth, 27% lebeda, and the rest of the hedgehog-leg, evaluated on June 15. The herbicidal effect was assessed by EWRC- scale.

Table 3 shows the rating scale, and Table 4 summarizes the results.

TABLE 3

EWRC-scale

Value effect in weed control destruction ° / o damage to crop plants in% 1 excellent 100 ALIGN! none 0 2 excellent 99 very weak 1 3 good 98 faintly 2 4 satisfactory 95 weak to mild 5 5 sufficient 90 moderate 10 6 insufficient 75 moderate 25 7 not good 50 strongly 50 8 very bad 25 very strong 75 9 inapplicable 0 full destruction 100 ALIGN!

plants

TABLE 4

Active substance and dose

2-Trifluoromethyl-4,6-dinitro phenol-Na 20 WSC

1 / ha 10 1 / ha

2-Trifluoromethyl-4,6-dinitrophenol 60 EC

1.6 l / ha 3.2 l / ha

Pigweed 3 1,5 4 2 lebeda 2 1 3,5 1 hedgehog 5 2 7 3.5 maize 1.5 1,5 1 1 Example 10 thyl-4,6-dinitrophenol-Na (20 WSC). 0.5 l / ha (= 0.05 kg / ha) was used. Each of the pa- Tests for influencing growth a production parallel experiments were carried out maize on an area of 4 hectares. For every hectare there was

50 liters of water were used. The corn was harvested

On 20 April, maize was sown on 3 November. The results are summarized in the table below. MSVC 3780 at 55,000 seeds / ha. At position 5. initially spraying was applied Values 2-trifluoromethyl- TABLE 5 Control Po, piece I Experiment II stick length, cm 16.07 + 2.19 17.06 + 2.71 17.33 + 1.87 percentage of non-full grain sticks,% 62 66 84 grains covered part of sticks cm 14.52 + 2.80 15.35 + 3.93 15.33 + 2.48 % 90.35 93.34 89.97 weight of one stick, g 229.6 ± 6 208.4 ± 5 191.6 ± 4 harvest yield, t / ha 4.25 4.08 3.55 % of control 119.7 114.9 100 ALIGN!

Experiments have shown that 2-trifluoromethyl-4,6-dinitrophenolate-Na affects yields by the formation of larger grains and better grain stick occupancy.

Example 11

Acaricidal activity tests

The experiments were carried out on apple trees with a clip of 7.5 m x 4.5 m (Golden delicious). On March 16th, before spraying the offshoots, the sprayer was sprayed with a high-pressure spray gun (20 bar). 48 hours after treatment, 5 x 10 fetal shoots (5 trees on each plot) are taken from each parcel, either treated or untreated, and monitored in the laboratory until all the spider mites hatch in the untreated culture (day 17) ). Mortality is determined from the number of hatched mites in% of control. The results are summarized in Table 6.

TABLE (i

substance konc, % hatched spider mites (pieces) of 5 x 10 shoots dead eggs % Pests in% control 2-Trifluoromethyl-4,6-dinitro- phenol-Na 20 WSC 2.5 19 Dec 96.35 3.6 2-Trifluoromethyl-4,6-dinitro- phenol ЕС 60 0.8 23 95.59 4.41 dinitro-orthokresol (DNOC-paste) 2,0 27 Mar: 94.82 5.18 untreated control - 521 0 100 ALIGN!

As can be seen from the table, the compounds of the formula I have an activity corresponding to the comparative substance dinitroortho-cresol (Novenda 25 paste).

Example 12

To a 4,000 cm ³ flask equipped with a stirrer, dropping funnel, reflux condenser and thermometer was charged 1,008 g (4 moles) of 2-hydroxy-3,5-dinitrobenzotrifluoride and 200 ml of acetonitrile, followed by 484 (4.8 moles) of tri ethylamine under cooling to 20-30 ° C. Acetyl chloride (312.8 g (4 moles)) was added over 1.5 hours while cooling to 20-22 [deg.] C. After the addition was complete, the mixture was stirred for 1 hour, then neutralized with triethylamine and triethylamine hydrochloride was filtered off. under vacuum, the residue is poured into water under cooling and stirring. the precipitated crystals are filtered, washed with ethanol and dried. yield _{2-trifluoromethyl-4-one} 6 dinitrofenolmethylkarbonyl. Purity 98 ° / o yield of 98 ° / o.

Claims (4)

An acaricidal, herbicidal and growth-regulating composition, characterized in that it contains, as an active ingredient, a compound of the formula (I): X is hydrogen, an alkali metal, an alkaline earth metal, a dimethylammonium group, a dimethanolamonyl group, a methylcarbonyl group or an ethylcarbonyl group. 2. A process for the preparation of compounds of the formula I wherein X is an alkali or alkaline earth metal as claimed in claim 1, characterized in that 2-chloro-3,5-dinitrobenzotrifluoride is hydrolyzed in an aqueous medium by treatment with an alkali metal or alkali metal hydroxide. zemin. Process according to claim 2, characterized in that the hydrolysis is carried out at a hydroxide concentration of from 5 to 20% by weight, preferably from 10 to 15% by weight. 4. Process according to claim 1 or 3, characterized in that the hydrolysis is carried out at a temperature of 20 to 100 ° C, preferably 60 to 80 ° C.