CA1280440C - Herbicidal, acaricidal and crop regulating compositions containing as active ingredient 2-trifluoromethyl-4, 6-dinitro-phenol and derivatives therefor - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
There are disclosed herbicides and crop regulating compositions, comprising as active ingredient 2-trifluoromethyl 1-4, 6-dinitro-phenol compounds and derivatives thereof and processes for their preparation.

Description

The present invention relates to herbicidal, acaric-idal and crop regulating compositions containing as active ingredient 2-trifluoromethyl-4,6-dinitro-phenol and derivatives thereof t of the general formula I

O -X
02N \ ~ CF3 ~ (I) wherein stands for hydrogen, alkali metal, alkali earth me-tal, Cl 10 alkyl - or alkenylcarbonyl, phenylcarbonyl halogen-substituted phenylcarbonyl, or a group of the general formula(a) H N Rl R2 R3 (a) wherein Rl, R2 and R3 are the same or di.f~erent and stand for hydrogen, alkyl, alkoxyalkyl, alkenyl, hydroxyalkyl, cycloalkyl, phenyl or phenyl substituted by halogen and/or trifluoromethyl in admixture with a suitable carrier or diluent.
The compounds of the general formula I show herbicidal and acaricidal and crop regulating activity.

-?-The compounds can be formulated to herbicidal, acar-icidal or crop regulating compositions, which preferably contain 0.1 to 80% by weight of active ingredient and the usual carriers and excipients.
The compositions may be prepared in the form of emulsifiable concentrates, aqueous suspensions, spray in the form of dust, oily paste, granulates, etc.
In another aspect the invention relates to a 2-trifluoromethyl-4, 6-dinitro-phenol of the general formula I

O-X
O2N ~ F3 (I) wherein ~.
X stands for hydrogen, alkali metal, alkali earth metal, Cl 10 alkylcarbonyl, C2 10 alkenylcarbonyl, phenyl-carbonyl, or halogen-substituted phenylcarbonyl or a group of the general formula (.a~.
+
H N Rl R2 R3 wherein Rl, R2 and R3 are the same or different and can stand for hydrogen, alkyl, alkoxyalkyl, alkenyl, hydroxyalkyl, cycloalkyl, phenyl or phenyl substituted by halogen and/or trifluoromethyl.

~o~
-2a-The present invention further provides a process for the preparatIon of the compounds of the general formula I by alkaline hydrolysis of 2~chloro~3,5-dinitro-benzotrifluoride in aqueous medium without catalyst, and if desired followed by the conversion of the obtained phenolate to the end product by method known per se.
The structurally similar 2-methyl-4,6-dinitro-phenol, i.e. the 50 called dinitro-ortho-cresol (DNOC) and alkali metal salts thereof are known to show herbicidal and acaricidal activlty.

~. ~
-~sr 1~

`` 1~8~

Known compositions containing such active ingredients are Novenda and Krezonit Similarly 2-sec.-butyl-4,6-dinitro--phenol /DN~P/ of similar chemical structure is a known herbicide, used at smaller ~4~ as biostimulator in corn cultures /Ohlrogge, A.J D The Development of DNBP /Dinoseb/
as a Biostimulant for Corn in Plant Crowth Re~ulators, editor: Stutte, 5.A. 79-87 pp~ Advances in chemistry series, 159 American Chemical Society, Washington, 1977./
No technical reference could be found concerning the preparation or biological activity of the compounds of the general formula I accordin~ to the invention only for similar compoùnds, In C~ PS 1 378 994 the preparation of 2,4-bis-/trifluoromethyl/-6-nitro-phenol and derivatives thereof is disclosed, In US PS 3 813 446 the preparation of 2,6-dinitro-4-trifluoromethyl-phenol and derivatives thereof is described. The known processes are performed ~ oh ~sæ
in an or6anic solvent, optionally in the presence of ~k~is_ transfer catalysts, In said processes undesired side-re-actions take place, such as ether derivative formation in methanol or hydrolysi~ of the trifluoromethyl group into carboxylic group. According to the present ïnvention no ~uch side reactions occur~
The process of the invention is suitable for the preparation of the compounds of the general formula I
; 25 at industrial scale economically and in pure state.
We have also found that the new compounds show a surprisin~ly good biological activity. After subjecting the various compositions of the invention containing 4~
_ 4 the compounds of formula I as active ingredient we have found that new herbicidal, acaricidal and crop regulating compositions were obtained.
When preparing the compounds of the general formula I
- wherein X stands for hydrogen, alkali metal, alkali earth metal, Cl 10 alkyl - or alkenylcarbonyl, phenylcarbonyl, halogen-substituted phenylcarbonyl, or a group of the general formula (a), wherein Rl, R2 and R3 are the same or different and stand for hydrogen, alkyl, alkoxyalkyl, alkenyl, hydroxy-alkyl, cycloalkyl, phenyl or phenyl substituted by halogenand/or trifluoromethyl - one may proceed by first preparing an alkali metal or alkali earth metal phenolate by reacting 2-chloro-3,5-dinitro-benzotrifluoride with alkali metal or alkali earth metal hydroxide. The reaction is conducted in an aqueous medium without catalyst at 20-100 C, preferably a-t 60-80 C at an alkali concentration of 5 to 20 % by weight preferably 10 to 15 % by weight. The phenolate formed during the alkaline hydrolysis is, if desired, converted to phenol with an acid by method known per se. The phenol is, if desired, converted to a phenolate derivative by using a base corresponding to the substitutents of the general formula I latter being used as pesticidal active ingredient after isolation from the mixture.
The pesticidal composition is prepared by using the conventionally used carriers and excipients. The active ingredient content can vary within a range of 0.1 to 80% by weight depending on the formulation type and i:

~L2 method of application. The composition is used as herbicide, acaricide or crop regulating agent.
The process of the invention is simple, economical and reproduceable and suitable for the preparation of the new compounds of the invention which broaden the selection of pesticide agents due to their bioactivity.
The details of` the invention are illustrated by the following Examples which serve merely for illustration and not for limitationO
Preparation of the compounds of the general formula I.

~.
To a 1000 cm3 flask equipped with a stirrer, dropp-ing funnel, reflux and thermometer 300 g /0.75 mole/ of a 10 % by weight NaOH solution are added, 81.3 g /0,3 mole/
of 2-chloro 3,5-dinitro-benzotrifluoride of a purity Or 95 % are added under stirring, Ihe temperature is raised to 60 C and the reaction mixture is stirred at 60-65 C
for 4 hours, while the aqueous suspension forms an emulsion.

The reaction mixture is then cooled to room ternperature /20-25 C/ under stirring and within 1 hour a 37 % hydro-chlorlc acid solution corresponding to 0.82 mole HCl is added in equal portions under vigorous stirring. The precipitated product is filtered, washed with water and dried to constant weight at room temperature. 2-Trifluoro-methyl-4,6-dinitro-phenol is obtained /68,lg " purity: 94 %/
Identification was carried out by a mass spectrometer connected to a gas chromatograph.
Yield: 90 %

Example 2 To 250 1 enamelled reactor equipped with a mixer, and reflux 60 kg. of water are added and under stirring 32.5 kg.
of 2-chloro-3,5-dinitro-benzo-trifluoride are added through a powder funnel. The reaction mixture is heated to 75C and at equal rate 65 kg. of a 20% NaOH solution are pumped in while the temperature is maintained at 75-80C. The reaction mixture is stirred at 75-80C for 3.5 hours. The reaction mixture is cool-ed to room temperature and within 1 hour 9.5 cc. HCl are added at equal rate. The precipitated product is centrifuged, washed wi-th water and dried at room temperature to constant weight.
The obtained product is 2-trifluoromethyl-4,6-dinitro-phenol, (28 kg.).
Purity: 94.3%, yield: 92.46.
Preparation of the composition '~A ~

:J .
~8014~0 - 6a - 23305-939 Example 3 60% by weight emulsifiable concentrate (EC) 433 g. of 97% 2-trifluoromethyl-4,6-dinitro-phenol are dissolved at 40C in a mixture of 200 g. of isophoron and 25 g. of xylene. The solution is cooled to room temperature and filtered through 0.1 micrometer GAF filter. To the filtrate 36 g of Tensiofix *B 7425 (a mixture of calcium dodecyl benzene sulphonate and ethoxylated and propoxylated nonylphenol) and 6 g. of Tensiofix ~S (a mixture of calcium dodecyl benzene sulphonate and ethoxylated nonylphenol) emulsifier are added under stirring.
Example 4 60% by weight of emulsifiable concentrate (EC).
One proceeds as disclosed in Example 3 but isophoron is replaced by cyclohexanone and xylene is replaced by aromatol solvent and the following emulsifying agents are used:

*Trade-Mark . . ~ . . .
A s C
.. . .. . _ Tensiofix AS g. 18 - 10 (a mixture of calcium dodecyl benzene sulphonate and ethoxylated nonylphenol) Tensiofix LS g. 24 Emulsogen *EL g. (e-thoxylated castor oil - 12 25 (EO number = 36-40/mole)) Sapoegenat *T 180 g. - 10 (ethoxylated tributyl phenol (EO number = 18/mole)) Sapoegenat T 500 g. - 20 7 (e-thoxylated tributyl phenol (EO number = 50/mole)) . . _ _ . _ . _ _ _ . . . _ . . . _ _ Example ~
20% by weight of water soluble concen-tra-te (WSC) To 300 g. of a 30% by weight of 2-trifluoromethyl-4,6-dinitro-phenol-Na aqueous solution 50 g. e-thylene glycol and 4 g. of Tensiofix CG-21(a mixture of ethoxylated fatty alcohol, etho~ylated fatty alcohol phosphate ester, e-thoxylated nonylphenol and ethoxylated nonylphenol phosphate ester) emulsif-iers are added. The solution is supplemented to 450 g. with ionexchanged water under stirring.
Example ~
20~ by weight of oily paste 620 g. of 97% 2-trifluoromethyl ~-4, 6-dinitro-phenol ~ . .
are dissolved in 500 g. of cyclohexanone and to this solution 120 g. of cosmetic Vaseline *oil are poured. The * Trade Mark ~L28~

obtained solution is emulsified with a 10% solution of Tensiofix PO-132(ethoxylated lauryl alcohol)emulsifier by means of Ultra-turrax mixer while the temperature is maintained at 30C. After cooling to 15C 50 g. of 0.2% by weight of Kelsan* (xantham gum type thickening agent~-ethylene glycol solution is dispersed in the mixture within 1 hour under slow stirring.
^~ Example ~
Herbicide activity test in green house In culture dishes white mustard, pig weed, fat hen, autumn wheat, Italian grass and corn seeds were sown. When the seeds were sprouted 10% EC and 10% WSC were prepared from the compounds to be tested, and after dilution with water 0.2%
spray was prepared. 2-~ leaves plants were sprayed with this liquid so that for each compound a dose corresponding to 2.5-5-10 kg./ha active ingredient was used. On the l~th day after the treatment the extent of the injury of -the plants was evaluated and expressed in %. The results are summarized in Table 1.

* Trade ~ark - 3 ~ ~2~0~

Table 1 Compound Dose white pig fat Italian autumn corn Kg/ha mustard weed hen grass wheat -2-trifluoromethyl- 1.25 45 50 75 0 0 0 -4,6-dinitro-phenol 2.55 75 85 90 10 5 5 5.0 95 100 100 30 10 15 2-trifluoromethyl- 1.25 40 50 70 0 0 0 4,6-dinitro-phenol- 2.5 60 60 75 diethanol-amine 5.0 80 85 80 10 10 10 2-trifluoromethyl 1.25 45 50 70 0 0 0 4,6-dinitro-phenol- 2.5 55 65 75 0 0 0 dimethyl-amine 5.0 75 80 85 20 10 10 2-trifluoromethyl- 1.25 50 60 70 0 0 0 4,6-dinitro-phenol- 2.5 80 85 90 10 0 10 -Na 5.0 100 100 100 15 15 15 2-trifl.uoromethyl- 1.25 65 45 70 0 0 0 4,6-dinitro-phenol- 2.5 75 85 90 10 0 10 ~ 5.0 90 100 100 15 15 15 ., ~, 1280~40 Example ~
Determination of Hill-reaction inhibition By means of the method of Arnon et. al. spinach chloroplastises were isolated. To 1 g. of leaves freed from the ribs 6 ml. of a 0.35 molar solution of NaCl and 0.6 ml. of .

~80~

0~2 molar TRIS~buffer were added, the mixture was ground, and the homogenizate was filtered through a gauze of several layers and centrifuged for 5 minutes at a rate of 2000 rotations. The chloroplastis precipitate was suspended ln a 0 035 molar NaCl, homogenized in a Potter tube and the thus obtained chloroplastis suspension was held at O C
until use. A reaction mixture of the chloroplastis suspension K3Fe/CN/6, K~HP04 9 TRIS~HCl buffer, MgC12 of suitable concentration and ratio and a solution of the compounds of the ~en~r~1 formula /I/ a~ inhibitor~ and N~/3,4-dichloro--phenyl/-N',N'-dimethyl urea /DCMU/ and dinitro-ortho--cresol /DNOC/ as standards of a molar concentration ofl x 10 1 x 10 3 were subjected to an exposure of 5000 lux light intensity for 20 minutes whereafter the reaction was quench-ed with 25 % trichloroacetic acid solution /TCA/. Theprecipitate was removed by centrifuging and the extinction of the solution was measured at 420 nm, with a photometer of typc ~pe-~e~e~-~44 The measuring series was conducted also with reaction mixtures held in the dark. Hill-reaction inhibition was deter~nined on the basts of the extinction differences measured in dark and light reactions and converted to /ug~ml potassium ferricyanide concentration on the basis of calibration curve The % values of khe inhibition are plotted against concentration and concentrations belonging to 50 % inhibition were read from this curve /I50/.
Results are shown in Table 2.

- ~ \
4as~3 Table 2 . . _ . ., . ~
Compound I50 micromole/dm3 2-trifluoromethyl- 0.21 4,6-dinitro-phenol 2-trifluoromethyl~ 0.57 4~6 dinitro-phenol-diethanol-amine 2-trifluoromethyl- 0.52 4,6-dinitro-phenol-dimethyl-amine 2-trifluoromethyl- 0 25 4,6-dinitro-phenol~NH4 2-trifluoromethyl- 0.20 4,6-dinitro-phenol-Na 2-trifluoromethyl- 0.31 4,6-dinitro-phenol-K

dinitro-ortho-cresol-Na standard 0 86 N~t3,4-dichloro-phenyl/-N',N'- 0.071 dimethyl urea _ .. . . , _ _ _ ..... __ . _ ~ \
- 12 ~2~
One can see that 2-trifluoromethyl-4,6-dinitro-phenol and salts thereof are similarly to N~/3,4-dichloro-phenyl/--N',N'-dimethyl-urea inhibitors of the 2. photochemical system and their effectivity is in between the effectivity of N-/3,4--dichloro-phenyl/-N',N'-dimethyl-urea and dinitro-ortho--cresol Among the 2-trifluoro-methyl-4,6-dinitro-phenol compounds the amine salts are less effective than the alkali and ammonium salts.

i ~ 10 Exam~le ~
Herbicide test in corn field The test was carried out with 2-trifluoromethyl-4,6-~dinitro~phenol-Na 20 WSC formulated according to Example 5 and with 2-trifluoromethyl~4,6-dinitro-phenol 60 EC formulat-ed according to Example 3, The test was performed on abrown forest soil containing 1,8 % of organic substance.
The soil was seeded on April 25th and 26th with corn of type Pioneer 3950 with a ~erm number of 73000Jha to a depth of 8 to 10 cm. Spraying was conducted on May 30th at 1.5 atm, by means of a parcel sprayine machine equipped with a .~
sprinkler of type Tee-Jet 11002 with water at a rate of 300 liter/ha. At this time the corn had 3-4 leaves, the main part of the weeds had 2-4 leaves~ The tests were repeated 4 times. At spraying the field was covered with weeds in 87.5 %, in 58 % with pig weed, in 27 % with fat hen and the residue was covered with barnyard grass~ The activity was evaluat-ed on June 15th. The weed killing activity and the phytotoxic symptoms observed in corn were evaluated by EWRC scale.

* ~ k _ 13 ~ ~L2~

The EWRC scale needed for evaluation is contained in Table 3 and the results are summarized in Table 4.
Data in Table 4 are average values obtained from 4 repetitions .

Table 3 EWBC va lue scale Value Weed killing effect Killirg 10scale: ~6 injury killing %

1. exce llent 100 no 0 2. excellent 99 very ~light 3, gocd 98 slight 2 4. satisfactory 95 sli~;htly 5 mcderate 5. sufficient 90 m~derate 10 6, insufficient 75 average 25 7, bad 50 strong 50 8 very bad 25 very strong 75 20 9~ tmsuitable ccmplete 100 killing Table 4 EWRC va lue.s Composition Dose pig fat Barnyard grass corn l/ha weed hen 2-trifluoromethyl- 5 3 2 5 1.5 -4,6-dinitro-phenol- 10 1.5 1 2 1.5 Na 20 WSC
2-trifluoromethyl- 1,6 4 3.5 7 4 ,6-dinitro-phenol3 .2 2 1 3 .5 J~ - 14 _ ... , ~ '~

Crop regulation of corn Test compound: 2-Trifl~oromethyl-4~6-dinitro-phenol--Na 20 % WSC
Corn of the type MVSC 3780 with a germ number of 55000/ha wa~ s~e~ed on April 20th. Spraying from helicopter was carried out on July 22nd at the beginning of the bloomin~ of the corn at a beard length of 4-5 cm.
Application rate 0.25 liter/ha -~0~05 kg./ha active 10 in~redlent~, The land3 of parcels were 4 ha and the test was repeated twice~ For each ha 50 liters of water was used.
Corn was harvested on November 3rd.
Results are summarized in Table 5.

~

length of length of corn-ear weight of corn-ear covered by grains corn car cm cm dkg 1. repetition ~.07~ 2.19 14,52~2.80 22.96+6 62 % cf the ears is 90.35 % of defective the corn-ear len~th i5 covered by grain 2, repetition 17.06+2,71 15.35~3.93 20.84~5 66 /0 of the ears is 93.34 % of the defective ears is cwered by grain 0 control 17.33~1.87 15.33+2,48 19.16~4 84 /0 of the corn-ears 89.97 % of the is defec~ive ears is covered by grain ~28 Crop averages:
1. repetition: 4,25 to/ha = 119.7 %
2, repetition: 4,08 to~ha = 11409 %
0 control: 3,55 to/ha - 100 %, According to the test 2-trifluoromethyl-4,6-dinitro--phenol-Na 20WSC could induce a significant crop increase due to its effect on the increase of the grain-size and on the better grain-density.
il ~-, 10 ~
Acaricideactivity test The test was adjusted on apples of Golden delicious type planted in a 7,5 m x 4.5 m ~ield in parcels of 5 trees arranged in rows, Spraying was carried out on March 16th before budding at a pressure of 20 bar by a manual high pressure spraying gun of Haflinger Qpraying car. Test--compounds; 2-trifluoromethyl-4,6-dinitro-phenol-Na 20 % WSC
and 2-trifluoromethyl-4,6-dinitro-phenol 60 % EC. Protective activity against eggs of spider mite living through the winter was evaluated by collecting 5 x 10 pieces of fruit--buds from the treated and untreated parcels 48 hours after the treatment. Observatiors were continued in the laboratory until the mite hatching terminated ~12 days/. Mortality %
was determined on the b~sis of the number of the hatched mites and expressed in the % of the control, Results are shown in Table 6, Table 6 Canp~3ition Concentration of number of egg infection the c~nposition in hatched mortality in % of the spray liguid mites in % the % 5xlO fruit- control -buds pieces 2-trifluarcmethyl-2,5 19 96.35 3.65 4 ,6~dinitro-phenol -Na 20 WSC
2-trifluaranethyl-0,,8 23 95,59 4.41 4,6 dinitro-phenol 60 ~C
Dinitro~ ho cresol. 2.0 27 94~82 5.18 /DNOC-25~paste Untreated control - 521 0 100 Compounds of` the general f`ormula I achieved the activity of Novenda-25 paste containing dinitro-ortho--cres o:L

Claims (7)

1. A 2-trifluoromethyl-4, 6-dinitro-phenol of the general formula I

(I) wherein X stands for alkali metal, alkali earth metal, C1-10 alkylcarbonyl, C2-10 alkenylcarbonyl, phenyl-carbonyl, or halogen-substituted phenylcarbonyl or a group of the general formula (a) H ? R1 R2 R3 (a) wherein R1, R2 and R3 are the same or different and can stand for hydrogen, alkyl, alkoxyalkyl, alkenyl, hydroxyalkyl, cycloalkyl, phenyl or phenyl substituted by halogen and/or trifluoromethyl.

2. A 2-trifluoromethyl-4, 6-dinitro-phenol of the general formula I

(I) wherein X stands for alkali metal, alkali earth metal, C1-10 alkylcarbonyl, phenylcarbonyl, or halogen-substituted phenylcarbonyl or a group of the general formula (a) H ? R1 R2 R3 (a) wherein R1, R2 and R3 are the same or different and can stand for hydrogen, alkyl, alkoxyalkyl, alkenyl, hydroxyalkyl, cycloalkyl, phenyl or phenyl substituted by halogen and/or trifluoromethyl,

3. A herbicidal, acaricidal or crop regulating compos-ition comprising as active ingredient a 2-trifluoromethyl-4, 6-dinitro-phenol of the general formula I

(I) wherein X stands for hydrogen, alkali metal, alkali earth metal, C1-10 alkylcarbonyl, C2-10 alkenylcarbonyl, phenyl-carbonyl, or halogen-substituted phenylcarbonyl or a group of the general formula (a) H ? R1 R2 R3 (a) wherein R1, R2 and R3 are the same or different and can stand for hydrogen, alkyl, alkoxyalkyl, alkenyl, hydroxyalkyl, cycloalkyl, phenyl or phenyl substituted by halogen and/or trifluoromethyl, in admixture with a suitable carrier or diluent.

4. A herbicidal, acaricidal or crop regulating compos-ition comprising as active ingredient a 2-trifluoromethyl-4, 6-dinitro-phenol of the general formula I

(I) wherein X stands for hydrogen, alkali metal, alkali earth metal, C1-10 alkylcarbonyl, phenylcarbonyl, or halogen-substituted phenylcarbonyl or a group of the general formula (a) H ? R1 R2 R3 (a) wherein R1, R2 and R3 are the same or different and can stand for hydrogen, alkyl, alkoxyalkyl, alkenyl, hydroxyalkyl, cycloalkyl, phenyl or phenyl substituted by halogen and/or trifluoromethyl, in admixture with a suitable carrier or diluent.

5. A composition as claimed in claim 3 or 4 wherein the active ingredient is present in an amount of about 0.1 to 80% by weight of the total composition.

6. A method of combating weeds which comprises applying to the weeds or a habitat thereof an effective amount of a compound of formula I as defined in claim 3 or 4.

7. A method of combatting insects which comprises applying to the insects or a habitat thereof an effective amount of a com-pound of formula I as defined in claim 3 or 4.