HUT61534A - 3,5-dioxo-3,4,5,6-tetrahydro-1,2-oxazine derivatives, herbicidal, acaricidal and plant growth regulating composition comprising such compounds as active ingredient, process for applying the composition and for producing the active ingredients, as well as 2-nitro-4-(trifluoromethoxy)-benzoic acid intermediate - Google Patents

Abstract

The present invention concerns substituted 3,5-dioxo-3,4,5,6-tetrahydrooxazines as herbicides, processes and intermediates for their preparation, compositions containing them and their use as herbicides and acaricides.

Description

The present invention relates to substituted 3,5-dioxo-3,4,5,6-tetrahydrooxazine herbicides, a process and intermediates for their preparation, compositions containing them, and their use as herbicides and acaricides.

U.S. Pat. No. 4,695,673 describes a series of acylated 1,3-dicarbonyl compounds, as well as their use as herbicides, but does not mention the 3,5-dioxotetrahydroxazine ring, which is the subject of the present invention.

More particularly, the present invention relates to compounds of formula I wherein:

R 1, R 2 and the substituents each independently represent hydrogen, C 1 -C 8 alkyl, carboxyl, C 1 -C 8 alkoxycarbonyl, phenyl or phenyl substituted with 1 to 3 substituents or R 1 and R _{2 taken} together

Form a C 3 -C 6 alkylene bridge;

R ₄ is hydrogen, C 1-8 alkyl, C 1-8 alkylcarbonyl, C 1-8 alkoxycarbonyl, C (O) NR ₇ R q, C 1-8 alkylsulfonyl, P (O) - (ORg) _{2, R?} A benzoyl group represented by the formula P (O) -ORg or a cation;

R is C 1 -C 8 alkyl optionally substituted with 1 to 6 halogen atoms, and alkoxy optionally substituted with 1 to 6 halogen atoms; «« ···· "·· *« · »·« · ·· * group, C1-8 alkylcarbonyl, C1-8 alkoxycarbonyl, -NR ₇ R, n ^{and o} ( °) n ^R 10 ' ^NR 7 ^R ^ 2 ^R 8, halogen, cyano or nitro;

R ₅ is C 1 -C 8 alkoxy substituted with 1 to 6 halogens,

Rg is hydrogen or the same as R;

R ₇ and R ₈ each independently represent hydrogen or C 1-8 alkyl;

Rg is C1-C8 alkyl;

R ₁₀ is C 1 -C 8 alkyl optionally substituted with 1 to 6 halogens;

n is 0 or 1;

n 'is 0, 1 or 2;

provided that in the case where R ^, _R2 and R are methyl, _R4 and R _& is hydrogen and R is nitro, then R ^ is not difluoromethoxy group.

As used herein, a halogen atom is suitably selected from chlorine, bromine or fluorine, and C1-C8 alkyl is preferably C1-C4 alkyl.

Preferably, each of R ₂ and R 8 is hydrogen, C 1-4 alkyl, most preferably hydrogen or C 1-3 alkyl.

Suitably R 1 is C 1-4 alkyl optionally substituted by halogen, - (O) -S (O) -, C 1-4 alkyl, halogen or nitro.

·· port.

is preferably fluoroalkoxy, more preferably OCF 4.

Preferably R < 1 > is hydrogen, C1-C4 alkyl,

C 1-4 alkoxy, bromo or chloro; more preferably hydrogen, chlorine or methoxy.

Suitably, R ₄ is hydrogen, C 1-4 alkyl, C 4-8 alkylcarbonyl, benzoyl, C 1-4 alkylsulfonyl, or a cation.

Preferably, it is hydrogen, methyl, ethyl, tert-butylcarbonyl, isobutylcarbonyl, benzoyl or methylsulfonyl. Preferably, as a cation, R ₄ is an alkali metal cation such as Na ⁺ , K ⁺ , Li ⁺ or ammonium.

R ₁ and R ₂ substituents are each particularly preferably represents e.g.

a) phenyl substituted with hydrogen, (C1-C4) alkyl, phenyl or (1-3) R;

b) phenyl substituted with H, C 1-4 alkylphenyl or 1-3 R substituents,

c) hydrogen, C 1-3 alkyl,

d) hydrogen, methyl;

e) C 1-3 alkyl;

the substituent R1 is particularly preferred

C 1-8 alkyl,

the)

b)

(C 1 -C 4) alkyl, · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·

c) methyl, ethyl;

a particularly preferred substituent R ₄ is hydrogen;

particularly preferred is the substituent R

(a) a chlorine atom, a nitro group or a CFg group,

(b) a chlorine atom or a nitro group,

c) nitro;

a particularly preferred substituent R ₅ is OCF ₃ -dubstituted;

a particularly preferred substituent R1 is hydrogen.

Combinations of the meanings of these substituents are particularly preferred.

A particularly preferred compound is 2,6,6-trimethyl-4- (4-trifluoromethoxy-2-nitrobenzyl) -2H-1,2-oxazine-3,5- (4H, 6H) -dione.

The compounds of formula (I) of the present invention are novel substances which can be prepared by analogy to methods known to those skilled in the art, such as those described and referenced in European Patent No. 186,117. In particular, it can be obtained, for example, by rearranging an enol ester of formula II, wherein R _p R ₂ , R 1 / R 1, R 8 and R 4 are as defined above, to a compound of formula I wherein R ₄ is hydrogen.

This rearrangement is conveniently carried out by reacting a compound of formula (II) with a cyanide and a mild base.

«4 ·· ·» · «· 49 · · · 4 44 •« · 4 · 4 · • · · 4 4 · «··

The reaction may be carried out, for example, in the presence of a molar excess of a cyanide anion source and / or hydrogen cyanide and a slight excess of an enol ester. The reaction is conveniently carried out in a solvent inert to the reaction conditions, such as 1,2-dichloroethane, toluene, acetonitrile, methylene chloride, ethyl acetate, dimethylformamide (DMF) or methylisobutyl ketone (MIBK). . Depending on the nature of the reagents and the cyanide source, rearrangements can be made at temperatures up to about 80 ° C. In some cases, for example, if there is a problem with the formation of too many by-products, the temperature may be maintained at or below 40 ° C.

Preferred sources of cyanide include alkali metal cyanides such as sodium and potassium cyanide; Methylalkyl ketone cyanohydrins containing C1-C4 alkyl groups such as acetone or methyl isobutyl ketone cyanohydrin; benzaldehyde cyanohydrin or C2-C5 aliphatic aldehydes such as acetaldehyde, propionaldehyde, and the like. cyanohydrins; zinc cyanide, tri (lower) alkylsilyl cyanides, namely trimethylsilyl cyanide; and hydrogen cyanide itself. A preferred source of cyanide among the cyanohydrin is acetone cyanohydrin. The cyanide source is used in an amount up to about 50 mol% based on the enol ester. Generally, a source of from 1 to 10 mol% of cyanide is preferred.

A mild base is understood to mean a substance which acts as a base, but which has a strong bases such as hydroxides, and weak bases such as tertiary amines and inorganic bases, such as w

alkali metal carbonates and phosphates. Bases which may be used as mild bases in this reaction include both organic bases such as tertiary amines and inorganic bases such as alkali metal carbonates and phosphates. Suitable tertiary amines include trialkylamines such as triethylamine, trialkanolamines such as triethanolamine, and pyridine. Suitable inorganic bases include potassium carbonate and trisodium phosphate. The base is used in an amount of about 1-4 moles, preferably 1.3-2 moles, per mole of enol ester.

In the case where the cyanide source is an alkali metal cyanide, particularly calcium cyanide, a phase transfer catalyst may be used in the reaction. Particularly suitable phase transfer catalysts are Crown ethers.

Compounds of formula (I) wherein they are other than hydrogen may be prepared by reacting a compound of formula (I) wherein R ₄ is hydrogen or

(a) R 4 -Q-OH and a catalyst; or

b) R ₄ group qQ - wherein Q represents a halogen atom - and the presence of a mild base (I) compound of the formula wherein R is the desired substituent at _4Q.

The reaction under (a) above is carried out in the presence of a catalyst such as concentrated sulfuric acid. The reaction is conveniently carried out in a solvent which is also the reagent, such as methanol and at elevated temperatures.

The reaction under (c) above is carried out in the presence of a mild base such as triethyl 8 amine or pyridine, preferably at room temperature or below.

The compounds of formula (I) can be recovered from the reaction mixture in which they are formed by conventional methods.

Compounds of formula (II) may be prepared by reacting a compound of formula (III) with a compound of formula (IV).

This reaction is carried out in the presence of a base such as triethylamine, potassium carbonate, pyridine, preferably triethylamine, and an inert solvent such as dichloromethane, acetonitrile, toluene, tetrahydrofuran, dimethylformamide.

The other compounds of formula II can be prepared in an analogous manner.

The compounds of formula (III) are novel and also form part of the invention.

They can be prepared by decarboxylating a compound of formula (V) wherein R ₂ q is alkoxy, especially ethoxy or methoxy, and R ₁₂ R ₂ and R ₃ are as defined above.

The reaction may be carried out at a higher temperature, for example at 80-90 ° C, and in an inert solvent such as wet dimethyl sulfoxide.

Compounds of formula (V) may be prepared analogously by known methods according to Reaction Scheme (1).

Reaction (a) may be carried out at room temperature in an inert solvent such as dichloromethane or aqueous ether and in the presence of a base such as triethylamine or sodium carbonate.

····

Reaction (b) may be carried out in an inert solvent such as toluene, benzene or tetrahydrofuran in the presence of a base such as sodium methoxide or sodium hydride.

The other starting materials and reagents used in the process described herein are either known or, if not known, can be prepared in an analogous manner to the methods described or known herein (see Koznowski et al., Bull.Soc. Chim. Francé 1966. No. 2. 683].

The 2-nitro-4-trifluoromethoxybenzoic acid compound is novel and is also part of the invention.

The compounds of the present invention wherein H is hydrogen may have, due to tautomerism, four structural formulas (Ia) to (Id).

It will be appreciated that when R 1 is not hydrogen, such compounds may exist in the form of the formulas (1b), (I) (c) and (1d) or in the form of a mixture of these forms.

The novel compounds of formula I are useful as herbicides both before and after emergence. The compounds of formula (I) are also useful as plant growth regulators and anti-mites. The compounds may be used in the form of powders, granules, solutions, emulsions, wettable powders and suspensions.

The use of the compounds of the present invention as herbicides in a known manner is carried out in amounts of less than 1 pound to 10 pounds per acre of herbicidal effective amounts. · 4 4 4 ·

4 · ·· * 4 4 4 «· • 4 · * applied to seeds or their place of planting. The application of the compounds of the present invention at the place of sowing can be carried out by treating the seed, the plant (weed) or parts of the plant or the soil with these compounds.

The application of a compound of the present invention to antifungal treatment is carried out in a known manner by applying an effective amount of an antifungal agent, generally between 100 g / ha and 1 kg / ha, to the infected area.

By herbicide is meant an active component which, by virtue of its phytotoxic or plant growth regulating property, modifies the growth of plants by delaying it or by damaging the plant to such an extent that it dies.

The compounds of the present invention exhibit strong herbicidal activity on broadleaf weeds, grasses, and sediments during or after emergence. They show selectivity against wheat, maize, cotton, some soybean varieties, and in some cases rice.

When used as a herbicide and acaricide, the compound of formula I, or mixtures thereof, is suitably used in the form of compositions with acceptable diluents for herbicide, acaricide or soil treatment. Such compositions are also part of the invention.

Suitable formulations of the compounds of the present invention for use in the formulation of liquid or solid carriers suitable for the preparation of formulations containing the compounds of the present invention. 0 0 • 000 ··· ·· 00 ··

Methods for making 11 are described, for example, in U.S. Patent Nos. 4,192,669 and 4,163,661, which are incorporated herein by reference. The optimal amount of compounds of the present invention to be used can be readily determined by those skilled in the art through routine assays such as drive house and small plot experiments.

Suitable formulations contain from 0.01 to 99% by weight of the active ingredient, from 0 to 20% by weight of surfactant and from 1 to 99.99% by weight of solid or liquid diluent (s). In some cases, a higher amount of surfactant / active ingredient is desirable and is achieved by appropriate alteration of the formulation or mixing in the mixing tank. The formulations generally contain from 0.01% to 25% by weight of the active ingredient. Depending on the intended use, the physical properties of the compound and the mode of application, other formulations of lower or higher active ingredient content may be employed. Concentrated preparations to be diluted before use generally contain from 2 to 90% by weight, preferably from 5 to 81% by weight.

Useful formulations of the compounds of Formula I include dusting agents, granules, suspension concentrates, wettable powders, and the like. These can be obtained by conventional methods, for example by mixing a compound of formula (I) with diluent (s) and optionally other components.

Alternatively, the compounds of formula (I) may be used in microencapsulated form.

«· ····

The compounds of formula (I) may also be combined with cyclodextrin in the form of a complex enclosed in cyclodextrin for weed control, mite control or soil treatment.

In order to improve the performance of the active ingredient and to avoid foaming, sinking and corrosion, agriculturally acceptable additives can be used, for example, in herbicidal compositions.

By surfactant is meant a substance which is agriculturally acceptable and has the property of emulsifying, spreading, wetting or ornamental dispersing or other surface modifying properties. Examples of such surfactants are sodium lignin sulfonate and lauryl sulfate.

By diluent is meant an agriculturally acceptable liquid or solid which is capable of achieving a useful or desired dilution of the concentrated material. Examples are dusts or granules such as talc, kaolin or diatomaceous earth, liquid concentrates such as hydrocarbons such as xylene or alcohols such as isopropanol or liquid compositions such as water or diesel.

The compositions of the invention may also contain other biologically active compounds, such as broad spectrum herbicidal, antitumor or herbicidal compounds having similar or complementary activity, or compounds having antimicrobial, antifungal, insecticidal or insecticidal activity.

The following examples illustrate the practice of the present invention

are intended to illustrate. Temperature data is in degrees Celsius. The SZH designation refers to room temperature and the term fraction to weight.

Example 1

2,6,6-Trimethyl-4- (2-nitro-4-trifluoromethoxybenzyl) -2H-1,2-oxazine-3,5 (4H, 6H) -dione (In the formula I, R ₁ = R ₂ = R ₃ is methyl, R ₄ = R _& is hydrogen, R is nitro; R $ represents OCF ₃ alkyl;. compound No. 1)

71.4 g of 2,6,6-trimethyl-5- (2-nitro-4-trifluoromethoxybenzoyloxy) -6H-1,2-oxazin-3-one are dissolved in 300 ml of acetonitrile and 49 ml of triethylamine. To this water-cooled solution was added 3.2 mL of acetone cyanohydride. The resulting solution was stirred at RT overnight under nitrogen. The reaction mixture was concentrated to a syrup and shaken with water (400 mL) and dichloromethane (150 mL). The combined extracts were washed with 2N hydrochloric acid, brine, dried and evaporated to an oily residue. The crude product is then recrystallized from ethanol.

M.p. 73-75.5 DEG C. 2,6,6-trimethyl-4- (2-nitro-4-trifluoromethoxybenzoyl) -2H-1,2-oxazine-3,5 (4H, 6H) -dione we get.

In an analogous manner to Example 1, the following compounds of formula (I) were obtained.

The table

Veovület __R ₂ __Rg__R Rg__Rg R ₄ mp.:

ch ₃ ch ₃ ch ₃ H

NO ₂ 4-OCF ₃ H 73-73.5 ch ₃ ch ₃ ch ₃ H,

cl

4-OCHF ₂ H 95-97 • · · ·

Example 2

Preparation of 2-Nitro-4-trifluoromethoxybenzonitrile

64.30 g of 2-nitro-4-trifluoromethoxyaniline [Zhur. Obschei. Khim., Vol. 31, 915-924. p. (1961)] A solution of sodium nitrite (20.0 g) in water (75 ml) was added dropwise over 35 minutes to a cooled O'C solution of concentrated hydrochloric acid (72 ml) and water (190 ml). After stirring at 0 ° C for an additional 45 minutes, the diazonium salt solution was added dropwise over 75 minutes to a solution of 82.69 g of potassium cyanide and 46.62 g of copper sulfate in 400 ml of water at 60-65 ° C. The gray-green solution was stirred at 60-65 ° C for an additional 30 minutes and then allowed to cool to SZH. The mixture was filtered through Celite and the precipitate was washed with dichloromethane (3 x 200 mL). The dichloromethane washes were used to extract the aqueous solution. The combined extracts were washed with water, brine, dried and evaporated to dryness to an oily residue which was then chromatographed on silica gel. 31.44 g of 2-nitro-4-trifluoromethoxybenzonitrile are obtained.

Example 3

2-Nitro-4-trifluoromethoxy-benzoic acid

A solution of 40.96 g of 2-nitro-4-trifluorobenzonitrile in 90 ml of concentrated sulfuric acid and 125 ml of water is heated at reflux for 45 hours. The reaction mixture was cooled and diluted with 200 mL of cold water. The supernatant aqueous solution was decanted from the brown crystalline gum. The crystalline gum was dissolved in ether and extracted with 0.5 N sodium hydroxide solution. The combined basic aqueous solution was cooled and acidified with concentrated hydrochloric acid and extracted with ether. The combined extracts were dried and evaporated to dryness. 119 ° C, crystalline 2-nitro-4-trifluoromethoxybenzoic acid is obtained.

Example 4

2.6.6-Trimethyl-5- (2-nitro-4-trifluoromethoxybenzoyloxy) -6H-1,2-oxazin-3-one [II, wherein ^R 1 ^{= R} 2 ^{= R} 3 is methyl; R ₄ = H, R _& meaning, R is nitrocsopordt, R ₅ is OCF ^ alkyl].

A solution of 43.98 g of 2-nitro-4-trifluoromethoxybenzoic acid in 100 ml of thionyl chloride was heated at reflux for 2 hours and then evaporated to dryness. Oil 2-nitro-4-trifluoromethoxybenzoyl chloride is obtained. A solution of 27.53 g of 2,6,6-trimethyl-2H, 1,2-oxazine-3,5 (4H, 6H) -dione and 35 ml of triethylamine in 290 ml of dichloromethane was stirred in an ice bath under cooling. a solution of 2-nitro-4-trifluoromethoxybenzoyl chloride in 100 ml of dichloromethane is added dropwise under nitrogen. After stirring at O'C for 2 hours, the reaction mixture was diluted with dichloromethane (150 mL) and the solution was washed with water, brine, dried and evaporated to dryness.

2.6.6-Trimethyl-5- (2-nitro-4-trifluoromethoxy-benzoyloxy) -. -6H-1,2-oxazin-3-one is obtained.

Claims (8)

CLAIMS 1. Compounds of formula (T) wherein: R _z R ₂ and R substituents are each independently selected from hydrogen, C1-8 alkyl, carboxy, C1-8 alkoxycarbonyl, phenyl or phenyl substituted with 1 to 3 R groups or R and R ₂ substituents form a C 3 -C 6 alkylene bridge; R ₄ is hydrogen, C 1-8 alkyl, C 1-8 alkylcarbonyl, C 1 -C 8 alkoxycarbonyl, C (O) NR ₇ R g, C 1-8 alkylsulfonyl, P (O) - (ORg) ₂ , R ₇ P (O) -OR 8, benzoyl or a cation; R is C 1-8 alkyl optionally substituted with 1-6 halogen atoms, C 1-8 alkoxy optionally substituted with 1-6 halogen atoms, C 1-8 alkylcarbonyl, C 1-8 alkoxycarbonyl, NR ₇ R _{g /} O _n S (0) _n R ₁₀ , NR ₇ SO ₂ R g, cyano, nitro or halogen; R ₅ is C 1-8 alkoxy substituted with 1 to 6 halogens; • · ···· ·· * ·· ^R 6 is hydrogen or R a specified group or halogen atom; R ₇ and R ₈ are independently hydrogen; ^R 9 atom or C 1-8 alkyl; optionally having 1 to 6 halogens substituted C 1-8 alkyl; n is 0 or 1; provided that when R1, R2 and 2. R 8 is methyl, then R ₄ and R 4 are hydrogen and R is nitro, and R ₅ is not difluoromethoxy. A compound of formula I according to claim 1, characterized by that in this formula ⁷ Rg and Rg are hydrogen; atom or C 1-4 alkyl; R C 1-4 alkyl optionally substituted with chloro, bromo or fluoro, - (O) - (C 1-4) alkyl, nitro or halo; - R ₅ is fluoroalkoxy; ^R 6 is hydrogen, C 1-4 -alkyl kil, C 1-4 alkoxy, bromine or chlorine; ^R 4 is hydrogen, C 1-4 alkyl, C4-C8 alkylcarbonyl, benzoyl, C1-C4 alkylsulfonyl, or a • · • · · · · · · · · · · · · · · · · · · · · · · · - 18 cations. A compound of formula (I) according to claim 2, wherein each of R 1, R ₂ and R 8 is hydrogen or C 1-3 alkyl; is hydrogen; R is nitro, trifluoromethyl or chloro. A compound of formula (I) according to claim 3 wherein each of R ₂ and R 8 is methyl; each of R ₄ and R 4 is hydrogen; R is nitro and Rg is OCFg. 5. A plant protection composition, wherein the composition of claims 1-4. A compound of formula (I) as claimed in any one of claims 1 to 6 together with an agriculturally acceptable carrier. 6. A method for controlling weeds, characterized in that the weeds or their growth site are as defined in claims 1-4. An effective amount of a herbicidal compound of the formula I as claimed in any one of claims 1 to 3. 7. A method for controlling acaridosis, wherein the acarid or their growth site is as defined in any of claims 1-4. An effective amount of a compound of formula (I) according to any one of claims 1 to 3 for controlling acariosis. A process for the preparation of a compound of formula (I) as defined in claim 1 wherein: a) a compound of formula (II) wherein Rp _R2, R, R, _R5 and R _& are as defined in claim 1 - an enol ester of formula (I) compounds ♦ • general · · which is desired for arranging, wherein R ₄ is hydrogen, b) in the case where R ₄ is not hydrogen, a compound of formula I wherein R ₄ is hydrogen, either with an a / R ₄₀ -OH group and a catalyst or a b / R ₄₀ -Q group with Q represents a halogen atom - and a mild base to give (I) compounds wherein the substituent R ₄ q is desired. 9. 2-Nitro-4-trifluoromethoxybenzoic acid.