NL8801580A - PYRIDINE COMPOUNDS AND METHODS FOR PREPARING AND USING THESE COMPOUNDS. - Google Patents

Description

* ί

Pyridine Compounds and Methods for Preparing and Using These Compounds.

The invention relates to new aza- and thia-5-cyclohexene-2f4-dions and 5f6-dihydro derivatives thereof, the use of such a compound® to control weeds, new herbicidal compositions containing such dione compounds and a method of preparing such new compounds.

More particularly, the invention relates to novel heterocyclic oxa or thia-5-cyclohexene-2,4-dione compounds and benzo / condensed or 5,6-dihydro derivatives thereof, which compounds are substituted in the 3-position by an ortho-substituted pyridoyl group and which may further contain substituent® in the 5- and 6-position if the hetero ring is monocyclic and in the 1-position the heteroatom is nitrogen (hereinafter referred to as compounds of formula A).

The term "ortho-substituted pyridoyl group" as used herein refers to any aryl-CO group in which aryl is a (2,3 or 4-) pyridyl group which is substituted in the ortho position of the CO group. Examples of suitable ortho substituents are halogen, nitro, alkyl of 1 to 4 carbon atoms, C 1 -alkyl-S (O) (where 1-4 n 20 n = 0.1 or 2) or haloalkyl of 1-4 carbon atoms and alkenyl with 2-5 carbon atoms. The pyridyl group can further contain 1 or 2 substituents. Examples of such further substituents of the aryl group, if desired, are halogen, alkyl of 1-4 carbon atoms, alkoxy of 1-4 carbon atoms, nitro, haloalkyl of 1-4 carbon atoms, cyano, R_B ^ N {SQ ^) ^ ( wherein and R 4, independently of one another, represent a hydrogen atom or an alkyl group having 1-4 carbon atoms and m = 0 or 1) and hydrocarbyl-S (O) ^ '(wherein hydrocarbyl represents an aliphatic, aromatic or araliphatic group, such as a alkyl group of 1-4 carbon atoms, phenyl group or benzyl group, any group may be substituted by, for example, halogen or cyano and wherein n '= 0.1 or 2). Preferably, any substituent of the pyridine portion adjacent to the ortho substituent is not in the ortho position of the CO group. The pyridoyl group is preferably mono-, di- or tri-substituted, Examples of suitable substituents in the 5-position. 8801580 - 2 - Λ of the oxa or thia-5-cyclohexene-2,4-dione ring or the 5,6-dihydro derivative of said ring (hereinafter referred to as base heterocycle) are halogen and alkyl of 1-4 carbon atoms.

Examples of suitable substituents in the 6-position 5 of the basic ring ring are hydrogen and aliphatic or aromatic hydrocarbyl groups, such as alkyl groups with 1-4 carbon atoms, cycloalkyl groups with 3-6 carbon atoms or phenyl groups. This phenyl group may be unsubstituted or substituted, for example mono or di-substituted, examples of suitable substituents of this phenyl group being alkyl groups having 1-4 carbon atoms and halogen atoms.

If the basic heterocycle is 5,6-dihydrogenated, this ring may also be disubstituted at the 5 and / or 6 position.

If the 5 and / or 6 position is disubstituted, it is, for example, di-15 c 4 alkylated.

If the base contains heterocycle nitrogen as the heteroatom, this ring nitrogen atom may or may not be substituted. Examples of suitable substituents on N are hydrocarbyl groups, such as alkyl groups of 1-4 carbon atoms, phenyl groups or phenyl-20 alkyl groups, or unsubstituted or substituted (e.g., alkyl of 1-4 carbon atoms) amino groups.

The compounds of formula A are acidic in nature and therefore can exist in the free acid form or in salt form, for example the alkali or alkaline earth metal salt form, such as the sodium salt, or in an acid addition salt form, for example with amines, such as trialkyl amines.

A recommended subset of the compounds of formula A suitable for use in the herbicidal compositions of the invention have formula I (Ia), wherein X = 0, S or NR, R 1, a pyridyl group which is ortho-substituted by halogen an alkoxy group with 1-4 carbon atoms, a nitro group, an alkyl group with 1-4 carbon atoms, a C 1-4 alkyl-S (O) ^ group, a haloalkyl group with 1-4 carbon atoms or an alkenyl group with

2-5 carbon atoms, optionally having 1 or 2 additional substituents selected from halogen, alkyl of 1-4 carbon atoms, alkoxy of 1-4 carbon atoms, nitro, haloalkyl of 1-4 carbon atoms, haloalkoxy of 1-4 carbon atoms, CN, R RN (SO4), C-alkyl-S (O), C, alkyl-CO

8801580 a * - 3 - or C 1 -alkoxy-CO, contains, represents, n and n ', independently, are 0, 1 or 2, m = 0 or 1, and R 1, independently, a hydrogen -5 atom or an alkyl group with 1-4 carbon atoms, A and B, independently, represent a hydrogen atom or an alkyl group with 1-4 carbon atoms or in which A and B together form a bond, a hydrogen or halogen atom or an alkyl group 10 with 1 to 4 carbon atoms, R 1 represents a hydrogen atom, an alkyl group with 1 to 4 carbon atoms or a phenyl group, which phenyl group is unsubstituted or is mono- or di-substituted by substituents selected from halogen or alkyl of 1-4 carbon atoms wherein when A and B form a bond together, R 1 and R 2 together may form a group -CH = CH-CH = CH-, and R a hydrogen atom, an alkyl group of 1-4 carbon atoms, a phenyl group or a phenyl -C 1-4 alkyl group.

As indicated above, the compounds of formula I may exist in their tautomeric form represented by formula Ia. A corresponding tautomerism of course also exists for the other compounds of formula A.

X is preferably oxygen.

The new compounds of formulas A and I can be obtained by esterification of the corresponding 3-position unsubstituted aza-, oxa or thia-3,5-cyclohexadiene-2-on-4-ols or -3- cyclohexen-2-on-4-ols with the desired pyridoyl halide, followed by rearrangement of the 4-pyridyloxy compound thus obtained.

This reaction can be illustrated by formulas for the preparation of the compounds of formula I starting with compounds of formula II, wherein X, R, R, A and B have the previously defined meanings, which are reacted with a compound of formula III, wherein R ^ has a previously defined meaning and Hal is a halogen atom, followed by herarran minor of the ester of formula IV thus obtained, wherein X, Rj, Rj, Rg.r A and B have the previously defined meanings to have.

The esterification of the 2-on-4-ol compounds with a .8801680-4-pyridoyl halide can be carried out in a manner known per se for preparing esters from an alcohol and an acid halide.

The reaction conveniently proceeds in a solvent that is inert under the reaction conditions, such as dichloroethane, preferably in the presence of an acid binding agent, such as, for example, triethylamine. A suitable reaction temperature is between 0 and 40 ° C, for example at 20 ° C.

The rearrangement of the esters to the desired compounds of formula A can be carried out under the conditions known for preparing a-acylated β-diketones from $ -ketoenol esters.

Such rearrangement can proceed in the presence of a Lewis acid catalyst or of a cyanide source, such as acetone cyano-hydrine with a tertiary amine base.

Suitable Lewis acid catalysts for such a rearrangement reaction are, for example, aluminum chloride or zinc chloride.

Examples of suitable solvents are methylene chloride, acetonitrile or toluene. The reaction temperature is suitably between 0 ° C and the reflux temperature and is preferably room temperature (about 20 ° C).

The compounds of formula A can be recovered from the reaction mixture in which they are formed by working up this reaction mixture in a conventional manner.

Depending on the reaction conditions, the compounds of formula A can be obtained in free acid form or in salt form.

The salts of the compounds of formula A are obtained from the free acid in a manner known per se and vice versa.

The starting materials and reagents used in the above-described method are known or, if they are new, can be obtained by methods analogous to the methods described herein or to known methods.

The previously defined compounds of formula A, in free acid form or in an agriculturally acceptable salt form, in particular the compounds of formula I, exhibit an interesting broad spectrum herbicidal activity.

8801580 - 5 -

The invention therefore also relates to a method of controlling weeds, which comprises applying a herbicidally effective amount of a compound of formula A in free form or in a salt form acceptable for agricultural purposes to a weed area.

The effect before and after hatching can be demonstrated in tests in greenhouses with dosages to be tested equivalent to application rates of 0.33, 1.0 and 3 kg per hectare. The amount of compound of formula A to be used will depend on the particular weeds to be controlled, the compound used, the mode of administration, the conditions of the treatment and so on. The appropriate amount to be used can be determined by routine expert testing or by comparison of the activity of the desired compound of Formula A with standards for which the amount used is known, for example, from greenhouse studies. In general, satisfactory results are obtained when a compound of formula A is used in an amount of about 0.03 to 3.0 kg / ha area with plants.

The compounds of formula A can and are preferably used as preparations with a herbicidal action together with one or a number of diluents acceptable in the agricultural field. Suitable formulations contain 0.01-99% by weight of active ingredient, 0-20% surfactant and 1-99.99% solid or liquid diluent (s). Larger surfactant to active ingredient ratios are sometimes desirable and are obtained by incorporation into the composition or by mixing in a tank. Application forms of a preparation generally contain between 0.01 and 25% by weight of active ingredient. Lower or higher levels of the active ingredient may of course be present depending on the intended use, the physical properties of the compound and the mode of application. Concentrated forms of a composition intended to be diluted before use generally contain between 2 and 90% by weight, preferably between 35 and 80% by weight, of the active ingredient.

Useful preparations of the compounds of formula A include powders, granules, concentrated suspensions, wettable powders, emulsifiable concentrated products, liquid products, and so on. They are produced in a usual manner. 8 8 0 1 h 8 0 - 6 - r · obtained, for example, by mixing a compound of formula A with one or more diluents and, if desired, with other ingredients.

It is also possible to use the compounds of formula A 5 in a microencapsulated form.

Acceptable additives in the agricultural field may be added to the herbicidal compositions in order to improve the activity of the active ingredient and, for example, reduce foaming, cake formation and corrosion.

The term "surfactant" used herein refers to an agri-acceptable material that imparts emulsifiability, spreading ability, wetting ability, dispersibility, or other surface modifying properties. Examples of surfactants are sodium lignin sulfonate and laurel sulfate.

The term "diluent" used herein denotes a liquid or solid agricultural acceptable material which is used to dilute a concentrated material to a useful product or desired concentration. For powders or granules, this may be, for example, talc, kaolin or diatomaceous earth, for concentrated liquid forms, for example, a hydrocarbon, such as xylene or an alcohol, such as isopropanol, and for liquid forms, water or diesel oil to be used.

The compositions of this invention may also contain other compounds with a biological activity, for example compounds with a corresponding or complementary herbicidal activity or compounds with an antidotal, fungicidal or insecticidal activity.

In the following examples, the parts and percentages are 30 parts by weight and parts by weight, respectively.

Herbicidal preparations.

Example A; wettable powder.

25 parts of a compound of formula A, for example the compound of Example 1 below, were mixed and ground with 25 parts of synthetic fine silica, 2 parts of sodium lauryl sulfate, 3 parts of sodium lignin sulfonate, and 180-180 parts of finely divided kaolin. that the average particle size was about 5 microns.

Example B; concentrated emulsion.

25 parts of a compound of formula A, for example the compound of Example 1 below, 50 parts of xylene, 15 parts of dimethyiformamide and 10 parts of emulsifier were intimately mixed until a homogeneous solution was obtained.

Herbicidal research / / 10 Research - example 1: treatment before hatching.

Seed pots were filled with a substrate equivalent to sandy loam. Seeds of Abutilon theophrasti, Amaranthus retroflexus, Sinapis alba, Solanum nigrum, Bromus tectorum, Setaria viridis were then sown in each pot. Avena fatua and

Echinochloa crus-galli.

Then, the compound of formula A to be tested was in an amount corresponding to 1 and 4 kilograms

active ingredient per ha using a volume corresponding to? Q

coming at 1000 liters per hectare (sprayed with an aqueous research liquid formulated, for example, according to example B). After application, the seeds were covered with a thin layer (about 0.5 cm) of substrate. The pots were kept at room temperature (20-24 ° C) for 21 days with 14 to 17 hours of light (daylight or 25 equivalent) per day.

The herbicidal effect assay was performed after the 21 day period. This determination included the visual assessment of the degree and quality of damage inflicted on the different seeded plants.

A herbicidal action has been observed.

Research example 2; treatment after hatching.

The procedure was similarly as described in Test Example 1, except that the test compounds were applied once the plants were at 2-4 leaves stage. The other experimental conditions (amount to be applied, volume applied, temperature and light) and the evaluation procedure (21 days after application) were the same „è 8 Q 15 8 υ τ - 8 - as described in study example 1.

A herbicidal action was observed.

Research example 3.

5

Corresponding tests as described in Test Examples 1 and 2 were carried out with different monocotyledonous and dicotyledonous weeds using different concentrations of the test compound, the concentrations being chosen to give the desired application rates. The volume used corresponded to 600 liters per hectare.

The evaluation was made 28 days after application. The herbicidal activity was observed at application rates from 30 to 1000 grams / ha.

Finished products.

Example 1; 3- (3,5-dichloro-2-pyridoyl) -4-hydroxy-6-methyl-2-pyron.

A suspension of 4.00 grams of 3,5-dichloro-2-pyridoyl chloride and 2.40 grams of 4-hydroxy-6-methyl-2-pyron in 80 ml CHCl 2 1.8 ml triethylamine was added dropwise at room temperature. After the exothermic reaction had ceased, the mixture was stirred at room temperature for an additional 6 hours. Then 2.8 ml of triethylamine followed by 0.7 ml of acetone cyanohydrin was added and the resulting solution was stirred overnight.

The reaction mixture was extracted with a 1M

Sodium hydroxide solution. The aqueous extract was washed with CH 2 Cl 2, then acidified to pH 3 µM hydrochloric acid) and three times.

extracted with CR ^ Cl ^. The combined C 1 Cl 2 extracts were washed with water, dried over magnesium sulfate, filtered and evaporated under reduced pressure to give a crude solid product. This solid product was recrystallized from C 1 Cl 2 and diethyl ether to yield 1.28 grams of white crystals, m.p. 166-168 ° C, corresponding to 1. according to H NMR with the desired structure.

.8801580 - 9 -

Elemental analysis: (theory%) C48.0; H2.4; N 4.7 and Cl 23.6 * (found%) C47.9; H 2.3; N 4.7 and Cl 24.2 Example 2.

Analogous to the procedure of Example 1, using the corresponding starting materials of formulas II and III, the following compounds of formula I were obtained (Table 10I).

Table I: Compounds of formula I wherein R ^ represents a 3,5-dichloro-2-pyridoyl group and X is O compounds A B ^ 2 ^ 3 characterization.

2.1 H CH3 H CH3 127 "128 ° 2.2 bond (A + B) H CH3 166 - 168 °

2.3 CH-CH CH CH

3 3 3 3 20

Intermediates: 3,5-Dichloro-2-pyridoyl chloride was obtained from 2,3,5-trichloropyridine (Compound V) by the following method:

Example 3: 2- / CH (COOCII) / -3,5-dichloropyridine 25-1 λ (compound VI).

A solution of 45.0 grams of diethyl-30 malonate in 100 ml of Ν was added in a nitrogen atmosphere to a suspension of 10.4 grams of 80% NaH (in mineral oil) in 500 ml of N, N-dimethylformamide at room temperature. , Ν-dimethylformamide. After all was added, the resulting mixture was stirred at room temperature for 15 minutes and then at 5 ° C for 30 minutes. A solution of 45.7 grams of 2,3,5-trichloropyridine in 100 ml of Ν, Ν-dimethylformamide was then added to this mixture and stirred overnight at 50 ° C.

The solvent was evaporated under reduced pressure, the residue was taken up in CH 2 Cl 2, washed with four portions of water, dried over magnesium sulfate, filtered and evaporated under reduced pressure. The resulting liquid was chromatographed on. 8 8 C 1 E 8 0 - 10 - silica gel with a mixture of hexane and ethyl acetate (9: 1). The fractions containing the product were contaminated with diethyl malonate, therefore these fractions were distilled under reduced pressure to obtain 25.2 grams of pure product, b.p. 103 ° C, 0.018 mroHg (nD 1.5068). . This liquid was consistent with the desired material by H NMR.

Example 4: 3,5-dichloro-2-methyl-pyridine (compound VII).

10.

A suspension of 70.0 grams (compound VI) in 2M sulfuric acid was heated at 110 ° C for 17 hours. The resulting mixture was cooled and extracted exhaustively with CH 2 Cl 2. The CH 2 Cl 2 extracts were dried over magnesium sulfate, filtered and evaporated under reduced pressure to give 37.0 grams of a solid product, mp 43-44 ° C C, according to H NMR in accordance with the desired product.

Example 5: 3,5-dichloropyridine-2-carboxylic acid 20 (compound VIII)

To a solution of 1.25 ml of aliquat 336 (tricaprylmethyl ammonium chloride) in 175 ml of water was first added 4.00 grams of 3,5-dichloro-2-methylpyridine and then a 19.8% KMnO 2 - 25 solution. resulting mixture was heated at 95 ° C for 90 minutes.

After cooling to room temperature, the water layer was washed with CH 2 Cl 2, acidified with concentrated sulfuric acid to pH 5 and concentrated under reduced pressure to 1/3 v / h volume. This solution was further acidified to pH1 and a white precipitate was filtered off. This material (0.95 grams) had a melting point of 152 ° C and was consistent with the desired product according to H NMR.

Example 6: 3.5-dichloro-2-pyridoyl chloride, 35

A suspension of 14.3 grams of 3,5-dichloro-pyridine-2-carboxylic acid in 60 ml of thionyl chloride was heated under reflux for 5 hours, whereby a solution was obtained. The cooled solution was evaporated under reduced pressure to give 15.7 grams. ISO 158 0-11 of a white solid product with a melting point of 58-60 ° G. that were consistent with the desired structure by NMR were obtained.

. ί S ί'1 5 8 0

Claims (8)

1. Heterocyclic aza, oxa or thia-5-cyclohexene-2,4-dione compounds and benzo / b / condensed or 5,6-dihydro derivatives thereof, which compounds are substituted in the 3-position by an ortho-substituted pyridoyl group and which may further contain 5 substituents at the 5 and 6 positions if the heterocycle is monocyclic and the hetero atom in the 1 position represents nitrogen. 2. Compounds according to claim 1, of formula I (Ia), wherein X = 0, S or HR, 10 represents a pyridyl group which is ortho-substituted by halogen, alkoxy with 1-4 carbon atoms, nitro, alkyl with 1-4 carbon atoms? C 1-4 alkyl-S (0) n or C 1-4 haloalkyl or alkenyl of 2-5 carbon atoms and optionally one or two additional substituents selected from 15 halogen, alkyl of 1-4 carbon atoms, alkoxy of 1-4 carbon atoms, nitro , haloalkyl of 1-4 carbon atoms, haloalkoxy of 1-4 carbon atoms, CN, R RN (SO), C. alkyl-S (O), C,. alkyl-CO or a b 2 m 1-4 n '1-4 J C,. alkoxy-CO contains, 1-4 and n1, independently, 0.1 or 2, m = 0 or 1, Rr. and R., independently, represent a hydrogen atom ab or an alkyl group of 1-4 carbon atoms, A and B, independently, represent a hydrogen atom or an alkyl group of 1-4 carbon atoms or wherein A and B together form a bond R2 represents a hydrogen or halogen atom or an alkyl group with 1-4 carbon atoms, R2 represents a hydrogen atom, an alkyl group with 1-4 carbon atoms or a phenyl group, which phenyl group is unsubstituted or by substituents selected from halogen, alkyl with 1-4 carbon atoms, mono or di-substituted, wherein when A and B together form a bond, R 1 and R 2 together may form a -CH = CH-CH = CH-, and R 1 a hydrogen atom, an alkyl group having 1-4 carbon atoms, a phenyl group or a phenyl-C 1-6 alkyl group. .88015 * 0 - 13 - Process for the preparation of dion compounds, characterized in that dion compounds as defined in claim 1 are prepared by esterification of aza, oxa or thia-5-cyclohexene-2,4-dione compounds, if desired benzo / b / condensed 5 or 5,6-dihydrogenated and may contain substituents at the 5 and 6 positions if the cyclodione ring is monocyclic and the heteroatom in the 1 position represents a nitrogen atom, with an orthosubstituted pyridoyl halide, followed by rearrangement of the thus obtained 4-pyridoyloxy compound. Process according to claim 3, characterized in that compounds of formula I, as defined in claim 2, are prepared by a compound of formula II, wherein X, R 1, R 1, A and B have the meanings defined in claim 2 to react with a compound of formula III, wherein R ^ has a meaning defined in claim 2, and then the thus obtained 4-pyridoyl ester of formula IV, wherein X, R ^, R ^, R ^, A and B have the <=> meanings defined in claim 2, to be rearranged. A herbicide containing one or more compounds according to claim 1 or 2. A method of weed control, characterized in that a herbicidally effective amount of a compound according to claim 1 or 2 is applied to a weed area. 7. Compounds as described in the description and / or examples. Molded preparations with herbicidal action according to claim 5. o-o-o-o-o-o-o s ή -H e p 15 p o