CS195696B2 - Method of preparing substituted n-/2,2-difluoralkanoyl/-o-phenylendiamines - Google Patents

Description

The invention relates to novel ring-substituted N- (2,2-difluoroalkanoyl) -o-phenylenediamines. These compounds are useful as herbicides.

Rumanowski, U.S. Patent 3,557,211, discloses N, N-bis (acetyl) -o-phenylenediamines useful for controlling plants, insects and fungi.

One feature of the invention is a process for preparing compounds that are effective systemic herbicides.

The invention relates to novel ring-substituted N- (2,2-difluoroalkanoyl) -o-phenylenediamines of formula I,

where

R 0 is a 2,2-difluoroalkanoyl radical of formula O. , || -C-CFA-Y, wherein Y is fluorine atom; R ¹ is hydrogen or 2,4-dichloro-8-methoxy-benzoyl,

R ³ is a chlorine atom,

R ⁴ is nitro, m is 0,1 or 4, n is 0 or 1, wherein when R ¹ is hydrogen, the ortho position on the ring relative to the -NH-R ¹ group contains one of the radicals listed for R ³ or R ^{3 4}

Compounds of formula -1 are prepared by introduction. characteristic 2,2-difluoroalkanoyl group to the corresponding corresponding diamine of the starting material. The introduction of this group can be carried out by any of the available acylation reactions using any of various kinds of acylating agents of formula IV, ^one

HO — C — CFž — Y li • o (IV) wherein Y is as defined above, or 2,2-difluoroalkanoyl halides of formula V

195898

With hal-C-CF 2 -Y (V) or 2,2-difluoroalkanoic anhydrides of formula VI,

~ ..... ~ O-IC-CF2-Y] 2:

(See where Y is as defined above. The diamine starting materials with which the acylation reaction proceeds are different.

Thus, the process for preparing compounds of formula I comprises acylating a compound of formula VII,

wherein R ¹ , R ³ , R ⁴ , m and n are as defined above, with an acylating agent of general formula (I); formula IV,

O 'II,.

HO - C - CF 2 - Y - (IV) wherein Y is as defined above, or with a halogenide or anhydride of a compound of formula IV. _Ί

In the case of compounds of formula I wherein R ¹ is hydrogen, the starting diamine is a compound of the following formula X

and introducing one acyl group (leaving R ¹ equal to the hydrogen atom).

If, on the other hand, R ¹ is any radical other than hydrogen, the appropriate starting material compound diaminovýro nesoiucí desired radical R ¹ of formula XIII,

195698 wherein the symbols have the meaning given above and / or the characteristic R ° group is similarly colored. wadi acylation.

. The preparation of amides by acylation of the corresponding α-toins with various acylating agents is a known synthetic method. These preparations are carried out according to the conventional methods used for this purpose. So. if the acylating agent is an anhydride, the reaction is preferably carried out at room temperature, an excess of the anhydride may be used as the solvent, except in the case of amides where R ¹ is a hydrogen atom; hydrogen chloride and preferably in the presence of an inert solvent and the reaction mixture is preferably cooled to a temperature of n to ΐη ° (Ί. For any acylating agent, the product is separated by conventional methods and can optionally be purified by known methods.

For consistency, starting materials and products are named, where possible, as o-phenylenediamines. In accordance with conventional nomenclature practice, the identification of the various substituent positions is as follows:

wherein either the nitrogen atom contains an alkanoyl or other (R °, R ¹ ) substituent, the ring position numbers are identified as a prime number to distinguish from the positions on the R ° or ¹ R ¹ substituents. . '

The starting materials used in the process of the invention are prepared by known methods and some of them are commercially available. Starting materials of formula X

Rm

(X / are prepared by multistage syntheses which are necessary to introduce the desired groups. Most preferably one or both of the NH 2 groups are introduced by halogen conversion. which already contain the groups R ³ and R ⁴ '. However, sometimes it is preferred that these substituents, e.g., nitro or halo, simultaneously introducing the synthetic steps leading to the introduction of amino groups.

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6

For example, if the diamine is tetrasubstituted, the corresponding tetrasubstituted benzene is filtered in both remaining orthopositions and the nitro groups are then reduced.

Those compounds of formula I wherein R ¹ is a substituent other than hydrogen are generally prepared from diamine starting materials that already have a substituent R ¹ . These starting materials are prepared from the corresponding diamine starting materials described above by reaction with the appropriate acyl halide. Alternatively, however, the following starting materials may be prepared from o-nitroanilines:

by acylation followed by reduction, by known methods.

The synthesis of the compounds of formula (I) is described in the following examples and allows those skilled in the art to carry out the process of the invention. Example 1 _; 3,4,5,6-Tetrachloro-o-phenylenedtamine (20 g) was dissolved in 50 ml of benzene and 0.8 ml of triethylamine and treated with trifluoroacetic anhydride (1.84 g). The resulting reaction mixture is heated to boiling for 16 hours, concentrated to 20 ml and the desired NMrifluoroacetyl-3 ', 4', 5 ', 6'-tetrachloro-o-phenylenediamine is then filtered off and recrystallized from chloroform. The product has a b, mp 245-247 ° C.

Example 2

The other compounds of the invention were prepared according to the preceding examples using analogous starting materials. These compounds are as follows:

N-Trifluoroacetyl-S-nitro-S-chloro-o-phenylenediamine, m.p. 184-186 ° C, prepared by reacting trifluoroacetanhydride with 3-nitro-5-chloro-o-phenylenediamine,

NMrfluoroacetyl-N ² - (2,4-dichloro-6-methoxyhenzoyl) -6'-nitro-o-phenylenediamine, mp 200-201 ° C.

All compounds of formula I may be formulated to be useful as herbicides. These compounds can be used in such a way that a broad herbicidal effect is obtained; thus, in the broadest sense, the invention relates to a method of application which is characterized in that growth is applied to plant parts such as a scape, stalks, flowers, fruits, roots or seeds or similar reproductive units of plants. The N- (2,2-difluoroalkanoyl) -O-phenylenedlamines of formula (I). However, these compounds may also be used by utilizing selective herbicidal activity. As will be appreciated by those skilled in the art, a mixture of more than one compound can also be used to achieve a herbicidal effect. When a mixture is used, the amount of each individual compound can be reduced so that the mixture exhibits only the desired herbicidal effect.

It is not critical to the herbicidal utility of the compounds whether undesirable vegetation is completely eliminated; it is sufficient if undesirable vegetation is merely deteriorated. In particular, as far as the selective effect is concerned, inhibition of less complete killing is sufficient, especially if combined with natural conditions such as limited humidity, which has the most beneficial effect on vegetation selectively inhibited than on useful plants. The compounds of formula I are suitable for various variations of herbicidal applications.

The various compounds of formula I to be used as active herbicidal agents are evaluated after pre-emergence application in different plant species. In this evaluation, a soil containing one part of sand and one part of the crushed top soil layer is prepared, perfectly mixed in a cement mixer. 4.5 liters of this soil is placed in a 25 X 35 cm galvanized metal bowl and the cellar is below the rim. They are executed in three rows

2.5 cm deep grooves in about two fifths of the bowl. Four corn kernels, five cotton seeds and five soybean seeds are planted in these grooves. In the remaining four grooves, the approximate number of each of the following seeds, each species in a single row, is sown in the remaining soil: 80- to 100-seed, 40 to 50-seeded cloud, seeds, 150 to 250 seed and 100 up to 150 seeds.

A further sufficient amount is then added to sufficiently cover the area.

Thus the weed seeds are covered with a layer of about 6 mm and the seeds of the useful plants with a layer of about 3 cm. _

In order to determine the effect of the composition as a herbicidal composition for use before emergence, the area is prepared as described above and is placed in a rotary chamber and air outlet chamber on the day of sowing or the following day. The herbicidal mixture, either a spray emulsion or a wettable powder, is applied to the surface with a modified de Vilbis atomizer attached to an air source. Twelve and a half millimeters of the mixture to be tested is then applied to each area either on the day of sowing or the following day. The severity of the lesion and the observation of the lesion type are performed 11 to 12 days after treatment. Damage is assessed according to the following scale:

no damage, - slight damage, - moderate damage, - considerable damage, - death.

Where there was performed one cub than ^one determination in said quantity being vypo195896 čítáván for evaluation · 'average damage. Each test compound is sprayed by one of the following procedures: In one test, the compound is wetted by mixing in a mortar with one part polyoxyethylene sorbitan monolaurate. Five hundred parts of water are slowly added to the resulting cream-colored paste to give an aqueous dispersion with a base concentration of 0.2%. Dispersion is suitable for spray application. In a second procedure, the compound is dissolved in one part of acetone and the acetone solution is diluted with nineteen parts of water containing 0.1% water ^. % polyoxyethylene sorbitan monolaurate.

The following table shows the evaluation results, column. 1 shows the name of the test compound, column 2 the amount in kilograms per hectare in which the compound is applied to the test area, and the remaining columns indicate the degree of damage to certain plant seeds or plant seedlings as assessed above.

Degree of damage during pre-emergence treatment.

kg / ha maize cotton soybean goosefoot grass

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Certain compounds of formula I were evaluated after emergence in plants including maize and some weed species. Evaluation is carried out according to the previous tests, except that the test solution is applied 9 to 12 days after preparation and sowing into the soil. The results are shown in the following table.

T a b u 1 k and 11

Degree of damage during emergence treatment.

sloocenlna

NMrlfluoroacetyl-T-nitro! -5´-chloro-o-phenylenediamine kg / ha maize

8.8 1 3 4

4.4 2 4 4

2.2 1 4 4

1,1 1 4 4 bor cloud

4

4

4

4

Claims (1)

SUBJECT TO INVENTION A process for the preparation of substituted N- (2,2-difluoroalkancyl) -o-phenylenediamines of formula I, wherein: R 0 is a 2,2-difluoroalkanoyl radical of the formula -C-CF 2 -Y,. II o where Y is a fluorine atom, R ¹ is hydrogen or 2,4-dichloro-8-methobtybenzoyl, R ³ is a chlorine atom; R ⁴ is n -trro, m is 0, 1 or 4, n is 0 or 1, wherein if, R ¹ is hydrogen, the ortho position to - NH-R ¹ carries one of the groups designated R ³ or R ⁴ ; characterized in that a compound of the formula VII, wherein R ¹ , R ³ , R ⁴ , have the meanings given above, is reacted with an acylating agent of the formula IV, O ' II: - HOC — CF2 — Y (IV) wherein Y is as defined above, or with a halide or anhydride of a compound of Formula IV.