DD149665A5 - PROCESS FOR THE PREPARATION OF O-HALOGENALKYL-2-HALOGENACETANILID DERIVATIVES - Google Patents

Abstract

The invention relates to processes for the preparation of novel o-haloalkyl-2-haloacetanilide compounds. The object of the invention was to find processes for the preparation of useful intermediates for the preparation of N-substituted 2 ', 6'-disubstituted 2-haloacetanilide derivatives which selectively control undesirable vegetation in agricultural crops. This object has been achieved satisfactorily by the process according to the invention in which the desired o-haloalkyl-2-haloacetanilide derivatives are obtained from suitable starting compounds by treatment with a halogenating agent such as molecular chlorine, bromine or N-bromosuccinimide with simultaneous exposure to UV light. Light or a light source for white light synthesized and obtained in the usual way.

Description

Field of application of the invention

The invention relates to novel o- (haloalkyl) -2-haloacetanilide derivatives and to processes for their preparation. The novel compounds are useful as intermediates for the preparation of certain o- (alkoxymethyl) -2-haloacetanilide derivatives which have selective herbicidal activity.

Characteristic of the Known Technical Solutions US Pat. No. 4,070,389 discloses quite generally the herbicidal use of certain chloroacetanilides, among which certain N-substituted 2 ^f _> 6 ^! - (haloalkyl) ~ 2-chloroacetanilides. However, US Pat. No. 4,070,389 does not teach one skilled in the art how to make or use the aforementioned compounds, but refers the artisan to certain German disclosure specifications for their preparation and use. Bind mentions the following DE disclosure documents: 2,212,228, 2,305,495, 2,328,340, 2,402,983, 2,405,153 and 2,405,479. Those skilled in the art will readily recognize that none of the above-mentioned publications are N-substituted 2 '. , 6 '- (haloalkyl) -2-chloroacetanilides disclosed. The only publication quite remotely suggesting the compounds mentioned is the ^2S patent publication 2 405 479 which corresponds to the British patent i 455 474.

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British Patent Specification 1 455 W discloses general herbicidal use of N- (2-methoxyethyl) - or N- (2-Xthoxyäthyl) -2 ^t - (trifluoromethyl) -6 ^l alkyl-2-chloroacetanilides. (Exemplary of this type of acetanilide is also U.S. Patent 4,152,137). In British Patent 1,455,474, no teaching is given of the compounds of the type claimed herein, ie N-methyl-, N- (bromomethyl) - or N- (chloromethyl) -o- (haloalkyl) -2-haloacetanilides.

With regard to the process for preparing the compounds according to the British publication, the phenyl ring substituents of the compounds disclosed in this publication must be introduced into the ring before reactions on the amino group are carried out. That is, suitably substituted aniline materials are reacted to form the desired haloacetanilides. There is no teaching in this patent of the new method disclosed and claimed herein, i. the selective halogenation of o-ring substituents and / or the N-alkyl substituent group of 2-haloacetanilides.

The prior art discloses the bromination of o-methylacetanilide using N-bromosuccinimide (NBS); E. α. Kleinschmidt et al., PHARMACEUTICAL, 24 ^ (2), p

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87 to Sk ₉ 19693. However, in contrast to the new process claimed here, the bromination process described in the aforementioned publication occurs completely on the phenyl ring, ie only nuclear bromination is observed when the ring is o-alkyl-substituted.

Ulrich et al., J. Org. Chem., J3 £ (19), pages 2897 to 2899, 1974 disclose the preparation of N- (chloromethyl) -N-phenylcarbamoyl chloride via the monochlorination of N-methyl-N-phenylcarbamoyl chloride in Presence of ultraviolet light. '

Object of the invention

The present invention relates to certain o- (haloalkyl) -2-haloacetanilides which are intermediates for the preparation of certain substituted o- (alkoxymethyl) -2-haloacetanilide derivatives which are useful herbicides.

Explanation of the essence of the invention

The compounds of the present invention have the general formula I.

O = C-CH ₂ X.

R-N

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wherein the index η is 0 or 1; if the index η is 1, then

X is chlorine, bromine or iodine,

R is hydrogen, methyl, chloromethyl or bromomethyl,

R is hydrogen, halogen, methyl, tert-butyl, trifluoromethyl or a radical of the following formula

X ²

I o

-C-

R is chlorine, bromine or straight-chain alkyl with

i to k carbon atoms,

12

Y and ¥, independently of one another, equal to hydrogen,

Halogen, methyl, tert-butyl, trifluoro-ethyl or a radical of the following formula

X ²

I 2

-C-R ^

1 2

X and X, independently of each other, equal to water

etoff, chlorine or bromine, provided that when R is straight chain alkyl of 1 to % carbon atoms, only one

1 * 2 of the radicals X and X is hydrogen, chlorine or bromine,

? 1 2 and further provided that the radicals R, X and X are not

Equilibrium may be chlorine or bromine; if the index η is 0, χ is chlorine, bromine or iodine R is chloromethyl,

R * is hydrogen, trifluoromethyl or halogen,

Y and Y, independently of one another, are hydrogen or halogen,

R is hydrogen.

Compounds of the above formula are new if the index η is 1.

The term "straight-chain alkyl of 1 to 4 carbon atoms *" used herein means methyl, x-butyl, n-propyl and n-butyl.

The term "halogen" means chlorine, bromine, fluorine and iodine atoms. Chlorine and bromine are preferably used in the present invention

The compounds of the present invention are prepared according to the following new process:

R - N

(II)

, Br ₂ or NBS R-N

OsC-CH ₂ X

(I)

^XY

-C-

In the compounds of general formula I, n, X, R,

1 ? 1 ? 1 P R, R, X .., X, Y and Y have the meaning described above.

In the compounds described by general formula II, the following meanings are attributed to the various substituent groups:

If the index η is i

1 2

R, X, Y and Y are as defined above,

R ^H is hydrogen, halogen, tert-butyl, trifluoromethyl or a group of the formula below

-C-R ¹ "H

is hydrogen or straight chain alkyl of 1 to 4 carbon atoms; if the index η is 0 ^{x is} chlorine, bromine or iodine

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R is methyl,

R "is hydrogen, trifluoromethyl or halogen,

1 2

Y and Ϊ, independently of one another, are hydrogen or halogen,

R ^w is hydrogen.

According to the above reaction scheme, the appropriate starting material, i. a compound of the type described by general formula II, dissolved in a suitable volume of a solvent inert to a halogenation. Examples of suitable solvents are carbon tetrachloride, chloroform, petroleum ether, methylene chloride and the like. This process relies on carbon tetrachloride. At this time, a catalyst, E.B. Benzoyl peroxide, to be added to the mixture to facilitate the reaction. However, the use of the catalyst is optional and is not required for the practice of the process. To this mixture is added a stoichiometrically equivalent amount of a halogenating agent selected from the group consisting of molecular chlorine, molecular bromine, N-bromosuccinimide (NBS), or other N-bromo equivalents such as N-bromo-N-methylacetamide or N-bromophthalimide , surrendered. It can be seen that greater than stoichiometrically equivalent amounts of halogenating Mit-

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tel can be used in the practice of the method according to the invention with equal ease. The resulting mixture is irradiated with an external and / or internal ultraviolet and / or white light source and the reaction is carried out. The reactants are mixed usually at room temperature, that is at about 25 ⁰ C and then maintained at reflux temperature, or in the vicinity of the reflux temperature. However, as explained in the examples below, lower temperatures may be used.

Separation of the resulting reaction product from the reaction mixture is easily accomplished by conventional methods. For example, unreacted halogenating agent and succinimide can be removed by filtration while the solvent is removed by stripping or distillation, preferably by vacuum distillation at low temperature. The product is usually purified by recrystallization from suitable solvents.

The starting materials, ie the compounds of general formula II, are known to the person skilled in the art, for example from US Pat. Nos. 3,442,445, 3,637,847, 3,966,811 and British Patent 1,455,474.

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In the process described above, chlorination or bromination of o-alkyl-2-haloacetanilides, unlike o-alkoxy-2-haloacetanilides, does not give halogenation on the phenyl ring, ie no nuclear halogenation. When the halogenation is performed with molecular chlorine using 2 *, 6V-dimethyl-N-methyl-2-chloroacetanilide as the starting material, both the N-methyl and the ring methyl groups (benzyl groups) chlorinate at comparable rates. When the o-alkyl-2-chloroacetanilides disclosed herein are subjected to bromination, the process eats slower and more selectively than the chlorination. Thus, to obtain optimum results, molecular bromine (dissolved in carbon tetrachloride) is added dropwise to an exposed (UV and / or white light) and refluxing solution of the amides containing about 0.1 % benzoyl peroxide. In general, if 2-halo-N-methyl-2 ^f , 6'-dialkylacetanilides are brominated using Br, only the phenyl ring (benzylic) side chain carbon atoms will be brominated.

Bromination with molecular bromine (B 1) of 2-chloroacetanilides of the type described by general formula II effects varying degrees of halogen exchange, with partial formation of 2-bromoacetanilides. secondary

ΊΟ

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and tertiary anilides are susceptible to such exchange when prepared in large quantities at higher bromine and amide concentrations. The bromine found in the 2-position prevents the exchange of chlorine with HBr to form HCl. The halogen exchange can be minimized by passing nitrogen to aid the hydrogen bromide (HBr) removal BU.

In order to avoid the halogen exchange and still obtain the advantages resulting from the bromination, recrystallized N-bromosuccinimide (NBS), or a similar N-bromo equivalent, such as N-bromo-N-methylacetamide or N-bromophthalimide, is coexistent with optionally added benzoyl peroxide, the reagent of choice. Only equimolar amounts of this convenient material are required to cause exclusive side-chain benzyl bromination to produce the by-product succinimide.

Molecular bromine or NBS brominates an o-methyl group exclusively in the presence of an o-tert-butyl group. On the other hand, chlorine is not as selective, with much chlorination of the tert-butyl moiety. ,

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In summary, the present invention relates to novel o-haloalkyl-haloacetanilide compounds and to processes for their preparation. The compounds are useful as intermediates for the preparation of N-substituted 2 ', (S'-disubstituted 2-haloacetanilide derivatives which control unwanted vegetation in agricultural crops.

The following examples illustrate in more detail how the compounds according to the invention can be prepared.

embodiments

* Example 1

Preparation of 2 * _> 6 ^> bis (1-bromoethyl) -2-bromo-N-methyla cetanilide

2-Chloro-N-methyl-2 ', 6'-di-ethylacetanilide (23.9 g, 0.1 mol) was added along with 0.2 g of benzoyl peroxide to 100 ml of carbon tetrachloride. After being heated to reflux, 16.0 g of bromine (0.2 mol) in 50 ml of carbon tetrachloride was added dropwise to the mixture, which was then subjected to both irradiation with an internal UV source and an external source of white light. The solvent was removed in vacuo and the crude product dissolved in ethyl acetate.

 II

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The solid product was repeatedly recrystallized from ethyl acetate to give 2 ¹ -, 6'-bis (1-bromoethyl) -2-bromo-N-methylacetanilide; Melting point 162 ° to 16 * I ^O C.

Analysis for Ο ^, Η ^ Βγ, ΝΟ:

Calculated: C 35.32%, Br ^ 5, 24 2, N 3.17 ti Found: C 35.18 Jf, Br ^ 5, 29%, N 3.16%.

Example 2

Preparation of 2 '- (Broinmethyl) -6- ^t- tert-butyl-2-bromo-N-methylacetanilide

To 38.0 g (0.15 mol) of 2-chloro-N-2'-dimethyl-6 "-tert-butyiacetanilide (38 g, 0.15 mol) dissolved in carbon tetrachloride was added 0.2 g of benzoyl peroxide and the mixture heated to reflux temperature. To the above mixture, bromine (2 x 1.0 g, 0.15 mol) in 50 ml of carbon tetrachloride was added dropwise, maintaining during the addition (1-1 / 2 hours) and then at reflux temperature (1/2 hour ). This was stripped off to remove the solvent. Scratching with a glass rod solidified the residue. The product was recrystallized from heptane and identified as 2 '- (bromomethyl) -e'-tert-butyl-bromo-N-methylacetanilide; Melting point 86 ° to 87 ⁰ Cj yield 65% * Analysis for C ₁ UH ₁

i 9 91 O

Calculated: C 44.59 %> Bi- 42.38 *, N 3.71 %; Found: C 4 $, 62 f $ Br 42.27 %, N 3.72 JL

Example 3 Preparation of 2 ~ Chloro-N _> 2 ^t , ^ '^

2-Chloro-N- (chloromethyl) -2 *, ^6f -dimethylacetanilide (0.04 mol, 10g) was added along with 0.14g of benzoyl peroxide to 100ml of carbon tetrachloride and the mixture exposed to an inner UV light source of 0.2 A and an external white light source of 150 W heated to reflux. To this mixture, 13 g of bromine in 50 ml of carbon tetrachloride were added, after addition of the theoretical amount of bromine additionally an additional 3j0 g of bromine was added. The mixture was cooled, the solvent removed and the resulting viscous oil triturated with ether to give a solid. NMR analysis indicated that the solid was crude 2-chloro-N-2 ·, 6 ^f -tris (cf. bromomethyl) -acetanilide acted. The crude product was not further purified, but was subsequently treated with 200 ml of boiling methanol, yielding 2 ¹ , 6'-bis (bromomethyl) -2-chloro-N- (methoxymethyl) -acetanilide; Melting point 127.5 ° to 129 ° C.

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Example 4

Preparation of 2 ^t - (bromomethyl) -2-chloro-6- ^t -tert.- butylacetilide

2-Chloro-2 ^l -methyl-6- ^t- tert.-butylacetanilide (5.6 g, 0.025 mol) was charged together with 0.15 g of benzoyl peroxide in about 120 ml of carbon tetrachloride and heated to reflux. Bromine ( ² μl, 0.025 mole) in 50 ml carbon tetrachloride is added dropwise. After the addition, the reaction, which was monitored by NiIR analysis, appeared to be complete. After removal of the solvent in vacuo, 7.0 g of a white solid were recovered. After subsequent recrystallization from isopropanol, the product, namely 2 '- (bromomethyl) -2-chloro-6 ^l -tert.-butylacetanilide, had a melting point of 1 * 12 ° to 147 ° C .; Yield 88 %. Analysis for C ^ H ^ BrClNO:

Calculated: C 49.00 Ji, Br 25.08 $, Cl 11.13 % l Found: C 47.93 %, Br 24.50 %, Cl 10.83 *.

Example 5 Preparation of 2-chloro-N, _^2>> 6'-tris (chloromethyl) -acetanilld

2-Chloro-N, 2 ', 6 ^t -trimethylacetanilide (21.1 g, 0.1 mol) was added to a 500 ml flask to 200 ml of carbon tetrachloride

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given and exposed by an internal UV light source of 0.2 A; Chlorine (0.1 mole, 7.0 g) was introduced with stirring below the surface. The reaction was mildly exothermic, with the temperature rising from 20 ° C to 40 ° C. After all the chlorine was added, a substantially colorless solution was obtained. The mixture was cooled to about 5 ° C and added again 0.1 mol of chlorine. Finally, a third molar equivalent of chlorine was added to the mixture. The material was allowed to stand for about 48 hours. Then the solvent was removed and a viscous oil was obtained. Portions of this oil were recrystallized from pentane / ether to yield crystals identified as 2-chloro-N, 2 ', e'-ethyl) -acetanilide; Melting point 70 ° to 75 ° C. The crude product was not further purified but was directly treated with boiling methanol to afford 2-chloro-K- (methoxyraethyl) -2 ^f, 6'-bis (chlorine thy I) acetanilide. The compound of Example 5 can also be also be prepared using 2-chloro-N- (chloromethyl) -2 ^f are prepared 6'-dimethylacetanilide as a starting material.

Example 6 Preparation of 2 ^f - (bromomethyl) -6 * -tert.-butyl-2-chloro-N-

(Chlorine t hy I) acetanilide

To 17.3 g (0.06 mol) of 2-chloro-N-chloromethyl-2 ^l - (methyl) -6 ^t -

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(tert-butyl) -aeetanilide dissolved in 250 ml of carbon tetrachloride was added 11.2 g (0.063 mol) of recrystallized N-bromosuccinimide (NBS) and 0.25 g of benzoyl peroxide. The resulting mixture was heated to reflux and the 500 ml 3-necked round bottom flask was illuminated by a submergible low amperage UV light source and an external source of white light. The reaction was essentially complete in about 0.5 hours, as determined by monitoring by NMR analysis. After standing at room temperature for a period of about 48 hours, 2.2 g of the product, 2 '- (bromo-tethyl) -6'-tert-butyl-2-chloro-N- (chloromethyl) -acetanilide, was isolated, m.p. ° to 125 ° C An additional amount (7 »9 g) was obtained after partial evaporation of the solvent. The product was not further purified but reacted with methanol to yield 2 '- (bromoethyl) -2-chloro-N- (methoxymethyl) acetanilide.

Example 7

Preparation of 2 '- (bromomethyl) -6 ^L -tert-butyl-2-chloro-N-methylacetanilide

2-Chloro-6 ^I- tert-butyl-N-2'-dimethylacetanilide (17.5 g, 0.069 mol) was dissolved in 250 mL of carbon tetrachloride along with 0.2 g of benzoyl peroxide and 13 g (0.072 mol)

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recrystallized NBS was added, the exposure and flask size being as described in Example 6. The reaction was complete after about 1/2 hour, with succinimide floating on the surface of the carbon tetrachloride solution. The material was filtered off and the filtrate washed with water, then treated in vacuo to remove the solvent. This gave 2Ί, 9 g of residue which recrystallized from hexane gave 14.8 g of product. A second recrystallization from hexane gave 2 '- (bromomethyl) -6 * -ether.-butyl-2-chloro-N-methylacetanilide; Melting point 112 ° to 114 ° C; Yield 63 %. Analysis for C ₁ IjH ₁ BrClNO:

Calculated: C 50.5 ¹ J %, Br 24.02 Ϊ, Cl 10.66 %; Found: C 50.33 %, Br 24.63 % _t Cl 10.61 %.

Example 8 Preparation of 2 ^t - (chloromethyl) -6 ~ ^t methyl - 2 - chlorac etanilid

2 ¹ * 6-dimethyl-2-chloroacetanilide was chlorinated according to the procedure described in method Beiepiel 5 to give a white solid which as 2 '- was identified -6'-methyl-2-chloracetanild (chloromethyl); Melting point 133 ° to 134 ° C

Analysis for C ₁₀ H ₁₁ Cl ₂ NO:

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FROM

Calculated: C 51.7 * %, H 4.77 %, N 6.03 % i Found: C 51.69 %, H 4.66 %, N 6.03 % ·

Match 9

Preparation of 2 * _> 6 ^t --Bis (bromomethyl) -2-chloro-N - (chloromethyl) -acetanilide

2-Chloro-N- (chloro-thy 1) -2 ·, ^6f -dimethylacetanilide (10.0 g, 0.04 mol) was dissolved in 100 mL of carbon tetrachloride along with 0.14 g of benzoyl peroxide. The material was heated to reflux temperature and the flask was exposed by means of an inboard low amperage submersible low voltage light source and an external white light source. To the mixture was added dropwise a solution of 13.0 g of molecular bromine in 50.0 ml of carbon tetrachloride. 3.0 g of additional bromine was added as soon as it was shown by NMR analysis that the reaction was almost complete. The mixture was cooled and the solvent removed in vacuo. The resulting viscous oil was triturated with Xther to yield a solid product which was identified as 2 ', 6 ¹ -bis (bromomethyl) -2-chloro-N- (chloromethyl) -acetanilide. The product was not further purified but treated with boiling methanol to give 2 ', e'-bis-bromomethyl) -2-chloro-N- (methoxymethyl) -aoetanilide.

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- 559 -

Example 10

Preparation before. 2 ^t - (Dibrominethyl) '- 6 ^t -tert-butyl-2-chloroacetanilide

The compound of Example 4 C9> 5 ** β> 0.03 mol) was added to 300 ml of carbon tetrachloride containing 0.3 g of benzoyl peroxide. Two (2) sources of white light were used to irradiate the reaction vessel. Subsequently, 4.8 g of bromine in 50 ml of carbon tetrachloride was added dropwise to the irradiated mixture with some nitrogen bubbled through the reaction medium. The irradiation source was removed after about 1-1 / 2 hours and the mixture was allowed to stand overnight and allowed to cool. The solid precipitate was filtered off and roan received the first fraction 10.4 g and the second fraction 1.4 g. The solid material was recrystallized from isopropanol to yield 2 ^l - (dibromomethyl) -6- ^t -butyl-2-chloroacetanilide; Melting point 145 ° to 147 ° C; Yield 99 2

Analysis for C ₁₃ H ₁₆ Br ₂ ClNO: Calculated: C 39.28 $, H $ 4.06, N 3.52%; Found: C 38.99 S, H 4.10 %, N 3.58 %.

SLO

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Example 11 Preparation of 2 ^> - (bromomethyl) -2 _> 6 ^t dichloroacetanilld

To 300 ml of carbon tetrachloride was added 15.0 g of 2,6'-dichloro-2- ^t- methylacetanilide (0.068 mol) and 0.5 g of benzoyl peroxide to a 500 ml flask. The reaction vessel was irradiated by two external white light lamps. The reaction mixture was heated to reflux and then 10.9 g of bromine (Br ₂ ) in 50 ml carbon tetrachloride was added dropwise while passing nitrogen through. An additional 2.5 grams of bromine was added as soon as the NMR analysis used for monitoring indicated that the reaction was incomplete. The solvent was removed in vacuo and the crude solid recrystallised from isopropanol and then sublimed in vacuo (0.05 mm) to give 2 ¹ - (bromomethyl) -2,6 ^l -dichloroacetanilide; Melting point 155 ° to 159 ° C; Yield 58 %. Analysis for C ₉ HgBrCl ₂ NO:

Calculated: C 36, MO JC, H 2.72 JC, N 4.72 *; Found: C 36.18 Ji, H 2.72 *, N H, 80 Jt.

Example 12

Preparation of 2 ^t - (Brominethyl) - 2 _> ^t- dichloro-6- ^t- tert-butylacetanilide

In a 1 liter flask, 2,3'-dichloro-1'-methyl-6- tert -butylacetanilide (15.0 g, 0.055 mol) was dissolved in 600 ml of carbon tetrachloride. The irradiation was carried out by two external white light sources. The reaction mixture was heated to reflux and then 8.8 g of molecular bromine in 50 ml of carbon tetrachloride was added dropwise, excess solvent was removed in vacuo, and the solid product recrystallized twice. This gave 2 * - (bromomethyl) -2,3'-dichloro-6 ¹ -tert.-butylacetanilide; Melting point 182 ° to 18 $ ° C; Yield 65 *. Analysis for C ₃ -ILgBrCl ₂ NO: Calculated: C $ 4.22 JS, H *, 57 ϊ, Ν 3.97 %; Found: C * »H, 09 $, H ή, 62 % _t N 3.96 %,

Example 13

Preparation of 2 ', 3 * -bis (bromoethyl) -2-chloro-6'-tert-butylacetanilide

In a 1 liter flask, 15 g (0.059 mol) of 2-chloro-2 ', - J'-dimethyl-6 * -tert.-butylacetanilide were dissolved in 6OO ml of carbon tetrachloride. The irradiation was carried out by two

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White light sources. The reaction mixture was heated to reflux temperature, passed through nitrogen and then send 9.44 g (0.059 mol) of elemental bromine in 50 ml of tetrachloride dropwise tetrachloride added. After a two molar molar equivalent of molecular bromine had been added and after about 48 hours, the reaction mixture was filtered and the solid recrystallized from isopropanol. This gave 2 x, 3 ^f bite (bromomethyl) -2-chloro-6 ^! tert-butylacetanilide; Melting point 180 ° to l82 ° C (vacuum sublimation, melting point 195 ° to 197 ° C). Analysis for C ₁₁ JH ₁ QBr ₂ ClNO: Calculated: C 40.85 %, H 4.41 Jf, N 3.40 %; Found: C 40.60 Z, H 4.37 X ₉ N $ 3.40 .

Example 14 Preparation of 2 ^t - (Brosimethyl) -2-chloroacetanilide

2-Chloro-2'-methylacetanilide (4.0 g, 0.02 mol) and N-bromosuccinimide (3.9 g, 0.02 mol) were dissolved in 300 ml of carbon tetrachloride together with 0.3 g of 2,2'- Azobis [2-methyl-propionitrile] dissolved. The mixture was exposed with a lens spotlight and heated at reflux for 2-1 / 2 hours. At this time, the mixture was allowed to cool to room temperature. The mixture was then filtered, washed once with water, getrock- about MgSOj ₁

net, filtered again and stripped off. A white solid was obtained which was recrystallized from toluene.

The yield was 2.2 g (38 %) of product, namely 2 ^f - (bromomethyl) -2-chloroacetanilide; Melting point 125 ° to 127 ° C, analysis for C ₉ H ₉ BrClNO:

Calculated: C 41.17 %, H 3, ¹ Io %, N 5.3 ¹ I % I Found: C 41.35 %, H 3.40 Jt, N 5.30 %.

Example 15 -

Preparation of 2 ^t - (bromomethyl) -6- ^t - (trifluoroethyl) -2-chloroacetanilide

To 300 ml of carbon tetrachloride in a 1 liter flask was added 12.5 g (0.05 KoI) 2 »-methyl-6 '- (trifluoromethyl) -2-chloroacetanilide and 10.0 g (0.056 mol) recrystallized KBS EU. The mixture was held for about 1 to 1-1 / 2 hours at room temperature and then for about 4 to 5 hours at 70 ° to 75 ⁰ C. The crude product was isolated as a solid (mustard agent) and weighed 17.7 g »ümkristallisation from isopropanol afforded 9.8 g of the product, namely 2 ^l - (bromomethyl) -6 ^l - (trifluoromethyl) -2-chloroacetanilide; Melting point 98 ° to 10 ° C; Yield 59.4 %. Analysis for C ₁₀ HgClBrF ₃ O: Calculated: C 36.34 %, H 2.44 %, N 4.24 %; Found: C 35.94 JC, H 2.27 %> N 4.19 %.

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Example 16 Preparation of 2-chloro-N-chloromethylacetanilide

Into a suitable flask equipped with stirrer, gas inlet tube, thermometer and internal low-pressure UV light source was charged 200.0 ml of a carbon tetrachloride solution containing 0.1 mol of 2-chloro-N-methylacetanilide. One molar equivalent of gaseous chlorine was slowly introduced into the flask at room temperature. The solution was then exposed and after a short induction period, the temperature of the solution rose to 38 ^° C. as a result of the exothermic chlorination. The NMR analysis of the carbon tetrachloride solution indicated a complete reaction after a 10% excess of chlorine had been introduced. After vacuum treatment to remove gases and solvent, a 98% yield of 2-chloro-N- (chloromethyl) -acetanilide as a heat-sensitive oil was obtained, which had the following NMR analysis data: (CDCl ₃ ), δ 3.9 (s, 2H , ClCH ₂ CsO), β 5.55 (s, 2H, ClCH ₂ N), δ 7.6 (broad s, 5H, ArH).

It has been found that the compounds of the present invention have herbicidal activity and also as intermediates for the preparation of certain o- (alkoxy

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methyl) -2-haloacetanilides which are effective herbicides. The process by which these latter compounds are prepared involves reacting the compounds of general formula I described above with an alcohol, preferably in the presence of metal cations, eg potassium, sodium, silver, lead, mercury, etc., or other Lewis acids. Acids, for example A1C1 ·, SnCljj, ZnCl ₂ , etc. When using the new compounds of the general formula I, it was found that the halogen attached to the o-haloalkyl groups, in particular halomethyl, to the (benzylic) ring portion of 2-haloacetanilide -MolekOls the general formula I, can be selectively replaced by a suitable alcohol without disturbing the otherwise labile 2-acetyl halide.

Although the present invention has been described with reference to a specific modification, it is not intended that the individual embodiments be construed as limiting, as it is obvious that numerous equivalents, changes, and codifications may be made, all within the scope of the present invention and it is to be understood that such equivalent embodiments are included in the present invention.

Claims (22)

He invention claim 1. A process for the preparation of o-haloalkyl-2-haloacetanilide derivatives of the general formula O * C-CH ₂ X. R-N in which the index η has the value O or 1, wherein in the case where η has the value 1, X is chlorine, bromine or iodine, R is hydrogen, methyl, chloromethyl or bromomethyl, R is hydrogen, halogen, methyl, tert-butyl, trifluoromethyl or a radical of the following general formula X ²  I 2 -C-R * R, chlorine, bromine or straight-chain alkyl with 1 to 4 carbon atoms, 12 Y and Y, independently, hydrogen; Halogen, 21 9 9tO Methyl, tert-butyl, trifluoromethyl or a radical of the following general formula Il X and X, independently of one another, denote hydrogen, chlorine or bromine, provided that, if R is straight-chain alkyl having 1 to ¹ J carbon atoms, only one of the radicals X and X ² 'may denote chlorine or bromine, and further provided that that R ² , X and X can not simultaneously be chlorine or bromine, and in the case where η is 0, YR is chloromethyl, R is hydrogen, trifluoromethyl or halogen, Y and Y, independently of one another, are hydrogen or halogen and R Is hydrogen, characterized in that a compound of general formula II O = C-CH ₂ X. R-N (ID in which the index η has the value 0 or 1, wherein if η is 1, R, X, Y ¹ and Y ^{2 are} the same 2 · 219 910 Meaning as in the general formula I, R "is hydrogen, halogen, methyl, tert-butyl, trifluoromethyl or a radical of the general formula below -rC-R " ¹ H and R ^{w is} hydrogen or straight-chain alkyl of 1 to 4 carbon atoms, and wherein if η is 0 L_X_Chf. pr, Srürn or fed j } jR is methyl, R "is hydrogen, trifluoromethyl or halogen, Y and Y, independently of one another, are hydrogen or halogen, and R ¹ " is hydrogen, with a halogenating agent in the presence of a halogenating inert solvent and using radiation implemented by an ultraviolet and / or white light source. 2 «method according to item 1, characterized in that the solvent is carbon tetrachloride. 3. The method according to item 2, characterized in that the halogenating agent is molecular chlorine. 21 9 91 ή. Process according to item 2, characterized in that the halogenating agent is molecular bromine. 5. The method according to item 2, characterized in that the halogenating agent is N-bromosuccinimide. 6. The method according to item!, Characterized in that in the compound of general formula II, the index n has the value 1. 7. Method according to point "f, marked in that, in the compound, the general porosity odecj
mel II R "is hydrogen, halogen, methyl, tert-butyl-trifluoromethyl 8. The method according to item 7, characterized in that in the compound of general For mel II R "is methyl, chlorine, tert-butyl or trifluoromethyl. 2! 9,910 9. The method according to item -8, '', characterized in that in the compound of general formula II R "is methyl. 10. The method according to item 8, characterized in that in the compound of general formula II R "trifluoromethyl. 11. The method according to item 8, characterized in that in the compound of general formula II R "tert-butyl. 12. The method according to item 8, characterized in that in the compound of the general formula II Y ¹ and Y ^{2 are} hydrogen. 13. The method according to item 8, characterized in that in the compound of general formula II Y ^{1 is} hydrogen and Y ^{2 is} chlorine. 1Ί. Process according to item 2, characterized in that in the compound of general formula II R " ^{1 is} straight-chain alkyl having 1 to Ί carbon atoms. -7 * 2.- 219,910 Method according to item 14, characterized in that in the compound of general formula II R ^{m is} ethyl. 16. The method according to item 1, characterized in that the Reaktionssteiiiperatur is reflux temperature or in the vicinity of the reflux temperature. 17. The method according to item 1, characterized in that the index η in the compound of general formula II has the value 0. 18. The method according to item 17, characterized in that in the compound of general formula II R ", Y ¹ and Y ^{2 are} hydrogen. 19. The method according to item 17, characterized in that in the compound of general formula II R ^{w is} chlorine or bromine, and Y ¹ and Y are hydrogen. 20. Method according to item 17, I denote η ei., Characterized in that in the compound of general formula II R "trifluoromethyl, and Y ¹ and Y ^{2 are} hydrogen. 21. The method according to item 1, characterized 21 9,910 in that the compound of general formula I is 2 '- (bromomethyl) -2-chloro-6' - (trifluoromethyl) acetanilide. 22. The method according to item 1, characterized in that the compound of general formula I is 2-chloro-2 '- (chloromethyl) -6 ^f - (trifluoromethyl) acetanilide is. 23. The method according to item 1, characterized in that the compound of general formula I 2 ^t - (bromomethyl) -2-chloro-6 ^l -methylacetanilid. 24. The method according to item 1, characterized in that the compound of general formula I is 2-chloro-2 ^f - (chloromethyl) -6'-methylacetanilide. 25. The method of item, characterized in that the compound of general formula I is 2-chloro-2 '- (dichloromethyl) -6 ^f - (trifluoromethyl) acetanilide is. 26. The method according to item 1, characterized in that the compound of general formula I is 2-chloro-N- (chloromethyl) -acetanilide. -TH-