FR2491462A1 - Halomethyl-halo:acetanilide derivs. prepn. - including new cpds., useful as herbicide intermediates - Google Patents

Abstract

Prepn. of haloacetanilides of formula (I) is carried out by reacting cpds. of formula (II) with a halogenating agent in an inert solvent while irradiating with UV and/or white light. In (I), (a) n = 1; X is Cl, Br or I; R is H, Me, CH2Cl or CH2Br; R1 is H, halogen, Me, t-Bu, CF3 or CX1X2R2; R2 is H, Cl, Br or 1-4C n-alkyl; Y1 and Y2 are H, halogen, Me, t-Bu, CF3 or CX1X2R2;X1 and X2 are H, Cl or Br, provided that only one of X1 and X2 can be H, Cl or Br (sic) when R2 is 1-4C-n-alkyl, and that R2, X1 and X2 cannot all be Cl or Br; R" is H, halogen, Me, t-bu, CF3 or CH2R'"; R'" is H or 1-4C n-alkyl; R' is H, Me, CH2Cl or CH2Br; or (b) n = 0; X is not defined; R is CH2Cl; R1 is H, CF3 or halogen; Y1 and Y2 are H or halogen; R2 is H; R' is Me; R" is H, CF3 or halogen; R'" is H. Cpds. (I; n = 1) are new. (I) are intermediates for herbicidal o-alkoxymethyl-2-haloacetanilides; they are also stated to have herbicidal activity themselves.

Description

 The present invention relates to new ortho- (haloalkyl) -2-haloacetanilide derivatives and to their process of preparation. The new compounds are useful as intermediates in the preparation of certain ortho- (alkoxymethyl) -2-haloacetanilide derivatives which exhibit selective herbicidal activity.

 US Patent No. 4,070,389 generically describes the herbicidal use of certain chloroacetanilides among which there are certain N-substituted-2 ', 6' - (haloalkyl) - 2-chloroacetanilides. However, US Patent No. 4,070,389 does not teach those experienced in the art how to make or use the compounds mentioned above, but directs those experienced in the art to certain "published German patent applications" for their preparation and use. The following references are mentioned: published German patent applications No. 2,212,268, No. 2,305,495, No. 2,328,340, No. 2,402,983, No. 2,405,183 and No. 2,405,479.

Those experienced in the art will recognize that none of the references mentioned above describe
N-substituted-2 ', 6' - (haloalkyl) -2-chloroacetanilides. The only reference which suggests these compounds from afar is the published German patent application no. 2,405,479, which corresponds to the British patent no. 1,455,474.

British Patent No. 1,455,474 generically describes the herbicidal use of N- (2-methoxyethyl) - or
N -ethoxyethyl) -2 '- (trifluoromethyl) -6'-alkyl-2-chloroac6- tanilides. As examples of this type of anilides, there are also those described in US Patent No. 4,152,137.

British Patent No. 1,455,474 does not teach compounds of the type shown here, i.e., N-methyl-, N- (bromomethyl) - or N-tchloromthyl) -ortho- (haloalkyl) -2-haloacetanilides.

 With regard to the process for preparing the co-poses of the British patent mentioned above, the substituents on the phenyl ring of the compounds described by this patent must be introduced on the ring before the reactions on the amino group are carried out. Thus, materials made up of appropriately substituted anilines are reacted to give the desired haloacetanilides.

 There is no teaching in this reference concerning the new process described here, that is to say the selective halogenation of substituents ortho on the nucleus and / or of the N-alkyl substituent group of 2-haloacetanilides.

 The prior art describes bromination of orthomethylacetanilide using N-bromosuccinimide (NBS) .ZE. G. Xleinschmidt, et al., PRARMAZIE, 24 (2), pages 87-94, 19693. However, unlike the new process indicated here, the bromination process described in the reference mentioned above occurs entirely on the phenyl group, that is, only bromination on the nucleus is observed when the nucleus has an ortho-alkyl substituent.

 Ulrich and colleagues in J. ORG. CHEZ., 39 (19), pages 2897-2899, 1974 describe the preparation of N- (chloromethyl) -N-phenylcarbamoyl chloride via the monochlorination of N-methyl-N-phenylcarbamoyl chloride, in the presence of ultraviolet light .

 The present invention relates to certain or tho! Haloalkyl) -2-haloacetanilides which are intermediates in the preparation of certain substituted ortho- (alkoxy-methyl) -2-haloacetanilides which are useful herbicides.

où n est égal a zéro ou un; quand n vaut un
X est le chlore, le brome ou l'iode;
R est l'hydrogène, le groupe méthyle, chlorométhyle, ou bromométhyle;
R1 est l'hydrogène, un halogène, le groupe méthyle, t-butyle, trifluorométhyle ou

The compounds of the present invention have the formula

where n is zero or one; when n is worth one
X is chlorine, bromine or iodine;
R is hydrogen, methyl, chloromethyl, or bromomethyl;
R1 is hydrogen, halogen, methyl, t-butyl, trifluoromethyl or

R2 is chlorine, bromine or a straight chain alkyl group containing 1 to 4 carbon atoms;
Y1 and Y2 independently represent hydrogen, halogen, methyl, t-butyl, trifluoromethyl or

 X1 and X2 independently represent hydrogen, chlorine or bromine parts, provided that when R2 represents a straight chain alkyl group containing 1 to 4 carbon atoms, only one of X1 and X2 can be hydrogen, chlorine or bromine and, in addition, provided that R2, X1 and X2 cannot simultaneously be chlorine or bromine; when n is zero, X is chlorine, bromine or iodine, R is chloromethyl group, R1 is hydrogen, trifluoromethyl group or halogen; Y1 and YS independently represent hydrogen or halogen and R2 is hydrogen. Compounds with the formula given above are new when n is one.

 When the expression "straight chain alkyl group containing 1 to 4 carbon atoms" is used here, we are referring to the methyl, ethyl, n-propyl and n-butyl groups.

 The term "halogen" refers to the chlorine, bromine, fluorine and iodine atoms. Chlorine and bromine are preferred for use in the present invention.

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

In the compounds of formula I, n, X, R, R1, R2,
X1, X2, Y1 and Y2 are as defined previously.

In the compounds indicated by formula II, the following meanings are given to the various substituent groups
when n is equal to one,
R, X, Y1 and Y2 have the meanings previously indicated;
R "is hydrogen, halogen, t-butyl, trifluoromethyl or
H -CR "';
H
R "'is hydrogen or a straight chain alkyl group containing 1 to 4 carbon atoms; when n is zero, X is chlorine, bromine or iodine, R is methyl;
R "is hydrogen, trifluoromethyl group or halogen;
Y1 and Y2 independently represent hydrogen or a halogen, and
R "'is hydrogen.

 According to the reaction scheme indicated above, the appropriate starting material, that is to say a compound of the type described by formula II, is dissolved in a suitable volume of an inert solvent vis- with respect to halogenation. Examples of suitable solvents are carbon tetrachloride, chloroform, petroleum ether, methylene chloride and the like. Carbon tetrachloride is preferred for use here. At this point, a catalyst, for example benzoyl peroxide, can be added to the mixture to facilitate the reaction. The use of this catalyst is, however, optional, and is not necessary in the practice of the process. To this mixture is added an equivalent stoichiometric amount of a halogenating agent selected from the group se component of molecular chlorine, molecular bromine, N-bromosuccinimide (NBS) or other N-brominated equivalents, such as, for example, N brorno-N-methylacetamide or N-bromophthalimide. It will be recognized that amounts of the halogenating agent may be used with equal ease in the practice of this process greater than the equivalent stoichiometric amounts. The resulting mixture is subjected to external and / or internal ultraviolet radiation and / or white light and the reaction is allowed to proceed. The reactants are usually mixed at room temperature, i.e. about 250C, and then held at or near reflux. However, lower temperatures can be employed as illustrated in the following examples.

 The separation of the resulting reaction product from the reaction mixture is easily carried out by conventional means. For example, the unreacted halogenating agent and the succinimide can be removed by filtration while the solvent can be removed by removal or distillation, preferably vacuum distillation at low temperatures. The product is usually purified by crystallization from suitable solvents.

 The starting materials, i.e. the compounds of formula II, are known in the art, for example from US Pat. Nos. 3,442,945, No. 3,637,847, No. 3,966,811 and from British Patent No. 1,455,474.

 In the process described above, the chlorination or bromination of ortho-alkyl-2-haloacetanilides, in opposition to ortho-alkoxy-2-haloacetanilides, does not give the halogenation of the phenyl nucleus, it is ie halogenation on the nucleus. When halogenation is carried out with molecular chloride using 2 ', 61-dimethyl-N-methyl-2-chloroacetanilide as the starting material, both the Nmethyl group and the methyl (benzylic) groups on the nucleus are chlorinated at comparable speeds. When the orthoalkyl-2-chloroacetanilides described here are subjected to bromination, the process is slower and more selective than chlorination. Thus, for best results, molecular bromine (dissolved in CC14) is added dropwise to a reflux and illuminated solution (ultravio-X-let radiation and / or white light) of amide containing approximately 0.1% of benzoyl peroxide. In general, when 2-halo-N-methyl-2 ', 6'-dialkylacetanilides are brominated using Brz, only the (benzyl) carbon atoms of the side chain of the phenyl ring are brominated.

Bromination with molecular bromine (Br2) of 2-chloroacetanilides of the type described by formula II gives rise to various degrees of mutual halogen exchange, with partial formation of 2-bromoacetanilides. Secondary and tertiary anilides are sensitive to this mutual exchange when prepared in large quantities with higher concentrations of bromine and amide. The bromine in position 2 comes from the mutual exchange of chlorine with
HBr to give HCl. Mutual halogen shedding can be minimized by nitrogen spraying to assist the removal of hydrobromic acid (HBr).

 To avoid the mutual exchange of halogens and still obtain the benefits from bromination, recrystallized Nbromosuccinimide (NBS) or a similar N-bromine equivalent such as, for example, N-bromo-N-methylacetamide, or N- bromophthalimide, possibly with added benzoyl peroxide, is the reactant of choice. Simply equimolar amounts of this properly handled material are required to provide exclusive benzyl bromination on the side chain, with the production of succinimide as a by-product.

 Molecular bromine or NBS bromines an ortho-methyl group exclusively in the presence of an ortho-tbutyl group. Chlorine, on the other hand, is not as selective, but there is some chlorination of the t-butyl portion.

 The manner in which the compounds of the present invention can be prepared is more specifically illustrated in the following examples.

EXAMPLE 1
2 ', 6'-bis (1-bromoethyl) -2-bromo-N- methylacetanilide 2-chloro-N-methyl-2', 6 '-diethylacetanilide (23.9 g, 0.1 mole) ) was placed in 300 ml of carbon tetrachloride with 0.2 g of benzoyl peroxide. After heating to reflux, 16.0 g of bromine (0.2 mole) in 50 ml of CC14 was added dropwise to the mixture, which was then subjected to internal ultraviolet radiation and external white light . Solvent was removed in vacuo and the crude product was dissolved in ethyl acetate. The solid product was repeatedly recrystallized from ethyl acetate to give 2 ', 6'-bis (1 bromoethyl) -2-bromo-N-methylacetanilide, mp 162-164 C.

Analysis calculated for C13Kl6Br3NO: C, 35, 32; Br, 54.24;
N, 3.17.

Found: C, 35.18; Br, 54.29;
N, 3.16.

EXAMPLE 2
Preparation of 2 '- (bromomethyl) -6' -t-butyl-2-bromo-
N-methylacetanilide A 38.0 g (0.15 mole) of 2-chloro-N, 2 'dimethyl-6'-t-butylacetanilide (38 g, 0.15 mole) dissolved in Cl14, 0.2 was added g of benzoyl peroxide and the mixture was heated to reflux. Bromine (24.0 g, 0.15 mole) in 58 ml of CC14 was added dropwise to the mixture indicated above; after addition (1 hour and a half) and subsequent reflux (1/2 hour), the material was removed to remove the solvent. By scraping, the residue solidified, the product was recrystallized from heptane and identified as being 2 '- (bromomehyl) -6'-t-butyl-2-bromo-N-methylacetanilide, pf 86-870C, render'.nt 65%.

Analysis calculated for C14H19Br2N0: C, 44.59; Br, t2.38;
N, 3.71.

Found: C, 44.62; Br, 42.27;
N, 3.72.

EXAMPLE 3
Preparation of 2-chloro-N, 2 ', 6'-tris (bromomethyl) acetanilide 2-chloro-N- (chloromethyl) -2', 6'-dimethylace tanilide (0.04 mole, 10 g) was placed in 100 ml of CC14 containing 0.14 g of benzoyl peroxide and the mixture heated to reflux with internal illumination by ultraviolet radiation of 0.2 amperes and an external white light of 150 watts. To this mixture was added 13 g of bromine contained in 50 ml of CC14; after the theoretical amount of bromine was added, an additional 3.0 g of bromine was added. The mixture was cooled, the solvent removed and the resulting viscous oil triturated with ether to give a solid which, by nuclear magnetic resonance, indicated the presence of 2-chloro-, 2 ', 6'-tris (bromomethyl ) crude acetanilide. The crude product has not yet been purified but has then been treated with 200 ml of boiling methanol to yield 2 ', 6'-bis (bromomethyl) -2-chloro -N- (methoxymethyl) acetanilide, mp 127.5-129 C.

EXAMPLE 4
Preparation of 2 '- (bromomethy) -2-chloro-61-t-butylacetanilide 2-chloro-2'-methyl-6'-t-butylacetanilide (5.6 g; 0.025 mol) was placed in approximately 120 ml of CCl4 with 0.15 g of benzoyl peroxide and heated to reflux. Bromine (4.0 g, 0.025 mole) in 50 ml CCl4 was added dropwise. After addition, the reaction as monitored by nuclear magnetic resonance appeared complete. After removing the solvent in vacuo, 7.0 g of a white solid was recovered. After successive recrystallization from isopropanol, the product, 2 '- (bromomethyl) -2-chloro-6' -t-butylacetanilide, melted at 142 -1470C; yield 88%.

Analysis calculated for C13Hl7BrCl: C, 49.00; Br, 25.08;
Cl, 11.13.

Found: C, 47.93; Br, 24.50;
C1, 10.83.

EXAMPLE 5
Preparation of 2-chloro-N, 2 ', 6'-tris (chloromethyl) acetanilide 2-chloro-N, 2', 6'-trimethylacetanilide (21.1 g, 0.1 mole) was placed in 200 ml CC14 and a source of internal ultraviolet radiation, 0.2 amps, illuminating the interior of a 500 ml flask; chlorine (0.1 mole, 7.0 g) was introduced below the surface with stirring. The reaction was moderately exothermic, the temperature rising from 200C to 40 C. After all of the chlorine had been added, an essentially colorless solution was obtained.

The mixture was cooled to about 50C and another 0.1 mole of chlorine was added. Finally, a third molar equivalent of chlorine was added to the mixture. The master was allowed to stand for approximately 48 hours. Then the solvent was removed to give a viscous oil. Parts of this oil were recrystallized from pentane-ether to give crystals identified as 2-chloro-N, 2 ', 6' -tris (chloromethyl) acetanilide, m.p. 70-750C. The crude product has not yet been purified but has been directly treated with boiling methanol to produce 2-chloro-N (methoxymethyl) -2 ', 6'-bis (chloromethyl) acetanilide. The compound of Example 5 can also be prepared using 2-chloro-N- (chloromethyl) -2 ', 6' -dimethylacetanilide as the starting material.

EXAMPLE 6
Preparation of 2 '- (bromomethyl) -6' -t-butyl-2-chloro- N- (chloromethyl) acetanilide A 17.3 g (0.06 mole) of 2-chloro N-chloromethyl-2 '- (methyl ) -6 '- (t-butyl) acetanilide dissolved in 250 ml of CC14, 11.2 g (0.063 mole) of recrystallized Nbromosuccinimide (NBS) and 0.25 g of benzoyl peroxide were added. The resulting mixture was heated to reflux and the 500 ml three-necked round bottom flask was illuminated with ultraviolet radiation, applied with immersion, low amperage and external white light. The reaction, as monitored by nuclear magnetic resonance, was essentially completed in about half an hour.

By standing at room temperature for about 48 hours, 2.2 g of the product, 2 '- (bromomethyl) -6'-t-butyl-2-chloro-N- (chloromethyl) acetanilide, ottoman. 124-1250C has been isolated.

An additional amount (7.9 g) was recovered by partial evaporation of the solvent. The product has not yet been purified but reacted with methanol to provide 2 '(bromomethyl) -2-chloro-N- (methoxymethyl) acetanilide.

 EXAMPLE 7 Preparation of 2 '- (bromomethyl) -6' butyl-2-chloro-N-methylacetanilide 2-chloro-6'-t-butyl-N, 2'-dimethylacetanilide (17.5 'g , 0.069 mole) was dissolved in 250 ml of CC14 with 0.2 g of benzoyl peroxide and 13 g (0.072 mole) of recrystallized NBS using lighting and. the flask size as described in Example 6. The reaction was completed in about half an hour, the succinimide floating over the CCl4 solution. The material was filtered and the filtrate washed with water, and then treated in vacuo to remove the solvent to provide 24.9 g of residue. The residue was recrystallized from hexane to give 14.8 g of product , and a second recrystallization from hexane provided 2 '- (bromomethyl) -6'-t-butyl-2-chloro-N-methylacetanilide, pf ll2-1I40C; yield 63%.

Analysis calculated for C14H19Br C1 NO: C, 50.54; Br, 24.02; C1,10,66.

Found: C, 50.33; Br, 24.63;
C1, 10.61.

EXAMPLE 8
Preparation of 2 '- (chloromethyl) -6'-methyl-2-chloroacetanilide Du 2', 6'-dimethyl-2-chloroacetanilide was chlorinated according to the procedure described in Example 5 to provide an identified white solid as 2 '- (chloromethyl) -6'-methyl-2-chloroacetanilide, mp 133-134 C.

Analysis calculated for CloH11C12NO: C, 51.74; H, 4.77;
N, 6.03.

Found: C, 51.69; H, 4.66;
N, 6.03.

EXAMPLE 9
Prezration of 2 ', 6'-bis (bromornethyl) -2-chloro-N- (chlorometyl) acetanilide 2-chloro-N- (chloromethyl) -2', 6'-dimethylacetanilide (10.0 g, 0 , 04 mole) was dissolved in 100 ml of CCl4 with 0.14 g of benzoyl peroxide. The material was heated to reflux and the flask lit by ultraviolet radiation applied by imTersion, at low amperage, and outside white light. To the mixture was added dropwise 13.0 g of molecular bromine contained in 50.0 ml of CCl4. An additional 3.0 g of bromine was added when nuclear magnetic resonance indicated that the reaction was almost complete. The mixture was cooled and the solvent removed in vacuo. The resulting viscous oil was triturated with ether to give a solid, identified as 2 ', 6'-bis (bromomethyl) -2-chloro- N- (chloromethyl) acetanilide. The product has not yet been purified but has been treated with boiling methanol to give 2 ', 6'-bis (bromomethyl) -2-chloro N- (methoxymethyl) acetanilide.

EXAMPLE 10
Preparation of 2 '- (dibromomethyl) -6'-t-butyl-2 chloroacetanilide The compound of Example 4 (9.54 g, 0.03 mole) was added to 300 ml of CC14 containing 0.3 g of peroxide benzoyl. Two white lights were used to irradiate the reaction vessel. Thereafter, 4.8 g of bromine in 50 ml of CCl4 were added dropwise to the irradiated mixture, while maintaining a moderate spray of nitrogen gas into the reaction medium. . The source of radiation was removed after about 1.5 hours, the mixture was allowed to stand and allowed to cool overnight. The solid precipitate was filtered to give 10.4 g of a first crop and 1.4 g of a second crop. The solid material was recrystallized from isopropanol to provide 2 '- (dibromomethyl) - 6 '-t-butyl-2-chloroacetanilide, mp 145-1170C, yield 99%.

Analysis calculated for C13H16Br2Cl NO: C, 39.28; H, 4.06;
a, 3.52.

Found: C, 38.99; H, 4.10;
N, 3.58.

EXAMPLE 11
preparation of 2 '- (bromomethl} -2,6'-dichloroacetanilide 15.0 g of 2', 6'-dichloro-2-methylacetanilide (0.068) were added to 300 ml of CC14 in a 500 ml flask mole) and 0.5 g of benzoyl peroxide. The reaction vessel was irradiated with two exterior white lights.

The reaction mixture was heated to reflux and then 10.9 g of bromine (Br2) in 50 ml of CC14 was added dropwise with nitrogen spray. An additional 2.5 g of Br2 was added when monitoring by nuclear magnetic resonance indicated that the reaction was incomplete. The solvent was removed in vacuo and the crude solid was recrystallized from isopropanol and then sublimed in vacuo (0.05 mm Hg) to provide 2 '- (bromomethyl) 2,61-dichloroacetanilide, m.p. 155-1590C, yield 58%.

Analysis calculated for -C9H8BrCl2 NO: C, 36.40 R, 2.72;
N, 4.72.

Found: C, 36.18; H, 2.72;
N, 4.80.

EXAMPLE 12
Preparation of 2 '- (bromomethyl) -2,3'-dichloro-6'- t-butylacetanilide In a 1 liter flask, 2,3'-dichloro-2'-methyl- was dissolved in 600 ml of CCl4 6'-t-butylacetanilide (15.0 g, 0.055 mole). The irradiation was provided by two exterior white lights. The reaction mixture was heated to reflux and then 8.8 g of molecular bromine in 50 ml of CC14 was added dropwise. The excess solvent was removed in vacuo and the solid product was twice recrystallized to provide 2 '- (bromomethyl) -2,3'-dichloro-6'-t-butylacetanilide, mp 1821840C, yield 65%.

Analysis calculated for C13H16BrCl2 NO: C, 44.22; E, 4.57;
N, 3.97.

Found: C, 44.09; H, 4.62;
N, 3.96.

EXAMPLE 13
Preparation of 2 ', 3'-bis (bromomethyl) -2-chloro-6'- t-butylacetanilide In a 1 liter flask, 15 g (0.059 mole) of 2-chloro- were dissolved in 600 ml of CC14 2 ', 3'-di methyl-6'-t-butylacetanilide. The irradiation was provided with two streams of white light. The reaction mixture was heated to reflux, sprayed with nitrogen and then 9.44 g (0.059 mole) of elemental bromine in 50 ml of CCl4 was added dropwise. After a second molar equivalent of molecular bromine was added, and after approximately 48 hours, the reaction mixture was filtered and the solid recrystallized from isopropanol to give 2 ', 3'bis (bromomethyl) -2-chloro-6'-t-butylacetanilide, pf 1801820C (vacuum sublimation, pf 195-1970C).

Analysis calculated for C14H18Br2Cl NO: C, 40.85; H, 4.41;
N, 3.40.

Found: C, 40.60; H, 4.37;
N, 3.40.

EXAMPLE 14
Preparation of 2 '- (bromomethyl) -2-chloroacetanili - 2-chloro-2'-m8thylacetanilide (4.0 g, 0.02 mole) and N-bromosuccinimide (3.9 g, 0.02 mole ) were dissolved in 300 ml of CC14 with 0.3 g of 2,2'-azobist [2-methyl-propionitrile]. The mixture was cleared with a projector and heated to reflux for 2.5 hours. At this time, the mixture was allowed to cool to room temperature, after which it was filtered, washed once with water, dried over MgSO4, filtered again and removed to provide a white solid. The solid was recrystallized from toluene to give 2.2 g of product consisting of 2 '- (bromomE-thyl) -2-chloroacetanilide, mp 125-1270C, yield 38%.

Analysis calculated for C9H9BrCl NO: C, 41.17; H, 3.46;
N, 5.34.

Found: C, 41.35; - H, 3.40;
N, 5.30.

EXAMPLE 15
Preparation of 2 '- (bromomethyl) -6' - (trifluoromethyl) -2-chloroacetanilide A 12.5 g (0.05 mole) of 2'-methyl-6 '- (trifluoromethyl) -2-chloroacetanilide, we have added 300 ml of carbon tetrachloride and 10.0 g (0.056 mole) of recrystallized NBS in a 1 liter flask. The mixture was kept at room temperature for about 1 hour-1.5 hours and then kept at 70-750C for about 4-5 hours. The crude product supplied was isolated as a solid product (vesicant product) in an amount of 17.7 g; recrystallization from isopropanol provided 9.8 g of a product consisting of 2 '- (bromomethyl) -6' - (trifluoromethyl) -2-chloroacetanilide, mp 98-101 C t yield 59.4% .

Analysis calculated for ClOH8ClBrF30: C, 36.34; H, 2.44,
N, 4.24.

Found: C, 35.94 H, 2.27
N, 4.19.

6 5,55 (s, 2H, C1CH2N),6 7,6 (large s, 5, ArH).EXAMPLE 16
Preparation of 2-chloro-N-chloromethylacetanilide
200.0 ml of a CC14 solution containing 0.1 mole of 0.1 ml of carbon dioxide was introduced into a suitable flask provided with a stirrer for a gas delivery tube, a thermometer and internal ultraviolet light at low pressure. 2-chloro-N-methyl-acetanilide. A molar equivalent of chlorine gas was slowly introduced at room temperature into the flask, the solution was then lit and, after a short priming period, the temperature of the solution rose to 38 C as a result of the chlorination exotherm. The nuclear magnetic resonance of the CCl4 solution showed a complete reaction after a 10% excess of chlorine had been introduced. By vacuum treatment to remove the gases and the solvent, a yield of 98% of 2- chloro-N (chloromethyl) acetanilide in the form of a heat-sensitive oil, which had the following nuclear magnetic resonance data (CDC13), 6 3.9

6 5.55 (s, 2H, C1CH2N), 6 7.6 (broad s, 5, ArH).

 The compounds of the present invention have been found to exhibit herbicidal activity and are also useful as intermediates for the preparation of certain ortho (alkoxymethyl> -2-haloacetanilides which are effective herbicides. The process by which the latter compounds are prepared involves reaction of the compounds described above, having the formula I, with an alcohol, preferably in the presence of metal cations, for example potassium, sodium, silver, lead, mercury, etc. or other acids of Lewis, for example AlC13, SnC14, ZnC12, etc. Using the new compounds of formula I, it has been found that halogen on ortho-haloalkyl groups, especially the halomethyl group, attached to the benzyl part of the nucleus of the 2-haloacetanilide molecule of formula I could be selectively replaced by an appropriate alcohol, without disturbing the otherwise mobile halogen of the 2-acetyl group.

 The present invention is not limited to the examples of embodiment which have just been described, it is on the contrary liable to variants and modifications which will appear to those skilled in the art.

Claims (17)

1 - Process for the preparation of compounds having the formula

 where n is zero or one; when n is one: X is chlorine, bromine or iodine;  R is hydrogen, methyl, chloromethyl or bromomethyl;  R1 is hydrogen, halogen, methyl, t-butyl, trifluoromethyl, or

 Y1 and Y2 independently represent hydrogen, halogen, methyl, t-butyl, trifluoromethyl or  R2 is chlorine, bromine or a straight chain alkyl group containing 1 to 4 carbon atoms;

Y1 and Y2 are as defined in formula I; R "is hydrogen, halogen, t-butyl, trifluoromethyl or  where n is zero or one; when n is equal to one, R, X,

R1 is hydrogen, the trifluoromethyl group or a halogen, Y1 and Y2 independently represent hydrogen or a halogen and R2 is hydrogen, characterized in that it consists in reacting a compound having the formula  X1 and X2 independently represent hydrogen, the chlorine or bromine parts, provided that, when R2 is a straight chain alkyl group containing 1 to 4 carbon atoms, only one of X1 and X2 can be chlorine or bromine, and , in addition, provided that R2, X1 and X2 cannot simultaneously be chlorine or bromine; when n is zero, X is chlorine, bromine or iodine, R is the chloromethyl group, R "'is hydrogen or a straight chain alkyl group containing 1 to 4 carbon atoms; when n is zero, X is chlorine, bromine or iodine, R is methyl, R" is I' hydrogen, the trifluoromethyl group or a halogen; Y1 and Y2 independently represent hydrogen or a halogen and R "'is hydrogen, with a halogenating agent in the presence of a solvent inert with respect to halogenation and in the presence of irradiation from a source of ultraviolet radiation and / or a source of white light.  2 - Process according to claim 1, characterized in that the solvent is carbon tetrachloride.  3 - Process according to claim 2, characterized in that the halogenating agent is molecular chlorine or molecular bromine or N-bromosuccinimide.  4 - Method according to claim 1, characterized in that, in formula II, n is one.  5 - Process according to claim 1, characterized in that, in the compound of formula II, R "is hydrogen, a halogen, the methyl group, t-butyl or trifluoromethyl.  6 - Process according to claim 5, characterized in that, in the compound of formula II, R "is the methyl group, chlorine, the t-butyl or trifluoromethyl group.  7 - Process according to claim 6, characterized in that, in the compound of formula II, R "is the methyl group, or the trifluoromethyl group, or the t-butyl group.  8 - Process according to claim 6, characterized in that, in the compound of formula II, Y1 and Y2 represent hydrogen.  9 - Process according to claim 6, characterized in that, in the compound of formula II, Y1 is hydrogen, and Y2 is chlorine.  10 - Process according to claim 2, characterized in that, in the compound of formula II, R "'is a straight chain alkyl group containing 1 to 4 carbon atoms.  11 - Process according to claim 10, characterized in that, in the compound of formula II, R "'is the ethyl group.  12 - Process according to claim 1, characterized in that the reaction temperature is the reflux temperature or in the vicinity of this temperature.  13 - Process according to claim 1, characterized in that, in the compound of formula II, n is zero.  14 - Process according to claim 13, characterized in that, in the process of formula II, R ", Y1 and Y2 represent hydrogen.  15 - Process according to claim 13, characterized in that, in the compound of formula II, R "is chlorine or bromine and Y1 and Y2 represent hydrogen.  16 - Process according to claim 13, characterized in that, in the compound of formula II, R "is the trifluoromethyl group and Y1 and Y2 represent hydrogen.  17 - Process according to claim 1, characterized in that the compound of formula I is chosen from the group consisting of 2 '- (bromomethyl) -2-chloro-6' - (trifluoromethyl) acetanilide, of 2-chloro -2 '- (chloromethyl) -6 "- (trifluoromethyl) acetanilide, 2' - (bromomethyl) -2-chloro-6'-methyl-acetanilide, 2-chloro-2 '- (chloromethyl) -6 '-methylacetanilide, 2-chloro-2' - (dichloromethyl) -6 '- (trifluoromethyl) acetanilide and 2-chloro-N- (chloromethyl) acetanilide.