DE19650199A1 - Polyhalogenhexenes, their production and the production of halogenated C¶4¶ carboxylic acids therefrom - Google Patents

Abstract

This invention concerns new polyhalogen hexenes of the formula (I): CF2X-CFX-CH2-CH=CHR-CH2X, in which the groups X can be the same or different and any of which can stand for chlorine, bromine or iodine and R for hydrogen, C1-C6 alkyl or C3-C7 cycloalkyl. They can be produced by reacting hexahalogen ethanes with butadiens in the presence of a catalyst and a solvent. Halogenated C4 carboxylic acids of the formula (V): X-CH2-COOH, in which Y stands for CF2X-CFX- or CF2=CF-, where X has the same meaning as for formula (I), are produced by reacting a polyhalogen hexene of formula (I) in the presence of a solvent with ozone and subsequently oxidizing it in acidic environment and, when producing halogenized C4 carboxylic acid of formula (V) with Y = CF2=CF-, an additional alpha , beta elimination is carried out.

Description

The present invention relates to new polyhalohexenes, a process for the preparation of polyhalohexenes from hexahalogenethanes and butadiene and the production of halogenated C ₄ -carboxylic acids from the polyhalohexenes. The halogenated C ₄ -carboxylic acids can be used, for example, as an intermediate for the production of crop protection agents (see EP-A 1 050 777) or of β, γ unsaturated α-amino acids with antibiotic properties (see AL Costel hano et al. Tetrah. Lett. 27, 2435 -2438 (1986)) can be used.

It is known to use polyhalogenated alkanes with the aid of catalysts conjugated alkadienes can add such that there is a 1,4-addition of Halogen atoms and the highly halogenated residue with simultaneous shift the double bond (see B. Boutevin et al. Phosphorus and Sulfur 20, 197-205 (1984) and V.V. Startsev et al. Zh. org. Khim. 21, 1128-1129).

In the reference Boutevin a reactivity sequence of different halo Generated residues of alkyl compounds indicated. Accordingly, it is a terminal Trichloromethyl group of an alkane is significantly more reactive than one positioned there Dichlorofluoromethyl group. Such can practically no longer be implemented.

New polyhalohexenes of the formula (I) have now been found

CF ₂ X-CFX-CH ₂ -CH = CHR-CH ₂ X (I),

in the
the radicals X can be the same or different and each represent chlorine, bromine or iodine and
R represents hydrogen, C ₁ -C ₆ alkyl or C ₃ -C ₇ cycloalkyl.

In formula (I), the X radicals are independently chlorine or bromine and R for hydrogen.

Particularly preferred compounds of the formula (I) are

5-chloro-1,6-dibromo-5,6,6-trifluorohex-2-ene
and

1,5,6-trichloro-5,6,6-trifluorohex-2-ene.

Furthermore, a process for the preparation of polyhalohexenes of the formula (I) was found, which is characterized in that a hexahalogen ethane of the formula

CF ₂ X-CFX ₂ (II),

in the
X has the meaning given for formula (I),
in the presence of a catalyst and a solvent with a butadiene of the formula (III)

CH ₂ = CHR-CH = CH ₂ (III),

in the
R has the meaning given for formula (I).

Preferred and particularly preferred compounds of the formulas (II) and (III) are those in which X and R are those specified in formula (I) drawn and particularly preferred meaning.

Hexahalogenethanes of formula (II) and butadienes of formula (III) are known Compounds and commercially available or by methods known from the literature.  

The compounds of the formulas (II) and (II) can be used, for example, in one Use a molar ratio of (II) to (II) of 0.1 to 100 to 1. Preferably this ratio is from 1 to 10 to 1.

As catalysts in the process according to the invention for the production of Polyhalohexenes e.g. B. metals of main group VIII and subgroups VI and VII, e.g. B. iron, cobalt, nickel, ruthenium, rhodium, palladium, chromium, Molybdenum and / or manganese can be used. The metals can be in elementary Form or in the form of compounds can be used. Suitable connections Examples are oxides, halides, sulfates, sulfites, sulfides, nitrates, acetates, Citrates, carbonates, cyanides and rhodanides as well as complexes with e.g. B. phosphines, Benzoin, benzoylacetate, acetylacetonate, phosphite, nitrile, isonitrile and / or carbon monoxide.

Examples are: iron (II) oxide, iron (II) and iron (IIII) bromides and chlorides, Chlorides of ruthenium, rhodium, palladium, cobalt and nickel, iron (II) - and iron (III) sulfate, iron (III) nitrate, manganese (III) acetate, iron (III) citrate, Ruthenium (II) dichloro-tris-triphenylphosphine, rhodium-tris (triphenylphosphine) - chloride, chromium, nickel, iron (III) -, cobalt (II) -, cobalt (III) - and manganese (II) - acetylacetonate, iron carbonyl-cyclopentadienyl complexes, molybdenum carbonylcyclo pentadienyl complexes, chromium tricarbonylaryl complexes, ruthenium (II) acetateocom plexes, chromium and molybdenum hexacarbonyl, nickel tetracarbonyl, iron penta carbonyl and cobalt and manganese carbonyl.

Metal complexes can optionally be generated in situ, e.g. B. by addition a metal powder or a metal compound and a complexing agent preferably in a stoichiometric ratio.

Mixtures of metals and / or metal compounds and / or other additives can be used. Examples are mixtures of iron powder with Iron (III) chloride (optionally with the addition of carbon monoxide), mixtures of iron (III) chloride and benzoin, mixtures of iron (II) - and / or iron (II) - chloride and trialkyl phosphites and mixtures of iron pentacarbonyl and iodine.

Preferred are iron (II) and iron (III) salts and complexes, iron powder and Iron shavings.  

Mixtures of iron (III) chloride and benzoin are particularly preferred Mixtures of iron powder and iron bromide.

The catalysts can e.g. B. in amounts of 0.01 to 10 mol%, preferably 0.1 up to 5 mol%, each calculated as metal and based on the compound of Formula (II) can be used.

It is advantageous to use a quaternary ammonium compound in addition to the catalyst, e.g. B. one of the formula

N (R ') ₄ ⁺ An⁻ (IV),

in the
the radicals R 'can be identical or different and each represent hydrogen or C ₁ -C ₆ alkyl and
An⁻ means an equivalent of an anion.

1 to 2 of the radicals R 'are preferably hydrogen and the other radicals R' are C ₁ -C ₃ -alkyl. An⁻ is preferably chloride.

Quaternary ammonium compounds can be used, for example, in amounts of 0.01 up to 50 mol%, based on the compound of formula (II). Preferential this amount is from 0.1 to 10 mol%.

The process according to the invention for the preparation of polyhalohexenes is described in carried out a solvent. Suitable solvents are e.g. B. such, in which the catalysts are sufficiently soluble or those with the catalysts Can form complexes and the compared to the starting compounds Formulas (II) and (III) are inert. Examples of such solvents are alkyl nitriles, especially those with 2 to 5 carbon atoms, such as acetonitrile, propionitrile and Butyronitrile, 3-alkoxypropionitrile with 1 to 2 carbon atoms in the alkoxy part such as 3- Methoxyprionitrile and 3-ethoxypropionitrile, aromatic nitriles such as benzonitrile, aliphatic ketones with e.g. B. 3 to 8 carbon atoms such as acetone, diethyl ketone, methyl isopropyl ketone, di-isopropyl ketone and methyl tert-butyl ketone, alkyl and alkoxy alkyl esters of aliphatic monocarboxylic acids with a total of 2 to 6 carbon atoms  such as methyl and ethyl formates, methyl, ethyl, n-butyl and -isobutyl ester and 1-acetoxy-2-methoxyethane, cyclic ethers such as tetrahydro furan, tetrahydropyran and dioxane, dialkyl ethers with 1 to 4 carbon atoms in each Alkyl parts such as diethyl ether, di-n-propyl ether and di-isopropyl ether, N, N-Di alkylamides of aliphatic monocarboxylic acids with 1 to 3 carbon atoms in Acid part such as N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylacet amide, N, N-dimethylmethoxyacetamide, ethylene glycol and diethylene glycol di alkyl ethers with 1 to 4 carbon atoms in each of the alkyl parts, such as ethylene glycol dimethyl, -diethyl and -di-n-butyl ether and diethylene glycol diethyl and -di-n-butyl ether and hexamethylphosphoric triamide.

Preferred solvents are alkyl nitriles with 2 to 5 carbon atoms and 3-alkoxy propionitriles with 1 to 2 carbon atoms in the alkoxy part, especially acetonitrile and 3- Methoxypropionitrile.

The reaction temperature is in the production process according to the invention of polyhalohexenes in general not critical and can continue within Limits vary. The reaction temperatures are preferably between 60 and 200 ° C, especially between 80 and 170 ° C. The reaction can be under pressure or be carried out without pressure. It is preferable to work in a closed one Vessel under the pressure which sets itself at the reaction temperature. As Enamelled autoclaves have proven particularly useful.

The process according to the invention for the production of polyhalogen can be used hexen z. B. perform so that the connection of the in an autoclave Formula (II), the solvent, the catalyst and optionally a quar presents ternary ammonium compound, pumped the compound of formula (III) and for some time after the pumping has ended, e.g. B. 2 to 20 hours, stirring.

Working up the reaction mixture can, for. B. done so that one too next separates solid constituents, the filtrate is washed with water and then the organic phase dries and distils.

The process according to the invention for the production of polyhalohexenes delivers Polyhalogenhexenes of the formula (I) in good yields, selectivities and pure units. This is surprising because, in addition to the desired 1,4 addition of  Compounds of formula (II) to compounds of formula (III) are an abundance other reactions between the two reaction partners possible.

The present invention further relates to a process for the preparation of halogenated C ₄ -carboxylic acids of the formula

Y-CH ₂ -COOH (V),

in the
Y stands for CF ₂ X-CFX- or CF ₂ = CF-, where X has the meaning given for formula (I),
which is characterized in that a polyhalohexene of the formula (I) is reacted with ozone in the presence of a solvent and then oxidized in an acid medium and in the case of the production of halogenated C ₄ -carboxylic acids of the formula (V) with Y = CF ₂ = CF- still performs an α, β elimination.

Chlorinated hydrocarbons, for example, come as solvents for this with, for example, 1 to 4 carbon atoms, such as dichloromethane, chloroform, Carbon tetrachloride, dichloroethane, trichloroethane and tetrachloroethane and Alcohols with, for example, 1 to 6 carbon atoms, such as methanol, ethanol, propanols and butanols. Mixtures of chlorinated hydrocarbons and Take alcohol.

The reaction with ozone can, for example, at temperatures in the range -50 up to + 50 ° C. It is preferred to work at 0 to 30 ° C. ozone is preferably at least in the stoichiometrically required amount for example in an amount of 1 to 2 mol, based on the polyhalohexene of formula (I) used.

The subsequent oxidation can in principle be carried out with any oxidizing agent which is suitable for converting an aldehyde function into a carboxylic acid function. Oxygen, ozone, hydrogen peroxide, percarboxylic acids or mixtures of hydrogen peroxide and acids are preferably used. The oxidizing agent is preferably used at least in the stoichiometrically required amount, for example in an amount of 1 to 5 mol / mol of polyhalohexene of the formula (I) used. A mixture of hydrogen peroxide and a C ₁ -C ₄ carboxylic acid is preferably used.

The oxidation can e.g. B. at temperatures in the range of 20 to 120 ° C, preferably 50 to 100 ° C, are carried out.

It is often advantageous to mix the reaction mixture between the ozone treatment and the oxidation in a vacuum.

From the reaction mixture present after the oxidation, the halogenated C ₄ -carboxylic acid of the formula (V) with Y = CF ₂ X-CFX- can be isolated, for example, by pouring the reaction mixture onto ice, with a water-immiscible solvent, e.g. B. a di-C ₁ -C ₄ alkyl ether, extracted, the organic phase is separated and the extractant is withdrawn from the organic phase.

The α, β-elimination additionally required for the production of halogenated C ₄ -carboxylic acids of the formula (V) with Y = CF ₂ = CF- can, for. B. with zinc powder in the presence of water at temperatures between -10 and 30 ° C and with good cooling. To work up the resulting reaction mixture can z. B. separate the solid components, extract the rest with an organic, water-immiscible solvent and separate the organic phase and free it from the extractant.

From the C ₄ carboxylic acid of the formula (V) with Y = CF ₂ = CF - obtainable as described above, a wide variety of derivatives can be prepared in a manner known per se, for example those of the formula

in the
Z for fluorine, chlorine or bromine,
R 'is hydrogen or C ₁ -C ₈ alkyl and
R ² for -CO-OR ³ or

stand,
in which
R ^{3 represents} hydrogen, C ₁ -C ₈ alkyl, C ₆ -C ₁₀ aryl or C ₄ -C ₉ hetaryl with up to 2 heteroatoms from the group consisting of oxygen, sulfur and nitrogen and
R ⁴ and R ^{5 are} identical or different and each represent C ₁ -C ₈ alkyl or together represent - (CH ₂ ) _n - with n = 2 to 6.

The C ₄ carboxylic acid of the formula (V) with Y = CF ₂ = CF and its derivatives, in particular the derivatives of the formula (VI) in particular, are intermediates for the preparation of pesticides. A number of such pesticides and their preparation are described in WO 92/15555 and WO 95/12977 and in US Pat. No. 5,389,680. Other pesticides can be obtained analogously. The pesticides are fluoro alkenyl compounds which are derived from the C ₄ -carboxylic acid of the formula (V) with Y = CF ₂ = CF- and which differ from such carboxylic acids in that the OH group of the carboxylic acid grouping is different Leftovers, e.g. B. Alk oxy, alkylthio, hydroxylamino or amino radicals is replaced. These pesticides can be used in particular as nemathocides, insecticides and acaricides.

With the present invention are described in the cited documents pesticides and analogous pesticides more accessible way than before.

It is surprising that in the process according to the invention for the production of Polyhalogenhexenes of the formula (I) z. B. both a trichlorofluoromethyl group also a bromochlorofluoromethyl group selectively with a diene corresponding 1,4-addition products are implemented. In contrast, difluor react Halogen methyl groups practically not under the same conditions.

With the inventive method for the preparation of polyhalohexenes of the formula (I) z. B. Easy access to 6,6,6,5,5-penta halogenohexene-4 compounds. These can then also be converted according to the invention by reaction with ozone and oxidation in a simple manner into the corresponding C ₄ -carboxylic acids, which in turn are important intermediates.

Examples example 1 5-chloro-1,6-dibromo-5,6,6-trifluorohex-2-ene

In a 1.3 l enamel autoclave at 120 ° C to a mixture of 585 g of 1-chloro-1,2-dibromo-1,1,2-trifluoroethane and 134 ml of acetonitrile after the addition of 7.8 g Iron filings, 2.8 g of iron (III) chloride hexahydrate, 2.0 g of benzoin and 1.1 g of diethylammonium chloride were pumped in with 77 g of butadiene. After the metering had ended, stirring was continued for 15 hours at the temperature indicated. The reaction mixture was then filtered and washed twice with 1,000 ml of water. The dried organic phase was purified by distillation. From booty 222 g of product.
¹⁹ F-NMR (standard CFCl ₃ ): δ = -60.5 ppm (2F J _FF = 12 s ^-1 ); -117.9 ppm (IF, m)
¹ H-NMR (standard TMS): δ = 3.00 ppm (2H, m); 3.95 ppm (2H, d); 5.80 ppm (1H, m); 5.95 ppm (1H, m).

Example 2 4-bromo-3-chloro-3,4,4-trifluorobutane carboxylic acid

In a solution of 6.7 g of 5-chloro-1,6-dibromo-5,6,6-trifluorohex-2-ene, 100 ml of Di chloromethane and 100 ml of methanol, 1.6 g of ozone were introduced. After that was the apparatus flushed with nitrogen and the reaction mixture at 25 ° C in Vacuum concentrated. The residue was mixed with 100 ml of formic acid and 14.6 g of 35% strength by weight aqueous hydrogen peroxide solution were added at 60 ° C. The The reaction temperature rose to 74 ° C with evolution of gas. It was stirred for a further 5 hours at 100 ° C. Then the reaction mixture was added Ice, extracted with methyl tert-butyl ether, dried the organic phase and constricted in a vacuum. 1.5 g of 4-bromo-3-chloro-3,4,4-trifluorobutane were thus obtained carboxylic acid.  

Example 3 3,4,4-trifluorobut-3-ene carboxylic acid

10 ml of water were added to 11.8 g of the product from Example 2 at 0 ° C. and then in portions over the course of 2 hours, add 3.0 g of zinc powder with cooling given. After a further 30 minutes, thawing followed by 30 minutes Stirred room temperature. The reaction mixture was worked up sucks, the residue washed with dichloromethane, the aqueous phase with Extracted dichloromethane and the combined organic phases dried and constricted. Yield (crude): 4.0 g.

Example 4 3,4,4-trifluorobut-3-ene carboxylic acid

16.6 g of zinc powder and 41 ml of water were introduced and then 65.2 g of the Pro Ductes from Example 2 added dropwise at 0 ° C with cooling. After the addition has ended was 30 minutes with thawing and then another 30 minutes with room temperature stirred. Working up was carried out as indicated in Example 3. Yield (raw): 26.5 g.

This was then followed by a combination with the product from Example 3 Distillation in a vacuum. 19.0 g were cleaned at 80 to 83 ° C. and 30 mbar Product isolated.

Example 5 1,5,6-trichloro-5,6,6-trifluorohex-2-ene

In a 3 liter enamel autoclave at 111 ° C to a mixture 1 125 g of 1,1,2-trichloro-1,2,2-trifluoroethane in 315 g of acetonitrile after adding 23.4 g of iron filings, 7.7 g of ferric chloride hexahydrate, 6.1 g of benzoin and 3.4 g of diethylamonium chloride 280 g of butadiene are pumped in. After the end of the Dosage was stirred at 110 ° C for 8 hours. The reaction mixture was then filtered and washed twice with 2,000 ml of water. The getrock  The organic phase was purified by distillation. Yield: 231 g Product.

Example 6 3,4-dichloro-3,4,4-trifluorobutane carboxylic acid

In a solution of 9.6 g 1,5,6-trichloro-5,6,6-trifluorohex-2-ene, 250 ml dichloro methane and 100 ml of methanol were introduced 3.3 g of ozone. After that the Purged with nitrogen and the reaction mixture at 25 ° C in a vacuum restricted to 30 mbar. The residue was mixed with 100 ml of formic acid and added 14.6 g of 35% by weight aqueous hydrogen peroxide solution at 60.degree. The The reaction temperature rose to 85 ° C with evolution of gas. It was stirred for a further 5 hours at 100 ° C. Then the reaction mixture was added Ice, extracted with methyl tert-butyl ether, dried the organic phase and constricted in a vacuum. 4.6 g of product were obtained.

Claims (9)

1. Polyhalogenhexenes of the formula
CF ₂ X-CFX-CH ₂ -CH = CHR-CH ₂ X (I),
in the
the radicals X can be the same or different and each represent chlorine, bromine or iodine and
R represents hydrogen, C, -C ₆ alkyl or C ₃ -C ₇ cycloalkyl. 2. Polyhalogenhexenes according to claim 1, characterized in that it is 5-chloro-1,6-dibromo-5,6,6-trifluorohex-2-ene or 1,5,6-trichloro-5,6,6-tri fluorhex-2-en is. 3. A process for the preparation of polyhalogenhexenes of claim 1, characterized in that a hexahalogenethane of the formula
CF ₂ X-CFX ₂ (II),
in the
X has the meaning given in claim 1 for formula (I),
in the presence of a catalyst and a solvent with a butadiene of the formula (III)
CH ₂ = CHR-CH = CH ₂ (III),
in the
R has the meaning given in claim 1 for formula (I). 4. The method according to claim 3, characterized in that the Ver bonds of formulas (II) and (III) in a molar ratio (II) to (III) of 0.1 up to 100 to 1. 5. Process according to claims 3 and 4, characterized in that as Catalysts metals of main group VIII and / or the subgroups VI and / or VII in elemental form, in the form of compounds and / or in the form of complexes and in amounts of 0.01 to 10 mol%, each calculated as metal and based on the compound of formula (II), starts. 6. The method according to claims 3 to 5, characterized in that as Solvents alkyl nitriles with 2 to 5 carbon atoms, 3-alkoxypropionitriles with 1 to 2 carbon atoms in the alkoxy part, aromatic nitriles, aliphatic ketones with 3 to 8 carbon atoms, alkyl and / or alkoxyalkyl esters of aliphatic Monocarboxylic acids with a total of 2 to 6 carbon atoms, cyclic ethers, Dialkyl ethers with 1 to 4 carbon atoms in each of the alkyl parts, N, N- Dialkylamides of aliphatic monocarboxylic acids with 1 to 3 carbon atoms in the acid part, ethylene glycol and diethylene glycol dialkyl ether with 1 to 4 each C atoms in the alkyl parts and / or hexamethylphosphoric triamide as Solvent is used. 7. Process for the preparation of halogenated C ₄ carboxylic acids of the formula
Y-CH ₂ -COOH (V),
in the
Y is CF ₂ X-CFX- or CF ₂ = CF-, where X has the meaning given in formula 1 in claim 1,
characterized in that a polyhalohexene of claim 1 is reacted with ozone in the presence of a solvent and then oxidized in an acidic medium and in the case of the production of halogenated C ₄ -carboxylic acids of the formula (V) with Y = CF ₂ = CF- still an α , β elimination is carried out. 8. The method according to claim 7, characterized in that as Oxidizing agents oxygen, ozone, hydrogen peroxide, percarboxylic acids or mixtures of hydrogen peroxide and acids. 9. Process according to Claims 1 to 8, characterized in that α, β-elimination with zinc powder in the presence of water which is additionally required for the preparation of the halogenated C ₄ -carboxylic acid of the formula (V) with Y = CF ₂ = CF- at temperatures of -10 and + 30 ° C.