WO2008043720A2

WO2008043720A2 - Process for the preparation of halogenated hydrocarbons with at least 3 carbon atoms in the presence of an ionic liquid

Info

Publication number: WO2008043720A2
Application number: PCT/EP2007/060625
Authority: WO
Inventors: Wolfgang Wiesenhöfer; Ercan Uenveren; Kerstin Eichholz; Johannes Eicher
Original assignee: Solvay (Société Anonyme)
Priority date: 2006-10-09
Filing date: 2007-10-08
Publication date: 2008-04-17
Also published as: WO2008043720A3

Abstract

A telomerisation process is described wherein a halocarbon is added to olefins like 2-chloroprop-1-ene in the presence of ionic liquids and/or compounds having at least two nitrogen atoms at least one of which is tricordinated and at least one of which is tetracoordinated. The reaction products, e.g. 1,1,3,3-tetrachloro-1-fluorobutane, can be further fluorinated.

Description

Process for the preparation of halogenated hydrocarbons with at least

3 carbon atoms

The instant invention concerns a process for the preparation of halogenated hydrocarbons comprising at least 3 carbon atoms by catalytic reaction between a haloalkane and an olefin.

Halogenated hydrocarbons can be prepared by the addition of haloalkanes to olefins.

EP-A-O 787707 (US-A 5917098) discloses the preparation of 1,1,1,3,3-pentachlorobutane from tetrachloromethane and 2-chloroprop-l-ene in the presence of a copper halide and certain amines.

WO 98/50330 (US-A 6399839) discloses the preparation of chloroalkanes or chlorofluoroalkanes by the addition of haloalkanes, such as tetrachloromethane, 1,1,1-trichloroethane or l,l,l-trichloro-2,2,2-trifluoroethane to olefins which may contain halogen atoms. In that process, an organically substituted copper compound is used as catalyst; a polar solvent and/or a cocatalyst selected among amines, amides and trialkyl phosphinoxides. Especially preferred compounds to be prepared are 1,1,1,3,3-pentachlorobutane and 1,1,1 ,3,3-pentachloropropane.

WO 98/50329 (US-A 6399840) discloses the preparation of 1,1,1,3,3-pentachlorobutane from tetrachloromethane and 2-chloroprop-l-ene in the presence of a copper (I) or copper (II) catalyst. WO 97/07083 (US-A 5902914) discloses a process for the preparation of halogenated hydrocarbons by the addition of alkanes to olefins in the presence of copper chloride and t-butylamine as cocatalyst.

Object of the present invention is to provide a novel process for the preparation of halogenated hydrocarbons. This object and other objects are achieved by the process of the present invention.

The present invention concerns a process for the preparation of halogenated hydrocarbons with at least 3 carbon atoms by the reaction of a halocarbon and an olefin in the presence of an ionic liquid and/or a compound with at least two amino groups wherein the nitrogen atom of at least one amino group is tetracoordinated and the nitrogen atom of at least one amino group is tricoordinated. Preferably, the addition reaction is performed in the presence of a catalyst. Optionally, the addition reaction can be performed in the presence of a cocatalyst.

One embodiment concerns performing the reaction in the presence of ionic liquids. The term "Ionic liquids" denotes in the present invention those liquids as defined by Wasserscheid and Keim in Angewandte Chemie Int. Ed. 2000,39, 3773 ff: ionic liquids are liquids that consist essentially from ions and are liquid at a temperature below 100⁰C (under ambient pressure).

In general, ionic liquids are inflammable, non-corrosive, have low viscosity and have no discernable vapor pressure (at ambient temperature).

The ions of ionic liquids suitable to be applied in the present invention may have one or more positive and one or more negative charges. Liquids with one positive and one negative charge are preferred.

Suitable ionic liquids are, for example, described in the publication of Wasserscheid and Keim cited above and in WO 02/074718. They are based on ionic liquids which comprise ammonium, guanidinium or phosphonium cations. In the present invention, ionic liquids are selected so that they do not react in an undesired way with the starting materials, reaction products, catalysts or, if comprised, cocatalysts. This can be safeguarded by simple tests. It can be advantageous to exclude water. In the frame of the present invention, ionic liquids based on ammonium cations are preferred.

Ionic liquids are commercially available. They may also be prepared by the reaction of the respective amine with an alkylating agent or with an acid.

In the following, suitable cations and anions are explained in detail; it is clear that the respective cation/anion pair must provide a liquid with a melting point below 100⁰C at ambient pressure. Especially preferred are those liquids having a melting point at or below 30⁰C.

Cations comprising phosphorus, especially phosphonium cations with four alkyl or aryl groups which may be the same or different, like the butyl group, octyl group or phenyl group are suitable and mentioned in the publication of Wasserscheid.

Cations based on ammonium are especially preferred and will be explained further. In principle, ionic liquids with any known ammonium cations which comprise at least one organic group as substituents in the ammonium cation are suitable. Generally, primary, secondary, tertiary and quaternary ammonium cations are suitable. It is possible to apply compounds which comprise one ammonium cation per molecule, two ammonium cations per molecule or even more ammonium cations. Substituents at the ammonium cation may, for example, be selected from linear and branched or cyclic alkyl or alkenyl groups with, e.g., 1 to 20 carbon atoms, in the case of alkenyl 2 to 20 carbon atoms. The alkyl or alkenyl groups can be substituted, e.g. by hydroxyl groups. They may also comprise hetero atomes like oxygen in the carbon chain. The alkyl groups can be the same or different. Aromatic groups like the phenyl group are suitable, too. If desired, the aromatic group can be substituted by one or more Cl to C3 alkyl groups. Another type of substituent are arylalkyl groups like benzyl. Guanidinium, isothiouronium and isouronium groups are also suitable cations (compounds with such groups are available from Merck, Darmstadt). Here, substituents at the nitrogen, oxygen or sulfur atoms can be linear or branched alkyl groups, e.g., alkyl groups with 1 to 6 carbon atoms, or aryl groups, in the case of nitrogen also hydrogen. As mentioned above, besides quaternary ammonium cations, also primary, secondary or tertiary ammonium cations are suitable in the frame of the present invention. Preferably, the organic groups substituting the nitrogen atom are aliphatic alkyl groups with 1 to 6 carbon atoms. As mentioned above, they can be prepared from the respective amine and an alkylating agent or an acid. Dialkyl sulfates, e.g. dimethyl sulfate or diethyl sulfate, are very suitable alkylating agents. Trifluoroacetic acid or trifluoromethylsulfonic acid are highly suitable acids. Types of a secondary ammonium cation are the methylisopropylammonium and ethylisopropylammonium cations. They can be prepared by the reaction of isopropylamine and, e.g., dimethylsulfate or diethylsulfate. Other suitable cations are tributylethylammonium, tetraethylammonium, diethyldiisopropylammonium, and t-butylethylammonium. If the salts of such compounds formed are solid at 100⁰C or below at normal pressure, they could still be applied together with salts which are liquid in the desired temperature range. Preferably, only salts which are liquid at or below 100⁰C are applied, and no such salts which are solid at or below 100⁰C are applied.

Another type of cations suitable as cation in ionic liquids according to the present invention are those cations described in US-A 6462014. The cations are alkoxylated quaternary ammonium compounds; one substitutent is a linear or branched, saturated or unsaturated C6 to C22 alkyl group; one substituent is a Cl to C6 alkyl group or a linear or branched, saturated or unsaturated C6 to C22 - A -

alkyl group; two substituents are C2 to C4 random or block polyoxyalkylene groups. Such substituents, which can be the same or different preferably have the formula (CF^CHRO)^ wherein A in both substituents are integers equal to or greater than 1 and the sum of A of both substituents is 2 to 50 and R independently at each occurrence is H or Cl to C2 alkyl. The proviso in

US-A 6462014 that in at least one occurrence, R must be a Cl or C2 alkyl does not apply in the present invention : R can be H in all occurrences. Among the preferred cations of this type is the "cocomonium" cation. In cocomonium, one substituent is a methyl group; the other substituent is a C14H29 group. The two other subsituents of the quaternary nitrogen atom are (CH2-CH2θ)_nCH2- CH2OH groups wherein n may be 1 to 25.

Ammonium cations with saturated cyclic groups are equally suitable. For example, the ammonium cations substituted with (optionally substituted) mono- or bicyclic saturated groups, as cited in DE 10114565, are very suitable. Examples are piperidinium or piperidinium substituted by hydroxyl groups. Cations of bicyclic amines mentioned there, especially those of l,5-Diazabicyclo[4.3.0]non-5-en und l,8-Diazabicyclo[5.4.0]-undec-7-en, as well as aminosubstituted cyclic amines like dialkylaminopiperidine and dialkylaminopiperazine (alkyl preferably denotes Cl to C4) are suitable in the form of the cations.

Other suitable cations are heterocyclic compounds comprising at least one N atom and optionally oxygen or sulfur. Such compounds are mentioned in WO 02/074718 on pages 4 to 6. Those cations are based on the structure of pyridine, pyridazine, pyrimidine, pyrazine, imidazole, lH-pyrazole, 3H-pyrazole, 4H-pyrazole, 1-pyrazoline, 2-pyrazoline, 3-pyrazoline, 1 -imidazoline,

2-imidazoline, 4-imidazoline, thiazole, oxazole, 1,2,4-triazole (positive charge on the 2- or 4-N atom), 1,2,3-triazole (positive charge on the 2- or 3 -N atom) and pyrrolidine. Detailed explanations and lists of suitable substituents of these cations are given in WO 02/074718 on pages 6 to 13. Pyridinium and imidazolium cations which are substituted by one or more groups selected from methyl, ethyl, butyl, octyl or decyl groups are very preferred there. They are mentioned on page 16 of WO 02/07418. Cations of N-alkylisochinoline, alkyltriazolium, N-alkylimidazoline are also suitable. These structures can be substituted by hydrogen or by alkyl groups with 1 to 18 C atoms (C2-C18-alkyl groups can comprise one or more oxygen atoms or sulfur atoms or imino groups in the chain), by C6 to C 12- aryl, C5 to C 12 cycloalkyl or a heterocyclic group with 5 or 6 members in the ring which comprise oxygen, nitrogen or sulfur. Two such substituents can form a saturated or unsaturated or aromatic ring which may comprise on e or more oxygen, sulfur atoms or imino groups. Said substituents can themselves be substituted by functional groups, aryl, alkyl, aryloxy, alkyloxy, halogen, heteroatoms and/or heterocycles.

The positively charged N atom can be substituted by Cl -Cl 8- alkylcarbonyl, Cl-C18-alkyloxycarbonyl, C5-C12-cycloalkylcarbonyl or C6-C12-arylcarbonyl; these substituents can once again be substituted by functional groups, aryl, alkyl, aryloxy, alkyloxy, halogen, heteroatoms and/or heterocycles.

Cations of such heterocycles with five- or sixmembered rings are especially preferred in the frame of the present invention. Highly preferred are imidazolium-, imidazolinium-, pyrazolium-, oxatriazolium-, thiatriazolium-, pyridinium-, pyradizinium-, pyrimidinium- or pyrazinium cations. The carbon atoms are preferably substituted by hydrogen, Cl to C 12 alkyl or C2 C 12 alkyl substituted by a OH or CN group. The positively charged N atom is preferably substituted by acetyl, methyl, ethyl, propyl or n-butyl. Optionally, it can be substituted by hydrogen or Cl to 12 alkyl groups. Likewise, other nitrogen atoms contained in the ring can be substituted by hydrogen or Cl to C 12 alkyl, preferably by methyl, ethyl, n-propyl, i-propyl and n-butyl.

Oligomers and polymers comprising cations as described above are also suitable, see for example M. Yoshizawa, W. Ogihara and H. Ohno, Polym. Adv. Technol. 13, 589-594, 2002. Monomeric cations are preferred in the context of the present invention. Imidazolium cations, which are substituted by one, two or three substituents with 1 to24 carbon atoms are especially preferred; the substituents themselves can be substituted e.g. by aryl groups. Outstandingly preferred are 1 ,3-dimethyl-imidazolium, 1 -ethyl-3-methyl-imidazolium, 1 -propyl-3-methyl- imidazolium, 1 -butyl-3-methyl-imidazolium, 1 -pentyl-3-methyl-imidazolium, 1 -hexyl-3 -methyl-imidazolium, 1 -heptyl-3 -methyl-imidazolium, 1 -octyl-3 - methyl-imidazolium, 1 -nonyl-3 -methyl-imidazolium, 1 -decyl-3 -methyl- imidazolium, 1 -undecyl-3 -methyl-imidazolium, 1 -dodecyl-3 -methyl- imidazolium, l-benzyl-3 -methyl-imidazolium and l-butyl-2,3-dimethyl- imidazolium. Ionic liquids with a cation selected from 1,3-dimethyl- imidazolium, 1 -ethyl-3-methyl-imidazolium ("EMIM"), 1-propy 1-3 -methyl- imidazolium und l-n-butyl-3 -methyl-imidazolium ("BMIM") are most suitable. The list of cations mentioned above is not intended to be exhaustive. Whether a cation not mentioned above is suitable can easily be found out by simple trials.

Another embodiment of the present invention is performed in the presence of cationic compounds which comprise at least two amino groups wherein the nitrogen atom of at least one amino group is tetracoordinated and the nitrogen atom of at least one amino group is tricoordinated. Accordingly, in this type of compounds, at least one nitrogen atom is an "onium" type nitrogen, and at least one nitrogen atom is in the form of a free base. Diamines one nitrogen atom of which is present in cationic form constitute preferred examples of this type of compounds. The amino groups can be separated by an aliphatic linear or branched saturated carbon chain of 1 to 10 C atoms or a linear or branched unsaturated carbon chain of 2 to 10 C atoms. Alternatively, the amino groups may be substituents of a cyclic saturated or unsaturated group which may comprise heteroatoms in the chain, or of an aromatic ring. Very suitable examples of such compounds wherein one nitrogen is in the cationic ("onium") form are based on ethylene diamine (= 1,2-diaminoethane), 1,3-diaminopropane, 1 ,4-diaminobutane, 1 ,6-diaminohexane, 1 ,3-diamino-2,2-dimethylpropane, 1 (3-aminopropyl)imidazole, 4-picolylamine, 3-dimethylamino- 1 -propylamine, 3-(methylamino)propylamine; one nitrogen atom of which is tetracoordinated and thus cationic. Generally, these cations are obtaineable by the reaction of the diamines with an alkylating agent or with an acid. For example, the cations obtainable by the reaction of said diamines with alkylating agents, for example, dialkyl sulfates, e.g., dimethyl sulfate or diethylsulfate, are very suitable cations. The reaction of ethylene diamine with diethylsulfate gives the cation

H3N⁺CH2CH2N(H)C2H5 (it was found that a proton was shifted from one amino group to the other during the alkylation reaction). This cation was obtained if ethylene diamine is reacted with one equimolar amount of a dialkyl sulfate, e.g., diethyl sulfate. Surprisingly, it has been found out that, in fact, two molecules of ethylene diamine seem to be involved in the reaction with, for example, one diethyl sulfate molecule. It is assumed that the cation H3N⁺CH2CH2N(H)C2H5 coordinates with the remaining ethylenediamine molecule to form a cationic complex. The other diamines formed such complexes, too. The dialkyl sulfate loses an alkyl group and forms the anion. In the described reaction, the anion is constituted by the formed monoalkylsulfate anion, specifically the monoethylsulfate anion. Compounds including such a cationic complex are novel, suitable to be present in telomerisation reactions and likewise an aspect of the present invention. Addition compounds obtainable by the reaction of dimethylsulfate or diethylsulfate with alkylene diamines wherein the alkylene bridge is linear or branched and comprises 2 to 6 carbon atoms, and wherein the ratio of the reacting diamine and dialkylsulfate is 2:1, are preferred. The substituents of the nitrogen atoms of the diamine are preferably selected from the group consisting of hydrogen, methyl and ethyl. It has to be emphasized that that type of adduct compounds (resulting from a reaction wherein two molecules of the diamine and one molecule of the dialkylsulfate is concerned) even forms when the starting ratio of amine and dialkylsulfate is 1 :1. This process for preparing the addition compounds is exothermic and thus can be performed at ambient temperature, if desired under cooling.

This embodiment which applies compounds with at least two ammonium groups can preferably performed in the additional presence of ionic liquids.

Now, the anions of the ionic liquids are explained in detail. These can be strongly coordinating anions like alkylsulfates or arylsulfates or weakly coordinating anions like trifluoromethansulfonate or hexafluorophosphate as long as the resulting salts are liquid at or below 100⁰C, likewise the anions of mono- or dibasic or multibasic oxygen acids or their derivatives like esters or amides, e.g. sulfonates or sulfonamides. Ionic liquids with anions selected from alkylcarboxylates with a total of 2 to 8 carbon atoms, e.g. acetate; sulfate; hydrogen sulfate; phosphate; hydrogen phosphate; dihydrogen phosphate; alkylsulfate with a C1-C12 linear or branched alkyl group, are very suitable. Anions to be mentioned are methyl-, ethyl-, n-propyl-, n-butylsulfate, up to n-octylsulfate; alkyl and dialkylphosphate with one or two Cl -C 12 alkyl groups, e.g. methyl-, dimethyl-, ethyl-, diethyl-, n-propyl-, di-n-propyl-, n-butyl-, di-n-butylphosphate;Cl-C12 alkylsulfonate, preferably C1-C4 alkylsulfonate, e.g. methyl-, ethyl-, n-propyl-, n-butylsulfate; sulfonate with a C1-C12 alkyl group substititued by one or more halogen atoms, especially by fluorine, e.g. trifluormethylsulfonate (triflate); arylsulfonate, e.g. tosylate; phosphonate with a Cl-Cl 2 alkyl group, which is directly bound to the P atom, e.g. methyl-, ethyl-, n-propyl-, n-butylphosphonate; phosphonate with a Cl-Cl 2 alkyl group which is substituted by one or more halogen atoms, preferably fluorine, and which is directly bound to the P atom, e.g. trifluormethylphosphonate; esters of said phosphonates with a Cl-Cl 2 alkyl groups which optionally is substituted by one or more halogen atoms, preferably fluorine atoms; imides of bis(Cl-C12- alkyl)sulfonat, wherein the alkyl groups may optionally be substituted by one or more halogen atoms, preferably fluorine atoms, e.g. bis(trifluoromethyl- sulfonyl)imid. Halide anions and the BF4 anion are also considered suitable as long as the resulting salts are liquid at or below 100⁰C, preferably at or below 30⁰C.

Preferred anions are Cl -C 12 alkylsulfates, most preferably Cl-C4-alkylsulfates, and triflate and tosylate and their mixtures. Methylsulfate, ethylsulfate, propylsulfate, butylsulfate, octylsulfate and hexylsulfate are especially preferred as anions. In this case, often also the ammonium cation will comprise at least one ethyl substituent. Highly suitable ionic liquids are : EMIM ethylsulfate; BMIM ethylsulfate; EMIM hexafluorophosphate;cocomonium methyl sulfate (cocomonium : (CH₃)(C₁₄H₂Q)[CCH₂CH₂O)_nCH₂CH₂O]₂ worin n fur 1 bis 25, z.B. 3 bis 7 steht, wie PEG5 cocomonium; tetraethylammonium ethylsulfate (obtainable from triethylamine and diethylsulfate); N-ethylpyridinium ethylsulfate and - methylsulfate (obtainable from pyridine and diethylsulfate and dimethylsulfate, respectively); ethyl-isopropyl ammonium ethylsulfate (obtainable from isopropylamine and diethylsulfate);N,N-diethyl-diisopropylammonium ethyl sulfate (obtainable from N-ethyl-diisopropylamine and diethylsulfate); the reaction product obtainable from ethylenediamine and diethylsulfate; the reaction product obtainable from 1,3-diaminopropane and diethylsulfate; the reaction product obtainable from 1 ,4-diaminobutane and diethylsulfate; the reaction product obtainable from 1 ,6-diaminohexane and diethylsulfate ;the reaction product obtainable from l,3-diamino-2,2-dimethylpropane and diethylsulfate; the reaction product obtainable from l(3-aminopropyl)imidazole and diethylsulfate; the reaction product obtainable from 3 -dimethylamino-1 -propylamine and diethylsulfate and the reaction product obtainable from 3-methylamino- propylamine and diethylsulfate; in case of the diamino compounds, "reaction product" means those reaction products obtained from the reaction between the diamine and the alkylsulfate in a molar ratio of 1 : 1 and 2:1 (i.e. also the complexes with another molecule of the diamine are comprised).

The haloalkanes which are used in the process of the present invention generally are saturated organic compounds. Preferably, they have one to three carbon atoms. Preferably, they are substituted by at least two chlorine atoms. They may be substituted by other halogen atoms or by alkyl or halogenoalkyl groups. Examples of suitable haloalkanes are dichloromethane, trichloromethane, tetrachloromethane, 1,1,1-trichloroethane and chlorofluoroethanes like l,l,l-trichloro-3,3,3-trifluoroethane, 1,1-dichloro-l- fluoroethane (HCFC-141b) and l-chloro-l,l-difluoroethane (HCFC-142b). Tetrachloromethane is especially preferred.

The olefin which is used as starting material in the process of the present invention is generally ethylene, propylene or a butene, which, in a preferred embodiment, are substituted by at least one halogen atom. Optionally they also are substituted by one or more alkyl groups, halogenoalkyl groups, nitril (CN) groups or carboxylic acid groups (COOH). Halogenated olefins are preferred. Chlorinated olefins are very suitable. Generally, they correspond to the formula RlR²C=CClCR³. In this formula, RI , R² and R³ independently represent H or Cl, linear, branched or cyclic alkyl or alkenyl, an aryl or a heteroaryl group. These alkyl, alkenyl, aryl or heteroaryl groups may be substituted. Examples for such halogenated olefins are vinyl chloride, vinylidene chloride, trichloroethylene, the isomers of chloropropene like 1-chloroprop-l-ene, 2-chloroprop-l-ene, and 3-chloroprop-l-ene. 2-chloroprop-l-ene is especially preferred. If chlorofiuoroalkanes like HCFC- 14 Ib or HCFC- 142b are used as haloalkanes, chlorofiuoroalkanes are obtained as reaction product.

The halogenated hydrocarbons obtained by the process of the present invention preferably belong to the family of chloropropanes, chlorobutanes and chloropentanes. The carbon atoms of the chloropropanes, chlorobutanes and chloropentanes can be substituted by other functional groups like other halogen atoms (e.g. bromine or iodine), alkyl groups, halogenoalkyl groups, nitrile (CN) groups or carboxylic acid groups (COOH). Chloropropanes, chlorobutanes and chloropentanes not substituted by such other functional groups are preferred. Halogenated hydrocarbons of the general formula C_nH(2n+2)-pClp are especially preferred reaction products. In this formula, n is an integer and stands for 3 or 4, p is an integer and stands for 3, 4, 5, 6 or 7. Examples of compounds which can be produced by the process of the present invention are 1,1,1 ,3 ,3-pentachloropropane, 1,1,1 ,3 ,3-pentachlorobutane, 1,1,1 ,3-tetrachloropropane, 1 , 1 ,3,3-tetrachlorobutane, 1,1,1, 3,3, 3-hexachloropropane and l,l-dichloro-2-trichloromethylpropane. 1,1,1,3,3-pentachlorobutane and 1,1,1,3,3-pentachloropropane are preferred. In an embodiment which provides good results, the reaction is performed in the presence of a catalyst. The catalyst can be selected from those catalysts which have been found suitable for telomerisation reactions concerning chloroalkanes and olefins. Very suitable are catalysts based on Cu salts. WO 98/50329 discloses certain Cu (I) and Cu (II) salts also suitable as catalyst for the present invention. Inorganic salts, like the halides, especially the chlorides and iodides, and organic salts are suitable. The organocopper compound suitable as catalyst in the process according to the present invention may be a compound formed with an organic acid compound. Carboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, acetylacetic acid, cyclo-hexanebutyric acid and benzoic acid typically constitute organic acid compounds. Chloro- or fluorocarboxylic acids, such as trichloroacetic acid and trifluoroacetic acid, are also suitable. Sulphonic acids, sulphinic acids and phosphonic acids, as well as chloro or fluoro derivatives thereof, may also be suitable. Other organic acid compounds are compounds having a hydrogen atom close to one or more electron-withdrawing groups such as carbonyl (C-O), nitrile (CN), sulphone (SO2R), nitro (NO2) and phenyl groups, as well as chloro or fluoro derivatives thereof. Among the organic acid compounds according to this definition, mention may be made in particular of acetylacetone, trifluoroacetylacetone, l,l,l,5,5,5-hexafluoropentane-2, 4-dione, acetonitrile, ethyl acetoacetate, nitromethane, diphenylmethane, phenol and dimethyl sulphone. Copper compounds formed with organic acid compounds such as those mentioned above can be used in the process according to the present invention. The copper compounds formed with compounds such as acetylacetone, ethyl acetoacetate, acetic acid or cyclohexanebutyric acid and the chloro and fluoro derivatives thereof, are preferred. Copper (II) compounds are particularly preferred. Advantageously, the catalyst in the process according to the present invention is chosen from copper (II) acetate, copper (II) cyclohexanebutyrate and copper (II) acetylacetonate. Among organosubstituted copper compounds, preference is most particularly given to the compound formed between copper (II) and acetylacetone (copper (II) acetylacetonate, abbreviated as Cu(acac)2). Iron, iron chloride or copper cyanide are also suitable as catalysts. Also Ru complexes have been proposed as telomerisation catalysts. Ru(II)dihalides complexed by triarylphosphin like Ru(II)Cl2-(Ph3)2 are preferred Ru catalysts. Cu (I) salts and copper (II) salts, especially the halides and acetates, are preferred catalysts.

If desired, the process according to the present invention might be carried out in the presence of a solvent, for example, in an alcohol, a nitrile, an amide, a lactone, a trialkylphosphine oxide or another polar solvent. Among the alcohols which can be used as reaction solvent are, in particular, methanol, ethanol, isopropanol and tert-butanol. Among the nitriles which could be used as reaction solvent are aliphatic nitriles, like acetonitrile, propionitrile or adiponitrile, and aromatic nitriles like benzonitrile or tolunitrile. Among the amides which could be used as reaction solvent are linear amides such as N,N-dimethylacetamide and N,N-dimethylformamide, and cyclic amides such as N-methylpyrrolidone. Mention may also be made of hexa-methylphosphoramide. Among the lactones which could be used as reaction solvent, mention may be made in particular of [gamma] -butyrolactone. Among the trialkylphosphine oxides which could be used as reaction solvent, mention may be made in particular of the compounds of formula (R⁴R⁵R⁶)PO, in which R⁴, R⁵ and R⁶ represent identical or different, preferably linear C3-C10 alkyl groups. Tri (n-butyl)-phosphine oxide, tri(n-hexyl)phosphine oxide, tri(n-octyl)phosphine oxide, n-octyldi(n- hexyl)phosphine oxide and n-hexyldi(n-octyl)phosphine oxide and mixtures thereof are selected in particular. As to other polar solvents, mention may also be made of l,3-dimethyl-2-imidazolidinone, dimethyl sulphoxide and tetrahydrofuran. Preferably, the solvent is an amide or a trialkylphosphine oxide. Good results have been obtained in particular with N-methylpyrrolidone, with N,N-dimethylacetamide and with a mixture of tri (n-hexyl)phosphine oxide, tri(n-octyl)phosphine oxide, n-octyldi(n-hexyl)phosphine oxide and n-hexyldi(n- octyl)-phosphine oxide. Also, starting material or reaction product might be used in an excess to serve as a solvent.

In a highly preferred embodiment, the reaction between halocarbon and olefin, is performed in the absence of any additional solvent except for starting material or reaction product which might be present in excess and have the effect of a solvent. In this preferred embodiment, the ionic liquid, optionally together with starting material or reaction product, serves as the only solvent present in the addition reaction.

In an embodiment, the reaction can be performed in the presence of a cocatalyst. Suitable cocatalysts are for example, amines and triphenylphosphine. Among the amines, aliphatic amines are preferred. Among primary, secondary and tertiary amines, primary amines are especially preferred. For example, n-butyl amine, t-butylamine, n-propylamine, isopropylamine or benzylamine are very suitable. If the reaction is performed in the presence of a cocatalyst, triphenylphosphin is preferred.

If desired, in a discontinuous process, the cocatalyst can be added progressively, and might at least be partially recovered for reuse. Such an embodiment is disclosed in WO 01/25175.

The recovery of the cocatalyst can be performed as described in WO 01/25177 from an aqueous phase by adding at least one base to it and recovering the cocatalyst from the aqueous phase.

In a discontinuous process, the molar ratio between catalyst and olefin often is greater than or equal to 0.001. Advantageously, it is equal to or greater than 0.002. Preferably, it is equal to or greater than 0.005. Often, the molar ratio between catalyst and olefin is lower than or equal to 5. Advantageously, it is lower than or equal to 1. Preferably, it is lower than or equal to 0.5.

In a continuous process, the molar ratio between catalyst and the olefin should lie in the range given above for a discontinuous process, but it may reach higher upper limits, e.g. it could be up to 10; here, the upper limit is preferably lower than or equal to 1.

In the less preferred embodiment of the process according to the invention where a cocatalyst is present, the molar ratio between the cocatalyst and the olefin is generally greater than or equal to 0.01. Preferably, this molar ratio is greater than or equal to 0.05. Advantageously, this molar ratio is greater than or equal to 0.1. However, this molar ratio is usually less than or equal to 2.

Preferably, this molar ratio is less than or equal to 1. Advantageously, this molar ratio is less than or equal to 0.5. The amount of cocatalyst used can vary, on a molar basis, from about 0.1 to about 100 times the amount of catalyst, preferably from about 0.5 to about 50 times. The amount of catalyst and cocatalyst is expressed in a discontinuous process relative to the initial concentration of the olefin. In a continuous process, it is relative to the stationary concentration of the olefin in the reactor.

The molar ratio between halocarbon and the olefin, e.g. 2-chloroprop-l- ene, can vary in a broad range. In general, the ratio is equal to or greater than 0.1. Advantageously, it is equal to or greater than 0.5. Preferably, it is equal to or greater than 1. Generally, the ratio is equal to or lower than 20. Advantageously, it is equal to or lower than 10. Preferably, it equal to or lower than 8. Still more preferably, it is equal to or less than 5. In case of such high ratios, depending on the pressure, the halocarbon also serves as a solvent.

Generally, the reaction is performed above ambient temperature. Preferably, the temperature is equal to or higher than 80⁰C. Advantageously, the reaction temperature is higher than or equal to 100⁰C. Generally, the temperature is equal to or lower than 160⁰C. Advantageously, it is lower than or equal to 130⁰C.

The reaction time in a discontinuous process or the residence time in a continuous process is dependent from parameters such as reaction temperature, catalyst concentration, concentration of the starting materials and the molar ratio of the components in the reaction mixture. Generally, the reaction time or residence time can vary from 5 seconds to 20 hours.

The pressure in the reactor is usually equal to or greater than ambient pressure. It is usually lower than or equal to 15 bars (abs.), preferably lower than or equal to 10 bars.

The process according to the present invention allows for the preparation of halogenated alkanes in an efficient manner. The alkanes produced are especially suitable as intermediates in chemical synthesis. For example, they can be fluorinated. The fluorinated products are useful, for example, as solvents, refrigerants or blowing agents. A part or, preferably, all of the chlorine atoms are substituted by fluorine atoms. The fluorination can be easily accomplished by reacting the halogenoalkanes obtained by the process of the present invention with HF which advantageously is anhydrous. The chlorine-fluorine exchange can be performed with or without added fluorination catalyst. Suitable fluorination catalysts are salts of antimony, salts of titanium, salts of tantalum or salts of tin. The halide salts, especially the fluorides, chlorides or chloro fluorides are preferred salts. Other suitable fluorination catalysts are compounds of chromium, aluminium and zirconium; the oxides are preferred compounds for catalyzing fluorination reactions.

Specific examples of hydro fluorocarbons produced by fluorination have the general formula C_nH(2n+2)-pFp- Iⁿ this formula, n is an integer and is 3 or 4, and p is an integer and is 3, 4, 5, 6 or 7. Especially preferred hydrofluorocarbons are 1,1,1,3,3-pentafluoropropane, 1,1,1, 3,3, 3-hexafluoropropane and 1,1,1,3,3-pentafluorobutane. The following examples are intended to explain the invention further without limiting it. Abbreviations :

IPA = isopropylamine TEA = triethylamine

Py = pyridine t-BA = tert-butylamine

ETDA = ethylenediamine

DAP = 1,3-diaminopropane DAB = 1 ,4-diaminobutane

DAH = 1 ,6-diaminohexane

DADMP = l,3-diamino-2,2-dimethylpropane

APIM = l-(3-aminopropyl)imidazole

DMAPA = 3-Dimethylamino-l -propylamine MAPA = 3-(Methylamino)propylamine

EMIM = l-ethyl-3-methyl-imidazolium

BMIM = l-propyl-3-methyl-imidazolium und l-n-butyl-3-methyl- imidazolium

Ac = Acetate Triflate = trifluorosulfonate

2-CPe = 2-chloroprop-l-ene

TPP = triphenylphosphine

Cocomonium = PEG 5 cocomonium

Preparation of onium compounds : General reaction conditions : the amine or diamine was reacted with alkyl sulfate or acid in a molar ratio of nearly 1 :1. A minimal excess of amine was applied when diethyl sulfate was used as alkylating starting material. The reaction took place at ambient temperature and was exotherm. Volatile compounds can removed in a vacuum. If diamines were used as starting material, complexes were obtained which correspond to a reaction between diamine and alkyl sulfate in a molar ratio of 2: 1. The respective reaction product is considered to be an adduct between one molecule of diamine and one molecule of the adduct of diamine and alkylating sulfate.

General reaction conditions of the telomerisation reaction :

3 ml of the ionic liquid, 20 mmol 2-chloroprop-l-ene,

36 mmol tetrachloromethane and typically 1 mol- % of the catalyst were reacted in an autoclave at the given temperature. After cooling down the reactor contents, conversion and selectivity were analysed by gas chromatography. Yield of pentachlorobutane was calculated as the product of conversion and selectivity.

The ionic liquids were either purchased or prepared by reacting the amine and dimethyl sulfate or diethyl sulfate. It has to be noted that trifluoroacetate liquids at higher temperature seem to split off CHF3.

Used ionic liquids, catalyst, reaction conditions and results are tabulated in the following : Table 1 : 1 mol- % Cu(I)Cl; 80⁰C

Table 3 : 1 mol- % Cu(I)Cl; 130⁰C

Table 4 : 1 mol- % catalyst; 130⁰C; ionic liquid used : EMIM ethylsulfate

Table 5 : RuCl₂-(Ph₃)2; 130⁰C

Example 28 : Reaction performed in the presence of IPA-Et₂S(M (= ethyl- isopropylammonium ethylsulfate).

7.4 g IPA-Et₂SO-I, prepared from IPA and diethyl sulfate in a molar ratio of 1 :0.95 comprises the onium salt in an amount of 3.6 equivalents of free amine in respect of Cu (II). It was mixed with 0.0005 mole Of CuCl₂ and 0.02 moles of 2-CPe and 0.04 mole CCI4. Then the reaction mixture was kept for two hours at 90⁰C. After the first run, 90 % conversion was obtained. The catalyst was recycled; the conversion decreased but could be improved by addition of 3.6 equivalents of IPA.

Examples 29 to 37: DAP-Et₂Sθ4 as ligand in the presence of ionic liquids.

Example 28 was repeated in the presence of ionic liquids (IL). The results are given in table 5.

In some examples, the ionic liquids which included the catalyst were used for several runs. In this case, after having performed the first run of the reaction, mixing of the reaction mixture was stopped whereupon a phase separation occurred, the phase comprising the reaction product was removed by drawing it into a syringe, and then, further starting material was added.

Table 5 :

Example 38 : Preparation in the presence of triphenylphosphine 0.02 moles 2-CPe and 0.04 moles tetrachloromethane were reacted for 2 hours in the presence of 3 ml BMIM BUSO4 and triphenylphosphine and 0.0005 mole CuCl₂. The results are compiled in table 6 : Table 6 :

Table 6 demonstrates that, in the second cycle after removal of the adduct produced in the first cycle (recycling step), conversion essentially keeps constant or decreases, while the isolated yield improves. After the second cycle, and more so after the third and fourth cycles (not shown in table 6), both conversion and yield decrease. It was found that both conversion and yield can be improved by addition of fresh triphenylphosphine. Tests have demonstrated that even the addition of only 1 equivalent, and even more so the addition of 2 or 3 equivalents of TTP result in conversions and yields of more than 45 %, in some cases of more than 70% conversion and more than 60% yield, respectively. Example 39 : Reaction in the presence of BMIM PFg + TPP 6.92 mmols of 2-CPe and 38. 65 mmols CCI4 were reacted for 2 hours at 100⁰C in the presence of 0.005 mmols CuCl2 and 0.002 mmols TPP. The conversion of 2-CPe was found to be 86.3 %, the selectivity to 1,1,1,3,3-pentachlorobutane was 97.2 %.

Claims

C L A I M S

1. Process for the preparation of halogenated hydrocarbons with at least

3 carbon atoms by the reaction of a halocarbon and an olefin in the presence of an ionic liquid and/or a compound with at least two amino groups wherein the nitrogen atom of at least one amino group is tetracoordinated and the nitrogen atom of at least one amino group is tricoordinated.

2. Process according claim 1 wherein the reaction is performed in the presence of a catalyst, preferably a copper (I) or copper (II) catalyst.

3. Process according to claim 1 or 2 wherein the olefin corresponds to the formula R!R²=CC1CR³, wherein R¹, R² and R³ independently represent H or Cl, linear, branched or cyclic alkyl or alkenyl, an aryl or a heteroaryl group, whereby the alkyl, alkenyl, aryl or heteroaryl groups may be substituted.

4. Process according to claim 3 wherein the olefin is selected from the group consisting of vinyl chloride, vinylidene chloride, trichloroethylene, and the isomers of chloropropene like 1-chloroprop-l-ene, 2-chloroprop-l-ene, and 3-chloroprop- 1 -ene.

5. Process according to claim 1 where in the process is performed in the presence of an ionic liquid selected from those having a cation from the group consisting of l-ethyl-3-methyl-imidazolium ("EMIM"), l-propyl-3-methyl- imidazolium und l-n-butyl-3-methyl-imidazolium ("BMIM") or secondary, tertiary or quaternary ammonium cations.

6. Process according to claim 1 wherein the anion is selected from the group consisting of Cl to ClO alkylsulfates.

7. Process according to claim 1 wherein the compound with at least two amino groups wherein the nitrogen atom of at least one amino group is tetracoordinated and the nitrogen atom of at least one amino group is tricoordinated is selected from reaction product obtainable from ethylenediamine and diethylsulfate; the reaction product obtainable from 1,3-diaminopropane and diethylsulfate; the reaction product obtainable from 1 ,4-diaminobutane and diethylsulfate; the reaction product obtainable from 1 ,6-diaminohexane and diethylsulfate ;the reaction product obtainable from l,3-diamino-2,2- dimethylpropane and diethylsulfate; the reaction product obtainable from l(3-aminopropyl)imidazole and diethylsulfate; the reaction product obtainable from 3 -dimethylamino-1 -propylamine and diethylsulfate and the reaction product obtainable from 3-methylamino-propylamine and diethylsulfate.

8. Process according to claim 7 wherein the compound with at least two amino groups and ethyl sulfate are reacted in a molar ratio of (1 ± 0.05): 1 to (2 ± 0.1): 1, preferably in a molar ratio of (1 ± 0.05): 1 or (2 ± 0.1): 1.

9. Process for the preparation of hydro fluorocarbons wherein a halogenated hydrocarbon prepared according to any one of claims 1 to 8 is fluorinated.

10. Adduct of an alkylene diamine and the monoaduct of a diamine and a dialkylsulfate.

11. Adduct of claim 10 wherein alkyl denotes linear or branched Cl to ClO alkyl and alkylene denotes a linear or branched Cl to C5 alkylene chain.