Title of Invention

"A PROCESS FOR THE PREPARATION OF FLUORINE-CONTAINING COMPOUNDS"

Abstract

A process for the preparation of fluroine-containing compounds of the kind such as herein described from halogen-containing, preferably chlorine-containing, compounds with halogen/fluorine exchange or by HF addition to C-C multiple bonds of the kind such as herein described in the presence of the HF adduct of a mono- or bicyclic amine with at least 2 nitrogen atoms, at least 1 nitrogen atom being incorporated into the ring system, as catalyst or fluorination agent.

Full Text

The invention relates to a process for the preparation of fluroine-containing compounds from halogen containing compounds with halogen/fluorine exchange or by addition of HF to C-C multiple bonds. Inorganic and organic fluorine compounds have a high standing in chemistry and technology. Inorganic acid fluorides, for example sulphuryl fluoride or sulphuryl chloride fluoride, are products for use per se and also intermediate products. Sulphuryl fluoride has for example been proposed as a catalyst for the preparation of fluorocarbon compounds. Sulphuryl chloride fluoride is an intermediate product for the preparation of sulphuryl fluoride. Sulphuryl fluoride can be added to unsaturated hydrocarbons; the sulphonyl fluoride formed can be used as a catalyst. Fluorine-containing carbon compounds and hydrocarbon compounds have multiple applications, for example as blowing agents for the production of plastics materials, as refrigerants or as solvents. Carboxylic acids and carboxylic acid derivatives (for example carboxylic acid esters or dicarboxylic acid esters), which have a carbon-fluorine bond, can again be used as such or intermediate products in chemical synthesis. Trifluoroacetic acid esters can for example be used as solvents and as intermediate products in the preparation of trifluoroethanol. α-fluoro-ß-dicarbonyl compounds are important intermediate products, for example in the preparation of α-fluoroacrylic acid esters, see EP-A-0 597 329. It is known from EP-A-0 597 329 and DE-OS 199 42 374 that HF adducts of amines an be used as catalysts in fluorination reactions or alternatively as fluorination agents. EP-A-1 072 576 discloses HF adducts of optionally cyclic, ureas and phosphoric acid amides as fluorination agents [sic]. JP-A-63/128 086 discloses the hydrofluoride of 1,8-diazabicyclo[5.4.0]-undec-7-ene as a constituent of ink. It is an object of the present invention to devise novel HF adducts of nitrogen compounds with improved properties and their application in fluorination. These objects are achieved by the novel HF adducts and the application process according to the invention. The process according to the invention for the preparation of fluorine-containing compounds from halogen-containing, preferably chlorine-containing, compounds with halogen/fluorine exchange or by HF addition from C-C multiple bonds is carried out in the presence of the HF adduct of a mono- or bicyclic amine with at least 2 nitrogen atoms, at least 1 nitrogen atom being incorporated into the ring system, as catalyst or fluorination agent. Preferably gaseous or liquid compounds are produced under normal conditions. According to one embodiment, monocyclic compounds are used. These are then saturated or unsaturated 5-ring, 6-ring or 7-ring compounds. At least 1 nitrogen atom is incorporated into the ring. A further nitrogen atom may also be incorporated into the ring system. Alternatively or additionally, the ring may be substituted by one or more amino groups. Dialkylamino groups in which the alkyl groups may be identical or different and comprise 1 to 4 carbon atoms are preferred. The amino group may also represent a saturated ring system, for example a piperidino group. Representatives of monocyclic ring systems which can be used effectively are dialkylaminopyridine, dialkylaminopiperidine and dialkylaminopiperazine. According to another embodiment, they are bicyclic compounds. Here too, 1, 2 or more nitrogen atoms may be integrated in the ring system. The compounds may be substituted by one or more amino groups. Dialkylamino groups, wherein the alkyl groups may be identical or different and comprise 1 to 4 C atoms or together with the nitrogen atom form a saturated ring system, such as for example the piperidinyl group, are again preferred. Bicyclic amines, in particular 1,5-diazabicyclo[4.3.0]-non-5-ene (DBN) and 1,8-diazabicyclo[5.4.0]-undec-7-ene (DBU) are very particularly preferred. It is clear from what has been stated above that at least 2 nitrogen atoms in the usable compounds must have basic properties and, depending on the type of bonds, are bonded to 2 or 3 carbon atoms. The above-mentioned compounds with at least 2 nitrogen atoms are used in the form of the HF adducts. They can either be prepared in advance, by reacting the amines with hydrogen fluoride; alternatively they can also be prepared in situ, if hydrogen fluoride is correspondingly introduced into the reaction mixture. According to one embodiment, inorganic or organic acid fluorides are prepared from corresponding acid chlorides. Preferred acid fluorides are sulphuryl chloride fluoride and sulphuryl fluoride. Both can be prepared from sulphuryl chloride or a mixture of chlorine and sulphur dioxide. Also alkyl and aryl fluorosulphonates can be prepared from the corresponding chlorosulphonates. Chlorophosgene can be fluorinated to form fluorophosgene. Also carboxylic acid fluorides can be prepared from carboxylic acid chlorides. Preferably carboxylic acid fluorides or dicarboxylic acid fluorides are prepared from the corresponding carboxylic acid chlorides or dicarboxylic acid chlorides with a chain length totalling up to 12 C atoms. Aliphatic and aromatic carboxylic acid fluorides can be prepared. These may also be substituted by halogen atoms, for example fluorine and/or chlorine atoms. Preferably aliphatic acid fluorides with a total of 2 to 7, in particular 2 to 4, carbon atoms are prepared. Preferably acetyl fluoride, difluoroacetyl fluoride, chlorodifluoroacetyl fluoride or trifluoroacetyl fluoride are prepared. Furthermore, propionyl fluoride and also propionyl fluoride substituted with 1 to 5 fluorine atoms can be very readily prepared. The process according to the invention can also be used to prepare fluorine-containing compounds with a C-F bond from chlorine-containing compounds with a C-CI bond. The conversion of C(0)CI groups C(0)F groups [sic] has already been mentioned above. For example, chloroalkanes with 1 to 5 carbon atoms can be converted into alkanes substituted by fluorine and optionally chlorine. The process is also highly suitable for chlorine/fluorine exchange on activated carbon atoms, for example on those carbon atoms which are in the a position to C(O) groups. For example chlorine-substituted ketones or diketones, chlorine-substituted aliphatic carboxylic acid compounds or dicarboxylic acid compounds substituted at the carbon bridge by chlorine can be fluorinated. Preferably fluorine-containing carboxylic acid derivatives such as fluorinated carboxylic acid fluorides, carboxylic acid esters or carboxylic acid amides are prepared. Equally preferably alkylene-bridged dicarboxylic acid derivatives or diketones are prepared, which are substituted in the alkylene bridge, which is preferably 1 to 2 carbon atoms long, by at least 1 fluorine atom. In that case, the starting point may be the chlorine compounds or alternatively bromine compounds. The process can be prepared [sic] very well for the preparation of the compounds described in EP-A 597 329. These are compounds of Formula (I) (Formula Removed) in which the two radicals A may be identical or different and each stand for alkyl, aryl, alkoxy, aryloxy or an amino group and R stands for hydrogen, fluorine, alkyl or aryl. The starting material is compounds of Formula (II) (Formula Removed) in which X stands for chlorine, bromine or iodine, A has the meaning given in Formula (I) and R' has the meaning given for R in Formula (I) and may additionally stand for chlorine, bromine or iodine. The reaction is expediently carried out at temperatures of 20°C to 100°C. If in the charge product of Formula (II) R' stands for chlorine, bromine or iodine, an α,α-difluoro-ß-dicarbonyl compound is obtained, that is, a compound of Formula (I), in which R stands for fluorine. In Formulae (I) and (II) A may for example stand for straight-chain or branched, non-substituted or substituted alkyl, non-substituted or substituted aryl, straight-chain or branched, non-substituted or substituted alkoxy, non-substituted or substituted aryloxy or a non-substituted or substituted amino group of Formulae (III) to (V) NH2, (III) NHR1 (IV) and NR2R3 (V) in which R1, R2 and R3 are alkyl, preferably C2-C6 alkyl, or aryl, preferably phenyl. R2 and R3 may in this case be identical or different. The substituents optionally present in the alkyl and alkoxy groups may be for example halogen atoms, preferably fluorine, chlorine and/or bromine, or nitro groups. The substituents optionally present on aryl and aryloxy groups may be for example d-C6 alkyl groups, preferably methyl or ethyl, halogen atoms, preferably fluorine, chlorine and/or bromine, or nitro groups. In the meaning of alkyl and alkoxy, A preferably contains 1 to 6 C atoms, in particular 1 to 2 C atoms, and in the meaning of aryl and aryloxy A preferably stands for phenyl. In Formulae (I) and (II), R and R' may for example stand for hydrogen, straight-chain or branched, non-substituted or substituted C1-C12 alkyl or non-substituted or substituted phenyl. Suitable substituents for alkyl groups are for example halogen atoms or nitro groups, and suitable substituents for aryl groups are for example C1-C6alkyl groups, halogen atoms or nitro groups. In Formula (II), R' may additionally stand for chlorine, bromine or iodine, in particular for chlorine or bromine. Preferably R and R' stand for hydrogen, or R' stands for chlorine and R for fluorine. In Formula (II) X preferably stands for chlorine or bromine. Preferably fluoromalonic acid dialkylesters and difluoromalonic acid dialkylesters are prepared. "Alkyl" here stands for C1-C4. Examples which can be prepared are also 2,2-difluoropropionic acid and its derivatives such as esters, for example C1-C4 alkyl or aryl esters, from the corresponding 2,2-dichloropropionic acid compounds. As has already been described in German Offenlegungsschrift 199 42 374, the hydrofluoride adduct may be used as fluorination agent. It should then be used in such a quantity, or the reaction is carried out for such a time, that the hydrofluoride adduct is not dehydrofluorinated to such an extent that HCI adducts form. Otherwise regeneration with hydrogen fluoride is recommended. As already described in DE-OS 199 42 374, it is also possible to use the hydrofluoride adduct as catalyst. Then HF is introduced into the reaction as fluorination agent. The quantity of HF is advantageously at least 1 mole HF/gram atom of chlorine to be exchanged. Spent HF adduct can be regenerated by means of HF. Since in this case the hydrofluoride adduct acts as a catalyst, a continuous procedure is possible. Another embodiment covers the addition of HF to nucleophilic or electrophiiic C-C double or triple bonds. The preferred starting material is unsaturated aliphatic hydrocarbon compounds, which may be substituted by 1 or more halogen atoms. Preferred compounds are those having a C2-C4 chain. Particularly preferably, these are substituted by at least 1 chlorine or fluorine atom. For example, HF can be added to hexafluoropropane for the preparation of 1,1,1,2,3,3,3-heptafluoropropane or also to tetrafluoroethylene for the preparation of pentafluoroethane. The method according to the invention can preferably be performed without solvent. This may be advantageous, since the working-up is simpler and no interactions such as secondary reactions with the solvent need be feared. The process can however alternatively also be carried out such that during or preferably after the reaction a solvent is added which causes the formation of two liquid phases, one phase containing the solvent and the organic compound and the other phase containing the amine/HF adduct, so that separation of organic compounds from their mixtures with amine/HF adducts is possible in a simple manner. Of course, the process also operates to separate mixtures containing two or more organic compounds. This embodiment with phase formation will now be described further. Mixtures of amine/HF adducts and organic compounds result for example from fluorination reactions, if hydrogen fluoride is fed in during the fluorination reaction and/or the amine/HF adduct is not used as fluorination agent to such an extent that after the reaction no more amine/HF adduct is present, but amine/HCI adduct, if it is a chlorine/fluorine exchange reaction. Corresponding procedures are described for example in German Offenlegungsschrift 199 42 374 and German application ... (101 04 663.4), which does not constitute a prior publication. Preferably the process with 2-phase formation is used for the separation of those organic compounds which are substituted by at least one fluorine atom. For example hydrocarbons, cycloaliphatic hydrocarbons, aromatic hydrocarbons, ester, thioesters or ketones substituted by at least one fluorine atom may be separated .off. The process is of course particularly advantageous when applied to organic compounds which cannot be separated, or can be separated only poorly, with conventional methods such as distillation directly from the mixture with amine/HF adducts or by aqueous working-up. These are for example [with] compounds having a boiling point higher than 50°C, or thermolabile compounds which do not withstand temperatures for example above 50°C without decomposing. The process is however in any case advantageous, since according to the invention the amine/HF adduct is not hydrolysed upon working-up. A further subject of the invention is novel hydrofluoride adducts of 1,5-diazabicyclo[4.3.0]-non-5-ene (DBN) and 1,8-diazabicyclo[5.4.0]-undec-7-ene (DBU), in the case of DBU with the proviso that the molar ratio of HF to the amine is greater than 1:1. They preferably have the formulae: DBN(HF)Xl wherein x is equal to 1 or stands for 1 DBU.(HF)y, wherein y stands for 1 The subject of the invention is also HF adducts of N-dialkylaminopyridine wherein alkyl signifies C1-C4, in particular adducts wherein the molar ratio of HF to the amine is greater than 1:1, preferably is equal to or less than 9; very particularly, HF adducts wherein alkyl stands for methyl. The process according to the invention makes it possible to perform the fluorine/chlorine exchange with high yield, particularly for diketones and diesters. The following examples are intended to explain the invention further, without limiting its scope. Examples 1 to 6: Chlorine/fluorine exchange on diesters General reaction equation: (Equation Removed) Fluorination tests with DBU and DBN-HF/amine complexes In the absence of a solvent Example 1: Batch: 0.15 mol diethyl 2-chloromalonate 29.3 g 0.3 mol 1,5-diazabicyclo[4.3.0]-non-5-ene x 1.73 HF 54.4 g Set-up and Performance: The amine complex was placed in a 100 ml PFA flask with reflux condenser (water cooling), then the diethyl chloromalonate was added and the mixture was heated to a constant temperature of 80°C in an oil bath while being stirred. After 1, 3, 6 and 12 hours, samples were taken from the solution. These were hydrolysed and dried with sodium sulphate and sent for GC analysis. After 12 hours 91.23% of the educt had reacted to form diethyl fluoromalonate. The selectivity was quantitative. Example 2: Batch: 0.15 mol diethyl 2-chloromalonate 29.3 g 0.3 mol 1,8-diazabicyclo[5.4.0]-undec-7-ene x 1.37 HF 56.5 g Set-up and Performance: The amine complex was placed in a 100 ml PFA flask with reflux condenser (water cooling), then the diethyl chloromalonate was added and the mixture was heated to a constant temperature of 80°C in an oil bath while being stirred. After 1, 3, 6, 12, 18 and 24 hours, samples were taken from the solution. These were hydrolysed and dried with sodium sulphate and sent for GC analysis. After 24 hours 72.5% of the educt had reacted to form diethyl fluoromalonate. The selectivity was quantitative. Example 3: Batch: 0.10 mol diethyl 2-chloromalonate 19.5 g 0.05 mol 1,5-diazabicyclo[4.3.0]-non-5-ene x 2.93 HF 8.8 g Set-up and Performance: The amine complex was placed in a 100 ml PFA flask with reflux condenser (water cooling), then the diethyl chloromalonate was added and the mixture was heated to a constant temperature of 80°C in an oil bath while being stirred. During the reaction, the solution darkened from orange to dark red. After 1, 3, 6, 12 and 18 hours, samples were taken from the solution. These were hydrolysed and dried with sodium sulphate and sent for GC analysis. After 18 hours 21.8% of the educt had reacted to form diethyl fluoromalonate with quantitative selectivity. Example 4: Batch: 0.10 mol diethyl 2-chloromalonate 19.5 g 0.05 mol 1,8-diazabicyclo[5.4.0]-undec-7-enex3.09 HF 10.7 g Set-up and Performance: The amine complex was placed in a 100 ml PFA flask with reflux condenser (water cooling), then the diethyl chloromalonate was added and the mixture was heated to a constant temperature of 80°C in an oil bath while being stirred. After 1, 3 and 6 hours, samples were taken from the solution. These were hydrolysed and dried with sodium sulphate and sent for GC analysis. After 6 hours 4.1% of the educt had reacted to form diethyl fluoromalonate. Example 5: (Comparison example) without solvent Batch: 0.23 mol diethyl 2-chloromalonate 53.1 g 0.16 mol triethylamine x 2.72 HF 24.6 g Set-up and Performance: The diethyl chloromalonate was placed in a 100 ml multi-necked flask with reflux condenser (water cooling), then the triethylamine complex was added dropwise with stirring. The solution was heated to a constant temperature of 100°C in an oil bath. After 3 and 6 hours, samples were taken from the solution. These were hydrolysed and dried with sodium sulphate and sent for GC analysis. After 6 hours 3.3% of the educt had reacted to form diethyl fluoromalonate. Example 6: Comparison test in the presence of solvent with triethylamine x HF complex Batch: 0.375 mol diethyl 2-chloromalonate 73.125 g 0.5 mol triethylamine x 2.72 HF 0.25 mol triethylamine 125 ml acetonitnle Set-up and Performance: The amine complex was placed in a 100 ml PFA flask with reflux condenser (water cooling) and the acetonitrile was added, then the diethyl chloromalonate was added thereto and the mixture was heated to a constant temperature of 80°C in an oil bath while being stirred. After 1, 3, 6, 12, 18 and 24 hours, samples were taken from the solution. These were hydrolysed and dried with sodium sulphate and sent for GC analysis. After 24 hours 66.02% of the educt had reacted to form diethyl fluoromalonate. Examples 7 to 11: Preparation of acid fluorides: (Equation Removed) Set-up and performance: (applies to all examples for the preparation of acid fluorides) The amine complex was placed in a 100 ml PFA flask with a reflux condenser and dropping funnel. The reflux condenser was fed with cold brine at a temperature of -30°C via a cryomat. In order to collect the reaction product, a steel cylinder (having a volume of approx. 300 ml) with dip pipe and gas outlet was connected after the condenser, the cylinder being heated to a temperature of -78°C in a Dewar flask with CO/methanol. S02CI2 was introduced into the oily, light-yellow solution slowly and with vigorous stirring at room temperature. A short time after introduction had begun, evolution of gas was observed. Once dropwise addition had ended, an oil bath at 100°C was placed under the flask and heating was continued for 1 h with cooling and 1 h without cooling in order to expel the resulting S02F2 completely. Example 7: Batch: 0.20 mol sulphuryl chloride S02CI2 26.99 g 0.24 mol 1,5-diazabicyclo[4.3.0]-non-5-ene x 2.67 HF 42.50 g Evaluation: After performing the above-mentioned general test procedure, 57.70% S02F2 and 35.27% S02FCI relative to the quantity of educt used could thus be isolated. Example 8: Batch: 0.20 mol sulphuryl chloride S02CI2 26.99 g 0.127 mol 1,5-diazabicyclo[4.3.0]-non-5-ene x 7.19 HF 42.50 g Evaluation: After performing the above-mentioned general test procedure, 90.65% S02F2 and 0.34% S02FCI relative to the quantity of educt used could thus be isolated. Example 9: Batch: 0.20 mol sulphuryl chloride S02CI2 26.99 g 0.253 mol 1,8-diazabicyclo[5.4.0]-undec-7-ene x 5.58 HF 40.90 g Evaluation: After performing the above-mentioned general test procedure, 0.04% S02F2 and 69.87% S02FCI relative to the quantity of educt used could thus be isolated. Example 10: (Comparison example) Batch: 0.20 mol sulphuryl chloride S02CI2 26.99 g 0.21 mol pyridine x 2.93 HF 28.50 g Evaluation: After performing the above-mentioned general test procedure, 5.03% S02F2 and 28.12% S02FCI relative to the quantity of educt used could thus be isolated. Example 11: Batch: 0.15 mol sulphuryl chloride S02CI2 20.25 g 0.16 mol 4-dimethylaminopyridine x 2.93 HF 28.90 g Evaluation: After performing the above-mentioned general test procedure, 16.40% S02F2 and 21.76% S02FCI relative to the quantity of educt used could thus be isolated. Example 12: Preparation of diethyl monofluoromalonate with extraction with ethyl trifluoroacetate (EtO)C(0)-CHCI-C(0)(OEt).(EtO)C(0)CHF-C(0)(OEt) 0.1 mol diethyl 2-chloromalonate was reacted with 0.2 mol 1,5-diazabicyclo[4.3.0]-non-5-ene-1.4 HF at 80°C over a period of 6 hours. After cooling, ethyl trifluoroacetate was added to the reaction mixture. Two phases formed. The phase containing the product and the solvent was separated off and the ethyl trifluoroacetate was distilled off to isolate the product. The phase separation was observed in the range from 25 to 70 mole percent. Example 13: Preparation of diethyl difluoromalonate with extraction with ethyl trifluoroacetate (EtO)C(0)-CCI2-C(0)(OEt).(EtO)C(0)CF2-C(0)(OEt) As in Example 1, 0.6 mol 1,8-diazabicyclo-[5.4.0]-undec-7-enel9 HF was reacted with 0.15 mol of the dichloromalonate. After the addition of ethyl trifluoroacetate, the resulting phases were separated and the product isolated. Test of further extracting agents: Phase separation could likewise be achieved with isopropyl trifluoracetate, trifluorotrichloroethane, hexane and cyclohexane. The extracting agent could then be separated off by means of flash distillation and the product could be precision-distilled. WE CLAIM:- 1. A process for the preparation of fluroine-containing compounds of the kind such as herein described from halogen-containing, preferably chlorine-containing, compounds with halogen/fluorine exchange or by HF addition to C-C multiple bonds of the kind such as herein described in the presence of the HF adduct of a mono- or bicyclic amine with at least 2 nitrogen atoms, at least 1 nitrogen atom being incorporated into the ring system, as catalyst or fluorination agent. 2. A process as claimed in claim 1, wherein the HF adduct of a mono-or bicyclic compound with 2 nitrogen atoms is used, one or both nitrogen atoms being incorporated into the ring system. 3. A process as claimed in claim 1 or 2, wherein a compound selected from the group of amino-substituted pyridines and bicyclic amines is used as mono-or bicyclic compound. 4. A process as claimed in claim 3, wherein the mono- or bicyclic compound is selected from the group consisting of diazabicyclonoane, diazabicycloundecane and dialkylaminopyridine. 5. A process as claimed in claim 1, wherein the inorganic or organic acid fluorides are prepared from corresponding acid chlorides. 6. A process as claimed in claim 5, wherein the sulphuryl chloride fluoride or sulphuryl fluoride are prepared. 7. A process as claimed in claim 1, wherein fluorine-containing compounds with a C-F bond are prepared from chlorine-containing compounds with a C-Cl bond. 8. A process as claimed in claim 7, wherein the fluorine-containing carbon or hydrocarbon compounds are prepared. 9. A process as claimed in claim 7, wherein the fluorine-containing carboxylic acid derivatives or carboxylic acid fluorides are prepared. 10. A process as claimed in claim 9, wherein the alkylene-bridged dicarboxylic acid derivatives are prepared, which are substituted in the alkylene bridge by at least 1 fluorine atom. 11. A process as claimed in claim 10, wherein the mono- or difluoromalonic acid esters are prepared. 12. A process as claimed in claim 1, wherein the HF adduct of the mono- or bicyclic compound is used as catalyst and hydrogen fluoride as fluorination agent. 13. A process as claimed in claim 1, wherein the spent HF adducts of the mono- or bicyclic compound are worked up again using hydrogen fluoride. 14. A process as claimed in claim 1, wherein organic compounds substituted by at least 1 fluorine atom are prepared, with a mixture of amine/HF adducts and the compound(s) substituted by at least 1 fluorine atom resulting, and a solvent is added which brings about the formation of two liquid phases, one phase containing the solvent and the organic compound(s) and the other phase the amine/HF adduct.

Documents:

1340-delnp-2003-abstract.pdf

1340-delnp-2003-claims.pdf

1340-delnp-2003-complete specification (granted).pdf

1340-delnp-2003-correspondence-others.pdf

1340-delnp-2003-correspondence-po.pdf

1340-delnp-2003-description (complete).pdf

1340-delnp-2003-form-1.pdf

1340-delnp-2003-form-13.pdf

1340-delnp-2003-form-19.pdf

1340-delnp-2003-form-2.pdf

1340-delnp-2003-form-3.pdf

1340-delnp-2003-form-5.pdf

1340-DELNP-2003-GPA.pdf

1340-delnp-2003-pct-304.pdf

1340-delnp-2003-petition-137.pdf

1340-delnp-2003-petition-138.pdf