JPS6254088B2 - - Google Patents

Description

[Detailed description of the invention]

This invention relates to an improved method for the fluorination of polycyclic hydrocarbons. More particularly, the present invention relates to an improved process for the fluorination, preferably perfluorination, of such hydrocarbons using a three-step reaction that effectively eliminates the production of undesired by-products. U.S. Patent No. 3,641,167 and parallel pending
Application No. 647,944, filed January 12, 1976, discloses a one-step process for making perfluoroalkyl adamantanes. Recent data using new analytical techniques now indicate that under the reaction conditions used herein using CoF ₃ and high temperatures, decomposition of the non-fluorinated ring structure with the formation of ring-opened products. According to the present invention, (1) the starting cyclic compound is partially fluorinated with a mild fluorinating agent under mild conditions in a first step, followed by (2) in a second step. reacting the partially fluorinated material with a strong fluorinating agent at a temperature just above the boiling point of the material to form a more highly fluorinated compound;
Thereafter, (3) the above-mentioned more highly fluorinated compounds are recycled into the same second stage reactor at substantially higher temperatures to produce essentially perfluorinated compounds free of any decomposed ring-cleaved compounds. It has now been discovered that polycyclic hydrocarbons can be perfluorinated with substantially no decomposition of the ring structure. The starting material for the improved perfluorination process of the present invention is a non-aromatizing polycyclic hydrocarbon selected from the group consisting of alkyladamantanes as described in U.S. Pat. No. 3,641,167. , 11~
1,3-dimethyladamantane, 1, having 30 carbon atoms, preferably 12 to 14 carbon atoms;
3,5-trimethyladamantane, 1-ethyladamantane, 1-methyladamantane, 1-ethyl-3-methyladamantane, 1-ethyl-3.
such as 5-dimethyladamantane, endo- and exo-tetrahydrodicyclopentadiene, 1,4-methanodecalin or 1,4,5-
It consists of methanodecalins such as 8-dimethanodecalin, hydrogenated pinene, camphuan, bicyclooctane, bicyclononane, etc. When these compounds are treated by the method of the invention, the corresponding perfluorinated polycyclic materials are obtained in high yield and purity, containing at least 95% and preferably 97% to 100% of hydrogen atoms. is replaced by a fluorine atom. Generally, according to the improved process, the conversion of the starting material to the corresponding perfluorinated compound is at least 50%, and most usually about 90% or more. These perfluorinated materials are useful in a variety of industrial and pharmaceutical applications. For example, alkyl adamantane fluorides are used in gas turbine coolants, transformers,
It is useful in dielectric coolants such as electrical generators, as well as components of synthetic blood compositions, perfusion media and similar biological applications. Perfluorinated cyclic materials are also useful as working fluids in heating tubes and Rankin cycle engines. The first step of the above process to provide a partially fluorinated intermediate is that the polycyclic hydrocarbons or their hydroxylated or carbonylated derivatives are converted into HF, HF, or HF, depending on the fluorinating agent used. - a fluorinating agent selected from the group consisting of pyridine complexes, AgF ₂ , MnF ₃ , SF ₄ , SbF ₅ , KCoF ₄ and fluoroolefins, and at various temperatures depending on the nature of the starting materials and the fluorinating agent used. This is carried out by contacting in a liquid phase under conditions such as , pressure, etc. These fluorinating agents are much milder in their action than CoF ₃ on hydrocarbons. As a result, the degree of fluorination can be controlled by appropriate selection of agents and starting materials. It has been found that the introduction of about 3 to 6 fluorine atoms into the hydrocarbon generally stabilizes the material against the more severe conditions used for intensive fluorination, e.g. with _CoF3 . . Generally, in this first partial fluorination step, the fluorinating agent may be reacted directly with the polycyclic hydrocarbon itself or, if desired, with a partially chlorinated or brominated derivative thereof. You can react. However, one exception to this is that these compounds
SF ₄ or dialkylaminosulfur fluoride, in which case the cyclic starting material must be carbonylated before it can be satisfactorily reacted with SF ₄ or dialkylaminosulfur fluoride. Thus, for example in the case of alkyladamantanes, these compounds should be converted into their corresponding ketone, aldehyde, acid or hydroxy derivatives before suitably reacting with SF ₄ or dialkylaminosulfur reagents. Illustrative methods of producing these adamantylcarbonyl derivatives are given, for example, in U.S. Pat.
33567403356741 (adamantyl ketone and diketone derivatives): US Patent 3250805 (adamantyldicarboxylic acid): US Patent 3383424, 3356718 and
3356709 (Adamantyl dihydroxide and dicarboxylic acids). Other similar reactions will be recognized and understood by those skilled in the art. Similarly other such carbonylated polycyclic starting materials can be made according to similar known techniques. Partial (i.e., first stage) fluorination of a polycyclic starting material is generally referred to when SF ₄ or fluorinated dialkylamino sulfur is used as the fluorinating agent. It will therefore be understood from the foregoing description that carbonyl derivatives are intended to be included. Besides the use of carbonyl derivatives of perfluorinated cyclic substances when SF ₄ is used, HF or HF
- The use of analogous known alcohol derivatives of these compounds when the pyridine complex is the partially fluorinating agent, and also the use of chlorinated or brominated derivatives when SbF ₅ is used. Alternatively, a cyclic diene such as 1,3-cyclohexadiene can be reacted with a fluoroolefin such as hexafluoro-propene in a Diels-Alder type reaction to form a partially fluorinated polycyclic diene, as detailed below. The formula hydrocarbon is obtained. These materials are then also perfluorinated according to the invention. These aforementioned Diels-Alder reaction products can thus also be included in the general definition of partially fluorinated polycyclic hydrocarbons which can then be perfluorinated, for example with CoF ₃ as described above. intended. It is thus within the scope of the present invention to completely fluorinate partially fluorinated and therefore stabilized cyclic hydrocarbons, regardless of how they are produced. It should be clear from the description. The amount of fluorination required to impart ring stability to the polycyclic material prior to reacting the polycyclic material with a strong fluorinating agent such as CoF ₃ in the second and third steps of the process of the invention. Although not critical, it should desirably include fluorine substitution of about 3 to 6 hydrogen atoms to as much as 50% of such hydrogen atoms. The position of these fluorine atoms can be either the nucleus or the side chain of the hydrocarbon molecule, or both. The product of the first stage fluorination may therefore contain either a single product of partially fluorinated substances or a mixture thereof, depending on the fluorinating agent used. This product is converted into CoF ₃ in the next step
The first fluorinating agent should first be separated, preferably by distillation, from the first fluorinating agent. In the second step of the process, the objective is to achieve as high a degree of fluorination as possible without degrading the cyclic structure of the compound. The effect of this fluorination step is that it provides much greater stability such that virtually 100% perfluorination can be achieved in the final step under much more severe reaction conditions without the formation of ring degradation by-products. fluorinated polycyclic substances. A high degree of fluorination in the second stage of 75% to 95% perfluorination is achieved by charging the partially fluorinated hydrocarbon mixture in the vapor phase (by preheating) at a moderate charge rate. CoF ₃ within a temperature range extending from just above the boiling point of the substance to approximately 50°C above its boiling point.
This is easily achieved by contacting with. Preferably a multi-zone reactor with gradually increasing temperatures from just above the boiling point to 50° above should be used. Since the reaction is exothermic, care should be taken to control the temperature within approximately these ranges to avoid decomposition of the molecules. The last step, also carried out in the vapor phase, consists of recycling the highly fluorinated products of the CoF ₃ reaction back to the same reactor, which is now at a significantly higher temperature, That is, heating is performed stepwise through the reactor at a temperature ranging from about 25°C to about 130°C above the temperature initially used in the advanced fluorination step to substantially increase the temperature. Complete fluorination is achieved, giving yields of approximately 50-95% based on the amount of original feedstock. The perfluorinated product is collected in several cooling traps as the perfluorinated product is removed from the reactor to collect not only the product but also the HF and any other gaseous products. It is preferably then cooled by passing it through a temperature of about 0°C to 80°C. The invention will now be illustrated by the following examples. The following four examples illustrate the production of partially fluorinated adamantanes that can be subsequently perfluorinated according to the method of the invention. Example 1 Adamantane dicarboxylic acid (22.4 g, 0.1 mol) and SF ₄ (27.0 g, 25% excess) were heated in a Hoke bomb at 110° C. for 24 hours. The contents of the pressurized vessel were cooled, extracted with CCl ₄ , filtered and the CCl ₄ removed by evaporation. The residue consisted of 21.8 g of bistrifluoromethyladamantane (80% yield). Example 2 2-adamantanone (15.0 g, 9.1 mol) and
SF ₄ (13 g, 25% excess) was heated as in Example 1. The product was worked up as described in Example 1 to give 12.9 g of 2,2-difluoroadamantane (75% yield). Example 3 5,7-dimethyl-1,3-adamantanedicarboxylic acid (25.2 g, 0.1 mol) and SF ₄ (27.0 g,
(25% excess) was heated and worked up as in Example 1 to give 18 g of 3,5-dimethyl-5,7-bis(trifluoromethyl)adamantane (60%). Example 4 1,3-dimethyladamantane (42 g) was slowly added to a slurry of MnF ₃ (1 lb.) in perfluoro 1-methyldecalin. After all the hydrocarbons have been added, the mixture is heated to 200 °C for 24 hours with rapid stirring, and the product is extracted with Freon 113 and Perfluoro 1.
- methyldecalin was distilled to remove both. The distillation residue consists of partially fluorinated 1,3-dimethyladamantane, for example C ₁₂ H ₁₂ F ₈ , whose molecules contain on average approximately 8 fluorine atoms. Example 5 Bistrifluoromethyladamantane (24 c.c.; 33.67 g, 0.123 mol) from Example 1 was added at 0.247 m/min.
cc was placed in the preheater. Preheater temperature is 250℃
and the CoF ₃ reactor temperature was gradually increased from 250°C in zone 1 to 300°C in zone 4. The product line was kept at 225°C. After all the hydrocarbons have been charged to the reactor, the reactor is flushed with nitrogen.
Purged for 3.25 hours. The crude product weighed 46.0g. This material was washed with water until the pH of the water was 5. This material from the second stage was dried overnight over molecular sieves and then 45.84 g was added to Zone 1 at a rate of 0.764 cc per minute.
The reaction vessel was reloaded for the final stage, which was increased gradually from 275°C in zone 4 to 380°C in zone 4. The reaction vessel was purged with nitrogen for 4 hours before removing the vessel containing 47.8 g of cooled condensed product. Fluorocarbon has a material balance of 75%. Gas chromatography analysis showed that the product contained 90% perfluoro-1,3-dimethyladamantane. This was confirmed by mass spectrometry and 19F NMR. A similar experiment was conducted with 1,3-bis(trifluoromethyl)-5,7-dimethyladamantane to give perfluorotetramethyladamantane in 55% yield. Melting point 132°C In a similar manner, Example 2 and Example 3 2.
2-difluoroadamantane and 3,5-dimethyl-5,7-bis(trifluoromethyl)adamantane were reacted with CoF ₃ according to the procedure of Example 5 to give the corresponding perfluoroadamantane in high purity and high yield. Gave. Comparative Example The following comparative example illustrates the results obtained when the first (partial) inventive fluorination step was not used. Exotetrahydrodicyclopentadiene (25
cc24.15 g, 0.1776 mol) was charged into the preheater at 0.494 cc per minute. Preheater temperature is 225℃,
CoF ₃ reactor temperature ranges from 200°C in zone 1 to 200°C in zone 4.
The temperature was gradually increased to 250°C. Product line is 225℃
was kept. After all the hydrocarbons were charged to the reaction vessel, the reaction vessel was purged with nitrogen for 3.25 hours. The crude product weighed 63.6g. This material was washed with water until the pH of the water was 5. The material from the second stage was dried over molecular sieves and then 55.84 g was recharged at a rate of 0.764 cc per minute into the reaction vessel ramped from 300°C in the first zone to 375°C in zone 4 for the final stage. It was done. The reaction vessel was purged with nitrogen for 4 hours before removing the vessel which received the cooled condensed product containing 60.8 g of fluorocarbon. 24.15g of prepared THDCP
87% substance balance based on . Gas chromatography analysis revealed that the products were 40% endo- and exo-perfluoro-tetrahydrodicyclopentadiene and 45% perfluorobicyclo [3.5.
0] decane and ~15% unknown fluorocarbon.

Table Tadiene Example 6 Exo-tetrahydrodicyclopentadiene (35 g) was slowly added to a slurry of MnF ₃ (1 lb.) in penfluoro(1-methyl)decalin solvent. After all the hydrocarbons were added, the mixture was heated to 200°C and stirred rapidly for 24 hours. The product was extracted with Freon 113 and distilled to remove both Freon 113 and perfluoro(1-methyl)decalin. The distillation residue is a partially fluorinated tetrahydrodicyclopentadiene whose molecules contain on average approximately 7 fluorine atoms;
It consists of C ₁₀ H ₉ F ₇ . When the partially fluorinated tetrahydrodicyclopentadiene thus obtained is then perfluorinated with CoF ₃ according to the procedure of Example 5, substantially pure exo- and endo-perfluorotetrahydrogen A high yield of dicyclopentadiene is obtained, which is essentially free of any by-products mentioned in the comparative examples. Example 7 Following the procedure of Example 6 but replacing partially fluorinated tetrahydrodicyclopentadiene with partially fluorinated camphuan hydrogenated pinane, 1,4-methanodecalin or 1,4-
Instead of 5,8-dimethanodecalin, the corresponding perfluorinated cyclocarvone was obtained in high yield and virtually without any ring-opened degradation by-products. Example 8 As shown above, for example, fluoroolefins and acetylenes readily undergo Diels-Alder type reactions and act as dienophiles in 1,4-cycloaddition reactions. Their reactivity toward dienes is generally higher than their hydrocarbon analogs. The following example shows that a partially fluorinated perfluorocyclocarbon can then be thoroughly fluorinated according to the procedure of Example 5 to give a perfluorocyclocarbon in high yield and with virtually no ring-opening side products. The production of fluorinated cyclocarbon is illustrated. A 1,3-cyclohexadiene (1 mol) is 25
% molar excess of hexafluoropropene and about 150
C. for 24 hours to give 2-(trifluoromethyl)2.3.3-trifluoro-bicyclo[2.2.2]octene. 2-(trifluoromethyl) by hydrogenation over rhodium
2,3,3-trifluoro-bicyclo[2.
2.2] Octane is obtained. B Similarly, cyclopentadiene and hexafluoro-but-2-yne were reacted at 100°C for 24 hours to obtain 2,3-bis(trifluoromethyl)bicyclo[2.2.1]heptadiene, which was then mixed with palladium When hydrogenated above, 2,3-bis(trifluoromethyl)bicyclo[2.2.
1] Heptane is obtained. C In addition, when octafluoro-but-2-ene and cyclopentadiene are reacted in a similar manner, 2.3
-difluoro-2,3-bis(trifluoromethyl)bicyclo[2,2,1]heptene is obtained, which is hydrogenated over ruthenium to give 2,
3-bis(trifluoromethyl)bicyclo[2.2.1]heptane is obtained. Example 9 Norbornadiene (1 mol) and 25% molar excess of hexafluorocyclopentadiene at 100°C
heat for an hour was obtained and after treatment with CoF ₃ according to the procedure of Example 5 highly pure perfluorinated 1.4.5.8-
Produces dimethanodecalin.

Claims (1)

[Scope of Claims] 1 (1) A non-aromatic, non-aromatizable polycyclic hydrocarbon and its carbonyl, aldehyde, carboxyl, hydroxy, chlorinated, or brominated derivative in a liquid phase in a first reaction zone. HF, HF-pyridine,
partially fluorinating the polycyclic hydrocarbon by contacting it with a fluorinating agent selected from the group consisting of Ag, F ₂ , MnF ₃ , SF ₄ , SbF ₅ , KCoF ₄ and fluoroolefin; 2) The partially fluorinated polycyclic hydrocarbon is then heated in the vapor phase in a second reaction zone at a temperature not exceeding 50°C above the boiling point of the fluorinated material.
Further fluorination with CoF ₃ results in approximately 95% perfluorination
(3) recovering and recycling said highly fluorinated material to said second reaction zone; and this material is heated in the vapor phase to a temperature lower than that originally used in (2) above, to about
A non-containing process consisting of re-contacting the CoF ₃ at stepwise increases in temperature ranging from 25°C to 130°C to give a substantially perfluorinated polycyclic hydrocarbon. A method for perfluorinating aromatic and non-aromatizable polycyclic hydrocarbons. 2. The method of claim 1, wherein the temperature of the first reaction zone is in the range of about 175-350<0>C. 3. The temperature of step (2) ranges from just above the boiling point of the partially fluorinated material sent from the first reaction zone in the first part of the second reaction zone to the temperature at the end of the second reaction zone. 2. A process according to claim 1, wherein the temperature is gradually increased to 50<0>C above the boiling point of the portion. 4. Claim 1 in which the polycyclic hydrocarbon is an alkyl adamantane having 11 to 30 carbon atoms.
The method described in section. 5. The process of claim 4, wherein the fluorinating agent in the first reaction zone is SF ₄ and the alkyl adamantane is a carbonylated derivative thereof. 6 Polycyclic hydrocarbon is alkyl adamantane, 1
-ethyladamantane, 1-methyladamantane, 1-ethyl-3-methyladamantane, or 1-ethyl-3,5-dimethyladamantane. 7. The method according to claim 1, wherein the polycyclic hydrocarbon is exo- or endo-tetrahydrodicyclopentadiene. 8. The method according to claim 1, wherein the polycyclic hydrocarbon is bicyclooctane or bicyclononane. 9. The method according to claim 1, wherein the polycyclic hydrocarbon is methanodecalin. 10 (1) Partially fluorinated polycyclic hydrocarbons in the vapor phase above the boiling point of the fluorinated substance 50
Further fluorination with CoF ₃ in the reaction zone at a temperature not exceeding , (2) recovering and recycling the highly fluorinated material to the reaction zone and treating it in the vapor phase with (1)
The substantially perfluorinated polycyclic compound is then re-contacted with CoF ₃ at stepwise temperatures ranging from approximately 25°C to 130°C above the temperature at which it was originally used. A method for perfluorinating non-aromatic and non-aromatizable polycyclic hydrocarbons, comprising providing a hydrocarbon. 11. The temperature of step (1) ranges from just above the boiling point of the charged partially fluorinated material in the first part of the reaction zone to above the boiling point in the last part of the reaction zone. 11. A method according to claim 10, wherein the temperature is gradually increased to above 50<0>C. 12. The method of claim 10, wherein the partially fluorinated hydrocarbon is partially fluorinated adamantane. 13. The method of claim 10, wherein the partially fluorinated hydrocarbon is partially fluorinated tetrahydrodicyclopentadiene. 14. The method of claim 10, wherein the partially fluorinated hydrocarbon is partially fluorinated bicyclooctane or bicycloheptane. 15. The method of claim 10, wherein the partially fluorinated hydrocarbon is partially fluorinated methanodecalin.