JP4684402B2 - Method for producing perfluoroalkadiene - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing α, ω-perfluoroalkadiene that can be used as a raw material for a polymer or an etching gas for a semiconductor.
[0002]
[Prior art]
As the most typical method for synthesizing α, ω-perfluoroalkagen, perfluorobutadiene, a compound having 4 carbon atoms, has been studied for a long time.
For example, R.A. N. Haszeldine; Chem. Soc. , The 4423 (1952), to give the CClF ₂ -CClFI by the addition of ICl to a CClF = CF ₂ in the raw material, followed by the presence of Hg, to synthesize CClF ₂ -CClF-CClF-CClF ₂ by photoreaction, It has been reported that CF ₂ = CF-CF = CF ₂ is obtained by treating this with zinc in ethanol. However, in this method, there are many steps, and there are problems such as using environmentally undesirable raw materials such as mercury.
[0003]
R. N. Haszeldine, J. et al. Chem. Soc. In 4026 (1954), reported the synthesis of _{CF 2 = CF-CF = CF} 2 by thermal decomposition of the perfluoro adipate. However, this reaction is not preferable as an industrial production method because the yield is low and isomers are produced in large quantities.
[0004]
W. T.A. In US Pat. No. 2,668,182 by Miller, CClF═CF ₂ is used as a raw material to react in a Pyrex tube at 550 ° C. to obtain CF ₂ ═CF—CClF—CClF ₂ , which is chlorinated or bromination, after conversion respectively CClF ₂ -CClF-CClF-CClF ₂ or _{CBrF 2 -CBrF-CClF-CClF 2} , the aforementioned J. Chem. Soc. , 4423 (1952), a dehalogenation reaction is performed with zinc to obtain CF ₂ = CF-CF = CF ₂ . In this reaction, the yield of the reaction for obtaining the first stage CF ₂ = CF—CClF—CClF ₂ is low, and there are many by-products, so this is also not an industrially suitable method.
[0005]
G. Bargilia, V. Tortelli, C.I. Tonelli, S.M. Mondena et al., European Patent Application 0 270 956, JP 62-26240, E. S. Elizabath: J.M. Org. Chem. , 36 (1971) 364, etc., produced by telomerization reaction of XCF ₂ —CF ₂ X (X═I, Br) obtained by adding iodine or bromine to CF ₂ ═CF ₂ as a raw material. XCF ₂ —CF ₂ —CF ₂ —CF ₂ X is reacted with an organometallic compound of Mg, Zn, Cd or Li in an aprotic solvent in the range of −80 ° C. to + 150 ° C. to give CF ₂ ═CF—CF═ Reactions to obtain CF ₂ have been reported. In this method, the raw material XCF ₂ —CF ₂ —CF ₂ —CF ₂ X can be obtained relatively easily, and it can be said that this method is relatively easy to industrialize. However, the halogen to be eliminated is limited to expensive bromine, iodine and fluorine, and inexpensive chlorine cannot be used. Further, since a large amount of highly active organometallic compound is required in the dehalogenation reaction, it is still not suitable for industrialization.
[0006]
This is because organometallic compounds have the following problems.
(1) Since it is sensitive to moisture, special care is required not to hydrolyze.
(2) Organometallic compounds are associated with considerable danger during production. For example, when synthesizing a Grignard reagent, if the reaction is miscontrolled, such as when cooling is insufficient, the reaction may run away and proceed explosively. Is often seen.
(3) Since organometallic compounds are extremely active compounds that easily react with moisture, oxygen, etc., it is difficult to store and use them in large quantities, and industrial handling is considered dangerous in terms of storage.
{Circle around (4)} The organometallic compound is quite expensive for the above reasons, and it is considered disadvantageous in terms of cost to use it in large quantities industrially.
[0007]
[Problems to be solved by the invention]
In view of the above-mentioned drawbacks of the prior art, the main object of the present invention is to provide a method for producing perfluoroalkadienes that is safe and suitable for industrial practice, in which these drawbacks are greatly reduced or eliminated. It is said.
[0008]
Thus, in the present invention, a molecule containing a chlorine atom can be used for the reaction, so that a cheaper compound can be used. For example, I.I. L. Knunants and G.K. G. Yakobson (Eds.): Synthesis of Fluoroorganic Compounds, P.M. 16 (1985) Springer-Verlag provides the above production method in which 1,2-dichloro-4-iodoperfluorobutane, which can be easily produced using chlorotrifluoroethylene as a raw material, can be used as a raw material. .
[0009]
An object of the present invention is to provide a method capable of industrially and inexpensively producing α, ω-perfluoroalkadiene.
[0010]
[Means for Solving the Problems]
The present invention has been made to solve the above-described problems.
The basic concept of the present invention is a production method in which an alkyl halide is present in a reaction system as a catalyst and a metal and a tetrahalogenated perfluoroalkane are reacted. Taking Mg as an example, a catalytic amount of an alkyl halide and Mg By separately putting in, it is not necessary to handle dangerous organometallic compounds directly, and mixing of moisture can be prevented only by sealing the reaction system with nitrogen. Therefore, handling of the medicine itself is very easy. In this method, a reaction with a small amount of a catalyst and a dehalogenating agent (a scale of 1/2 to 1/20 when performing a Grignard reaction) can be performed in a large amount of solvent, so that the reaction is gentle and safe. is there. Further, storage problems can be solved by using a relatively less active metal and an alkyl halide separately. Since the amount of alkyl halide used can be reduced to 1/2 to 1/20, this is also advantageous in terms of cost.
[0011]
That is, in a specific embodiment of the present invention, a tetrahalogenated perfluoroalkane which is industrially available or can be synthesized by various methods is used as a catalyst in an organic solvent such as tetrahydrofuran at a temperature range of −78 ° C. to + 200 ° C. Reacting with metals such as Mg, Zn, Cd, Al, Cu, Na or Li in the presence of an appropriate amount of alkyl halide to obtain α, ω-perfluoroalkadiene in high yield by dehalogenation reaction It is. Since it is highly hygroscopic, easily decomposed, and does not use an expensive organometallic compound, it is a manufacturing method that is inexpensive and suitable for mass production, and can improve workability and safety.
[0012]
The target compound of the present invention is represented by the following general formula (1) having double bonds at both ends of the carbon chain:
_{CF 2 = CF- (CF 2 CF} 2) a (CF 2 CF (CF 3)) b -CF = CF 2 (1)
(Wherein, a and b are integers of 0 to 2 and may be the same or different.)
Are perfluoroalkadienes.
[0013]
Tetrahalogenated perfluoroalkanes used as raw materials for the reaction are represented by the following formula (2):
XCF ₂ CFX (CF ₂ CF ₂ ) _a (CF ₂ CF (CF ₃ )) _b -CFY-CF ₂ X (2)
(Wherein, a and b are as defined above, X represents chlorine, bromine or iodine, and Y represents chlorine, bromine, iodine or fluorine.)
Indicated by
[0014]
The alkyl halide used as the catalyst has the following general formula (3):
RX (3)
(Wherein X is any one of chlorine, bromine and iodine, and R represents a linear, branched or cyclic alkyl group). The amount of the alkyl halide used as the catalyst is in the range of 0.05 equivalent to 0.5 equivalent relative to the starting tetrahalogenated perfluoroalkane. If it is less than 0.05 equivalent, the catalytic effect is low, and the target product cannot be obtained in a satisfactory yield. Conversely, the effect obtained by increasing the amount of the catalyst to more than 0.5 equivalent is the same, and 0.5 equivalent or less is desirable from the viewpoint of cost.
[0015]
Further, 'the alkylene dihalide represented by -X (R' formula X- R as a reaction of the active agent is a straight, branched, or cyclic hydrocarbon of 1-7 carbon atoms, X is the street.) and the like can be started easily react with addition of a small amount of iodine, more desirable.
[0016]
As the metal used for the reaction, Mg, Zn, Cd, Al, Cu, Na, Li or the like is desirable. These metals are used alone or in combination of two or more. The shape is a cut piece, block, or powder, and the size can be selected as appropriate. The amount used is equal to or more than the equivalent, but is preferably about 1.0 to 5 equivalents from the viewpoint of reaction efficiency and cost.
[0017]
Solvents that can be used to carry out the reaction are linear, branched or cyclic ethers such as tetrahydrofuran, dioxane, ethyl ether, isopropyl ether, polyethers such as dimethoxyethane, 2-methoxyethyl ether or hexane, octane, Nonanes, hydrocarbons such as petroleum ether, esters such as ethyl acetate, methyl acetate and ethyl propionate, phosphate esters such as triethyl phosphonate, chain chains such as diethyl carbonate and ethylene carbonate, cyclic carbonates, acetonitrile and benzo Alkyl or aryl nitrile such as nitrile, ketones such as acetone and methyl ethyl ketone, acid anhydrides such as acetic anhydride, amides such as N, N′-dimethylformamide (DMF) and N, N′-dimethylacetamide, dimethyl Sulfoxides such as sulfoxide (DMSO), aliphatic or aromatic nitro compounds such as nitroethane or nitrobenzene, nitrogen-containing heterocyclic compounds such as pyridine and piperidine, sulfone compounds such as dimethylsulfone and phenylsulfone, diethyl sulfide or diphenyl sulfide And dialkyl or diaryl sulfides.
[0018]
The reaction temperature is in the range of −78 ° C. to + 200 ° C.
A perfluoroalkadiene of the formula (1) is produced from the above formula (2) by adding a metal and an alkyl halide in the above-mentioned organic solvent and heating or boiling reflux.
[0019]
The amount of the solvent to be used is preferably adjusted so that the tetrahalogenated perfluoroalkane used as a raw material for the reaction is 0.1M to 2M, preferably 0.2M to 1.0M during the reaction. It is not limited to this range. The tetrahalogenated perfluoroalkane used as a raw material for the reaction is preferably diluted with the same solvent as described above.
[0020]
EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to this.
[0021]
[Example 1]
In a 100 mL three-necked flask equipped with a reflux condenser connected to a trap pipe cooled to −78 ° C. and a dropping funnel with a pressure equilibrium pipe, 1.5 equivalents of Mg and 20 mL of tetrahydrofuran, 1,2- 2 drops of dibromoethane (1 drop is 0.05 mL) and 0.2 equivalent of catalyst bromoethane were added. The solution was heated to reflux and 5.0 g of 1,2-dichloro-4-iodoperfluorobutane diluted with 5 mL of tetrahydrofuran was slowly added to the solution so that foaming was not too intense. The generated gas was collected by a trap tube at -78 ° C. After completion of the dropwise addition, boiling reflux was continued, and CF ₂ = CF-CF = CF ₂ remaining in the reaction solvent was driven out. The liquid is collected in a trap tube was analyzed by gas _{chromatography, CF 2 = CF-CF =} CF 2 was generated 1.77 g (yield: 83%).
[0022]
[Example 2]
In a 100 mL three-necked flask equipped with a reflux condenser connected to a trap pipe cooled to −78 ° C. and a dropping funnel with a pressure equilibrium pipe, 1.2 equivalents of Mg and 20 mL of tetrahydrofuran, 1,2- Two drops of dibromoethane and 0.2 equivalent of catalyst isopropyl bromide were added. The solution was heated to reflux and 5.0 g of 1,2-dichloro-4-bromoperfluorobutane diluted with 5 mL of tetrahydrofuran was slowly added to the solution so that foaming was not excessive. The generated gas was collected by a trap tube at -78 ° C. After completion of the dropwise addition, boiling reflux was continued, and CF ₂ = CF-CF = CF ₂ remaining in the reaction solution was driven out. The solution was collected in a trap tube was analyzed by gas _{chromatography, CF 2 = CF-CF =} CF 2 was generated 2.07 g (yield: 85%).
[0023]
[Example 3]
In a 100 mL three-necked flask equipped with a distillation apparatus with a Vicra tube connected to a trap tube cooled to −78 ° C. and a dropping funnel with a pressure equilibrium tube, 1.2 equivalents of Mg and 50 mL of tetrahydrofuran under a nitrogen atmosphere, Two drops of 1,2-dibromoethane and 0.1 equivalent of the catalyst bromopropane were added. This solution was heated to reflux, and 5.0 g of 1,2-dichloro-6-iodoperfluorohexane diluted with 10 mL of tetrahydrofuran was slowly added to the solution so that foaming was not excessive. The reaction product is distilled with the solvent through a distillation apparatus. After completion of the dropwise addition, boiling reflux was continued, and the product remaining in the reaction solution was distilled together with the solvent through a distillation apparatus. The liquid is collected in a trap tube was analyzed by gas _{chromatography, CF 2 = CF-CF 2} -CF 2 -CF = CF 2 was generated 1.96 g (yield: 72%) .
[0024]
[Example 4]
In a 100 mL three-necked flask equipped with a reflux condenser connected to a trap tube cooled at −78 ° C. and a dropping funnel equipped with a pressure equilibration tube, 1.2 equivalents of Mg and tetrahydrofuran 20 mL, 1, 2, -2 drops of dibromoethane and 0.2 equivalents of catalytic bromoethane were added. This solution was heated to reflux, and 5.0 g of 1,2,3,4, -tetrachloroperfluorobutane diluted with 5 mL of tetrahydrofuran was slowly added thereto so that foaming was not excessive. The generated gas was collected by a trap tube at -78 ° C. After completion of the dropwise addition, boiling reflux was continued, and CF ₂ = CF-CF = CF ₂ remaining in the reaction solvent was driven out. The liquid is collected in a trap tube was analyzed by gas _{chromatography, CF 2 = CF-CF =} CF 2 was generated 2.34 g (yield: 88%).
[0025]
[Example 5]
In a similar manner to Example 2, except that Zn-Cu (95: 5 combination) was used instead of Mg and bromoethane was used instead of the catalyst isopropyl bromide, 5.0 g of 1,2-dichloro-bromo Perfluorobutane was added and refluxed to the boil. The liquid trapped in the trap was analyzed by gas _{chromatography, CF 2 = CF-CF =} CF 2 was generated 2.04 g (yield: 84%).
[0026]
[Comparative Example 1]
In a 200 mL three-necked flask equipped with a reflux condenser connected to a trap pipe cooled to −78 ° C. and a dropping funnel with a pressure equilibrium pipe, 3 equivalents of Zn and 50 mL of ethanol were added under a nitrogen atmosphere. The solution was heated to reflux and 5.0 g of 1,2-dichloro-4-iodoperfluorobutane diluted with 5 mL of ethanol was slowly added to the solution so that foaming was not too intense. The generated gas was collected by a trap tube at -78 ° C. After completion of the dropwise addition, the boiling reflux was continued, and the gas remaining in the reaction solvent was expelled. When the liquid collected in the trap tube was analyzed by gas chromatography, CF ₂ = CF-CF = CF ₂ was found only slightly, and most of the obtained gas was 4H-perfluoro-1 -Butene.

Claims (3)

The following general formula (1) having double bonds at both ends of the carbon chain:
_{CF 2 = CF- (CF 2 CF} 2) a (CF 2 CF (CF 3)) b -CF = CF 2 (1)
(Wherein, a and b are integers of 0 to 2 and may be the same or different.)
In a method for producing a perfluoroalkadiene represented by:
The following general formula (2):
_{XCF 2 CFX- (CF 2 CF 2} ) a (CF 2 CF (CF 3)) b -CFY-CF 2 X
(2)
(Wherein, a and b are as defined above, X represents chlorine, bromine or iodine, and Y represents chlorine, bromine, iodine or fluorine.)
A tetrahalogenated perfluoroalkane represented by:
In an organic solvent, at least one metal selected from Mg, Zn and Cu , 1,2-dibromoethane and the following general formula (3):
RX (3)
(Wherein X is any one of chlorine, bromine, and iodine, and R represents a linear, branched, or cyclic alkyl group). A process for producing a perfluoroalkadiene of general formula (1) from a tetrahalogenated perfluoroalkane of general formula (2), characterized in that it is carried out. Formula (3):
RX (3)
(Wherein X is any one of chlorine, bromine, and iodine, and R represents a linear, branched, or cyclic alkyl group .) The alkyl halide represented by the raw material is a tetrahalogenated perfluoroalkane. The method for producing perfluoroalkadiene according to claim 1, which is added in an amount of 0.05 to 0.5 equivalents. The method for producing a perfluoroalkadiene according to claim 1 or 2, wherein the reaction system is carried out with nitrogen sealing.