JP4684401B2 - Method for producing perfluoroalkadiene - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing an α, ω-perfluoroalkadiene that can be used as a raw material for a polymer for paints or an etching gas for semiconductors, for example.
[0002]
[Prior art]
As the most typical method for synthesizing α, ω-perfluoroalkadiene, perfluorobutadiene, a compound having 4 carbon atoms, has been studied for a long time.
[0003]
For example, R.A. N. Haszeldine: J.M. 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.
[0004]
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.
[0005]
W. T.A. In US Pat. No. 2,668,182 by Miller, CClF = CF ₂ is used as a raw material to carry out a reaction in a Pyrex tube at 550 ° C. to obtain CF ₂ = CF—CClF—CClF ₂ , which is chlorinated. Alternatively brominated, 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.
[0006]
G. Bargilia, V. Tortelli, C.I. Tonelli, S.M. Mondena et al European Patent Application No. 0 270 956, Japanese Patent Application Laid-Open No. 62-26240 by the group et al. S. Elizabath: J.M. Org. Chem. , 36 (1971) 364 In like, CF ₂ = CF ₂ to XCF ₂ -CF ₂ obtained by iodine addition or bromine added to the material X (X = I, Br) XCF 2 -CF produced by telomerization reactions of ₂ -CF ₂ organic solvent aprotic range from -CF ₂ X a + 150 ℃ from -80 ℃, Mg, Zn, CF by reaction with an organometallic compound of Cd or _{Li 2 = CF-CF = CF} 2 The reaction to obtain is 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, since a large amount of highly active organometallic compound is required in the dehalogenation reaction, it is still not suitable for industrialization.
[0007]
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.
[0008]
[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 which is safe and suitable for industrial practice, in which these drawbacks are reduced or eliminated.
[0009]
Thus, in the present invention, an alkyl halide is present as a catalyst in the reaction system without using an organometallic compound, and the metal and XCF ₂ —CF ₂ —CF ₂ —CF ₂ X (X═I, Br) are reacted. To provide a new manufacturing method. That is, taking Mg as an example in the present invention, a catalytic amount of alkyl halide and Mg are separately put into the reaction system, so that it is not necessary to handle dangerous organometallic compounds directly, and moisture is mixed in the reaction system with nitrogen. It can be prevented by sealing. Therefore, handling of the reagent itself is very easy. In this method, a reaction with a small-scale 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 the reaction is gentle and safe. It is. 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.
[0010]
It is also an object of the present invention to provide a method capable of industrially producing an inexpensive α, ω-perfluoroalkadiene.
[0011]
[Means for Solving the Problems]
The present invention has been made to solve the above-described problems. That is, α, ω-diiodo or dibromoperfluoroalkane, which is industrially available, is used in an organic solvent such as tetrahydrofuran in the range of −78 ° C. to + 200 ° C. in the presence of an appropriate amount of alkyl halide as a catalyst. , Al, Cu, Na, Li, and the like are reacted with deIF or deBrF to obtain α, ω-perfluoroalkadiene in high yield. Since it is highly hygroscopic and easily decomposed and does not use an expensive organometallic compound, it is an inexpensive and industrially suitable production method 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]
The α, ω-dihalogenated perfluoroalkane used as a raw material for the reaction is represented by the following formula (2):
_{XCF 2 CF 2 - (CF 2} CF 2) a (CF 2 CF (CF 3)) b -CF 2 -CF 2 X (2)
(In the formula, a and b are as defined above, and X at both ends is iodine or bromine.)
Indicated by
[0014]
The alkyl halide used as the catalyst has the general formula (3):
RX (3)
Wherein X is any one of chlorine, bromine, and iodine, and R is selected from compounds represented by a linear, branched, or cyclic alkyl group . The amount of the alkyl halide (3) used as the catalyst is in the range of 0.05 equivalents to 0.5 equivalents relative to the starting α, ω-dihalogenated perfluoroalkane (2).
[0015]
Moreover, the general formula X- R 'alkylene dihalide (R represented by -X' and a reaction activator in a compound having a carbon number 1 to 7 of the linear, branched, or represented by a cyclic alkylene group X is as described above. )) And / or addition of a small amount of iodine or the like is preferable because the reaction can be easily started.
[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. The shape can be 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 or branched, 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 desirably within the range of −78 ° C. to + 200 ° C.
The perfluoroalkadiene of the formula (1) is produced from the above formula (2) by heating or boiling reflux together with the metal and the alkyl halide in the above organic solvent.
[0019]
The amount of the solvent to be used is preferably adjusted so that the α, ω-dihalogenated perfluoroalkane (2) as a raw material of the reaction is 0.1M to 2M, preferably 0.2M to 1.0M during the reaction. However, the raw material species is not limited to this range. It is desirable to dilute the α, ω-dihalogenated perfluoroalkane used as a raw material for the reaction with the same solvent as described above.
[0020]
Hereinafter, the present invention will be further described with reference to typical reaction examples of the present invention, but the present invention is not limited thereto.
[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, 1.2 equivalents of Mg and 20 mL of tetrahydrofuran, 1,2- Dibromoethane (0.1 mL) and catalytic bromoethane (0.2 equivalent) were added. This solution was heated to reflux, and 5.0 g of 1,4-diiodoperfluorobutane diluted with 5 mL of tetrahydrofuran was slowly added to the solution so as not to cause excessive foaming. 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 1.57 g (yield: 88%).
[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 40 mL of tetrahydrofuran, 1,2- Dibromoethane (0.1 mL) and catalytic isopropyl bromide (0.3 equivalent) were added. This solution was heated to reflux, and 5.0 g of 1,4-dibromoperfluorobutane diluted with 10 mL of tetrahydrofuran was slowly added thereto so as not to cause excessive foaming. 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 liquid is collected in a trap tube was analyzed by gas _{chromatography, CF 2 = CF-CF =} CF 2 was generated 1.91 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, 0.1 mL of 1,2-dibromoethane and 0.1 equivalent of catalyst 1-bromopropane were added. This solution was heated to reflux, and 5.0 g of 1,6-diiodoperfluorohexane diluted with 10 mL of tetrahydrofuran was slowly added thereto so as not to cause excessive foaming. 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 1.85 g (yield: 78%) .
[0024]
[Example 4]
A 100 mL three-necked flask equipped with a reflux condenser connected to a trap pipe cooled at −78 ° C. and a dropping funnel equipped with a pressure equilibrium tube was cooled to −70 ° C. in a nitrogen atmosphere, and 30 mL of anhydrous hexane and 1.5 equivalents were added. Of Li and 0.2 equivalent of catalyst 1-bromobutane was added. This solution was heated to reflux, and 5.0 g of 1,4-diiodoperfluorobutane diluted with 5 mL of anhydrous hexane was slowly added thereto so as not to cause excessive foaming. The generated gas was collected by a trap tube at -78 ° C. After completion of the dropwise addition, further performs the boiling reflux expel _{CF 2 = CF-CF = CF} 2 remaining in the reaction solvent. The liquid is collected in a trap tube was analyzed by gas _{chromatography, CF 2 = CF-CF =} CF 2 was generated 1.42 g (yield: 80%).
[0025]
[Example 5]
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 equilibration pipe, cooled to −70 ° C. in a nitrogen atmosphere, 40 mL anhydrous hexane and 1.5 mL An equivalent amount of Na was added. The solution was heated to reflux and 5.0 g of 1,4-diiodoperfluorobutane diluted with 5 mL of anhydrous hexane and 0.2 equivalents of 1-bromobutane were slowly added to avoid excessive bubbling. added. The generated gas was collected by a trap tube at -78 ° C. After completion of the dropwise addition, further subjected to boiling under reflux, to drive off the _{CF 2 = CF-CF = CF} 2 remaining in the reaction solvent. The liquid is collected in a trap tube was analyzed by gas _{chromatography, CF 2 = CF-CF =} CF 2 was generated 1.10 g (yield: 62%).
[0026]
[Example 6]
In Example 1, 5.0 g of 1,4-diiodoperfluorobutane was added in the same manner except that Zn—Cu (combination of 95: 5) was used in place of Mg, and boiling reflux was performed. . The liquid is collected in a trap tube was analyzed by gas _{chromatography, CF 2 = CF-CF =} CF 2 had 1.50g produced (yield: 84%).
[0027]
[Comparative Example 1]
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 was placed under a nitrogen atmosphere, 1.5 equivalents of Mg and 40 mL of tetrahydrofuran, 1,2- Dibromoethane (0.1 mL) and catalytic bromoethane (0.02 equivalent) were added. The solution was heated to reflux and 10.0 g of 1.4-diiodoperfluorobutane diluted with 10 mL of tetrahydrofuran was added to it over 30 minutes. 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. When the gas in the gas phase was analyzed by gas chromatography, the target CF ₂ = CF-CF = CF ₂ was slightly produced, but the liquid was hardly collected in the trap tube.

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:
Formula (2):
_{XCF 2 CF 2 - (CF 2} CF 2) a (CF 2 CF (CF 3)) b -CF 2 -CF 2 X
(2)
(Wherein, a and b are as defined above, and X at both ends represents iodine or bromine.)
An α, ω-dihalogenated perfluoroalkane represented by:
In an organic solvent, at least one metal selected from Mg, Zn 3 , Cu 2 , Na and Li, and an amount in the range of 0.05 to 0.5 equivalents relative to the α, ω-dihalogenated perfluoroalkane. Formula (3):
RX (3)
(In the formula, X is any one of chlorine, bromine, and iodine, and R represents a linear, branched, or cyclic alkyl group .)
A method for producing a perfluoroalkadiene of the general formula (1), which is subjected to heating or boiling reflux together with an alkyl halide represented by the formula: As active agent, the general formula: X- R '-X (R' represents a linear 1-7 carbon atoms, a branched or cyclic alkylene group, X is chlorine, either bromine or iodine The process for producing a perfluoroalkadiene according to claim 1, wherein an alkylene dihalide is present. The process for producing a perfluoroalkadiene according to claim 1 or 2, wherein the reaction is carried out in a dry or anhydrous atmosphere.