JPH0222060B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a novel method for producing perfluoro(N-vinylamine). More specifically, the present invention provides readily available perfluoro(N-vinylamine) compounds useful as synthetic intermediates and polymeric monomers for fluorine-containing products such as surfactants, agricultural chemicals, and pharmaceuticals. Using raw materials,
The present invention relates to a high-yield, economical manufacturing method. Background Art In recent years, fluorine-containing olefin compounds have been in the spotlight as synthetic intermediates and raw materials for various fluorine-containing products, such as surfactants, agricultural chemicals, pharmaceuticals, etc. Widely used as a monomer for polymer production. By the way, the general formula [In the formula, R ₁ and R ₂ are each a perfluoroalkyl group having 1 to 5 carbon atoms, and both are bonded directly or through an oxygen atom or a nitrogen atom, and together with the nitrogen atom to which both are bonded, a five-membered perfluoro(N-vinylamine) which may form a ring or a six-membered ring, and X is F or OM (however, M is an alkali metal or alkaline earth metal corresponding to a monovalent value)
In this class, a perfluoroalkylamino group is bonded to one of the carbon atoms of the double bond. Therefore, by using this compound as an intermediate raw material, various useful compounds containing the perfluoroalkylamino group can be produced. It is possible to produce compounds. Furthermore, by copolymerizing the compound with another fluoroolefin and introducing a perfluoroalkylamino group into the polymer, it is possible to reduce the crystallinity and improve the mechanical properties of the polymer. As described above, perfluoro(N-vinylamine) is an extremely useful compound as a synthetic intermediate or a source for producing fluorine-containing polymers. These perfluoro(N-vinylamines) are already known compounds, and have been produced so far by two methods as shown below. The first method is to cause an addition reaction between a perfluoroalkylamino radical and a suitable fluorine-containing olefin, and then to perform a dehydrohalogenation reaction or a thermal decomposition reaction to reform unsaturated bonds. For example, perfluoro(N,N-dimethylvinylamine) (U.S. Pat. No. 3,311,599), perfluoro(N-vinylmorpholine) [Journal of Chemical Society, Parkin I
(J.Chem.Soc., Perkin)” page 5 (1973
)], perfluoro(N-vinylpiperidine)
[Journal of Chemical Society (J.
Chem. However, this method uses special compounds as starting materials, which are not easy to obtain.
In addition, the process is complicated and the yield is low. On the other hand, the second method is a recently developed method in which perfluorocarboxylic acid derivatives are thermally decomposed to produce perfluoro(N-vinylamines). ) using perfluorocarboxylic acid derivatives represented by formulas (a) and (b), respectively.
Perfluoro(N-vinylamine) represented by
There is a known method for manufacturing the
No. 19501, No. 63-8102). [A in the formula is a chemical bond, CF ₂ , O or RN
(However, R is a perfluoroalkyl group), X has the same meaning as above, and X ₁ is F, a perfluoroalkoxy group, or OM (however, M has the same meaning as above)] However, this second In this method, only perfluorocarboxylic acid derivatives represented by general formulas () and () are used as raw materials, and reactions using other perfluorocarboxylic acid derivatives are not known. Problems to be Solved by the Invention The purpose of the present invention is to solve the problems of perfluoro(N
The object of the present invention is to provide a method for easily producing vinylamines by thermal decomposition reaction using readily available raw materials. Means for Solving the Problems By the way, as shown in the following reaction formula, perfluoro(2-alkoxypropionyl fluoride) and its acid alkali metal salts undergo a decarboxylation reaction when thermally decomposed. Perfluorovinyl ether is obtained with high efficiency, but in the case of perfluoro(3-alkoxypropionyl fluoride) and its alkali metal salts,
It is known that only tetrafluoroethylene and lower perfluorocarboxylic acid fluoride are produced as thermal decomposition products (Japanese Patent Publication No. 39-26709). (However, Rf is a perfluoroalkyl group having 1 to 8 carbon atoms, R'f is F or a perfluoroalkyl group having 1 to 7 carbon atoms, and X has the same meaning as above.) Therefore, perfluoro(3-alkoxypropion Similarly, in the case of perfluoro (propionic acid substituted with a 3-alkylamino group), which is an isoelectronic compound with an acid), its acid fluoride and metal salt decompose as shown in the following reaction formula. It was thought that (However, R' ₁ and R' ₂ are perfluoroalkyl groups having 1 to 5 carbon atoms, R ₃ is a perfluoroalkyl group having one fewer carbon atoms than R' ₂ , and X has the same meaning as above.) For this reason, However, this compound has not been considered as a raw material for the production of perfluoro(N-vinylamine). The present inventor focused on the fact that perfluoro(3-alkylamino group-substituted propionic acid) is easily available, and conducted extensive research in order to develop a method for producing perfluoro(N-vinylamine) using this as a raw material. As a result, when this perfluoro(3-alkylamino group-substituted propionic acid) is thermally decomposed, surprisingly, the main product is the general formula ()
Perfluoro(N-vinylamine) represented by
The present invention was completed based on this finding. That is, the present invention provides the general formula [In the formula, R ₁ and R ₂ are each a perfluoroalkyl group having 1 to 5 carbon atoms, and both are bonded directly or through an enzyme atom or a nitrogen atom, and together with the nitrogen atom to which they are bonded, a five-membered It may form a ring or a six-membered ring, and X is F or OM (however, M is an alkali metal or alkaline earth metal corresponding to a monovalent value).
The present invention provides a method for producing perfluoro(N-vinylamine) represented by the general formula (), which is characterized by heating at a temperature in the range of . The above general formula () obtained by the method of the present invention
Perfluoro(N-vinylamine) represented by
in class

[Formula] Specific examples of groups include:

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

(However, n and m are integers of 1 to 5). In the method of the present invention, a perfluoro compound represented by the above general formula (), namely perfluoro(3-alkylamino or 3-cyclic aminopropionyl fluoride), or perfluoro(3-alkylamino or 3-cyclic aminopropionic acid) is used as a raw material. ) are used as alkali metal salts or alkaline earth metal salts. The former perfluoro (3-alkylamino or 3-cyclic aminopropionyl fluoride) can be produced, for example, by electrolytic fluorination of a reactive derivative of 3-alkylamino or 3-cyclic aminopropionic acid in liquid hydrogen fluoride. easily obtained (US Pat. No. 3,471,484). In addition, perfluoro(3-alkylamino or 3-cyclic aminopropionate) is added to the thus obtained perfluoro(3-alkylamino or 3-cyclic aminopropionyl fluoride) with an alkali metal or alkaline earth metal. It can be easily obtained by reacting with hydroxide etc. In the method of the present invention, the desired general formula (R ₁ and R ₂ in the formula have the same meanings as above)
Perfluoro(N-vinylamine) represented by
can be easily obtained by simply thermally decomposing the perfluoro compound represented by the above general formula (). Perfluorinated compounds used as raw materials include:
Perfluoro(3-alkylamino or 3-cyclic aminopropionyl fluoride), perfluoro(sodium 3-alkylamino or 3-cyclic aminopropionate) and perfluoro(potassium 3-alkylamino or 3-cyclic aminopropionate) are preferred. be. As the temperature for thermal decomposition, a temperature in the range of 100 to 500°C, preferably 100 to 300°C is selected. If this temperature is too high, side reactions such as decomposition are likely to occur, and if this temperature is too low, the conversion rate will decrease. The reaction time varies depending on the reaction temperature, but is usually in the range of 10 seconds to 2 hours. When a high reaction temperature is selected, the reaction time becomes short, and when a low reaction temperature is selected, the reaction time becomes long. In this thermal decomposition reaction, the reaction pressure is not an important factor, and the reaction can be carried out under reduced pressure, atmospheric pressure, or increased pressure.
It is preferable to carry out the reaction under atmospheric pressure or reduced pressure because it is relatively easy to recover the reaction product. In addition, the thermal decomposition reaction may include nitrogen,
Inert gases such as helium, argon, carbon dioxide, polyethers, tetrachloroethylene,
It may also be carried out using an aprotic liquid compound such as n-heptane as a diluent. In this case, the dilution ratio is preferably 100 times or less. Furthermore, in the thermal decomposition reaction, it is important that all materials used in the reaction do not contain water. In the method of the present invention, when perfluoro (3-alkylamino or 3-cyclic aminopropionyl fluoride) is used as a raw material, it is preferable to carry out the thermal decomposition reaction in the presence of a metal salt or metal oxide. In this case, the desired perfluoro(N-vinylamine) can be easily obtained by continuously supplying raw materials to a packed layer of metal salts or metal oxides maintained at a predetermined temperature and carrying out a thermal decomposition reaction. . There are no particular restrictions on the material of the pyrolysis reactor, but stainless steel or Hastelloy is usually used. There is no particular restriction on the type of the packed bed, and any type such as a fixed bed, moving bed, or fluidized bed can be used. Examples of the metal salt include sodium carbonate,
Potassium carbonate, lithium carbonate, sodium phosphate, potassium phosphate, barium carbonate, calcium carbonate, magnesium carbonate, potassium sulfate, sodium sulfate, etc.; examples of metal oxides include zinc oxide, cadmium oxide, etc.; Solid bases such as sodium carbonate and potassium carbonate are toxic substances generated in thermal decomposition reactions.
It is particularly suitable because it can decompose COF ₂ . Effects of the Invention According to the method of the present invention, perfluoro(N-vinylamine) can be obtained in high yield from easily available raw materials through an extremely simple process. It is useful as an industrial manufacturing method. Further, the obtained perfluoro(N-vinylamine) is suitably used as a synthetic intermediate for fluorine-containing products such as surfactants, agricultural chemicals, and pharmaceuticals, and as a monomer for producing fluorine-containing polymers. Examples Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples in any way. Example 1 As a raw material, a product obtained by electrolytic fluorination of methyl 3-dimethylaminopropionate was distilled to remove most of the low-boiling compounds, and the remaining crude product was used. Perfluoro(3-
The content of dimethylaminopropionyl fluoride) was 48.0% by weight. First, 200ml with reflux condenser and dropping funnel
Put 12.00 g of the above crude product [perfluoro (containing 5.75 g of 3-dimethylaminopropionyl fluoride)] and 30 ml of water into a three-neck flask, add phenolphthalein as an indicator, and stir magnetically. While cooling on ice, a concentrated aqueous potassium hydroxide solution was added dropwise to neutralize the solution until it became slightly alkaline.Next, the contents were transferred to a 300ml beaker.
After the water was evaporated on a hot plate, it was further transferred to a 200 ml flask and kept at 70°C for about 8 hours to perform vacuum drying. The white solid substance in the flask thus obtained was pulverized, a gas introduction pipe was connected to the upper part of the flask, and the flask was heated in an oil bath while flowing helium gas at a rate of 80 ml/min.
The temperature was slowly raised from 150°C to 200°C over a period of minutes, and the temperature was maintained for an additional hour to carry out a thermal decomposition reaction. The product was condensed and collected in a trap cooled to -78°C. The collected fluorocarbons are
It was 4.53g. This material was subjected to gas chromatography [liquid phase:
1,6-bis(1,1,12-trihydroperfluorododecyloxy)hexane, carrier: 60-80 mesh chromosorb PAW, carrier: helium], IR, ¹⁹ FNMR, Mass, etc. analysis revealed that the main product was Perfluorinated (N, N-
The results were consistent with the spectroscopic data of dimethylvinylamine (Japanese Patent Application No. 162631/1982). The amount of perfluoro(N,N-dimethylvinylamine) was 3.85 g, and the yield was 86.0%. Example 2 A flash evaporator for vaporizing raw materials and a diluent gas flow control device were connected to the inlet side, and the outlet side was equipped with a low-temperature trap for condensing and collecting reaction products.Length 48.0 cm A stainless steel tube with an inner diameter of 2.5 cm was used as a horizontal reactor, and 86.2 g of powdered sodium carbonate was filled horizontally to approximately the middle of the reactor, and both ends were filled with metal wool. Ta. First, the reactor was kept at 220° C. and helium gas was allowed to flow at 100 ml/min. Next, a fluorocarbon mixture [purity of perfluoro(3-morpholinopropionyl fluoride): 71.5%]
7.17 g was fed into the flash evaporator using a micro-metering pump over a period of 55 minutes, vaporized and mixed with the quantitatively fed helium gas, and then introduced into the reactor, while the product was passed through the outlet. It was condensed and collected in a trap cooled to -78°C. As a result, 4.47 g of fluorocarbon was obtained,
When this product was analyzed in the same manner as in Example 1, it was found to contain 3.24 g of perfluoro(N-vinylmorpholine). The conversion rate is 100% and the yield is 76.7
It was %. Example 3 The same reactor as in Example 2 was used, except that 84.4 g of powdered sodium carbonate was charged and a fluorocarbon mixture with a purity of 71.7% perfluoro(3-pyrrolidinopropionyl fluoride) was used as the raw material. The reaction was carried out in the same manner as in Example 2. 5.15 g of the fluorocarbon mixture was fed to the reactor for 27 minutes and pyrolyzed, leaving 3.56 g of fluorocarbon in the cooling trap. When this product was analyzed in the same manner as in Example 1, it was found that 2.31 g of perfluoro(N-vinylpyrrolidine) was contained. The conversion rate was 100% and the yield was 76.5%. Example 4 Using the same reactor as in Example 2, 84.4 g of powdered potassium carbonate was charged, a fluorocarbon mixture with a purity of 61.0% perfluoro(3-piperidinopropionyl fluoride) was used as a raw material, and further reaction was carried out. The reaction was carried out in the same manner as in Example 2, except that the temperature was 200°C. 13.49 g of the fluorocarbon mixture was fed into the reactor for 60 minutes and pyrolyzed, yielding 8.53 g of fluorocarbon in the cooling trap. When this product was analyzed in the same manner as in Example 1,
4.85g perfluoro(N-vinylpiperidine)
It was included. The conversion rate was 100% and the yield was 70.2%.

Claims (1)

[Claims] 1. General formula [In the formula, R ₁ and R ₂ are each a perfluoroalkyl group having 1 to 5 carbon atoms, and both are bonded directly or through an oxygen atom or a nitrogen atom, and together with the nitrogen atom to which both are bonded, a five-membered It may form a ring or a six-membered ring, and X is F or OM (however, M is an alkali metal or alkaline earth metal corresponding to a monovalent value).
General formula, characterized by heating at a temperature within the range of (R ₁ and R ₂ in the formula have the same meanings as above) Perfluoro(N-vinylamine)
Methods of manufacturing products.