JP2019127466A - Method for producing 1h,2h-perfluorocycloalkene - Google Patents

Abstract

To provide a novel method for producing 1H,2H-perfluorocycloalkene.SOLUTION: In the present invention, 1H,1H,2H-perfluorocycloalkane represented by the following formula (I) is brought into contact with alkylamine in the presence of a water-insoluble solvent and water, to obtain 1H,2H-perfluorocycloalkene represented by the following formula (II).SELECTED DRAWING: None

Description

  The present invention relates to a method of producing 1H, 2H-perfluorocycloalkene.

  Fluorinated hydrocarbons are industrial gases such as dry etching gas and gas for chemical vapor deposition (CVD) used in the field of production of semiconductor devices, etc., blowing agents, fluorine-containing pharmaceutical intermediates, and fluorine-based compounds. Useful as a solvent.

  In particular, 1H, 2H-perfluorocycloalkene can be suitably used as a plasma etching gas, a gas for CVD, and the like in the field of manufacturing a semiconductor device using a plasma reaction.

  The following patent documents 1 to 4 and non-patent documents 1 to 3 exist as techniques related to a method for producing 1H, 2H-perfluorocycloalkene.

  In Patent Document 1, 3,1,3,2,3 heptafluorocyclopentane is used as a starting material and brought into contact with a 2 M aqueous solution of potassium hydroxide at a temperature condition of 60 ° C. It is reported that 4,4,5,5-hexafluorocyclopentene (1H, 2H-perfluorocyclopentene) can be obtained.

  In Patent Document 2, 1,1,2,2,3,3,4-heptafluorocyclopentane is used as a starting material, and a Lewis base such as N, N-dimethylformamide or N, N-dimethylacetamide is defluorinated. It is possible to obtain 3,3,4,4,5,5-hexafluorocyclopentene (1H, 2H-perfluorocyclopentene) by reacting under high temperature of 150 to 170.degree. C. by using as a hydrogen peroxide agent. It has been reported.

  In Patent Document 3, two chlorine atoms of 1,2-dichloro-3,3,4,4,5,5-hexafluorocyclopentene are reduced by hydrogen in the presence of a transition metal catalyst such as copper or nickel. It is reported that 3,3,4,4,5,5-hexafluorocyclopentene (1H, 2H-perfluorocyclopentene) is obtained.

  In Patent Document 4, by contacting 1-chloro-2,2,3,3-tetrafluorocyclobutane with a mixture of an alkali metal hydroxide such as potassium hydroxide and a dehydrating agent such as calcium chloride, 3 It is reported that 3,4,4-tetrafluorocyclobutene (1H, 2H-perfluorocyclobutene) is obtained.

  In Non-Patent Document 1, 3,3,4,4-tetrafluorocyclobutene (1H, 2H-perfluorocyclobutene) is obtained by heating a closed vessel filled with tetrafluoroethylene and acetylene to 225 ° C. It has been reported that it can be obtained.

  In Non-patent Document 2, 3,3,4,4-tetrafluorocyclobutene (1H, 2H-perfluorocyclobutene) is obtained by bringing hexafluorocyclobutene into contact with lithium aluminum hydride as a reducing agent. It has been reported that

  In Non-Patent Document 3, decafluorocyclohexene as a raw material is brought into contact with lithium aluminum hydride to give 3,3,4,4,5,5,6,3 as one of several products. It is reported that 6-octafluorocyclohexene (1H, 2H-perfluorocyclohexene) can be obtained.

WO 2008/081804 Chinese Patent Application Publication No. 105330513 JP 2000-86548 A JP 2006-225298 A

J. L. Anderson et al, Fluorodienes. I. Synthesis from Cyclobutenes, Journal of the American Chemical Society, 1961.1.1, Vol. 83, p. 382-385 G. Fuller et al, Some Isomeric Hexafluorocyclobutanes and Pentafluorocyclobutenes, Journal of Chemical Society, 1961, p. 3198-3203 D. E. M. Evans et al, Fluorocyclohexanes, Part VIII. Lithium Aluminum Hydride Reduction of Decafluorocyclohexene, Journal of Chemical Society, 1963. p. 4828-4834

  Here, in particular, 1H, 2H-perfluorocycloalkene which can be used as a gas in the field of manufacturing semiconductor devices is required to have high purity.

  However, according to the production method described in Patent Document 1, 2H, 3H-perfluorocyclopentene, which is an isomer, is by-produced in addition to the target 1H, 2H-perfluorocyclopentene. Therefore, it may be difficult to obtain high purity 1H, 2H-perfluorocycloalkene by this production method.

  Moreover, from an industrial viewpoint, it is preferable that the production of 1H, 2H-perfluorocycloalkene is carried out under mild conditions.

  However, according to the method described in Patent Document 2, it is necessary to heat N, N-dimethylformamide and N, N-dimethylacetamide above the boiling point in a closed vessel. In addition, this method requires a container having pressure resistance. Furthermore, according to this method, there is a possibility that the equipment may be damaged due to the generation of an acid (such as formic acid or acetic acid) accompanying the decomposition of N, N-dimethylformamide or N, N-dimethylacetamide.

  In addition, it is considered that it is difficult to produce high purity 1H, 2H-perfluorocycloalkene under mild conditions also by the production methods described in Patent Documents 3 to 4 and Non-patent Documents 1 to 3 .

  Then, an object of the present invention is to provide a method for highly selective production of 1H, 2H-perfluorocycloalkene under mild conditions while suppressing isomer by-production.

  As a result of intensive studies to achieve the above object, the inventor of the present invention has removed fluoride by bringing the starting material 1H, 1H, 2H-perfluorocycloalkane into contact with an alkylamine in the presence of a water-insoluble solvent. It has been found that 1H, 2H-perfluorocycloalkene can be produced highly selectively and under mild conditions by hydrohydrogenation. However, in the above method using the alkylamine, as the reaction proceeds, the raw alkylamine-hydrogen fluoride salt is formed in the above-mentioned method using the alkylamine, so that the stirring becomes difficult. In addition, it was revealed that there is a problem that the operation of recovering 1H, 2H-perfluorocycloalkene from the reaction product is complicated because the alkylamine-hydrogen fluoride salt is mixed in the reaction product. Therefore, the present inventor further studies, and when 1H, 1H, 2H-perfluorocycloalkane is brought into contact with an alkylamine in addition to a non-water-soluble solvent, 1 H, from the reaction product is obtained. The inventors have found that the recovery of 2H-perfluorocycloalkene is facilitated, and completed the present invention.

  That is, the present invention aims to solve the above-mentioned problems advantageously, and the process for producing 1H, 2H-perfluorocycloalkene according to the present invention has the following formula (I)

（式（Ｉ）中、ｎは１以上３以下の整数を表す。）
で示される１Ｈ，１Ｈ，２Ｈ−パーフルオロシクロアルカン（以下、「出発原料」と称することがある）を、非水溶性溶媒及び水の存在下、アルキルアミンと接触させる反応工程を含む、下記式（ＩＩ）

(In the formula (I), n represents an integer of 1 or more and 3 or less.)
1H, 1H, 2H-perfluorocycloalkane (hereinafter sometimes referred to as “starting material”) represented by the following formula, comprising a reaction step of contacting with an alkylamine in the presence of a water-insoluble solvent and water: (II)

（式（ＩＩ）中、ｎは式（Ｉ）と同じ整数を表す。）
で示される１Ｈ，２Ｈ−パーフルオロアルケン（以下、「目的物」と称することがある）の製造方法である。

(In formula (II), n represents the same integer as in formula (I).)
It is a manufacturing method of 1H, 2H-perfluoro alkene (Hereinafter, it may be called an "object") shown.

  According to the production method of the present invention, it is possible to highly selectively produce 1H, 2H-perfluorocycloalkene which is an object, while suppressing by-production of isomers under mild conditions. Also, recovery of 1H, 2H-perfluorocycloalkene from the resulting reaction product is facilitated.

  In the method for producing 1H, 2H-perfluorocycloalkene of the present invention, the alkylamine preferably has 6 or less carbon atoms. If such an alkylamine is used, the solubility in water of the alkylamine-hydrogen fluoride salt generated in the reaction step or the salt formed when the unreacted alkylamine is neutralized with an acid is enhanced, and the reaction product is formed. The 1H, 2H-perfluorocycloalkene can be easily recovered from the product.

  Further, in the method for producing 1H, 2H-perfluorocycloalkene of the present invention, the alkylamine is preferably a water-soluble alkylamine. If it is a water-soluble alkylamine, since the unreacted alkylamine remaining after the reaction step is dissolved in water, recovery of 1H, 2H-perfluorocycloalkene from the resulting reaction product is facilitated, and 1H, 1H, The purity of 2H-perfluorocycloalkene can be further improved.

  Furthermore, in the method for producing 1H, 2H-perfluorocycloalkene according to the present invention, it is preferable that the alkylamine be a primary alkylamine. If it is a primary alkylamine, the target 1H, 2H-perfluorocycloalkene can be produced more highly selectively by further suppressing isomer by-production.

  Furthermore, in the method for producing 1H, 2H-perfluorocycloalkene according to the present invention, the boiling point of the non-water-soluble solvent is preferably 20 ° C. or more higher than the boiling point of 1H, 2H-perfluorocycloalkene. If such a water-insoluble solvent is used, 1H, 2H-perfluorocycloalkene can be easily purified by distillation.

  According to the present invention, 1H, 2H-perfluorocycloalkene can be produced highly selectively while suppressing isomer by-product under mild conditions, and 1H, 2H from the reaction product Recovery of perfluorocycloalkenes can be facilitated.

  Hereinafter, embodiments of the present invention will be described in detail.

(Method for producing 1H, 2H-perfluorocycloalkene)
The method for producing 1H, 2H-perfluorocycloalkene of the present invention is a method for producing the above-mentioned target product by bringing the above-mentioned starting material into contact with an alkylamine in the presence of a water-insoluble solvent and water. . The method for producing 1H, 2H-perfluorocycloalkene of the present invention includes a reaction step in which the above-described starting material is contacted with an alkylamine in the presence of a water-insoluble solvent and water. The organic layer recovery process which isolate | separates an aqueous layer from the reaction product obtained later and obtains an organic layer may be further included. The organic layer obtained in the organic layer recovery step may be subjected to a removal step of removing unreacted alkylamine and / or a purification step of purifying 1H, 2H-perfluorocycloalkene.

[1H, 1H, 2H-perfluorocycloalkane]
1H, 1H, 2H-perfluorocycloalkane used as a starting material in the present invention is a compound represented by the following formula (I).

  In formula (I), n represents an integer of 1 or more and 3 or less. As representative examples of 1H, 1H, 2H-perfluorocycloalkanes represented by the formula (I), for example, 1,1,2-trihydropentafluorocyclobutane, 1,1,2-trihydroheptafluorocyclopentane, 1 And 1, 2- trihydro nona fluoro cyclohexane etc. can be mentioned.

  The 1H, 1H, 2H-perfluorocycloalkanes of the formula (I) can be prepared by methods known in the art.

  Specifically, 1,1,2-trihydropentafluorocyclobutane in the case of (n = 1) in the above formula (I) is disclosed, for example, in JP-A-2004-182671 and JP-A-2007-106726. It can be synthesized according to the method described. The former uses 2,2,3,3-tetrafluorocyclobutanol as a raw material and N, N-diethyl-α, α-difluoro- (2-methoxy) benzylamine as a fluorinating agent. It is a method of synthesis. On the other hand, the latter is a method of synthesizing raw material 1,4,4-trifluorocyclobutene by contacting the double bond site with cobalt trifluoride or manganese trifluoride in contact. .

  In addition, 1,1,2-trihydroheptafluorocyclopentane in the case of (n = 2) in the above formula (I) is described in, for example, JP-A-2000-226346 and JP-A-2000-247912. It can be synthesized according to the method. The former is a method of synthesis by hydrogen reduction using 1,1-dichlorooctafluorocyclopentane as a raw material under a catalyst of palladium or platinum. On the other hand, the latter is a method of synthesizing by hydrogen reduction using 1-chloroheptafluorocyclopentene as a raw material and a palladium catalyst containing a metal such as copper, zinc, molybdenum and bismuth.

  1,1,2-trihydrononafluorocyclohexane in the case of (n = 3) in the above-mentioned formula (I) can be synthesized, for example, according to the method described in Non-Patent Document 3. According to this method, the target compound is obtained by reducing the chlorine atom of 1H-1,2-dichrononafluorocyclohexane obtained by chlorinating 1H-nonafluorocyclohexene with lithium aluminum hydride 1 , 1,2-Trihydrononafluorocyclohexane can be synthesized.

[Water-insoluble solvent]
The water-insoluble solvent used in the present invention is a solvent having a solubility of 1.5% by mass or less in water at 20 ° C., and when the water-insoluble solvent is mixed with the same volume of water, the organic layer and the aqueous layer are rapidly And solvents that can be separated into two layers.

  Examples of non-water soluble solvents include benzene (boiling point: 80.1 ° C.), toluene (boiling point: 110.6 ° C.), o-xylene (boiling point: 144 ° C.), m-xylene (boiling point: 139 ° C.), p -Xylene (boiling point: 138 ° C), 1,3,5-trimethylbenzene (boiling point: 165 ° C), chlorobenzene (boiling point: 131 ° C), o-dichlorobenzene (boiling point: 180.5 ° C), m-dichlorobenzene (boiling point: 180.5 ° C) Boiling point: 173 ° C), p-dicyclobenzene (boiling point: 174 ° C), benzotrifluoride (boiling point: 102 ° C), anisole (boiling point: 154 ° C), etc .; n-butyl ether (boiling point: 142 ° C) , Cyclopentyl methyl ether (boiling point: 106 ° C), di-n-butyl ether (boiling point: 142 ° C), diisobutyl ether (boiling point: 122 ° C), di-n-pen Alkyl ethers such as ether (boiling point: 186 ° C.), perfluorobutyltetrahydrofuran (boiling point: 102 ° C.), decafluoro-3-methoxy-2- (trifluoromethyl) pentane (boiling point: 100 ° C.); n-propyl acetate ( Boiling point: 102 ° C), n-butyl acetate (boiling point: 126 ° C), sec-butyl acetate (boiling point: 112 ° C), t-butyl acetate (boiling point: 96 ° C), n-pentaethyl acetate (boiling point: 149 ° C) And esters such as n-hexyl acetate (boiling point: 169 ° C.), n-butyl propionate (boiling point: 145 ° C.), isopentyl propionate (boiling point: 161 ° C.), and the like. Among these solvents, from the viewpoint of safety, benzene, toluene, xylene (o-, m-, p-isomer), 1,3,5-trimethylbenzene, chlorobenzene, dichlorobenzene (o-, m-, p Aromatic hydrocarbons such as benzotrifluoride, anisole, etc., cyclopentyl methyl ether, di-n-butyl ether, di-i-butyl ether, di-n-pentyl ether, decafluoro-3-methoxy-2- (tri) Alkyl ethers such as fluoromethyl) pentane are preferred, and toluene, xylene (o-, m-, p-form), 1,3,5-trimethylbenzene, chlorobenzene, dichlorobenzene (o-, m-, p-form) More preferred are aromatic hydrocarbons such as benzotrifluoride and anisole. In addition, a non-water-soluble solvent can be used individually or in mixture of 2 or more types in arbitrary ratios.

  The water-insoluble solvent used in the present invention is appropriately selected in consideration of the boiling point of 1H, 2H-perfluorocycloalkene from the viewpoint of easily purifying the desired 1H, 2H-perfluorocycloalkene by distillation. be able to. The boiling point of the water-insoluble solvent is preferably higher than the boiling point of 1H, 2H-perfluorocycloalkene, specifically 20 ° C. or more, preferably 30 ° C. or more, more preferably 50 ° C. or more More preferably. If the boiling point of the water-insoluble solvent is 20 ° C. or more higher than the boiling point of 1H, 2H-perfluorocycloalkene, it is easy to distill the desired 1H, 2H-perfluorocycloalkene from the reaction product obtained in the reaction step Can be purified. In the present specification, the “boiling point of the non-water-soluble solvent” refers to the lowest boiling point among the boiling points of the multiple types of non-water-soluble solvents when multiple types of non-water-soluble solvents are used. Moreover, the "boiling point" of each substance refers to the boiling point of the said substance under the conditions of 1 atm pressure.

[water]
The water used by this invention is not specifically limited, For example, distilled water, ion-exchange water, etc. can be used.

[Alkylamine]
Examples of the alkyl amine used in the present invention include alkyl monoamines and alkyl diamines. Examples of the alkyl monoamine include methylamine, ethylamine, propylamine, and butylamine. As an alkyl diamine, N, N, N, N- tetramethyl ethylenediamine, N, N, N, N- tetramethyl propane diamine etc. can be mentioned, for example. These alkylamines can be used alone or in admixture of two or more at any ratio.

  The carbon number of the alkylamine is not particularly limited, but is preferably 6 or less, more preferably 3 or more and 6 or less, and still more preferably 3 or 4. If an alkylamine having 3 or more carbon atoms is used, the boiling point of the alkylamine is suitable, and the handling becomes easy. On the other hand, when an alkylamine having 6 or less carbon atoms is used, the solubility of the alkylamine-hydrogen fluoride salt produced in the reaction step or the salt produced when the unreacted alkylamine is neutralized with an acid in water And the 1H, 2H-perfluorocycloalkene can be easily recovered from the reaction product.

  The alkylamine used in the present invention is preferably a water-soluble alkylamine. In the present specification, the water-soluble alkylamine is an alkylamine mixed with water at an arbitrary ratio at least at 20 ° C. If it is a water-soluble alkylamine, since the unreacted alkylamine remaining after the reaction step is dissolved in water, recovery of 1H, 2H-perfluorocycloalkene from the resulting reaction product is facilitated, and 1H, 1H, The purity of 2H-perfluorocycloalkene can be further improved.

  Examples of the alkylamine include alkylamines having 1 or 2 carbon atoms such as methylamine, dimethylamine, ethylamine, and ethanolamine; n-propylamine, i-propylamine, cyclopropylamine, N-ethylmethylamine, and the like. Alkyl amine having 3 carbon atoms; alkyl amine having 4 carbon atoms such as n-butylamine, sec-butylamine, t-butylamine, isobutylamine, cyclobutylamine, diethylamine and morpholine; n-pentylamine, 2-pentylamine, 3 -Amine having 5 carbons such as pentylamine, isopentylamine, neopentylamine, etc .; Aliphatic monoamines having 6 carbons such as cyclohexylamine; and the like. Among these alkylamines, from the viewpoint of easy handling, alkylamines having 3 carbon atoms such as n-propylamine, i-propylamine, cyclopropylamine, N-ethylmethylamine, n-butylamine, sec -An alkylamine having 4 carbon atoms such as butylamine, t-butylamine, isobutylamine, cyclobutylamine, diethylamine and morpholine is preferred. In addition, n-propylamine, i-propylamine, n-butylamine, sec-butylamine, and t-butylamine are more preferable from the viewpoint that the reaction step can be completed at a relatively low temperature and in a short time.

  In the present invention, the above-mentioned alkylamine is preferably a primary alkylamine. Examples of primary alkylamines include methylamine, ethylamine, n-propylamine, n-butylamine, isobutylamine, t-butylamine, n-pentylamine, neopentylamine and the like. If the alkylamine is a primary alkylamine, the target 1H, 2H-perfluorocycloalkene can be more selectively produced by further suppressing the formation of isomers.

<Reaction process>
The method for producing 1H, 2H-perfluorocycloalkene of the present invention includes a reaction step. In this reaction step, 1H, 1H, 2H-perfluorocycloalkane represented by the above-mentioned formula (I) is contacted with an alkylamine in the presence of a water-insoluble solvent and water. In the present specification, contacting 1H, 1H, 2H-perfluorocycloalkane with an alkylamine in the presence of a water-insoluble solvent and water means 1H in a solvent containing the water-insoluble solvent and water. , 1H, 2H-perfluorocycloalkane and alkylamine are mixed.

  The amount of alkylamine used in the reaction step is preferably 1.1 molar equivalent or more, 1.5 mol or more, in terms of amino groups in the alkylamine relative to the starting material 1H, 1H, 2H-perfluorocycloalkane. It is more preferably equal to or greater than the equivalent weight, preferably equal to or less than 3 molar equivalents, and more preferably equal to or less than 2.5 molar equivalents. When the amount of alkylamine relative to the starting material is equal to or more than the above lower limit value, it is possible to prevent the starting material from remaining after the reaction step and to shorten the time required for the reaction step. On the other hand, if the amount of alkylamine relative to the starting material is less than the above upper limit, the viscosity of the reaction solution is kept low to facilitate stirring and at the same time suppress large amounts of unreacted alkylamine to remain. It is possible to reduce the amount of acid needed to neutralize the unreacted alkylamine later.

  The amount of the water-insoluble solvent used in the reaction step is preferably 1.0 mL / g or more and 3.5 mL / g or less in volume ratio (mL / g) of the water-insoluble solvent per unit mass of the starting material . If the amount of use of the water-insoluble solvent is equal to or more than the above lower limit value, the viscosity of the reaction solution can be kept low and stirring can be facilitated, whereby the time required for the reaction step can be shortened. On the other hand, if the amount of use of the non-water soluble solvent is equal to or less than the above upper limit, the time required for the reaction step can be shortened by enhancing the contact efficiency between the starting material and the alkylamine.

  The amount of water used in the reaction step may be an amount capable of sufficiently dissolving the alkylamine-hydrogen fluoride salt produced in the reaction step in water, but the amount of water used is the volume of the water-insoluble solvent Preferably, the volume is 0.5 times or more and 1.5 times or less. If the amount of water used is the above lower limit value or more, the solubility of the alkylamine-hydrogen fluoride salt produced in the reaction step or the salt produced when the unreacted alkylamine is neutralized with an acid By further enhancing, 1H, 2H-perfluorocycloalkene from the reaction product can be more easily recovered. On the other hand, if the amount of water used is equal to or less than the upper limit value, post-treatment becomes easy by reducing the amount of waste water after the reaction step.

  The reaction step is carried out under normal pressure, usually at a reaction temperature of 0 ° C. or more and 100 ° C. or less, preferably 0 ° C. or more and 70 ° C. or less, more preferably 20 ° C. or more and 50 ° C. or less. When the reaction temperature is equal to or higher than the above lower limit value, the starting material can be efficiently converted to the desired product, and the time required for the reaction process can be shortened. On the other hand, if reaction temperature is below the said upper limit, byproduct of an isomer can be suppressed further. In the reaction step, the reaction may be performed while keeping the value of the reaction temperature constant, or may be performed while changing the value of the reaction temperature arbitrarily. Also, depending on the type of alkylamine used, the reaction process may be exothermic. From this, it is preferable to start the reaction at a low temperature in the reaction step and to continue the reaction at a normal temperature (20 ° C.) or higher thereafter.

  Although the reaction time in the reaction step depends on the size of the apparatus used, the capacity of the stirrer, the scale of the reaction, etc., it is usually preferably 1 hour or more and 20 hours, preferably 3 hours or more and 10 hours or less. It is more preferable that If the reaction time is equal to or more than the above lower limit value, the yield of 1H, 2H-perfluorocycloalkene to be obtained can be sufficiently high. On the other hand, if the reaction time is less than or equal to the above upper limit, undesirable side reactions such as addition to 1H, 2H-perfluorocycloalkene produced by unreacted alkylamine after the reaction step can be sufficiently suppressed.

  As a reaction embodiment, for example, a method of charging the starting material, a non-aqueous solvent and water in a reactor, setting the reactor to an arbitrary temperature, and dropping the alkylamine while stirring the contents in the reactor Can take. At that time, the remaining amount of the starting material may be monitored using, for example, gas chromatography and the stirring may be stopped when it is confirmed that the starting material is consumed. In addition, as a reactor and a stirrer used for stirring, a well-known thing can be used.

<Organic layer recovery process>
According to the method for producing 1H, 2H-perfluorocycloalkene of the present invention, the reaction product obtained in the reaction step separates into two layers of an aqueous layer and an organic layer after standing. In addition, the alkylamine-hydrogen fluoride salt produced in the reaction step is dissolved in water, and the target 1H, 2H-perfluorocycloalkene is dissolved in the organic layer. Therefore, in the organic layer recovery step that can be optionally performed, the aqueous layer is separated from the obtained reaction product to obtain an organic layer containing the desired product. Thus, in the reaction step of the production method of the present invention, a reaction product in a state in which the alkylamine-hydrogen fluoride salt formed in the reaction step is dissolved in the aqueous layer is obtained. The alkylamine-hydrogen fluoride salt can be easily separated without performing operations such as addition and mixing of water to the reaction product as compared with the case where the above is carried out. Therefore, it is easy to recover 1H, 2H-perfluorocycloalkene from the reaction product. When a water-soluble alkylamine is used as the alkylamine in the reaction step, the unreacted water-soluble alkylamine can also be separated from the reaction product in the state of being dissolved in the water layer in the organic layer recovery step.

<Removal process>
The organic layer obtained in the organic layer recovery step contains unreacted alkylamine that could not be completely dissolved in the aqueous layer, in addition to the target 1H, 2H-perfluorocycloalkene and the water-insoluble solvent. May be included. Therefore, for example, after separating the aqueous layer, an acid such as dilute hydrochloric acid is added to the organic layer to neutralize the unreacted alkylamine, and then the organic layer is washed with saturated multistory water, saturated saline, etc. Unreacted alkylamine can be removed to increase the purity of 1H, 2H-perfluorocycloalkene. In addition, the organic layer after washing | cleaning can be dried by adding desiccants, such as magnesium sulfate and sodium sulfate.

<Purification process>
In the purification step, the desired substance 1H, 2H-perfluorocycloalkene can be purified by distilling the organic layer. As described above, if a water-insoluble solvent having a boiling point 20 ° C. higher than the boiling point of the target 1H, 2H-perfluorocycloalkene is used as the water-insoluble solvent, for example, a rectifying column or the like The object can be easily recovered using Further, the purification may be repeated to obtain the desired product of high purity.

  According to the present invention, highly selective production of 1H, 2H-perfluorocycloalkene represented by the following formula (II) in a reaction step under mild conditions while suppressing isomer by-production Can do. In Formula (II), n represents the same integer as Formula (I) described above. Further, according to the present invention, 1H, 2H-perfluorocycloalkene can be easily recovered from the reaction product obtained in the reaction step. Examples of 1H, 2H-perfluorocycloalkene obtained after the reaction step include 1,2-dihydrotetrafluorocyclobutene (boiling point 51 ° C.), 1,2-dihydrohexafluorocyclopentene (boiling point 77 ° C.), 1 And 2-dihydrooctafluorocyclohexene (boiling point 86 ° C.) and the like.

  Since 1H, 2H-perfluorocycloalkene obtained by the production method of the present invention has high purity, it can be suitably used, for example, as a gas for semiconductor production.

  EXAMPLES Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to these examples.

The conditions of gas chromatography analysis adopted below are as follows.
Device: HP-6890 (manufactured by Agilent)
Column: GL Science "Inert Cap-1" (length 60 m, inner diameter 0.25 mm, film thickness 1.5 μm)
Column temperature: maintained at 40 ° C. for 10 minutes, then raised at 20 ° C./min, then maintained at 240 ° C. for 10 minutes Injection temperature: 200 ° C.
Carrier gas: nitrogen split ratio: 100/1
Detector: Hydrogen flame ionization detector (FID) (Temperature: 250 ° C, detection limit: 1 ppm)

Example 1
In a 200 mL round bottom glass reactor with a stirrer and a dropping funnel, 19.6 g of 1,1,2-trihydroheptafluorocyclopentane (manufactured by Nippon Zeon Co., Ltd., product name: ZEOLORA H) as a raw material, 50 mL of toluene and 30 mL of water were charged, and the reactor was immersed in an ice bath. From the dropping funnel, 15.4 g of n-butylamine was dropped over about 15 minutes. After completion of the dropwise addition, stirring was continued for 30 minutes, after which the ice bath was removed and stirred at room temperature (23 ° C.) for 3.5 hours. After the stirring was stopped, the aqueous layer and the organic layer were separated, and the obtained organic layer was analyzed by gas chromatography. As a result, the raw material 1,1,2-trihydroheptafluorocyclopentane disappeared (detection limit It was confirmed that 1,2-dihydrohexafluorocyclopentene was produced. The production of 2,3-dihydrohexafluorocyclopentene, which is an isomer, was not confirmed (below the detection limit).

Example 2
The reaction was carried out in the same manner as in Example 1 except that 15.4 g of n-butylamine was changed to 15.4 g of sec-butylamine in Example 1. After stopping the stirring, as a result of analyzing the organic layer by gas chromatography, the raw material 1,1,2-trihydroheptafluorocyclopentane disappears (below detection limit) and 1,2-dihydrohexafluorocyclopentene is formed Was confirmed. The production of 2,3-dihydrohexafluorocyclopentene, which is an isomer, was not confirmed (below the detection limit).

[Example 3]
In Example 1, 15.4 g of n-butylamine was changed to 15.4 g of t-butylamine, and the reaction was carried out in the same manner as in Example 1 except that stirring was performed at room temperature (23 ° C.) for 6.5 hours. After the stirring was stopped, the organic layer was analyzed by gas chromatography. As a result, the raw material 1,1,2-trihydroheptafluorocyclopentane disappeared (below the detection limit), and 1,2-dihydrohexafluorocyclopentene was produced. Was confirmed. The production of 2,3-dihydrohexafluorocyclopentene, which is an isomer, was not confirmed (below the detection limit).

Example 4
The reaction was carried out in the same manner as in Example 1 except that 15.4 g of n-butylamine was changed to 12.4 g of n-propylamine in Example 1. After stopping the stirring, as a result of analyzing the organic layer by gas chromatography, the raw material 1,1,2-trihydroheptafluorocyclopentane disappears (below detection limit) and 1,2-dihydrohexafluorocyclopentene is formed Was confirmed. The production of 2,3-dihydrohexafluorocyclopentene, which is an isomer, was not confirmed (below the detection limit).

[Example 5]
The reaction was carried out in the same manner as in Example 1 except that 15.4 g of n-butylamine was changed to 12.4 g of i-propylamine in Example 1. After stopping the stirring, as a result of analyzing the organic layer by gas chromatography, the raw material 1,1,2-trihydroheptafluorocyclopentane disappears (below detection limit) and 1,2-dihydrohexafluorocyclopentene is formed Was confirmed. The production of 2,3-dihydrohexafluorocyclopentene, which is an isomer, was not confirmed (below the detection limit).

[Example 6]
The reaction was carried out in the same manner as in Example 1 except that 15.4 g of n-butylamine was changed to 21.2 g of cyclohexylamine in Example 1. After the stirring was stopped, the organic layer was analyzed by gas chromatography. As a result, the raw material 1,1,2-trihydroheptafluorocyclopentane disappeared (below the detection limit), and 1,2-dihydrohexafluorocyclopentene was produced. Was confirmed. The production of 2,3-dihydrohexafluorocyclopentene, which is an isomer, was not confirmed (below the detection limit).

[Example 7]
The reaction was carried out in the same manner as in Example 1 except that 15.4 g of n-butylamine was changed to 15.4 g of diethylamine in Example 1, and the mixture was stirred at a temperature of 50 ° C. for 5.5 hours. Stirring was stopped, and after cooling to room temperature (23 ° C.), the organic layer was analyzed by gas chromatography, and it was confirmed that the raw material 1,1,2-trihydroheptafluorocyclopentane disappeared. Below detection limit). Moreover, it was confirmed from the peak area by gas chromatography that 1,2-dihydrohexafluorocyclopentene and 2,3-dihydrohexafluorocyclopentene were produced at a ratio of 99.1: 0.9.

[Example 8]
A reaction was carried out in the same manner as in Example 1 except that 15.4 g of n-butylamine was changed to 13.9 g of N, N, N, N-tetramethylethylenediamine in Example 1, and stirring was conducted at 80 ° C. for 9 hours. did. Stirring was stopped, and after cooling to room temperature (23 ° C.), the organic layer was analyzed by gas chromatography, and it was confirmed that the raw material 1,1,2-trihydroheptafluorocyclopentane disappeared. Below detection limit). Further, it was confirmed from the peak area by gas chromatography that 1,2-dihydrohexafluorocyclopentene and 2,3-dihydrohexafluorocyclopentene were produced at a ratio of 99.8: 0.2.

[Example 9]
The reaction was carried out in the same manner as in Example 1 except that 15.4 g of n-butylamine was changed to 15.6 g of N, N, N, N-tetramethylpropanediamine in Example 1, and stirring was carried out at 80 ° C. for 10 hours. Carried out. Stirring was stopped, and after cooling to room temperature (23 ° C.), the organic layer was analyzed by gas chromatography, and it was confirmed that the raw material 1,1,2-trihydroheptafluorocyclopentane disappeared. Below detection limit). Moreover, it was confirmed from the peak area by gas chromatography that 1,2-dihydrohexafluorocyclopentene and 2,3-dihydrohexafluorocyclopentene were produced at a ratio of 99.4: 0.6.

[Example 10]
The reaction was carried out in the same manner as in Example 1 except that toluene was changed to p-xylene in Example 1. After the stirring was stopped, the organic layer was analyzed by gas chromatography. As a result, the raw material 1,1,2-trihydroheptafluorocyclopentane disappeared (below the detection limit), and 1,2-dihydrohexafluorocyclopentene was produced. That was confirmed. The production of 2,3-dihydrohexafluorocyclopentene, which is an isomer, was not confirmed (below the detection limit).

[Example 11]
The reaction was carried out in the same manner as in Example 1 except that toluene was changed to di-n-butyl ether. After stopping the stirring, as a result of analyzing the organic layer by gas chromatography, the raw material 1,1,2-trihydroheptafluorocyclopentane disappears (below detection limit) and 1,2-dihydrohexafluorocyclopentene is formed Was confirmed. The production of 2,3-dihydrohexafluorocyclopentene, which is an isomer, was not confirmed (below the detection limit).

[Example 12]
In Example 1, the reaction was carried out in the same manner as in Example 1 except that toluene was changed to n-butyl acetate. After stopping the stirring, as a result of analyzing the organic layer by gas chromatography, the raw material 1,1,2-trihydroheptafluorocyclopentane disappears (below detection limit) and 1,2-dihydrohexafluorocyclopentene is formed Was confirmed. The production of 2,3-dihydrohexafluorocyclopentene, which is an isomer, was not confirmed (below the detection limit).

[Example 13]
The reaction was carried out in the same manner as in Example 1 except that toluene was changed to benzotrifluoride in Example 1. After stopping the stirring, as a result of analyzing the organic layer by gas chromatography, the raw material 1,1,2-trihydroheptafluorocyclopentane disappears (below detection limit) and 1,2-dihydrohexafluorocyclopentene is formed Was confirmed. The production of 2,3-dihydrohexafluorocyclopentene, which is an isomer, was not confirmed (below the detection limit).

Example 14
In Example 1, the reaction was performed in the same manner as in Example 1 except that toluene was changed to decafluoro-3-methoxy-2- (trifluoromethyl) pentane (HFE-7300, 3M). After stopping the stirring, as a result of analyzing the organic layer by gas chromatography, the raw material 1,1,2-trihydroheptafluorocyclopentane disappears (below detection limit) and 1,2-dihydrohexafluorocyclopentene is formed Was confirmed. The production of 2,3-dihydrohexafluorocyclopentene, which is an isomer, was not confirmed (below the detection limit).

[Example 15]
Example 1 and Example 1 except that 19.6 g of 1,1,2-trihydroheptafluorocyclopentane as a raw material was changed to 14.6 g of 1,1,2-trihydropentafluorocyclobutane in Example 1. The reaction was carried out in the same manner. After stopping the stirring, as a result of analyzing the organic layer by gas chromatography, the raw material 1,1,2-trihydropentafluorocyclobutane disappears (below detection limit) and 1,2-dihydrotetrafluorocyclobutene is formed Was confirmed. The production of 2,3-dihydrotetrafluorocyclobutene, which is an isomer, was not confirmed (below the detection limit).

Comparative Example 1
A 200 mL round bottom glass reactor equipped with a stirrer was charged with 19.6 g of 1,1,2-trihydroheptafluorocyclopentane as a raw material and 100 mL of 2N aqueous potassium hydroxide solution, and the reactor was immersed in an ice bath. . Stirring was continued for 30 minutes, after which the ice bath was removed and the mixture was stirred at room temperature (23 ° C.) for 4.5 hours. Stirring was stopped, and after standing, the lower layer was analyzed by gas chromatography. As a result, it was confirmed that the raw material 1,1,2-trihydroheptafluorocyclopentane has disappeared (below the detection limit) . Further, from the peak area by gas chromatography, it was confirmed that 1,2-dihydrohexafluorocyclopentene and 2,3-dihydrohexafluorocyclopentene which is an isomer were produced at a ratio of 90.5: 9.5.

Comparative Example 2
19.6 g of 1,1,2-trihydroheptafluorocyclopentane, 50 mL of toluene, and 100 mL of 2N aqueous potassium hydroxide solution are charged in a 200 mL round-bottom glass reactor equipped with a stirrer, and the reactor is placed in an ice bath Soaked. Stirring was continued for 30 minutes, after which the ice bath was removed and the mixture was stirred at room temperature (23 ° C.) for 9.5 hours. The stirring was stopped, and after standing, the lower layer was analyzed by gas chromatography. As a result, it was confirmed that the raw material 1,1,2-trihydroheptafluorocyclopentane disappeared (below the detection limit). Further, from the peak area by gas chromatography, it was confirmed that 1,2-dihydrohexafluorocyclopentene and 2,3-dihydrohexafluorocyclopentene, which is an isomer, were produced at a ratio of 91.5: 8.5.

Comparative Example 3
A 200 mL round bottom glass reactor equipped with a stirrer was charged with 14.6 g of 1,1,2-trihydropentafluorocyclobutane and 100 mL of 2N aqueous potassium hydroxide, and the reactor was immersed in an ice bath. Stirring was continued for 30 minutes, after which the ice bath was removed and the mixture was stirred at room temperature (23 ° C.) for 5.5 hours. Stirring was stopped, and after standing, the lower layer was analyzed by gas chromatography. As a result, it was confirmed that the raw material 1,1,2-trihydropentafluorocyclobutane disappeared (below the detection limit). In addition, from the peak area by gas chromatography, it was confirmed that 1,2-dihydrotetrafluorocyclobutene and the isomer 2,3-dihydrotetrafluorocyclobutene were formed at a ratio of 91.9: 8.1. It was.

  From the above results, by contacting 1H, 1H, 2H-perfluorocycloalkane with an alkylamine in the presence of a water-insoluble solvent and water, the formation of isomers is suppressed under mild conditions, It can be seen that 1H, 2H-perfluorocycloalkene can be produced highly selectively.

  According to the present invention, it is possible to provide a production method capable of producing 1H, 2H-perfluorocycloalkene under mild conditions.

Claims (5)

Formula (I)

(In the formula (I), n represents an integer of 1 or more and 3 or less.)
Comprising a reaction step of contacting 1H, 1H, 2H-perfluorocycloalkane represented by the formula (II) with an alkylamine in the presence of a water-insoluble solvent and water:

(In formula (II), n represents the same integer as in formula (I).)
The manufacturing method of 1H, 2H-perfluorocycloalkene shown by these.   The method for producing 1H, 2H-perfluorocycloalkene according to claim 1, wherein the alkylamine has 6 or less carbon atoms.   The method for producing 1H, 2H-perfluorocycloalkene according to claim 1 or 2, wherein the alkylamine is a water-soluble alkylamine.   The method for producing 1H, 2H-perfluorocycloalkene according to any one of claims 1 to 3, wherein the alkylamine is a primary alkylamine.   The preparation of 1H, 2H-perfluorocycloalkene according to any one of claims 1 to 4, wherein the boiling point of the water-insoluble solvent is 20 ° C or more higher than the boiling point of the 1H, 2H-perfluorocycloalkene. Method.