JP7181486B1 - Method for producing monofluoroalkane - Google Patents

Abstract

Kind Code: A1 A method is provided for industrially inexpensively obtaining a monofluoroalkane with high yield and high selectivity. A method for producing a monofluoroalkane comprises at least one fluoride selected from the group consisting of alkali metal fluorides and alkaline earth metal fluorides, and the following general formula (1): TIFF0007181486000007.tif26132 (Wherein, R is the same or different and represents an alkyl group having 1 to 10 carbon atoms, and X represents Cl, Br or I.). A manufacturing method comprising the step of obtaining [Selection figure] None

Description

The present disclosure relates to methods for producing monofluoroalkanes.

As a method for producing a monofluoroalkane such as CH ₃ F, a method of preparing tetrabutylammonium from tetrabutylammonium cyanide (TBACN) and hexafluorobenzene and reacting it with methyl iodide is known (for example, See Non-Patent Document 1).

Journal of American Chemical Society, 2005, 127 (7), pp 2050-2051.

An object of the present disclosure is to provide a method capable of obtaining a monofluoroalkane at high yield and high selectivity at low industrial cost.

The present disclosure includes the following configurations.

Section 1. A method for producing a monofluoroalkane, comprising:
at least one fluoride selected from the group consisting of alkali metal fluorides and alkaline earth metal fluorides;
The following general formula (1):

(Wherein, R is the same or different and represents an alkyl group having 1 to 10 carbon atoms, and X represents Cl, Br or I.)
A production method comprising a step of obtaining the monofluoroalkane by reacting with a tetraalkylammonium salt represented by.

Section 2. Item 1. The production method according to item 1, wherein the Rs are the same or different and are alkyl groups having 1 to 4 carbon atoms.

Item 3. Item 3. The production method according to Item 1 or 2, wherein the reaction temperature in the step is 50 to 250°C.

Section 4. Item 4. The production method according to any one of Items 1 to 3, wherein the molar ratio of the tetraalkylammonium salt and the fluoride in the step is 1:0.1 to 1:10.

Item 5. Item 5. The production method according to any one of Items 1 to 4, wherein the step is performed in a solvent containing a nitrogen-containing compound.

Item 6. The solvent is selected from the group consisting of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, N,N-dimethylpropyleneurea, and pyridine. Item 6. The manufacturing method according to Item 5, comprising at least one of

Item 7. The following general formula (2):
RF (2)
(Wherein, R represents an alkyl group having 1 to 10 carbon atoms.)
A monofluoroalkane represented by, and
A composition containing an alkene having 1 to 10 carbon atoms.

Item 8. Item 8. The composition according to item 7, wherein the content of the monofluoroalkane is 90 mol% or more when the total number of moles of the monofluoroalkane and the alkene is 100 mol%.

Item 9. Item 9. The composition according to item 7 or 8, which is used as a cleaning gas, an etching gas, a synthetic raw material, or a synthetic intermediate.

According to the present disclosure, a monofluoroalkane can be obtained industrially at low cost with high yield and high selectivity.

As used herein, "contain" is a concept that includes both "comprise," "consist essentially of," and "consist of." Further, in this specification, when a numerical range is indicated by "A to B", it means from A to B.

In the present disclosure, "selectivity" means the ratio (mol%) of the total molar amount of the target compound contained in the gas after the reaction to the total molar amount of compounds other than the raw material compounds in the gas after the reaction. .

In the present disclosure, the “conversion rate” means the ratio (mol%) of the total molar amount of compounds other than the raw material compound contained in the gas after the reaction to the molar amount of the raw material compound supplied to the reactor.

In the present disclosure, "yield" means the ratio (mol%) of the total molar amount of the target compound contained in the gas after the reaction to the molar amount of the raw material compound supplied to the reactor.

1. Method for Producing Monofluoroalkane The method for producing monofluoroalkane of the present disclosure includes at least one fluoride selected from the group consisting of alkali metal fluorides and alkaline earth metal fluorides;
The following general formula (1):

(Wherein, R is the same or different and represents an alkyl group having 1 to 10 carbon atoms, and X represents Cl, Br or I.)
and a tetraalkylammonium salt represented by to obtain the monofluoroalkane.

Conventionally, for example, as a method of producing a monofluoroalkane that is CH ₃ F, a method of preparing tetrabutylammonium from tetrabutylammonium cyanide (TBACN) and hexafluorobenzene and reacting it with methyl iodide has been adopted. was This method is not suitable for industrial use because it takes time to prepare TBAF in-situ and TBACN, hexafluorobenzene, and hexacyanobenzene are generated as waste products, and new monofluoroalkanes are obtained with high yield and high selectivity. A method is desired that can be obtained at a rate.

According to the present disclosure, as described above, by reacting at least one fluoride selected from the group consisting of alkali metal fluorides and alkaline earth metal fluorides with a specific tetraalkylammonium salt, A monofluoroalkane can be obtained industrially at low cost with high conversion and high selectivity.

(1-1) Tetraalkylammonium salt A tetraalkylammonium salt as a raw material compound that can be used in the production method of the present disclosure has the following general formula (1).

(wherein R is the same or different and represents an alkyl group having 1 to 10 carbon atoms, and X represents Cl, Br or I).

The above Rs are the same or different and are alkyl groups having 1 to 10 carbon atoms. From the viewpoint of being able to obtain a monofluoroalkane at a higher conversion rate and a higher selectivity at a higher industrial cost, the number of carbon atoms in R is preferably 1 to 8, more preferably 2 to 6, and further 3 to 4. preferable.

In general formula (1), the alkyl group represented by R includes, for example, methyl group; ethyl group; propyl group such as n-propyl group and i-propyl group; n-butyl group, i-butyl group, sec- butyl groups such as butyl group and t-butyl group; pentyl groups such as n-pentyl group, i-pentyl group, sec-pentyl group, t-pentyl group and neopentyl group; Among these, a methyl group, an ethyl group, an n-propyl group, and an n-butyl group are preferable from the viewpoint of being able to obtain a monofluoroalkane at a higher conversion rate and a higher selectivity at a lower industrial cost, and a methyl group. , an ethyl group is more preferred.

In general formula (1), X is a chlorine atom, a bromine atom or an iodine atom. Among these, a chlorine atom and a bromine atom are preferable from the viewpoint that a monofluoroalkane can be obtained industrially at a lower cost with a higher conversion rate and a higher selectivity.

As a tetraalkylammonium salt as a raw material compound, R is an alkyl group having 1 to 4 carbon atoms, from the viewpoint of being able to obtain a monofluoroalkane at a lower industrial cost with a higher conversion rate and a higher selectivity, Moreover, X is preferably a tetraalkylammonium salt that is a chlorine atom or a bromine atom.

Specifically, the tetraalkylammonium salt as the raw material compound that satisfies the above conditions is as follows.

等が挙げられる。これらのテトラアルキルアンモニウム塩は、単独で用いることもでき、２種以上を組合せて用いることもできる。このようなテトラアルキルアンモニウム塩は、公知又は市販品を採用することができる。

etc. These tetraalkylammonium salts can be used alone or in combination of two or more. As such a tetraalkylammonium salt, a known or commercially available product can be adopted.

(1-2) Fluoride The step of obtaining a monofluoroalkane in the present disclosure includes at least one fluoride selected from the group consisting of alkali metal fluorides and alkaline earth metal fluorides, and the tetraalkylammonium salt. to react. The above fluorides function as fluorine sources and can produce monofluoroalkanes with particularly high conversions, yields and selectivities.

Alkali metal fluorides are not particularly limited, but from the viewpoint that monofluoroalkanes can be produced with particularly high conversion, yield and selectivity, 4th to 7th period alkali metals Fluorides are preferred, and potassium fluoride (KF), cesium fluoride (CsF) and the like are more preferred.

Alkaline earth metal fluorides are not particularly limited, but from the viewpoint that monofluoroalkanes can be produced with particularly high conversion, yield and selectivity, 4th to 7th period alkalis Fluorides of earth metals are preferred, and calcium fluoride (CaF ₂ ), magnesium fluoride (MgF ₂ ) and the like are more preferred.

The above fluorides can be used alone or in combination of two or more.

(1-3) Molar ratio between tetraalkylammonium salt and fluoride The molar ratio between tetraalkylammonium salt and fluoride in the above step is preferably 1:0.1 to 1:10, more preferably 1:0.5 to 1:0.5. 1:5 is more preferred. When the molar ratio is within the above range, the yield and selectivity of monofluoroalkane are further improved.

(1-4) Solvent The step in the present disclosure is preferably a step of reacting a tetraalkylammonium salt with a fluoride in a solvent. By reacting the tetraalkylammonium salt and the fluoride in a solvent, the yield and selectivity of the monofluoroalkane are further improved.

The solvent is not particularly limited, and examples thereof include solvents containing nitrogen-containing compounds. Examples of such nitrogen-containing compounds include N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, N,N-dimethylpropyleneurea, pyridine and the like. Among these, N-methylpyrrolidone, N,N-dimethylformamide and pyridine are preferred, and N-methylpyrrolidone is more preferred. These nitrogen-containing compounds can be used alone or in combination of two or more.

The concentration of the tetraalkylammonium salt in the solvent is not particularly limited, and is preferably 0.01 to 10 mol/L from the viewpoint that the monofluoroalkane can be produced with particularly high conversion, yield and selectivity. 0.05 to 5 mol/L is more preferred.

The concentration of fluoride in the solvent is not particularly limited, and is preferably 0.01 to 10 mol/L, preferably 0.05, from the viewpoint that monofluoroalkane can be produced with particularly high conversion, yield and selectivity. ~5 mol/L is more preferred.

(1-5) Reaction temperature In the step of obtaining a monofluoroalkane by reacting a fluoride with a tetraalkylammonium salt represented by the general formula (1) in the present disclosure, the reaction temperature is 50 to 300°C is preferred, 50 to 250°C is more preferred, and 80 to 220°C is even more preferred, from the viewpoint of being able to produce with high conversion, yield and selectivity.

(1-6) Reaction time When the step in the present disclosure is a step of reacting a tetraalkylammonium salt and a fluoride in a solvent, the reaction time is such that the conversion rate of the reaction is particularly high, and the monofluoroalkane is more 0.1 hr to 48 hr is preferable, and 1 hr to 24 hr is more preferable from the viewpoint of obtaining high yield and high selectivity.

(1-7) Reaction pressure The reaction pressure in the above steps in the present disclosure is preferably -0.05 to 2 MPa from the viewpoint that monofluoroalkane can be produced with particularly high conversion, yield and selectivity, and - 0.01 to 1 MPa is more preferable, and normal pressure to 0.5 MPa is even more preferable. In addition, in the present disclosure, pressure is assumed to be gauge pressure unless otherwise specified.

In the reaction of the present disclosure, the reactor for reacting the gas containing fluoride and optionally fluorine with the raw material compound (tetraalkylammonium salt) should be able to withstand the above temperature and pressure. And the structure is not particularly limited. Examples of reactors include vertical reactors, horizontal reactors, multitubular reactors, and the like. Examples of materials for the reactor include glass, stainless steel, iron, nickel, and iron-nickel alloys.

(1-8) Reaction exemplification In the process of obtaining a monofluoroalkane in the present disclosure, a solvent, a raw material compound (tetraalkylammonium salt), and a fluoride are charged into a reactor and reacted batchwise. (Tetraalkylammonium salt) can be continuously charged, and the target compound (monofluoroalkane) can be continuously withdrawn from the reactor by any system of a continuous stirred tank reactor.

Regarding the atmosphere when performing the step of obtaining a monofluoroalkane in the present disclosure, an inert gas atmosphere is preferable from the viewpoint of suppressing deterioration of fluoride. Examples of the inert gas include nitrogen, helium, argon, and the like. Among these inert gases, nitrogen is preferable from the viewpoint of cost reduction. The concentration of the inert gas is preferably 0 to 50 mol % of the gas components introduced into the reactor.

After completion of the reaction, a monofluoroalkane can be obtained by purification treatment according to a conventional method, if necessary.

(1-9) Target compound The target compound of the present disclosure thus obtained is a monofluoroalkane having an alkyl group having 1 to 10 carbon atoms, and is represented by general formula (2):
RF (2)
(Wherein, R represents an alkyl group having 1 to 10 carbon atoms.)
A monofluoroalkane represented by is mentioned.

In general formula (2), R is an alkyl group having 1 to 10 carbon atoms. The number of carbon atoms in R is preferably 1-8, more preferably 1-6, and even more preferably 1-4.

In the general formula (2), the alkyl group represented by R includes, for example, methyl group; ethyl group; propyl group such as n-propyl group and i-propyl group; n-butyl group, i-butyl group, sec- butyl groups such as butyl group and t-butyl group; pentyl groups such as n-pentyl group, i-pentyl group, sec-pentyl group, t-pentyl group and neopentyl group; Among these, a methyl group, an ethyl group, an n-propyl group, and an n-butyl group are preferable from the viewpoint of being able to obtain a monofluoroalkane at a higher conversion rate and a higher selectivity at a lower industrial cost, and a methyl group. , an ethyl group is more preferred.

In addition, said R is the same as R in said general formula (1).

The monofluoroalkane obtained by the present disclosure can be effectively used for various applications such as etching gas, cleaning gas, synthetic raw material, or synthetic intermediate for forming state-of-the-art microstructures such as semiconductors and liquid crystals.

2. Compositions Monofluoroalkanes can be obtained in the manner described above, and may also be obtained in the form of compositions containing monofluoroalkanes.

Such compositions include, for example, general formula (2):
RF (2)
(Wherein, R represents an alkyl group having 1 to 10 carbon atoms.)
and a composition containing a monofluoroalkane represented by

In this case, the lower limit of the content of the monofluoroalkane represented by the general formula (2) is preferably 90.0 mol% or more, more preferably 95 mol% or more, with the total amount of the composition of the present disclosure being 100 mol%. Further, the upper limit of the monofluoroalkane content is preferably as high as possible, and may be 100 mol % or less, 99.8 mol % or less, or 99.0 mol % or less.

The composition may also contain alkenes having 1 to 10 carbon atoms. The number of carbon atoms in the alkene is the same as the number of carbon atoms in R of the monofluoroalkane represented by the general formula (2) contained in the composition of the present disclosure. For example, when the monofluoroalkane represented by the general formula (2) is CH ₃ CH ₂ F, the alkene is ethylene. Moreover, when the monofluoroalkane represented by the general formula (2) is CH ₃ CH ₂ CH ₂ CH ₂ F, the alkene is butene.

In this case, the upper limit of the content of the alkene having 1 to 10 carbon atoms is preferably 10.0 mol% or less, more preferably 5.0 mol% or less, with the total amount of the composition of the present disclosure being 100 mol%. The lower limit of the content of alkenes having 1 to 10 carbon atoms is preferably as low as possible, and may be 0 mol % or more, 0.2 mol % or more, or 1.0 mol % or more.

In addition, according to the production method of the present disclosure, even when the composition is obtained as described above, the monofluoroalkane represented by the general formula (2) can be industrially inexpensively converted to the reaction conversion rate of Since it can be obtained at high yield and high selectivity, it is possible to reduce components other than monofluoroalkane represented by general formula (2) in the composition, so general formula ( It is possible to reduce the cost and energy required for refining to obtain the monofluoroalkane represented by 2).

Such a composition of the present disclosure can be effectively used for various applications such as etching gas and cleaning gas for forming state-of-the-art fine structures such as semiconductors and liquid crystals.

Although the embodiments of the present disclosure have been described above, various changes in form and detail are possible without departing from the spirit and scope of the claims.

Examples are provided below to clarify features of the present disclosure. The disclosure is not limited to these examples.

Examples 1-5
An autoclave was charged with 5 mL of N-methylpyrrolidone as a solvent. Then, a tetraalkylammonium salt shown in Table 1 and KF as a fluoride were added in a molar ratio of 1:1, and the lid was closed. Then, the reaction was allowed to proceed by heating at the temperature shown in Table 1 for 24 hours.

After completion of the reaction, the generated gas was washed with water. Then, mass spectrometry was performed by gas chromatography/mass spectrometry (GC/MS) using gas chromatography (manufactured by Shimadzu Corporation, trade name “GC-2014”), and NMR (manufactured by JEOL, trade name). "400YH") was used for structural analysis by NMR spectrum.

From the results of mass spectrometry and structural analysis, it was confirmed that a monofluoroalkane was produced as the target compound.

In addition, the conversion rate was calculated by measuring the remaining amount of KF by ion chromatography and calculating the number of moles of the remaining amount of KF with respect to the number of moles of KF charged. Table 1 shows the results.

Claims (6)

A method for producing a monofluoroalkane, comprising:
at least one fluoride selected from the group consisting of alkali metal fluorides and alkaline earth metal fluorides;
The following general formula (1):

(Wherein, R is the same or different and represents an alkyl group having 1 to 10 carbon atoms, and X represents Cl, Br or I.)
A production method comprising a step of obtaining the monofluoroalkane by reacting with a tetraalkylammonium salt represented by. The production method according to claim 1, wherein the Rs are the same or different and are alkyl groups having 1 to 4 carbon atoms. The production method according to claim 1 or 2, wherein the reaction temperature in said step is 50 to 250°C. The production method according to any one of claims 1 to 3, wherein the molar ratio of said tetraalkylammonium salt and said fluoride in said step is 1:0.1 to 1:10. The production method according to any one of claims 1 to 4, wherein the step is performed in a solvent containing a nitrogen-containing compound. The solvent is selected from the group consisting of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, N,N-dimethylpropyleneurea, and pyridine. The manufacturing method according to claim 5, comprising at least one of