JP2002173454A - Method for producing fluorine-containing alkanol - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a fluorine-containing alkanol, capable of efficiently giving the objective alkanol in a high yield with high selectivity by controlling the content of a specified compound in the reaction system. SOLUTION: This method for producing the fluorine-containing alkanol, such as HCF2CF2CH2OH, comprises reacting an alkanol, such as methanol with a fluorine-containing olefin such as CF2=CF2, in the presence of a radical initiator, wherein the unreacted alkanol is recovered from the reaction product after the completion of the reaction, and the recovered alkanol is reused in the reaction under such a condition that the content of a diakloxy compound formed as a by-product of the reaction is not more than 0.5 wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a fluorinated alkanol.

[0002]

2. Description of the Related Art Fluorinated alkanols are water- and oil-repellents,
It is useful as a surfactant or an intermediate for photographic color-forming materials (JP-A-54-154707). Also,
Since this compound is insoluble in a plastic substrate such as polycarbonate, it is also useful as a solvent such as a dye for an optical recording material (JP-A-4-8585, JP-A-5-258346, etc.).

Heretofore, as a method for producing a fluorinated alkanol represented by the formula H (CF ₂ CF ₂ ) _m CH ₂ OH (wherein m is an integer of 1 or more), 1) JP-A-54-154
No. 707 discloses a method in which methanol and a radical initiator are collectively charged in the presence of an acid acceptor such as magnesium oxide, calcium oxide, calcium carbonate, and the like, and tetrafluoroethylene is continuously added and reacted. Have been. 2) Japanese Patent No. 3026804 discloses that methanol and tetrafluoroethylene or hexafluoropropylene are reacted in a reactor in the presence of an acid acceptor and a radical initiator, and then the reaction solution is distilled in a distillation column. Hydrogen fluoride and water, which are by-produced by the reaction, are removed from the reaction solution as side-cut fractions, and methanol is distilled off from the top of the column to be recovered, and the recovered methanol is returned to the reactor and reused. A method for producing an alkanol is disclosed.

[0004]

The method 1) has a problem that the pH is decreased due to an acidic substance generated as the reaction proceeds, and the reaction rate is significantly reduced.
Therefore, an acid acceptor is added in order to prevent a decrease in the reaction rate due to the decrease in the pH. However, since solid powder is used as the acid acceptor, there has been a problem that the fine powder of the acid acceptor is mixed into the obtained fluorinated alkanol. Further, in the method 2), only the removal of by-produced hydrogen fluoride and water, which inhibit the above reaction, when the recovered methanol is reused, is described.

According to the study of the present inventors, when methanol is recovered from which only by-produced hydrogen fluoride and water have been removed and reused in the above-mentioned reaction, it is still difficult to eliminate the inhibition of the reaction. Was found. Further, the inventors have found that the reaction inhibition is caused by a specific compound produced by the action of an acidic substance produced as the reaction proceeds.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies on a method of recovering and reusing unreacted alkanol when producing a fluorinated alkanol, and as a result,
By controlling the content of the specific compound in the reaction system, it has been found that the reaction inhibition is eliminated, and the desired fluorinated alkanol can be efficiently obtained with high yield and high selectivity, and the present invention has been found. It was completed. That is, the present invention is disclosed in the following (1) to (5).

(1) An alkanol (A) represented by the following formula 2 and a fluorinated olefin (B) represented by the following formula 3 are reacted in the presence of a radical initiator (C) to be represented by the following formula 1. In the method for producing a fluorinated alkanol (D), unreacted alkanol (A) is recovered from the reaction product of the above reaction, and the alkanol (A) is converted to a dialkoxy compound (E) by-produced by the reaction. Wherein the content of is reduced to 0.5% by mass or less and reused in the above reaction. H (CFR ³ CF ₂ ) _n CR ¹ R ² OH Formula 1 CHR ¹ R ² OH Formula 2 CF ₂ = CFR ³ Formula 3 wherein the symbols in the formula have the following meanings. Show. R ¹ and R ² each independently represent a hydrogen atom or a lower alkyl group. R ³ : a fluorine atom or a fluorine-containing monovalent organic group. n: an integer from 1 to 4.

(2) The radical initiator (C) is a di-te
The method for producing a fluorinated alkanol according to (1), which is rt-butyl peroxide. (3) The method for producing a fluorinated alkanol according to (1) or (2), wherein the alkanol (A) is methanol. (4) The method for producing a fluorinated alkanol according to (1), (2) or (3), wherein the dialkoxy compound (E) is 2,2-dimethoxypropane and / or dimethoxymethane. (5) A mixture containing the unreacted alkanol (A) and the remaining radical initiator (C) is recovered from the reaction product, and the mixture is reused in the above reaction (1) to (1). The method for producing a fluorinated alkanol according to any one of 4).

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In Formula 2, R ¹ and R ² each independently represent a hydrogen atom or a lower alkyl group. R
^{As 1} and R ² , a hydrogen atom is particularly preferred. In the formula 2, when R ¹ and R ² are lower alkyl groups, the lower alkyl group may have a straight-chain structure or a branched structure, for example, an alkyl group having 1 to 3 carbon atoms. And specific examples include a methyl group, an ethyl group, a propyl group, and an isopropyl group. Of these, a methyl group is preferable.

Specific examples of the alkanol (A) used in the present invention include methanol, ethanol, 2-propanol and the like. Among them, methanol or ethanol is preferable, and methanol is more preferable.

In the formula 3, R ³ represents a fluorine atom or a fluorine-containing monovalent organic group, and among them, a fluorine atom is preferable. When R ³ is a fluorine-containing monovalent organic group (hereinafter, referred to as an R ^F group), the R ^F group is a group that does not include a structure that reacts with an alkanol, such as a polyfluoroalkyl group ( hereinafter referred to as ^the R ^f group.) are preferable.

The R ^f group is a group in which two or more hydrogen atoms of an alkyl group have been replaced by fluorine atoms. The R ^f group may have a linear structure or a branched structure.
The number of carbon atoms of the ^f group is preferably from 1 to 20, particularly preferably 1
-18, with 1-16 being particularly preferred. When the R ^f group has a branched structure, the branched portion is preferably a short chain having a terminal portion of the R ^f group and having about 1 to 4 carbon atoms. The structure of the terminal portion of the R ^f group includes —CF ₃ ,
_{-CF 2 CF 3, -CF (CF} 3) 2, -CF 2 H, -CF
H _{2 and the} like, and —CF ₃ is particularly preferable.

[0013] The number of fluorine atoms in the R ^f groups, [(R ^f number of fluorine atoms in the group) / (R ^f number of hydrogen atoms contained in the alkyl group corresponding same carbon number and group)] × 100 When expressed in (%), it is preferably at least 60%, particularly preferably at least 80%. Further, the R ^f group is a perfluoroalkyl group in which all of the hydrogen atoms of the alkyl group are substituted with fluorine atoms, or the perfluoroalkyl group is a group represented by R ^f
Groups having terminal groups are preferred.

R^fSpecific examples of the group include, for example,
Groups. In the following specific examples, the same
Including structurally isomeric groups,
No. CF_Three-, C_TwoF_Five-, C_ThreeF₇-[For example, CF_Three(C
F_Two)_Two−, (CF_Three)_TwoCF-], C_FourF₉-[Eg F
(CF_Two)_Four−, (CF_Three)_TwoCFCF_Two−, (CF_Three) _ThreeC
-, CF_ThreeCF_TwoC (CF_Three) F-], C_FiveF₁₁-[Parable
BA F (CF_Two)_Five−], C₆F₁₃-[For example, F (CF_Two)
₆−], C₇F₁₅-[For example, F (CF_Two)₇−], C₈F
₁₇-[For example, F (CF_Two)₈−], C₉F₁₉-[Parable
BA F (CF_Two)₉−], C_TenF_{twenty one}-[For example, F (C
F_Two)_Ten−], C₁₂F_{twenty five}-[For example, F (CF_Two)
₁₂−], C₁₄F₂₉-[For example, F (CF_Two)₁₄−], C
₁₆F₃₃-[For example, F (CF_Two)₁₆−], H (CF_Two)_t
− (Where t is an integer of 4 to 16), (CF_Three)_TwoCF
(CF_Two)_k-(Where k is an integer of 1 to 13) and the like.

The R ^f group may have a halogen atom other than a fluorine atom. Said other halogen atoms, R ^f
It is preferably present at the terminal part of the group. As another halogen atom, a chlorine atom is preferable. As R ^f is a group having the other halogen atom, and the structure of the terminal portion is ^the R ^f group is, for example, -CF ₂ Cl, particularly Cl
_{(CF 2) s -, (} . Wherein, s is an integer of 4-16) and the like.

The R ^f group may have a heteroatom and / or a heteroatom group. ^The R ^f group having a hetero atom and / or heteroatom groups, the carbon in the ^the R ^f group -
Heteroatoms such as an etheric oxygen atom and a thioetheric sulfur atom and / or an ester bond (-
COO -, - OCO -), -. SO 2 NR- (R is a hydrogen atom or a methyl group, an ethyl group, a propyl group, an isopropyl group, a lower alkyl group such as butyl group) hetero atom group inserted such Groups. The ^the R ^f group may, inter alia preferably perfluoroalkyl group having 1 to 4 carbon atoms.

The fluorine-containing olefin (B) used in the present invention is, for example, an olefin in which two or more hydrogen atoms in the olefin are substituted with a fluorine atom, and a perfluorinated olefin in which all hydrogen atoms in the olefin are substituted with a fluorine atom. Polyfluoroolefins such as olefins are preferred.

Specific examples of the polyfluoroolefin include the following compounds. CF ₂ = CF ₂ , CF ₃ CF = CF ₂ , CF ₃ CF ₂ CF = CF ₂ , CF ₃ (CF ₂ ) ₂ CF = CF ₂ , CF ₃ (CF ₂ ) ₃ CF = CF ₂ , CF ₃ (CF ₂ ) ₄ CF = CF ₂ , CF ₃ (CF ₂ ) ₅ CF = CF ₂ , CF ₃ (CF ₂ ) ₆ CF = CF ₂ , CF ₃ (CF ₂ ) ₇ CF = CF ₂ , CF ₃ (CF ₂ ) ₈ CF = CF ₂ . Among these polyfluoroolefins, CF ₂ ＣC
F ₂ and CF ₃ CF ＝ CF ₂ are preferred, especially CF ₂ ＣC
F ₂ is preferred.

In the formula 1, R ¹ and R ² each independently represent a hydrogen atom or a lower alkyl group; R ³ represents a fluorine atom or a fluorine-containing monovalent organic group;
Indicates an integer of 4. The above R ¹ and R ² are R
¹ and R ² and the meaning of the same, R ³ denote the same as R ³ in Formula 3. Further, n is an integer of 1 to 4, preferably 1 or 2, and more preferably 1.

Specific examples of the fluorine-containing alkanol (D) obtained by the production method of the present invention include the following compounds. HCF ₂ CF ₂ CH ₂ OH, HCF ₂ CF ₂ CH (CH ₃ ) O
_{H, HCF 2 CF 2 C (} CH 3) 2 OH, H (CF 2 CF 2)
₂ CH ₂ OH, H (CF ₂ CF ₂ ) ₂ CH (CH ₃ ) OH, H
(CF ₂ CF ₂ ) ₂ C (CH ₃ ) ₂ OH, CF ₃ CHFCF ₂
CH ₂ OH, CF ₃ CHFCF ₂ CH (CH ₃ ) OH, CF
₃ CHFCF ₂ C (CH ₃ ) ₂ OH, CF ₃ (CH ₂ ) ₃ O
H, CF ₃ (CF ₂ ) ₃ (CH ₂ ) ₃ OH, CF ₃ (CF ₂ ) ₇
(CH ₂ ) ₃ OH, CF ₃ (CH ₂ ) ₂ CH (CH ₃ ) OH,
CF ₃ (CF ₂ ) ₃ (CH ₂ ) ₂ CH (CH ₃ ) OH, CF _{3
(CF 2) 7 (CH 2} ) 2 CH (CH 3) OH.

Among these fluorinated alkanols (D), HCF ₂ CF ₂ CH ₂ OH, CF ₃ CHFCF
₂ CH ₂ OH and H (CF ₂ CF ₂ ) ₂ CH ₂ OH are preferred, and HCF ₂ CF ₂ CH ₂ OH is more preferred.

The radical initiator (C) used in the present invention
Preferred are peroxides such as alkyl hydroperoxide, dialkyl peroxide, peroxyketal, diacyl peroxide, peroxycarboxylic acid ester, peroxycarboxylic acid, and peroxycarbonate.

As a specific example of the peroxide, for example,
1-bis (tert-butylperoxy) -3,3,5
-Trimethylcyclohexane, 1,1-bis (tert
-Butylperoxy) cyclohexane, tert-butylperoxyisopropyl carbonate, tert-butylperoxyisobutyrate, tert-butylperoxypivalate, di-tert-butylperoxide, tert-butylhydroperoxide, tert-
Butyl cumyl peroxide and the like.

Among these peroxides, those having a half-life at the reaction temperature of about 10 hours are preferably used, and those which are excellent in heat stability and can be distilled are particularly desirable, and di-tert-butyl is preferable. Dialkyl peroxides such as peroxides and tert-butylcumyl peroxide are more preferred, and di-tert-butyl peroxide is particularly preferred.

In the production method of the present invention, the dialkoxy compound (E) contained in the alkanol (A) to be recovered is, for example, dimethoxymethane, 2,2-
Examples include dimethoxypropane and 1,2-dimethoxyethane. Although the production process of the dialkoxy compound (E) is not always clear, it is presumed that the dialkoxy compound (E) is produced through the production process shown in the following scheme 1 or 2, for example.

First, the dialkoxy compound (E) presumed to be obtained from the production process shown in the following scheme 1 will be described. Scheme 1 below is an example using methanol as the alkanol (A), and the dialkoxy compound (E) obtained is dimethoxymethane.

[0027]

Embedded image

That is, alkanol (A) (here, methanol) and fluorinated olefin (B)
Is reacted in the presence of the radical initiator (C) to form formaldehyde as a by-product. The formaldehyde reacts with methanol by the action of an acidic substance further produced as a by-product from the reaction to form an acetal, thereby producing dimethoxymethane as a dialkoxy compound (E).

Next, the dialkoxy compound (E) presumably obtained from the production process shown in the following scheme 2 will be described. Scheme 2 below is an example in which methanol is used as the alkanol (A) and di-tert-butyl peroxide is used as the radical initiator (C). The resulting dialkoxy compound (E) is 2,2.
-Dimethoxypropane.

[0030]

Embedded image

That is, the alkanol (A) (here, methanol) and the fluorinated olefin (B)
And a radical initiator (C) (here, di-tert-
Butyl peroxide. ), The di-tert- used as the radical initiator (C)
A tert-butoxy radical is generated from butyl peroxide (step 1). Next, the bond between the methyl group and the tertiary carbon atom in the generated tert-butoxy radical is broken, and acetone and a methyl radical are generated (step 2). Further, the generated acetone reacts with methanol by the action of the acidic substance generated from the above reaction to form a ketal, and as a dialkoxy compound (E), 2,2
-Dimethoxypropane is formed (step 3).

In the production method of the present invention, the method of recovering unreacted alkanol (A) from the reaction product of the reaction between alkanol (A) and fluorinated olefin (B) comprises:
It is preferably carried out by distillation. The unreacted alkanol (A) is the unreacted alkanol (A) in the reaction between the alkanol (A) and the fluorinated olefin (B). Further, when recovering the unreacted alkanol (A) from the reaction product, the alkanol (A) may contain a residual radical initiator (C). When a mixture containing the remaining radical initiator (C) together with the unreacted alkanol (A) is recovered from the reaction product, the reaction product is converted into a mixture such as an azeotropic mixture, a pseudo-azeotropic mixture, or another mixture. Preferably, it is recovered by distillation.
The reaction product is a reaction solution after completion of the reaction in which the alkanol (A) and the fluorinated olefin (B) are reacted in the presence of the radical initiator (C).

The distillation for recovering the unreacted alkanol (A) may be performed at normal pressure or under reduced pressure. Further, when a large excess of the alkanol (A) is used, the distillation is preferably performed near the boiling point of the alkanol (A). For example, when methanol is used as the alkanol (A), the reaction is usually carried out at 50 to 100 ° C., preferably 50 to 70 ° C. under normal pressure.

The content of the dialkoxy compound (E) in the recovered unreacted alkanol (A) can be adjusted by, for example, distillation, extraction, crystallization by cooling, adsorption by an adsorbent, or other compound and dialkoxy compound (E). Examples of the method include a reaction with E), decomposition, and the like, and among them, distillation is preferable. When unreacted alkanol (A) is recovered by distillation from the reaction product, unreacted alkanol (A) is removed by the distillation.
The content of the dialkoxy compound (E) therein can also be adjusted.

When the content of the dialkoxy compound (E) in the unreacted alkanol (A) is adjusted by distillation,
The reaction may be carried out at normal pressure or under reduced pressure, preferably at normal pressure. The distillation is preferably carried out at around the boiling point of the alkanol (A) used. For example, when methanol is used as an alkanol, the
The temperature is appropriately selected from the range of 100 ° C, preferably 50 to 70 ° C.

It is preferable that the recovered unreacted alkanol (A) does not contain the dialkoxy compound (E), and when the dialkoxy compound (E) is contained, the alkanol (A) Any amount that does not inhibit the reaction with the fluorinated olefin (B) may be used, and is 0.5% by mass or less, preferably 0.45% by mass or less, based on the total amount of the unreacted alkanol (A) recovered. Preferably, it is 0.0001 to 0.45% by mass, more preferably 0.1 to 0.45% by mass.
It is appropriately selected from the range of 001 to 0.4% by mass.

The recovered unreacted alkanol (A) is
After adjusting the content of the dialkoxy compound (E) to 0.5% by mass or less, all or a part of the dialkoxy compound (E) is reused in the reaction between the alkanol (A) and the fluorinated olefin (B) to obtain a fluorinated alkanol (D) is manufactured.

The unreacted alkanol (A) thus recovered is reused in the production method of the present invention by reducing the content of the dialkoxy compound (E) to 0.5% by mass or less. The content of the dialkoxy compound (E) therein can be controlled, and the desired fluorinated alkanol (D) can be efficiently produced. On the other hand, from the residue obtained after recovering the alkanol (A) from the reaction product, that is, from the bottom liquid,
Further distillation is continued to obtain a desired fluorinated alkanol (D).

The method for producing the fluorinated alkanol (D) of the present invention is preferably carried out, for example, by the following method. That is, alkanol (A) and fluorinated olefin (B)
Are reacted in the presence of a radical initiator (C), if necessary, in an inert gas atmosphere. After completion of the reaction, the reaction product of the reaction is distilled as it is in a reactor in which the reaction has been carried out, for example, or in a distillation column to recover unreacted akanol (A) as a distillate. After recovering the unreacted alkanol (A), the distillation of the bottom liquid is further continued to obtain a fraction containing the unreacted alkanol (A) and the remaining radical initiator (C), and then a compound derived from the radical initiator. And after distilling off a fraction containing unreacted alkanol (A), the desired fluorinated alkanol (D)
To obtain a fraction containing

Here, examples of the compound derived from the radical initiator include a decomposition product of the radical initiator (C). For example, when a dialkyl peroxide is used, an alcohol derived from the dialkyl peroxide may be used. The recovered unreacted alkanol (A) is prepared by adjusting the content of the dialkoxy compound (E) to 0.5% by mass or less.
The alkanol (A) and the fluorinated olefin (B) are reused to produce the fluorinated alkanol (D).

The amount of the alkanol (A) and the fluorinated olefin (B) used in the production method of the present invention is usually 2 to 100 mol of the alkanol (A) per 1 mol of the fluorinated olefin (B). Preferably it is 3 to 20 mol. The amount of the radical initiator (C) to be used is appropriately selected usually from the range of 0.0001 to 0.1 mol, preferably from 0.001 to 0.05 mol, per 1 mol of the alkanol (A).

In the production method of the present invention, the reaction temperature when the alkanol (A) and the fluorinated olefin (B) are reacted in the presence of the radical initiator (C) depends on the radical initiator (C) used. Different, usually 40-1
The radical initiator (C) is appropriately selected from the range of 60 ° C.
The half-life temperature is preferably ± 30 ° C., for example, when di-tert-butyl peroxide is used as the radical initiator (C), the range is preferably 95 to 155 ° C., and industrially advantageous conditions are 100 to 140 ° C. Is more preferable.

The reaction time is appropriately selected usually in the range of 1 to 40 hours, preferably 5 to 25 hours. The reaction pressure is preferably 1.5 MPa (gauge pressure, the same applies hereinafter) or less, more preferably 0.2 to 1.2 MPa, and particularly preferably 0.1 to 1.2 MPa.
5 to 1.0 MPa is preferable. As the inert gas when the production method of the present invention is carried out in an inert gas atmosphere as required, nitrogen gas, argon gas and the like can be mentioned.

In the production method of the present invention, the reaction between the alkanol (A) and the fluorinated olefin (B) is a telomerization reaction. This telomerization reaction is a chain reaction,
The reaction proceeds by the following mechanism. That is, first, the radical initiator (C) is decomposed to generate a radical, and the generated radical extracts a hydrogen atom bonded to the carbon to which the hydroxy group of the alkanol (A) is bonded, thereby generating an alkanol radical. . Next, a fluorinated olefin (B) is added to the generated alkanol radical,
The desired fluorinated alkanol (D) is produced. In the telomerization reaction, a fluorinated alkanol (D) having a desired molecular weight can be obtained by controlling the number of addition of the fluorinated olefin (B).

However, it has been generally considered that when a fluorinated alkanol (D) is produced by the telomerization reaction as described above, an acidic substance generated as the reaction proceeds suppresses the telomerization reaction. Moreover, when the recovered alkanol (A) was reused in the above reaction to carry out the telomerization reaction, the progress of the reaction was further suppressed. On the other hand, in the present invention, it has been found that, in addition to the acidic substance, the dialkoxy compound (E) presumed to be generated by the action of the acidic substance further suppresses the telomerization reaction. Thereby, when performing the telomerization reaction, the unreacted alkanol (A) is recovered from the reaction product, and the content of the dialkoxy compound (E) in the recovered unreacted alkanol (A) is reduced to 0.5%. The content of the dialkoxy compound (E) in the telomerization reaction can be controlled by making the telomerization reaction less than or equal to the mass%, and the desired fluorinated alkanol (D) can be obtained in high yield and high selectivity. ) Can be manufactured efficiently.

If a mixture containing the unreacted alkanol (A) and the remaining radical initiator (C) is recovered and reused in the reaction between the alkanol (A) and the fluorinated olefin (B), the reaction product Since it is not necessary to decompose the residual radical initiator (C) in the product, the workability is improved, the amount of radicals generated in the initial stage of the reaction is increased, and a high yield of a fluorine-containing alkanol (D) is produced in a short time. it can.

Further, after the recovered unreacted alkanol (A) is reused in the above reaction and the production method of the present invention is carried out, the reaction product of the above reaction is distilled again, and the unreacted alkanol (A) is removed. Is recovered and the operation utilized for the same reaction between the alkanol (A) and the fluorinated olefin (B) is repeated, whereby the production method of the present invention can be carried out efficiently.

The fluorinated alkanol (D) obtained by the production method of the present invention can be used as a raw material for a functional polymer material, for example, a raw material intermediate for a water- and oil-repellent agent, a surfactant, or a raw material for a photographic coloring material. It is suitable as a solvent or the like when manufacturing an information recording medium provided with a recording layer on which information can be written and / or read by a laser.

[0049]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Reference Examples (Example 1), Examples (Examples 2 and 3), and Comparative Examples (Examples 4 and 5), but the present invention is not limited thereto. .

Example 1 5 L of methanol and di-ter
73 g of t-butyl peroxide was charged into an autoclave made of Hastelloy C (hereinafter, referred to as autoclave),
After the autoclave was replaced with nitrogen, CF ₂ ＣＦCF ₂ was supplied, and the autoclave was heated to 125 ° C. to cause a reaction. Further, with the constant pressure of CF ₂ = CF _{2 set} to 0.8 MPa, the amount consumed by the reaction was supplied by an automatic valve over 20 hours. The supply amount of CF ₂ = CF ₂ of total 2800
g.

After completion of the reaction, the reaction product is
Distillation was carried out at normal pressure in a clave, and di-tert-
284 g of methanol containing 13 g of butyl peroxide
Collected. Next, at a tower top temperature of 64 ° C., methanol (hereinafter, referred to as
Recorded as recovered methanol 1. 2708 g) was recovered.
Further distillation is continued to remove tert-butyl alcohol.
213 g of methanol fraction contained, HCF_TwoCF_TwoCH_Two
OH and H (CF_TwoCF_Two)_TwoCH_TwoObtain fraction containing OH
Was. This HCF_TwoCF_TwoCH_TwoOH and H (CF _TwoC
F_Two)_TwoCH_TwoThe fraction containing OH is distilled to give 640 g of H
CF_TwoCF_TwoCH_TwoOH was obtained. Gas chromatography
From the result of (GC), 2,2-di-
0.62% by weight of methoxypropane and dimethoxymetha
0.083% by mass.

Example 2 900 g of the recovered methanol 1 in Example 1 was distilled under a normal pressure at a reflux ratio of 1 in a distillation column having an inner diameter of 29 mm and a height of 400 mm filled with a packing material (Dickson 6 mm). Methanol containing 0.23% by mass of 2-dimethoxypropane and 0.024% by mass of dimethoxymethane (hereinafter referred to as recovered methanol 2) 80
0 g was obtained.

Next, the recovered methanol 2
0 g and di-tert-butyl peroxide 14.6
g was charged into an autoclave. Then,
After the gas is replaced with nitrogen, CF_Two= CF_TwoSupply
The internal temperature of the toclave was heated to 125 ° C. to cause a reaction. Sa
In addition, CF_Two= CF_TwoWith 0.8MPa constant pressure
The amount consumed by the automatic valve over 20 hours
Was. Total CF_Two= CF_TwoWas 550 g.
After completion of the reaction, the mixture was cooled to 40 ° C., and the reaction solution was analyzed by GC.
As a result, the methanol conversion was 20.2% and the selectivity was 95.
% Of target HCF _TwoCF_TwoCH_TwoOH was obtained.

Example 3 900 g of the recovered methanol 1 in Example 1 was distilled at normal pressure at a reflux ratio of 20 in the distillation column used in Example 2 to give 2,2-dimethoxypropane 10 ppm.
And 800 g of methanol containing 1 ppm of dimethoxymethane (hereinafter referred to as recovered methanol 3).

Next, 80 of the obtained recovered methanol 3 was
0 g and di-tert-butyl peroxide 14.6
g was charged into an autoclave. Next, after the autoclave was replaced with nitrogen, CF ₂に C was added to the autoclave.
F ₂ was supplied, and the internal temperature of the autoclave was heated to 125 ° C. to cause a reaction. Further, 0.8 MPa of CF ₂ = CF ₂
At a constant pressure, the amount consumed by the reaction was supplied by an automatic valve over 20 hours. The total supply of CF ₂ = CF ₂ is 7
It was 20 g. After completion of the reaction, the mixture was cooled to 40 ° C., and the reaction solution was analyzed by GC. As a result, the conversion of methanol was 27.2.
% And selectivity was 95% to obtain the desired HCF ₂ CF ₂ CH ₂ OH.

Example 4 900 g of the recovered methanol 1 in Example 1 was distilled at a reflux ratio of 0.5 at normal pressure in the distillation column used in Example 2 to obtain 0.48 of 2,2-dimethoxypropane.
Methanol containing 8% by mass and 0.040% by mass of dimethoxymethane (hereinafter referred to as recovered methanol 4) 8
00 g were obtained.

Next, 80 of the recovered methanol 4
0 g and di-tert-butyl peroxide 14.6
g was charged into an autoclave. Then, after the autoclave was replaced with nitrogen, the autoclave to CF ₂ = C
F ₂ was supplied, and the internal temperature of the autoclave was heated to 125 ° C. to cause a reaction. Further, CF ₂ = CF _{2 is set} to 0.8 MPa.
At a constant pressure, the amount consumed by the reaction was supplied by an automatic valve over 20 hours. The total supply of CF ₂ = CF ₂ is 3
20 g. After completion of the reaction, the mixture was cooled to 40 ° C., and the reaction solution was analyzed by GC. As a result, the conversion of methanol was 11.9.
% And selectivity was 95% to obtain HCF ₂ CF ₂ CH ₂ OH.

[Example 5] 2, recovered in the same manner as in Example 1
Methanol 800 containing 0.62% by weight of 2-dimethoxypropane and 0.083% by weight of dimethoxymethane
g and 14.6 g of di-tert-butyl peroxide were charged to an autoclave. Then, after the autoclave was replaced with nitrogen, CF ₂ = CF ₂ was supplied to the autoclave, and the autoclave was heated to 125 ° C. to cause a reaction. Further, with the pressure of CF ₂ = CF ₂ set to a constant pressure of 0.8 MPa, the amount consumed by the reaction was supplied by an automatic valve over 20 hours. The supply amount of CF ₂ = CF ₂ The total 205g
Met. After completion of the reaction, the reaction solution is cooled to 40 ° C.
As a result, the reaction rate of methanol was 7.5% and the selectivity was 95% to obtain the target HCF ₂ CF ₂ CH ₂ OH.

[0059]

According to the present invention, the content of the dialkoxy compound (E) in the recovered unreacted alkanol (A) is reduced to 0.5% by mass or less, and the alkanol (A) and the fluorinated olefin (B ),
The content of the dialkoxy compound (E) during the reaction can be controlled. Thereby, the desired fluorinated alkanol (D)
Is obtained efficiently and is economically useful.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4H006 AA02 AC21 BA93 BD33 BD36 BD52 FE11 FE71 FE74 4H039 CA12 CF10

Claims (5)

[Claims] An alkanol (A) represented by the following formula (2) and a fluorinated olefin (B) represented by the following formula (3) are reacted in the presence of a radical initiator (C) to react with an alkanol represented by the following formula (1). In the method for producing a fluoroalkanol (D), an unreacted alkanol (A) is produced from a reaction product of the above reaction.
Wherein the content of the dialkoxy compound (E) by-produced by the reaction is reduced to 0.5% by mass or less, and the alkanol (A) is reused in the reaction. Manufacturing method. H (CFR ³ CF ₂ ) _n CR ¹ R ² OH Formula 1 CHR ¹ R ² OH Formula 2 CF ₂ = CFR ³ Formula 3 wherein the symbols in the formula have the following meanings. Show. R ¹ and R ² each independently represent a hydrogen atom or a lower alkyl group. R ³ : a fluorine atom or a fluorine-containing monovalent organic group. n: an integer from 1 to 4. 2. The method according to claim 1, wherein the radical initiator (C) is di-tert-
The method for producing a fluorinated alkanol according to claim 1, which is butyl peroxide. 3. The method for producing a fluorinated alkanol according to claim 1, wherein the alkanol (A) is methanol. 4. The process for producing a fluorinated alkanol according to claim 1, wherein the dialkoxy compound (E) is 2,2-dimethoxypropane and / or dimethoxymethane. 5. The method according to claim 1, wherein a mixture containing the unreacted alkanol (A) and the remaining radical initiator (C) is recovered from the reaction product, and the mixture is reused in the reaction. 5. The method for producing a fluorinated alkanol according to 2, 3, or 4.