JPS5944296B2 - Method for producing ester group-containing acid fluoride - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an acid fluoride containing an ester group,
More specifically, the present invention relates to a novel method for producing an ester group-containing acid fluoride by reacting a specific dicarboxylic acid difluoride with an alcohol.

The ester group-containing acid fluoride according to the invention has the general formula FO
It has C-CO2R or FOC-A-CO2R.

In this formula, A represents a difunctional perfluorinated group having 1 to 10 carbon atoms. However, A is -CFOCF2-(B)p-
(CF2)q- (in the formula, B is a bifunctional perfluorinated group having 1 to 10 carbon atoms, p is o or an integer of 1, and q is an integer of 1 to 8). Moreover, R represents an organic group. Such ester group-containing acid fluorides are produced by the following novel reaction between specific difluorides and alcohols. A and R in this formula are as defined above. The monoesterified acid fluoride produced by the present invention is useful as an intermediate for the synthesis of various fluorine-containing compounds, particularly various fluorine-containing compounds having an ester group at the terminal.

For example, perfluorovinyl ether containing an ester group can be synthesized by reacting with hexafluorinated propylene epoxide and then thermally decomposing the reaction product.
JP-A-52-83417, JP-A-52-1051
See Publication No. 18, etc. Further, by reaction with an alkali metal carbonate, an alkali metal salt of fluorocarboxylic acid containing an ester group can be synthesized, and such a metal salt can also be thermally decomposed. See JP-A-52-78826, JP-A-5278827, etc. Regarding FOC-CO2R, it is reacted with propylene hexafluoride epochiside in the same manner as above, and then, if necessary, after converting the FOC- group to an alkali metal carboxylic acid salt, the reaction product is thermally decomposed. According to CF2-CFOCF2CO2R
It can be used as a raw material for the synthesis of ester group-containing perfluorovinyl ethers such as. See Japanese Unexamined Patent Application Publication No. 1692-1983. The difluoride used as a raw material in the method of the present invention can be produced by reactions such as those described in JP-A-52-23020, JP-A-52-39665, and the like. That is, it can be synthesized by reacting an α,ω-diiodoperfluoroalkane or a terminal iodine-containing perfluoro acid fluoride with fuming sulfuric acid. It can also be obtained by converting perfluorodicarboxylic acid cyclolade into difluoride with NaF or KF in a polar solvent. It should be noted that alcohol, which is another raw material, needs no particular explanation and can be obtained over a wide range. Usually, the number of carbon atoms in R is 1 to
Eight alcohols are employed, and R may be linear or branched. Therefore, in the difluoride represented by the general formula FOC-A-COF, A is a bifunctional perfluorinated group having 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, but this A may be branched. You don't have to.

That is, A can be linear or can have one or more ether linkages. However, as mentioned above, A is -CFOCF2-(B)p-(CF2)q
-(In the formula, B is a bifunctional perfluorinated group having 1 to 10 carbon atoms, p is an integer of 0 or 1, and q is an integer of 1 to 8)
except when For example, in the present invention, FOC
-(CF2)n-COF (integer, n is an integer from 1 to 10) or FOCFOC-CFO(CF2)MOCF-COF
(Tazoshi, m is an integer of ~6) etc., the general formula FOC-A
-COF may be exemplified as a specific example of difluoride.

Usually, it is preferable that A is a bifunctional perfluoroalkylene group having 1 to 10 carbon atoms, particularly 1 to 8 carbon atoms. Further, in the alcohol represented by the general formula ROH, R represents an alkyl group, usually an alkyl group having 1 to 10 carbon atoms, and preferably a lower alkyl group having 1 to 5 carbon atoms.
The reaction between difluoride and alcohol in the present invention is preferably carried out under dilution with an inert organic solvent.

That is, since the reaction between difluoride and alcohol is extremely violent, in order to selectively obtain the desired monoesterified acid fluoride, it is desirable to dilute the reaction system with an inert organic solvent. The solvent used for dilution is not particularly limited as long as it is inert to the alcohol, difluoride, and the reaction product, is liquid under the reaction conditions, and is compatible with the difluoride and alcohol. For example, hydrocarbon nitriles with 2 to 12 carbon atoms such as propionitrile, benzonitrile, acetonitrile, ethylene glycol dimethyl ether (monoglyme), diethylene glycol dimethyl ether (diglyme), triethylene glycol dimethyl ether (triglyme), tetraethylene glycol Polar solvents such as dimethyl ether (tetraglyme), aliphatic polyethers having 4 to 16 carbon atoms such as dioxane, and alicyclic ethers can be suitably used. In the present invention, it is preferable to use a polar solvent as a diluent to carry out the reaction between difluoride and alcohol, but salt fluorinated alkanes such as trichloromonofluoromethane and trichlorotrifluoroethane and other halogenated alkanes may also be used. Can be adopted. The range of dilution with the inert organic solvent can be selected as appropriate, but it is usually desirable to dilute both the difluoride and the alcohol before reacting.

That is, the difluoride is diluted with a solvent/difluoride (ml/9) of about 0.1 to 10, preferably 0.3 to 10.
3.0 is adopted, and the alcohol dilution is about 0.1 to 40 with solvent/alcohol (g/9), preferably 1
．． 0-10 is adopted. Of course, it is also possible to react by diluting either difluoride or alcohol, or it is also possible to add difluoride and alcohol little by little to an inert organic solvent and react in a good diluted state by uniform stirring. In order to increase the selectivity of monoesterification, it is desirable to perform it under such dilution, and dilution with alcohol is particularly effective. Various reaction molar ratios of alcohol and difluoride can be adopted, but in order to selectively obtain the desired monoesterified acid fluoride,
It is desirable that the molar ratio of alcohol/difluoride is 2 or less, and it is particularly preferable to employ a molar ratio of 0.5 to 1.5.

In the present invention, 1 mole of alcohol and difluoride can be added by selecting conditions such as 1) reaction molar ratio of alcohol and difluoride, 2) dilution with an inert organic solvent, 3) type of solvent, and 4) reaction temperature. Product FOC-
It has been newly discovered that CO2R or FOC-A-CO2R can be selectively produced.

Therefore, the reaction between alcohol and difluoride in the present invention is preferably carried out under substantially anhydrous conditions.
In the presence of water, difficulties arise such as the reaction of difluoride with water to generate HOOC-COOH or HOOC-A-COOH, or the reaction of the product 1 molar adduct with water, which may not meet the objectives. The yield of monoesterified acid fluoride decreases. Further, problems such as increased corrosion of the reactor occur. The reaction temperature is not particularly limited, but since the reaction between difluoride and alcohol is extremely violent and generates a large amount of heat, it is usually between -8°C and preferably +100°C in order to carry out the reaction under well-controlled conditions. −
A suitable temperature is 40 to +50°C.

In this way, the production of diester, which is an undesirable by-product, can be suppressed, and the desired monoesterified acid fluoride can be obtained in good yield. In the present invention, hydrogen fluoride is produced as a by-product by the reaction of alcohol and difluoride, as shown in the above reaction formula.

This hydrogen fluoride can be easily separated and removed by the presence of a hydrogen fluoride scavenger such as NaF or by distillation after the reaction is completed. Normally, in order to smoothly process the reaction solution after the reaction, it is desirable to add a hydrogen fluoride scavenger to the reaction system in advance. Examples of hydrogen fluoride scavengers include those in the Periodic Table 1, such as NaF.
Fluorides of elements belonging to Group A are preferred. As the reactor, a container lined with a metal material such as NI steel, for example stainless steel or Hastelloy, is preferably used; a reaction container made of glass cannot be used because of the hydrogen fluoride produced as a by-product.

That is, it is sufficient to select a material that is not corroded by hydrogen fluoride or the like. Note that the reaction of the present invention is preferably carried out under substantially anhydrous conditions, so the reaction raw materials, inert organic solvent, hydrogen fluoride scavenger, and other reaction vessels used are as follows:
It is appropriate to dehydrate the material by a dehydration method, drying method, etc. suitable for each method before use. The method of the present invention can be carried out using various operations or conditions.

It is also possible to react by charging a predetermined amount of alcohol and difluoride in a reaction vessel in advance, but preferably, alcohol diluted with a predetermined amount of solvent is gradually added to difluoride diluted with a predetermined amount of solvent while controlling the reaction temperature. It is preferable to add the components separately or sequentially. In order to allow the reaction to proceed smoothly and to selectively obtain a monoesterified acid fluoride, it is desirable to employ uniform mixing means such as vigorously stirring the inside of the reaction system. After the reaction is completed, the target product can be isolated by filtering the reaction solution, removing solids from the reaction solution, and distilling the filtrate. Next, embodiments of the present invention will be described in more detail, but it goes without saying that the present invention is not limited by such explanations.

Example 1 Sodium fluoride (NaF) was placed in a stainless steel autoclave.
1629 (3.85 mol) of 1,629 (3.85 mol) of 1,629 (special grade reagent) was added and thoroughly dried.

Next, 150ml of dehydrated diglyme was placed in an autoclave, and after cooling with liquid nitrogen, oxalyl fluoride (F
1469 (1.56 mol) of OC-COF) was introduced into the autoclave in gaseous form. While maintaining the temperature in the autoclave at -8 to 0°C and stirring vigorously, add an ethanol-diglyme mixed solution (diglyme/ethanol = 3
/1 (weight ratio)) was continuously supplied, and the reaction was completed at ethanol/oxalyl fluoride -1.03 (mole ratio).

When the liquid in the autoclave was filtered to remove solids in the reaction solution and the filtrate was distilled, ethogizalyl fluoride (FOC-CO2C2H5) (B.p. 46-48℃/
90 mmHg) was obtained in a yield of 69 mol (:!) (based on oxalyl fluoride).

Example 2 Methanol/oxalyl fluoride = 0.7 (
molar ratio).

After filtering the reaction solution, by distilling the filtrate, 48~
50℃/200m77! 169 methogyzaryl fluoride (FOC-CO2CH3) was isolated as HI Rumin. Example 3 Sodium fluoride 520 in a stainless steel autoclave
89 (4.95 mol) dehydrated diglyme 400ml11
Perfluorosuccinic acid difluoride 4009 (2.0
6 mol of ethanol/perfluorosuccinic acid difluoride was charged, the temperature was kept at -40°C, and a mixed solution of ethanol and diglyme (diglyme/ethanol 6/1 (weight ratio)) 3 was continuously fed under stirring. The reaction was completed at -1.1 (molar ratio).

When the liquid in the autoclave was filtered to remove solids in the reaction liquid and the filtrate was distilled, 3-carbo-4ethoxyperfluoropropionyl fluoride (B.p.llO
~112 pC/160 mmHg) was obtained in a yield of 66 mol% (based on perfluorosuccinic acid difluoride).

Example 4 100% sodium fluoride in a stainless steel autoclave
9 (2.38 mol), dehydrated diglyme 200ml11
Perfluorosuccinic acid difluoride 2009 (1.0
At -400C, an ethanol-diglyme mixed solution (diglyme/ethanol = 9/1 (weight ratio)) was continuously supplied, and the ethanol/diglyme mixture solution (diglyme/ethanol = 9/1 (weight ratio))
The reaction was completed when perfluorosuccinic acid difluoride=1.2 (molar ratio).

When the isolation operation was performed in the same manner as in Example 3, 3
-Carboethoxy perfluoropropionyl fluoride was obtained in a yield of 75 mol% (based on perfluorosuccinic acid difluoride).

Example 5 In a stainless steel autoclave, 200 g (4.76 mol) of sodium fluoride, 400 ml of trichlorotrifluoroethane (R-113), and 4009 (2.60 mol) of perfluorosuccinic acid difluoride were placed at -20°C. , under stirring, ethanol-R-11
3 mixed solution (R-113/ethanol = 5/1 (weight ratio)) was continuously supplied, and the reaction was completed at ethanol/perfluorosuccinic acid difluoride -1.2 (mole ratio).

The isolation procedure was carried out in the same manner as in Example 3, and 3-carboethoxyperfluoropropionyl fluoride was isolated from 5
2 mol% (based on perfluorosuccinic acid diololide)
It was obtained in a yield of . Example 6 Soda fluoride 1009 in stainless steel autoclave
(2.38 mol), dehydrated diglyme 200ml11 perfluorosuccinic acid difluoride 2709 (1,39
2 methanol/perfluorosuccinic acid difluoride, and continuously supplied methanol/diglyme mixed solution (diglyme/methanol = 4/1 (weight ratio)) at -10°C with stirring. The reaction was completed at -1.1 (molar ratio).

When the isolation operation was performed in the same manner as in Example 3, 3
- Carbomethoxy perfluoropropionyl fluoride (B.p. 97 L/76 ml Hg) 63 mol 0
1) (based on perfluorosuccinic difluoride).

Example 7 100% sodium fluoride in a stainless steel autoclave
f! (2.38 mol), dehydrated Tetraglyme 200
m1 perfluoroadipate difluoride 3009 (
1.02 mol) was prepared, and the ethanol-tetraglyme mixed solution (tetraglyme/
Ethanol/perfluoroadipate difluoride-1 was continuously supplied with ethanol/perfluoroadipate difluoride-1 (weight ratio).
．． The reaction was completed at a molar ratio of 2 (molar ratio).

When the liquid in the autoclave was filtered to remove solids in the reaction liquid and the filtrate was distilled, 5-carboethoxyperfluoropentanyl fluoride (B.p.68-7'C
/30 mmHg) was obtained in a yield of 40 mol 0/) (based on perfluoroadipic acid fluoride).

Claims (1)

[Claims] 1 FOC-COF or general formula FOC-A-COF (wherein A in the formula represents a bifunctional perfluorinated group having 1 to 10 carbon atoms. However, A is a ▲ mathematical formula, a chemical formula , tables, etc. ▼ (B in the formula is a bifunctional perfluorinated group having 1 to 10 carbon atoms, p
is an integer of 0 or 1, and q is an integer of 1 to 8). ) and the dicarboxylic acid difluoride represented by the general formula R
OH (wherein R represents an organic group) is reacted with an alcohol represented by the general formula FOC-CO_2R or FOC-A-CO_2R (however, A and R in the formula are the same as above). A method for producing an ester group-containing acid fluoride, the method comprising: producing an acid fluoride containing an ester group. 2. The production method according to claim 1, wherein the reaction molar ratio of alcohol/dicarboxylic acid difluoride is 2 or less. 3. The production method according to claim 1 or 2, wherein the reaction is carried out under dilution with an inert organic solvent. 4. The manufacturing method according to claim 3, wherein a polar solvent is used as the inert organic solvent. 5 Inert organic solvent/dicarboxylic acid difluoride (m
The method according to claim 3 or 4, wherein a dilution ratio of 0.1 to 10 (l/g) is used. 6 Inert organic solvent/alcohol (g/g) 0.1~
5. Process according to claim 3 or 4, using a dilution ratio of 40. 7. The production method according to claim 1, 2, 3, or 4, wherein the reaction is carried out at a reaction temperature of -80°C to +100°C. 8. The production method according to claim 1 or 3, wherein the reaction is carried out under substantially anhydrous conditions. 9. The production method according to claim 1 or 3, wherein the reaction is carried out in the presence of a hydrogen fluoride scavenger. 10. The production method according to claim 9, wherein a fluoride of an element belonging to Group I-A of the Periodic Table is used as the hydrogen fluoride scavenger.