JPS62153257A - Production of perfluoromonoester carboxylic acid chloride - Google Patents

Abstract

PURPOSE:To obtain a compound useful as a synthetic intermediate for various fluorine-containing compounds in high yield with good selectivity, by reacting a perfluorodicarboxylic acid dichloride with an alcohol in an inert solvent. CONSTITUTION:A perfluorodicarboxylic acid dichloride is reacted with an alco hol in an inert polar solvent, e.g. polyakylene ether such as ethylene glycol dimethyl ether or alkylnitrile such as acetonitrile, etc., at -80-+100 deg.C, prefer ably -50-+50 deg.C to afford the aimed substance. The solvent is used in an amount of 0.01-10, preferably 0.1-1 expressed in terms of dilution ratio (l/mol) based on the total amount of the alcohol to the perfluorodicarboxylic acid dichloride is preferably 0.1-2.0 to carry out the reaction.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is directed to the production of perfluoromonoester carboxylic acid chloride (hereinafter simply referred to as mono- The present invention relates to a novel method for producing ester acid chlorides (also referred to as ester acid chlorides). Specifically, the method for producing monoester acid chloride is characterized by using an inert polar solvent as a diluent in the above reaction.

[Prior Art] Monoester acid chloride is useful as an intermediate for various fluorine-containing compounds, particularly as an intermediate for synthesizing various fluorine-containing compounds having an ester group at the terminal. For example, a method of reacting monoester acid chloride with NaOH/HzOz to synthesize perfluorodiacyl peroxide containing an ester group, and a method of reacting monoester acid chloride with an alkali metal fluoride to form perfluoromonoester carboxylic acid fluoride. , is useful for a method of synthesizing perfluorovinyl ether containing an ester group by reacting this with hexafluoropropylene oxide and then thermally decomposing the reaction product.

Conventionally, as a method for producing monoester acid chloride, for example, in U, S, P, 3461155, (1) a method of directly reacting dicarboxylic acid dichloride and alcohol.

(2) Perfluoro acid anhydride is reacted with alcohol to form perfluoro monoester carboxylic acid, and this is converted into P
A method for converting CQ, s, 5OC into acid chloride with 0,2.

It has been known.

[Problems to be Solved by the Invention] However, the methods (1) and (2) above each have the following drawbacks, and are still insufficient as industrial manufacturing methods. Ta.

That is, in the method (]), the reaction between the dicarboxylic acid dichloride and the alcohol is violent, diesters are produced to a large extent, and the desired monoester carboxylic acid chloride is selectively produced.
And it is difficult to obtain with good yield. In addition, in method (2), when dicarboxylic acid dichloride is used as a starting material, the reaction to reach the target substance via the acid anhydride involves four steps, making the operation complicated and disadvantageous in industrial implementation. Moreover, in the reaction of converting perfluoromonoester carboxylic acid into acid chloride, when PGIs are used, the by-product elJL/1"POCQ, 3 (boiling point (b, p-) 106℃/760m+aHg) is The boiling point of monoester acid chloride, which is the target product of the by-product (for example, the boiling point of 3-carbomethoxyperfluoroprobionyl chloride is 109-111°C/76°a
nHg), making separation by distillation difficult. Furthermore, when a liquid chlorinating agent is used, the yield is often low. Therefore, an object of the present invention is to produce monoester acid chloride in a simple process and with good yield by reacting dicarboxylic acid dichloride and alcohol.

[Means for Solving the Problem] The present invention provides a perfluoromonoester carbonaceous solution, which is characterized in that perfluorodicarboxylic acid dichloride and alcohol are reacted in an inert polar solvent (hereinafter referred to as inert polar solvent). This is a method for producing acid chloride.

That is, according to the present invention, by carrying out the reaction of dicarboxylic acid dichloride and alcohol in an inert polar solvent,
The diester by-product produced in a considerable amount in the conventional method is extremely effectively controlled, and the desired monoester acid chloride can be obtained in high yield.

The inert polar solvent used in the present invention is inert to dicarboxylic acid dichloride, alcohol and reaction products,
It is also a polar solvent that is liquid under the reaction conditions and is compatible with dichloride and alcohol. That is, as a result of repeated research by the present inventors on a method of diluting dicarboxylic acid and alcohol with an inert solvent and reacting them,
It has been found that by using a polar inert solvent as the inert solvent, the by-product of diester can be extremely effectively prevented in the reaction, and the reaction rate can also be significantly improved. In the present invention, examples of particularly suitable inert polar solvents include ethylene glycol dimethyl ether and diethylene glycol dimethyl ether (hereinafter referred to as diglyme).

Polar solvents include polyalkylene ethers such as trimethylene glycol dimethyl ether (hereinafter referred to as tetraglyme), and alkyl nitriles such as acenitrile and propionitrile.

Incidentally, it is preferable that the inert polar solvent used in the present invention is sufficiently dehydrated before use.

In the present invention, the dicarboxylic acid dichloride has the general formula CI
OC (CF 2) n coal (where n is 1
- 10 integers) are generally used, among which dicarboxylic acid dichlorides in which n is 2 to 4 are particularly preferred.

Further, as the alcohol, an alcohol represented by the general formula ROH (wherein R represents an organic group) can be used without particular limitation. The above-mentioned organic group R is an alkyl group having 1 to 10 carbon atoms, a general formula H(CF2) n CH2- (where n is 1
~5 integer), general formula F (CF2)n CH2 (however, n is an integer from 1 to 5), general formula CF3 (CH2)n
- (however, n is an integer of 1 to 5), general formula R+ (Rf
)CH- (wherein R represents an alkyl group and Rf represents a perfluorocarbon group), X(CHz)nOH (where n is an integer from 1 to 5 and X represents a halogen), etc. are common. A specific example of a typical alcohol is CH30HI CzHsOl(,C)13 (CH3
)Cl0)I, CH3(C2H5)CHOH; HCI'
2CH20H; CF3CF2CF2CH20H+ CF
3 (CF2) 3cHzOH; CFzCHzOH,C
F3CHzCH20H, CF3 (CH2) 30H:
CHzCHzCHzC(CF3)CHOH,CH3(C
H2)s (CF3)CHOH;FCH2CH20H,
BrCHzCHzOH.

Examples include CKL CH2CH20H. Among these alcohols, alcohols having a lower alkyl group having 1 to 5 carbon atoms as an organic group are particularly preferred.

In the present invention, the reaction between dicarboxylic acid dichloride and alcohol is not particularly limited as long as the reaction is carried out by contacting the two in a state in which they are dissolved in an inert polar solvent. For example, ■ a method of diluting either dicarboxylic acid dichloride and alcohol with an inert polar solvent and reacting;
Examples include (1) a method in which the dicarboxylic acid dichloride and the alcohol are diluted with an inert polar solvent and then reacted; (2) a method in which the dicarboxylic acid dichloride and the alcohol are separately supplied into an inert polar solvent and the reaction is carried out. Among these methods, embodiments (1) and (2) are particularly preferred.

In each of the above embodiments, the amount of the inert polar solvent used is not particularly limited, but generally the dilution degree ((1 mol)) is 0.01 to 10.0% relative to the total amount of dicarboxylic acid dichloride and alcohol. In particular, it is preferable to use an inert polar solvent of 0.1 to 1 because it has a high effect of preventing diester by-products.

In the reaction of the present invention, other known conditions may be applied without restriction, but in particular, the reaction molar ratio of alcohol and dicarboxylic acid dichloride is determined in order to selectively obtain the desired monoester acid chloride with a high specific gravity. Alcohol/
The molar ratio of perfluorodicarboxylic acid dichloride is 0.1
The molar ratio is preferably 2.0 to 2.0, particularly 0.5 to 1.5, and the reaction temperature is -80°C to 100°C at a temperature at which the inert polar solvent is present in liquid form.
However, since the reaction between perfluorodicarboxylic acid dichloride and alcohol is extremely violent and accompanied by a large heat of reaction, it is desirable to sufficiently control the temperature of the reaction system, especially between -50 and 50°C. It is preferable to carry out within a range.

The reaction pressure may generally be the self-generated pressure in the reaction, but a pressure range from 0 to several 100 atmospheres can be used if necessary. Furthermore, the reaction time depends on the reaction temperature, the raw materials used,
Depending on the inert polar solvent, etc., it cannot be determined exactly, but usually several minutes to several hours is sufficient.

The monoester acid chloride produced by the method of the present invention may be separated from the inert polar solvent by a known separation means such as distillation.

[Function and Effect] As understood from the above explanation, the method of the present invention selects monoester acid chloride in a single reaction by carrying out the reaction between alcohol and dicarboxylic acid dichloride in an inert polar solvent. It is possible to obtain monoester acid chloride with good properties and high yield, and it is possible to industrially produce monoester acid chloride very freely.

In the present invention, although the mechanism by which the above effects are exerted by the use of an inert polar solvent is not clear, the present inventors have demonstrated that using an inert polar solvent for dicarboxylic acid dichloride as a raw material and monoester acid chloride as a product. It is presumed that the reaction between alcohol and dicarboxylic acid dichloride is selectively carried out due to the difference in solubility of , and the formation of diester is effectively prevented.

[Examples] The present invention will be specifically described below using Examples, but the present invention is not limited to these Examples. still,
The inert polar solvent used in the following examples was thoroughly dehydrated with molecular sieves. Moreover, the yield and production rate are values based on dicarboxylic acid dichloride.

Example 1 100 g (0.36 mol) of perfluoroglutaryl chloride was diluted with 100 mQ of tetraglyme in a 300 mQ four-bottle flask equipped with a stirring device, a dropping funnel, a cooling tube with a drying tube attached to the top, and a thermometer. mixed solution (
The dilution rate is 0.27), and the temperature in the reactor is 15 to 0.
℃ and with vigorous stirring, add 12 g of methanol.
(0.38 mol) of tetraglyme 40 m 9. A mixed solution diluted with (dilution degree 0.11) was added dropwise over 30 minutes. The reaction solution was distilled, and the distillate was collected as 4-carbomethoxyperfluorobutychloride (b, p, 7B-7
The yield of 4-carbomethoxy perfluorobutyl chloride was 70%. Moreover, the production rate of diester was 15%.

Example 2 150 g of perfluoroglutaryl chloride was placed in a 500 m 9.0 four-bottle flask equipped with a stirrer, a dropping funnel, a cooling tube with a drying tube attached to the top, and a thermometer.
, 54 mol) diluted with 150 m of tetraglyme (dilution degree 0.28), and while maintaining the temperature in the reactor at -20°C and stirring vigorously, methanol 1
A mixed solution of 8 g (0.57 mol) diluted with 90 mQ of tetraglyme (dilution level 0.16) was added dropwise over 40 minutes to react. Distill the reaction solution and use it as a distillate ↓
- Carbomethoxy perfluorobutyryl chloride 74
% yield. Moreover, the production rate of diester was 13%.

Example;) A reaction was carried out under exactly the same conditions as in Example 1, except that 17 g (0.37 mol) of ethanol was used instead of methanol. The reaction solution was distilled and 4-carboethoxyperfluorobutyryl chloride (b, p, 59-60°C/16m+nHg)6
9g was obtained. The yield was 67%. Moreover, the production rate of diester was 14%.

Comparative Example 1 100 g of perfluoroglutaryl chloride in a 300 mQ flask equipped with the same equipment as used in Example 1.
(0.36 mol) and set the temperature in the reactor to -20℃.
While stirring vigorously, add 12 g of methanol (
0.38 mol) was added dropwise over 15 minutes. The reaction solution was isolated by distillation to obtain 54 g of 4-carbomethoxyperfluorobutyryl chloride. The yield was 55%. Also,
The production rate of diester was 22%.

Example 1L In a 1000 m cross four-lobe flask equipped with a stirrer, a dropping funnel, a cooling tube with a drying tube attached to the top, and a thermometer,
Charge 200 g (0.88 mol) of perfluorosuccinyl chloride and a mixed solution diluted with 300 m of diglyme (dilution level 0.34), maintain the temperature of the reactor at -10°C, and add 29 g of methanol while stirring vigorously. (0,
A mixed solution (dilution level: 0.11) diluted with 91 mol) and 1 oorrl of diglyme was added dropwise over 1 hour. The reaction solution was isolated by distillation, and 3-carbomethoxyperfluoroprobionyl chloride (b, p, 109-113.'C/7
137 g of 60 mm ml (1 g) was obtained. The yield was 70%. Moreover, the production rate of diester was 12%.

Example 5 100 g of perfluoroadipic acid dichloride (0,
A mixed solution diluted with 100 m of tetraglyme (dilution level 0.32) was charged, and while maintaining the temperature in the reactor at -5°C and stirring vigorously, 15 g of ethanol was added.
(0.33 mol) and a mixed solution (dilution degree 0.15) diluted with 50 ml and 9 tons of 1,000 tora glyme was added dropwise over 30 minutes.

The reaction solution was isolated by distillation, and 5-carboethoxyperfluoropentanoyl chloride (b, P, 167-170°C/
760 mmHg) was obtained in a yield of 68%. Moreover, the production rate of diester was 13%.

Claims (1)

[Scope of Claims] 1. A method for producing perfluoromonoester carboxylic acid chloride, which comprises reacting perfluorodicarboxylic acid dichloride and an alcohol in an inert polar solvent. 2. The method according to claim 1, wherein the polar solvent is polyalkylene ethers or alkyl nitriles. 3. The degree of dilution (l/mol) is 0.0 with respect to the total amount (mol) of perfluorodicarboxylic acid dichloride and alcohol.
3. The method according to claim 1 or 2, wherein an inert polar solvent of 01 to 10 is used. 4. The method according to claim 1 or 2, wherein the reaction molar ratio of alcohol/perfluorodicarboxylic acid dichloride is from 0.1 to 2.0. 5. The method according to claim 1 or 2, wherein the reaction is carried out at a reaction temperature of -80°C to 100°C.