JP2001064228A - Production of fluorocarboxylic acid anhydride - Google Patents

Abstract

PROBLEM TO BE SOLVED: To synthesize a fluorocarboxylic acid anhydride in high yield with a single step without generating HF having corroding action on its reactor by using RfCOF and an alkali metal or alkaline earth metal carbonate. SOLUTION: The objective fluorocarboxylic acid anhydride of the formula (BfCO)2O can be produced by reacting a compound of the formula RfCOF (Rf is a 1-30C saturated hydrocarbon group substituted at least a part of H atoms with F or F and other halogens and optionally containing oxygen) with a compound of the formula MmCO3 [M is an alkali metal or an alkaline earth metal; (m) is 2 when M is an alkali metal and 1 when M is an alkaline earth metal] preferably at 20-100 deg.C, preferably under a reaction pressure between atmospheric pressure and 20 kg/cm2 (gauge). For example, the compound of the formula (C7F15CO)2O can be produced by stirring C7F15 and LiCO3 and reacting at 90 deg.C for 6 hr. The obtained compound of the formula (RfCO)2O can be used as an agent for introducing RfCO group or a dehydration agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a fluorocarboxylic anhydride using R _f COF as a raw material.

[0002]

2. Description of the Related Art Methods for synthesizing fluorocarboxylic anhydrides used as R _f CO agents and dehydrating agents are already known. For example, in the case of (CF ₃ CO) ₂ O, the following four synthesis methods are known. 1. CF ₃ CO ₂ H + P ₂ O ₅ → (CF ₃ CO) ₂ O + polyphosphoric acid (Bourne EJ, Stacey M., Tatlow JC, Tedder JM,
J. Chem. Soc., 1949, 2976) 2. _{(CHCl 2 CO) 2 O +} 2CF 3 CO 2 H → (CF 3 CO) 2 O + 2CHCl 2 CO
₂ H (Japanese Patent Publication No. 61-33139). CF ₃ COCl + ZnO, CuO, CdO → (CF ₃ CO) ₂ O + ZnCl ₂ ,
CuCl ₂ , CdCl ₂ (Japanese Patent Publication No. 46-6888). CF ₃ COCl + CF ₃ CO ₂ Na → (CF ₃ CO) ₂ O + NaCl
(No. 5-38532)

As can be seen from the above reaction formula,
(CF_ThreeCO)_TwoThe raw material of O is CF _ThreeCO_TwoH or C
F_ThreeOnly COCl is present. CF_ThreeCOF as raw material
Then, via the above-mentioned prior art reaction (CF_ThreeCO)_TwoO
Is synthesized, CF_ThreeCOF to CF_ThreeCO_TwoH or C
F_ThreeThe following method further comprising the step of converting to COCl
Used. Method 1 CF_ThreeCOF + H_TwoO → CF_ThreeCO_TwoH + HF CF_ThreeCO_TwoH + P_TwoO_Five → (CF_ThreeCO)_TwoO + P_TwoO_Five(H_TwoO) Method 2 CF_ThreeCOF + H_TwoO → CF_ThreeCO_TwoH + HF CF_ThreeCO_TwoH + SOCl_Two or PCl_Five + Et_ThreeN → CF_ThreeCOCl + (SO_Two+ HC
l, POCl_Three+ HCl) CF_ThreeCOCl + (CF_ThreeCO_TwoNa, ZnO, CuO, CdO) → (CF_ThreeCO)_TwoO

[0004] In the method 1, H is generated together with the formation of CF ₃ CO ₂ H.
Since F is generated, usable reactor materials are limited. In addition, P ₂ O ₅ used for dehydration of CF ₃ CO ₂ H usually dehydrates three molecules of water. However, for dehydration of fluorocarboxylic acid, only one molecule of dehydration ability can be exerted. The reaction stops as it is. Therefore, it is difficult to perform post-treatment of P ₂ O ₅ after completion of the reaction.

[0005] In the method 2, HF is generated in the same manner as described above.
Restriction on reactor material, SO in the second step _TwoAnd / or hydrochloric acid
For removal, it is necessary to use a tertiary amine or the like. Less than
From the above, cost increases due to the increase in the number of raw materials used and the number of processes
Higher.

Further, in Synthesis Method 3 (Japanese Patent Publication No. 46-6888), the reaction was carried out by replacing CF ₃ COCl with CF ₃ COF, but the reaction did not proceed. From this fact, it was found that the reactivity of CF ₃ COF and CF ₃ COCl was different. Synthesis Method 4 (JP-B-45-3853)
No. 2) requires a complicated operation for synthesis of CF ₃ CO ₂ Na as a raw material.

[0007]

An object of the present invention is to provide a method for synthesizing (R _f CO) ₂ O from R _f COF without the above-mentioned drawbacks, that is, without including a plurality of steps. It is to be. Another object is to obtain (R _f CO) ₂ O without generating HF that can corrode the reactor.

[0008]

In order to solve the above-mentioned problems, the use of R _f COF and an inexpensive alkali metal or alkaline earth metal carbonate allows (R _f CO) _{2 to} be obtained in high yield.
A method for synthesizing O was found. The present invention provides a method for synthesizing (R _f CO) ₂ O using R _f COF as a raw material.

The present invention provides a method for producing (R _f CO) ₂ O by reacting R _f COF with M _m CO ₃ : [where R _f represents all or a part of hydrogen as F or F and other A halogen-substituted saturated hydrocarbon group having 1 to 30 carbon atoms which may have oxygen, M is an alkali metal or an alkaline earth metal, and m is 2, M if M is an alkali metal; Is 1 if is an alkaline earth metal. ]I will provide a.

By reacting R _f COF and MCO ₃ (R _f C
The method for producing O) ₂ O is represented by the following reaction formula: 2R _f COF + M _m CO ₃ → (R _f CO) ₂ O + mM F _{2 / m} + C
O ₂ [In the formula, R _f represents one or more carbon atoms which may have oxygen and in which all or a part of hydrogen is substituted with F or F and another halogen.
~ 30 saturated hydrocarbon groups, M is an alkali metal or an alkaline earth metal, m is 2 if M is an alkali metal, and 1 if M is an alkaline earth metal. ].

Further, the present invention provides a reaction formula: mR _f COF + (R _f CO ₂ ) _m M → m (R _f CO) ₂ O + m
MF _{2 / m} wherein R _f , M and m are as described above. And reacting R _f COF with R _f CO ₂ M (R _f CO)
A method for producing ₂ O is provided.

R _f is a saturated hydrocarbon group having 1 to 30 carbon atoms, particularly 1 to 10 carbon atoms, which may have oxygen, wherein all or part of hydrogen is substituted by F or F and another halogen. .
R _f has at least one fluorine atom. R _{f is, X (C m X 2m)} n -, X (C m X 2m) n (C s X 2s) t - X (C m X 2m O) n -, or X (C _m X _2m O) _{n (C s X 2s) t} - in [wherein, each X is a halogen atom or a hydrogen atom, at least one X is a fluorine atom. n
Is an integer of 1 to 10, m is an integer of 1 to 5, s is an integer of 1 to 5, and t is an integer of 1 to 10. ].

R _f is a perfluoroalkyl group (F (CF
₂ ) _i- ), which may be linear or branched. i is 1 to 30, for example 1 to 10, preferably 1 to 7.

Specific examples of R _f COF include HCF ₂ COF CF ₃ COF CF ₃ CF ₂ COF CF ₃ CF ₂ CF ₂ COF H (CF ₂ CF ₂ ) _n COF Cl (CF ₂ CFCl) _n CF ₂ COF CF _{3 CF 2 O (CF 2 CF} 2 CF 2 O) n CF 2 CF 2 COF CF 3 CF 2 CF 2 OCF (CF 3) COF [n is 1-10. ].

M is an alkali metal or an alkaline earth metal, and is preferably Li, Na, K or Ca. (R _f C
The yield of O) ₂ O varies depending on the carbonate used, and the higher the stability of the MF _{2 / m} salt formed during the reaction, the better. As carbonates, BaCO ₃ , CaCO ₃ , Na ₂ CO ₃ , Li ₂ C
O ₃ is preferred. There is no difference in the selectivity of the reaction depending on the mixing ratio of R _f COF and the carbonate, but it affects the conversion. The mixing ratio is preferably from 0.1 to 10.

The reaction is carried out at a pressure of, for example, atmospheric pressure to 20 kgG / cm ² while stirring R _f COF and the carbonate. The reaction temperature is preferably from 20 to 100C, for example, from 50 to 90C. When R _f COF having a low boiling point (for example, CF ₃ COF having a boiling point of −50 ° C.) is used as a raw material, a solid-gas reaction occurs and the reaction efficiency is reduced, so that a solvent can be used during the reaction. . As the solvent, a solvent that does not react with the raw material or the product, for example, a hydrocarbon-based or halogen-based solvent can be used. Examples of solvents are hexane, CCl ₄ , C ₄ F ₆ Cl ₄ , CCl ₂ FCClF ₂ and the like. The stirring may be performed by a stirring blade.However, since the reaction speed is reduced by the fluoride salt generated as the reaction proceeds covering the surface of the raw material carbonate, the ultrasonic wave is used to scrape off the generated fluoride salt. Stirring or the like can be performed.

(R _f CO) ₂ O obtained by the present invention
Can be used as an R _f CO agent and a dehydrating agent.

[0018]

EXAMPLE 1 Dimroth, flask CaCl ₂ tube with C ₇ F ₁₅ CO
F 4.13 g (9.93 mmol) and Li ₂ CO ₃ 0.0
917 g (1.24 mmol) was added, and the mixture was stirred with an ultrasonic washing machine and reacted at 90 ° C. for 6 hours. As a result of quantification by GC measurement, the yield of (C ₇ F ₁₅ CO) ₂ O was 0.1%.
874 g (conversion rate 10.9%, selectivity 100
%).

EXAMPLE 2 C ₇ F ₁₅ CO was added to a flask equipped with a Dimroth and CaCl ₂ tube.
3.746 g (9.01 mmol) of F and Na ₂ CO ₃ 0.
1193 g (1.13 mmol) was added, and the mixture was stirred with an ultrasonic cleaner and reacted at 90 ° C. for 5 hours. As a result of quantification by GC measurement, the yield of (C ₇ F ₁₅ CO) ₂ O was 0.137 g (conversion 1.9%, selectivity 100).
%).

Example 3 C ₇ F ₁₅ CO was added to a flask equipped with a Dimroth and CaCl ₂ tube.
4.236 g (10.18 mmol) of F and CaCO ₃
0.1274 g (1.27 mmol) was added, and the mixture was stirred with an ultrasonic cleaner and reacted at 90 ° C. for 5 hours. G. FIG.
C. As a result of quantification by measurement, the yield of (C ₇ F ₁₅ CO) ₂ O was 1.029 g (conversion rate 12.5%, selectivity 100%).

[0021]Example 4 CaCO2 in a 250 ml autoclave_Three 3
0.1 g (0.301 mol) was charged.
Cool the autoclave with ice / acetone and remove CF_ThreeCO
15.7 g (0.135 mol) of F was charged. He
Set the temperature to 70 ° C and stir for 705 minutes.
I let you. Reaction pressure is 12.5 kgG / cm ^TwoRise to
Finally 12.1kgG / cm^TwoDown to. Product
With a dry ice / acetone cold trap,
¹⁹As a result of quantification by F-NMR, (CF_ThreeCO)_TwoO
Was 4.253 g (15% conversion, selectivity).
100%).

[0022]Example 5 CaCO in 250ml autoclave_Three 30.0g
(0.301 mol) and C as solvent_FourF₆Cl_Four50c
c, CF_ThreeCOF 15.2 g (0.131 mol) was prepared.
And stirred and reacted at 70 ° C. for 915 minutes. The reaction pressure is
9.8kgG / cm ^TwoUp to 7.6kg
G / cm^TwoDown to. Dry the product with dry ice / aceto
Collected in cold traps,¹⁹Perform quantification by F-NMR
As a result, (CF_ThreeCO)_TwoThe yield of O was 7.84 g.
(Conversion 28.5%, selectivity 100%).

Reference Example 1 C ₇ F ₁₅ CO was added to a flask equipped with a Dimroth and CaCl ₂ tube.
1.62 g (3.89 mmol) of F and C ₇ F ₁₅ CO ₂ L
0.254 g (0.604 mmol) of i was added, and the mixture was stirred by an ultrasonic washing machine and reacted at 90 ° C. for 1 hour.
G. FIG. C. As a result of quantification by measurement, (C ₇ F ₁₅ CO) ₂
The yield of O was 0.336 g (10.7% conversion,
Selectivity 100%).

Reference Example 2 C ₇ F ₁₅ CO was added to a flask equipped with a Dimroth and CaCl ₂ tube.
1.340 g (3.22 mmol) of F ₇ and C ₇ F ₁₅ CO ₂
0.219 g (0.503 mmol) of Na was added, and the mixture was stirred with an ultrasonic washing machine and reacted at 90 ° C. for 1 hour. G. FIG. C. As a result of quantification by measurement, (C ₇ F ₁₅ C
O) ₂ O yield was 0.041 g (conversion 1.5
7%, selectivity 100%).

[0025]

According to the present invention, R _f COF is used as a raw material, and HF is not generated in a one-step reaction, but (R _f C
O) ₂ O can be produced.

Claims (3)

[Claims] 1. The reaction of R _f COF with M _m CO ₃ (R _f COF)
CO) ₂ O: [where R _f is a saturated carbon atom having 1 to 30 carbon atoms which may have oxygen and all or part of hydrogen is substituted with F or F and another halogen. A hydrogen group, M is an alkali metal or an alkaline earth metal, m is 2 if M is an alkali metal, or 1 if M is an alkaline earth metal; ]. 2. The method according to claim 1, wherein the reaction temperature is 20 ° C. to 100 ° C. 3. The reaction pressure is from atmospheric pressure to 20 kgG / cm ^2.
The method according to claim 1, which is (gauge pressure).