JP2007106726A - Method for producing 1,1,2,2,3-pentafluorocyclobutane - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for efficiently producing 1,1,2,2,3-pentafluorocyclobutane by using an inexpensive material suitable for mass production. <P>SOLUTION: The method for producing 1,1,2,2,3-pentafluorocyclobutane comprises fluoridating 1,4,4-trifluorocyclobutene represented by chemical formula (1) by using fluorine gas or a high-valence metal fluoride. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a method for producing a fluorine-containing compound useful as a cleaning agent.

しかし、原料の1,3,3,4,4-ペンタフルオロシクロブテンの合成には、1)クロロトリフルオロエチレンの環化反応、2)還元反応、3)水素添加反応、4)脱フッ化水素反応といった多くのステップを要することが知られている。
後者の方法では、1,1,2,2,3−ペンタフルオロシクロブタンの収率や選択性の情報が得られなかったため、本発明者らが再試験を行ったところ、テトラフルオロエチレンの２量化反応が優先して進行し、フッ化ビニルをテトラフルオロエチレンの3倍量用いても1,1,2,2,3−ペンタフルオロシクロブタンの収率は10%程度と極めて低いことを確認している。（特許文献２）

Fluorine-containing compounds are widely used industrially for polymer materials, refrigerants, cleaning agents, foaming agents, pharmaceuticals, agricultural chemicals and the like. In particular, hydrofluorocarbons (HFCs) composed of carbon, fluorine, and hydrogen atoms are expected to be used as refrigerants, foaming agents, cleaning agents, etc. as substitutes for fluorocarbons. The 1,1,2,2,3-pentafluorocyclobutane targeted in the present invention is expected to be used as a cleaning agent. (Patent Document 1)
1,1,2,2,3-pentafluorocyclobutane can be produced by hydrogenation of 1,3,3,4,4-pentafluorocyclobutene and cyclization of tetrafluoroethylene and vinyl fluoride. Two methods are known.
In the former method, 1,1,2,2,3-pentafluorocyclobutane can be synthesized with high yield. (Non-Patent Document 1)

However, for the synthesis of 1,3,3,4,4-pentafluorocyclobutene as a raw material, 1) cyclization reaction of chlorotrifluoroethylene, 2) reduction reaction, 3) hydrogenation reaction, 4) defluorination It is known that many steps such as hydrogen reaction are required.
In the latter method, information on the yield and selectivity of 1,1,2,2,3-pentafluorocyclobutane could not be obtained, and when the present inventors conducted a retest, dimerization of tetrafluoroethylene was performed. It was confirmed that the reaction proceeded preferentially, and the yield of 1,1,2,2,3-pentafluorocyclobutane was as low as 10% even when vinyl fluoride was used in 3 times the amount of tetrafluoroethylene. Yes. (Patent Document 2)

WO 9505448 DE2157397 Bull. Soc. Chim. Fr., 1969, 842-847.

The present invention has been made in order to overcome the above-described problems of the prior art, and efficiently uses 1,1,2,2,3-penta by using an inexpensive raw material suitable for mass production. A method of producing fluorocyclobutane is provided.

で表わされる1,4,4−トリフルオロシクロブテンを、フッ素ガス又は高原子価金属フッ化物を用いてフッ素化することを特徴とする下記化学式（２）

で表わされる1,1,2,2,3−ペンタフルオロシクロブタンの製造方法である。
また、本発明の1,1,2,2,3−ペンタフルオロシクロブタンの製造方法では、高原子価金属フッ化物として３フッ化コバルト ３フッ化マンガン、４フッ化カリウムコバルトから選ばれる化合物の１種又は２種以上を用い、その使用量は1,4,4−トリフルオロシクロブテン１当量に対して０．１〜２０当量であることが好ましい。
As a result of intensive studies to solve the above-mentioned problems, the present inventor obtained 1,1,2,2 efficiently by reaction of 1,4,4-trifluorocyclobutene with fluorine gas or high-valent metal fluoride. It has been found that 2,3-pentafluorocyclobutane can be obtained, and the present invention has been completed.
That is, the present invention
The following chemical formula (1)

1,4,4-trifluorocyclobutene represented by the following formula (2), characterized by fluorination using fluorine gas or high-valent metal fluoride

Is a method for producing 1,1,2,2,3-pentafluorocyclobutane represented by the formula:
Further, in the method for producing 1,1,2,2,3-pentafluorocyclobutane of the present invention, as a high-valent metal fluoride, 1 of a compound selected from cobalt trifluoride, manganese trifluoride, and potassium cobalt fluoride. The seeds or two or more kinds are used, and the amount used is preferably 0.1 to 20 equivalents per equivalent of 1,4,4-trifluorocyclobutene.

The advantage of the method for producing 1,1,2,2,3-pentafluorocyclobutane by the process of the present invention is that the number of reaction steps is reduced by using raw materials that can be synthesized more easily than conventional methods, and the target product can be more efficiently obtained. It can be manufactured. That is, 1,4,4-trifluorocyclobutene as a raw material of the present invention is 1,2-dichloro-2,3,3 obtained by [2 + 2] cyclization reaction of chlorotrifluoroethylene and vinyl chloride. It can be easily obtained by the reduction reaction of -trifluorocyclobutane. Furthermore, 1,1,2,2,3-pentafluorocyclobutane can be efficiently produced by reacting this raw material in the process of the present invention.

Examples of the high-valent metal fluoride that can be used in the present invention include compounds selected from cobalt trifluoride and silver difluoride. Cobalt fluoride, manganese trifluoride, and potassium cobalt tetrafluoride are suitable, and it is desirable to use one or more of these. The amount used is generally 0.05 to 100 equivalents, preferably 0.1 to 20 equivalents per equivalent of 1,4,4-trifluorocyclobutene.
The reaction temperature depends on the type of high-valent metal fluoride used, but if it is too low, the reaction rate will be slow, and if it is too high, the selectivity of 1,1,2,2,3-pentafluorocyclobutane Therefore, the temperature is usually 0 ° C to 500 ° C, preferably 30 ° C to 300 ° C, and more preferably 50 ° C to 200 ° C.

Although reaction time changes with reaction temperature etc., it is 0.01 to 500 hours normally, Preferably it is the range of 0.1 to 50 hours.
This reaction can be carried out without using a solvent, but can also be carried out using a solvent. However, since high-valent metal fluoride has the ability to fluorinate hydrogen of carbon-hydrogen bonds in the solvent, considering the purification of reaction products, the increase in the amount of high-valent metal fluoride used, etc. It is preferable not to use it.
In addition, the reaction of the present invention is not limited to a batch method, and can be performed by a flow method.

After drying the stainless steel pressure reaction vessel having an internal volume of 50 ml, 1.12 g of manganese trifluoride was weighed in the reaction vessel. The system was deaerated while cooling the reaction vessel with liquid nitrogen, and then 108 mg of 1,4,4-trifluorocyclobutene was introduced using a vacuum line. The reactor was kept at 100 ° C. and stirred for 24 hours. The crude product obtained by the reaction was purified by a vacuum line and analyzed by ¹ H-NMR and ¹⁹ F-NMR. As a result, 69 mg of the desired 1,1,2,2,3-pentafluorocyclobutane (yield 47 %).

  In the same manner as in Example 1, the reaction of manganese trifluoride and 1,4,4-trifluorocyclobutene was carried out at 100 ° C. for 72 hours. As a result of analysis in the same manner as in Example 1, 102 mg (yield 70%) of the desired 1,1,2,2,3-pentafluorocyclobutane could be obtained.

  Using 1.16 g of cobalt trifluoride instead of manganese trifluoride, the reaction with 1,4,4-trifluorocyclobutene was carried out at 100 ° C. for 24 hours in the same manner as in Example 1. As a result of analysis in the same manner as in Example 1, the desired 1,1,2,2,3-pentafluorocyclobutane (64 mg, yield 44%) was obtained.

  In the same manner as in Example 3, the reaction of cobalt trifluoride and 1,4,4-trifluorocyclobutene was carried out at 100 ° C. for 3 hours. As a result of analysis in the same manner as in Example 1, 99 mg (yield 68%) of the desired 1,1,2,2,3-pentafluorocyclobutane could be obtained.

  In place of manganese trifluoride, 1.46 g of silver difluoride was used, and the reaction with 1,4,4-trifluorocyclobutene was carried out at 150 ° C. for 1 hour in the same manner as in Example 1. As a result of analysis in the same manner as in Example 1, 19 mg (yield 13%) of the desired 1,1,2,2,3-pentafluorocyclobutane could be obtained.

  Using 1.74 g of potassium cobalt tetrafluoride instead of manganese trifluoride, the reaction with 1,4,4-trifluorocyclobutene was carried out at 200 ° C. for 24 hours in the same manner as in Example 1. As a result of analysis in the same manner as in Example 1, 37 mg (yield 25%) of the desired 1,1,2,2,3-pentafluorocyclobutane could be obtained.

  In the same manner as in Example 6, the reaction of potassium cobalt tetrafluoride and 1,4,4-trifluorocyclobutene was carried out at 200 ° C. for 144 hours. As a result of analysis in the same manner as in Example 1, the desired 1,1,2,2,3-pentafluorocyclobutane (64 mg, yield 44%) could be obtained.

  After drying the 50 mL stainless steel pressure reactor, the system was degassed while cooling the reaction vessel with liquid nitrogen, and then 108 mg of 1,4,4-trifluorocyclobutene was introduced using a vacuum line. Further, 1 mmol of fluorine gas was introduced. The reactor was placed in an ethanol slush at −120 ° C., stirred, and warmed to room temperature over about 15 hours. As a result of analysis in the same manner as in Example 1, 35 mg (yield 24%) of the intended 1,1,2,2,3-pentafluorocyclobutane could be obtained.

The reaction formula of the present invention is represented by the following formula: 1,4,4-trifluorocyclobutene 1 is fluorinated to obtain 1,1,2,2,3-pentafluorocyclobutane 2 as the target product.

Comparative Example 1
Using 2.16 g of cerium tetrafluoride instead of manganese trifluoride, the reaction with 1,4,4-trifluorocyclobutene was carried out at 200 ° C. for 1 hour in the same manner as in Example 1. As a result of analysis in the same manner as in Example 1, 113 mg (90%) of 1,4,4-trifluorocyclobutene was recovered, but the target 1,1,2,2,3-pentafluorocyclobutane was obtained. I couldn't.

All the specific examples of the production of 1,1,2,2,3-pentafluorocyclobutane are shown in Table 1 including Examples and Comparative Examples.

According to the present invention, 1,4,4-trifluorocyclobutene represented by the chemical formula (1) is reacted with a high-valent metal fluoride, which is represented by the chemical formula (2). 1,2,2,3-pentafluorocyclobutane can be efficiently obtained, and a fluorine-containing compound useful as a cleaning agent can be provided at low cost.

Claims (2)

The following chemical formula (1)

1,4,4-trifluorocyclobutene represented by the following formula (2), characterized by fluorination using fluorine gas or high-valent metal fluoride

The manufacturing method of 1,1,2,2,3-pentafluorocyclobutane represented by these.
The high-valent metal fluoride is one or more compounds selected from cobalt trifluoride, manganese trifluoride, and potassium cobalt fluoride, and the amount used is 1,4,4-trifluorocyclobutene. 2. The method for producing 1,1,2,2,3-pentafluorocyclobutane according to claim 1, wherein the amount is from 0.1 to 20 equivalents per equivalent.