KR100361445B1 - A method for preparing 2,2,2-trifluoroethyl difluoromethyl ether - Google Patents

Abstract

The present invention relates to a process for the preparation of 2,2,2-trifluoroethyl difluoromethyl ether, and more particularly, by reacting CF ₃ CH ₂ OH with CHCl ₃ and HF in the presence of a catalyst, A method for preparing 2-trifluoroethyl difluoromethyl ether is provided.

The catalyst that can be used in the present invention is preferably a metal oxide or a halide, and more preferably an oxide, fluoride or chloride of a metal selected from the group consisting of B, Sn, Ti, Al, Zn and Ce. .

When using the above production method, not only can 2,2,2-trifluoroethyl difluoromethyl ether be prepared easily, but a high yield can be obtained by using a small amount of catalyst.

Description

A manufacturing method of 2,2,2-trifluoroethyl difluoromethyl ether {A METHOD FOR PREPARING 2,2,2-TRIFLUOROETHYL DIFLUOROMETHYL ETHER}

The present invention relates to a process for the preparation of 2,2,2-trifluoroethyl difluoromethyl ether, and more particularly, by reacting CF ₃ CH ₂ OH with CHCl ₃ and HF in the presence of a catalyst, A method for preparing 2-trifluoroethyl difluoromethyl ether is provided.

The present invention also reacts CF ₃ CH ₂ OH, CHCl ₃ and HF by using oxides, fluorides or chlorides of metals selected from the group consisting of B, Sn, Ti, Al, Zn and Ce as catalysts. It relates to a process for preparing, 2-trifluoroethyl difluoromethyl ether.

CFC, which has been widely used as a refrigerant, a blowing agent, and a cleaning agent, has been found to be the main cause of ozone layer destruction and is now replaced by HCFC and HFC. However, HCFCs and HFCs are not suitable as complete CFC substitutes due to their high global warming index, so there is an active search for next generation CFC alternatives. One of the materials currently being considered as a third generation CFC replacement is the fluorine-containing ether compound.

2,2,2-trifluoroethyl difluoromethyl ether (CF ₃ CH ₂ OCHF ₂ ) is one of these fluorine-containing ether compounds, and a number of papers have been published on their use.

Japanese Patent Laid-Open No. 8-269442 discloses that the compound can be used as a working fluid of a refrigerator or a compressed heat pump, and German Patent No. 4425066 discloses that it can be used as a solvent of a toner based on polystyrene. European Patent 600 538 discloses that a mixture of the compound and alcohol can be used as a detergent. In addition, European Patent 482 938, Japanese Patent Laid-Open Nos. Hei 6-192154 and Hei 4-273839, and J. Fluorine Chemistry, 85, 111 (1977) are also known as difluoroethyl ether, aka desflurane, currently used as an inhalation anesthetic. It is disclosed that the compound can be used as a raw material for preparing desflurane.

As for the synthesis method of 2,2,2-trifluoroethyl difluoromethyl ether having the above use, the following method is known.

J. Fluorine Chemistry, 85, 111 (1977) describes a method for synthesizing 2,2,2-trifluoroethyl difluoromethyl ether by reacting trifluoroethanol with FSO ₂ CF ₂ COOH under a CuI catalyst. Doing. However, this method is not easy to prepare one of the raw material FSO ₂ CF ₂ COOH, there is a problem that a large amount of by-products such as CHF ₃ , SO ₂ , CO ₂ is produced after the reaction. EP 574 839 describes a method for synthesizing 2,2,2-trifluoroethyl difluoromethyl ether by reacting trifluoroethanol with Zn (CF ₃ ) Br, which is also one of the raw materials. Since Zn (CF ₃ ) Br must be prepared, there is a problem that is not suitable for industrial application. US Pat. No. 3,637,477 describes a process for synthesizing 2,2,2-trifluoroethyl difluoromethyl ether by reacting trifluoroethanol with CHF ₂ Cl in the presence of KOH or NaOH, but yields of 30 Low as 40%, there is a problem that KCl / NaCl is formed as a by-product.

It is therefore an object of the present invention to provide a novel process which allows the preparation of 2,2,2-trifluoroethyl difluoromethyl ether in a simple and high yield.

We have prepared 2,2,2-trifluoroethyl difluoromethyl ether when reacting 2,2,2-trifluoroethanol (CF ₃ CH ₂ OH) with CHCl ₃ and HF. It has been found that 2,2,2-trifluoroethyl difluoromethyl ether can be prepared effectively.

The amount of CHCl ₃ , the starting material of the present invention, is preferably in the range of 1-10 mol, preferably 2-8 mol, per mol of trifluoroethanol, and HF is 5-50 mol per mol of trifluoroethanol. It is preferable to exist in the range of 10-30 mol preferably. When the amount of HF used is less than 5 mol, not only is the yield of the reaction low, but also the amount of by-product CF ₃ CH ₂ OCHFCl or CF ₃ CH ₂ OCHFCl is increased. The reaction temperature is preferably 100-200 ° C, preferably 120-180 ° C. When the reaction temperature is 200 ° C or higher, by-products such as CHF ₂ Cl and CHFCl ₂ increase, and the reaction temperature is less than 100 ° C. In case of slow reaction progress, it is ineffective.

The preparation method of the present invention is usually carried out in the presence of a catalyst, and the type of catalyst that can be used is not particularly limited, but is preferably an oxide or halide of a metal, most preferably B, Sn, Ti, Al, Zn And oxides, fluorides or chlorides of metals selected from the group consisting of Ce. The amount of the catalyst to be used is not particularly limited, but is used at a ratio of 0.005 to 1 mol, preferably 0.01 to 0.5 mol, per mol of 2,2,2-trifluoroethanol. If the amount of the catalyst used is less than 0.005 mole, the yield of the reaction is too low. If the amount of the catalyst is used more than 1 mole, the use of more catalyst than necessary is uneconomical. When the catalyst is used in the form of an oxide, during the reaction, the catalyst reacts with HF to form water, but there is no significant effect on the reaction.

According to an embodiment of the present invention, the oxide of the metal selected from the group consisting of boron (B), tin (Sn), titanium (Ti), aluminum (Al), zinc (Zn), cerium (Ce), fluoride Or using chloride in an amount in the range of 0.005-1 mole per mole of 2,2,2-trifluoroethanol gave the best results.

Hereinafter, the present invention will be described in more detail with reference to the following examples. The scope of the present invention is not limited to these Examples.

Example 1

A 100 ml high pressure reactor was charged with 10 g (0.1 mol) of CF ₃ CH ₂ 0H, 29.5 g (0.25 mol) of CHCl ₃ , 40 g (2 mol) of HF, and 0.95 g (0.005 mol) of SnCl ₂ , 5 at 150 ° C. The reaction was carried out for a time. After the reaction was completed, the temperature of the reactor was lowered to 100 ° C., and gas mixtures in the reactor were passed through a water trap of 50 ° C. to remove HF. HF-free gas was collected in a dry ice / acetone trap at -78 ° C and analyzed by GC and GC-Mass to give a mixture with the following composition: CHFCl ₂ 16.7%, CF ₃ CH ₂ 0CHF ₂ 33.1 %, CHCl ₃ 50.2%. The yield of CF ₃ CH ₂ 0CHF ₂ was 63.8% based on the raw material CF ₃ CH ₂ 0H calculated using the internal standard method.

Example 2-10

Table 1 shows the results of the reaction experiments under varying catalyst types under the same conditions as in Example 1.

(a) Yield of CF ₃ CH ₂ 0CHF ₂ based on CF ₃ CH ₂ OH

Example 11-14

Table 2 shows the results of the reaction experiments while varying the amount of catalyst and the reaction temperature under the same conditions as in Example 1.

(a) Yield of CF ₃ CH ₂ 0CHF ₂ based on CF ₃ CH ₂ OH

Example 15-18

Table 3 shows the results of the reaction experiments under varying amounts of CHCl ₃ and HF under the same conditions as in Example 1.

(a) Yield of CF ₃ CH ₂ 0CHF ₂ based on CF ₃ CH ₂ OH

Process for preparing 2,2,2-trifluoroethyl difluoromethyl ether by reacting with CHCl ₃ and HF, according to the present invention, selected from the group consisting of B, Sn, Ti, Al, Zn and Ce When using oxides, fluorides or chlorides of metals as catalysts, high yields can be obtained even with small amounts of catalysts.

Claims (7)

In the process for preparing 2,2,2-trifluoroethyl difluoromethyl ether, CF _{3 in} the presence of an oxide, fluoride or chloride catalyst of a metal selected from the group consisting of Sn, Ti, Al, Zn and Ce A process for producing 2,2,2-trifluoroethyl difluoromethyl ether characterized by reacting CH ₂ OH, CHCl ₃ and HF. delete The process according to claim 1, wherein the amount of the catalyst is 0.005-1 mol per mol of trifluoroethanol. A process according to claim 1 wherein the amount of catalyst is from 0.01 to 0.5 moles per mole of trifluoroethanol. The process according to claim 1, wherein the amount of CHCl ₃ used is 1-10 moles per mole of trifluoroethanol. The method according to claim 1, wherein the amount of HF used is 5-50 mol per mol of trifluoroethanol. The process according to claim 1, wherein the reaction temperature is 100-200 ° C.