JPS5912651B2 - Method for producing α, α, α-trifluoro-O-Toluitsuku fluoride - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing α.α.α-trifluoro-Toluik fluoride.

The present inventors previously discovered that 1,1,3,3-tetrachloro 1
・3-dihydroisobenzofuran (hereinafter referred to as compound ■).

) has been found to react with excess hydrogen fluoride under pressure at 15°C to obtain α·α·α-trifluoro-0-toluikfluoride (hereinafter referred to as Compound I) in a good yield. (Patent Application No. 54-31300).
NooClCl 92 α2 (■) (I) In addition, the present inventors previously developed a compound (■) and α・α゜α-trichloro-0-toluic chloride (hereinafter referred to as compound ■).

It has been discovered that compound (I) can be obtained in a good yield by reacting a mixture of (1) with excess hydrogen fluoride under pressure (same patent application). Furthermore, the present inventors previously discovered that o-toluic chloride (Compound (V)) was sufficiently chlorinated to obtain Compound () and Compound (), and this mixture was reacted with hydrogen fluoride in accordance with the above procedure. If so, the compound (
It has been found that 1) can be obtained (same patent application).

The inventors of the present invention have obtained new knowledge as a result of various studies on improving the above-mentioned fluorination reaction to be carried out under atmospheric pressure.

That is, each of the above-mentioned reactants, that is, the compound () or the compound ()
It has been found that compound (1) can be easily obtained by reacting a mixture of compound (2) and compound (2) in a molten state with hydrogen fluoride under normal pressure in the presence of a fluorination catalyst. Also,. Hitoto, L
．． If chloride is sufficiently chlorinated, the compound ()
A mixture containing the compound (1) and the compound (1) is obtained, but this mixture can also be easily converted into the compound (1) by reacting it with hydrogen fluoride in the molten state in the presence of a fluorination catalyst under normal pressure.
was found to be obtained. The fluorination catalyst used in the present invention has . Any catalyst that participates in the reaction of the compound () or a mixture of the compounds () and () with hydrogen fluoride and helps promote the progress of the reaction may be used, such as tantalum pentachloride (TaCl5), pentafluoride, etc. Tantalum (TaF
5), antimony pentachloride (SbCl5), tin tetrachloride (SnCl4), titanium tetrachloride (TiCl4), niobium pentachloride (NbCl5), rhenium pentachloride (ReCl5)
, molybdenum trichloride (MOCl3), molybdenum tetrachloride (MOCl4), molybdenum pentachloride (MOCl5), molybdenum oxychlorides (MOOCl3, MOOCl4,
MOO2Cl2), molybdenum pentafluoride (MOF5), and the like.

The amount of such a catalyst to be used can be determined as appropriate from a quantitative range that provides a catalytic effect, and for example, it is preferably selected from the range of 0.01 to 10% (by weight) based on the chlorinated product to be fluorinated. . Particularly preferred amount is 0.1-1%
(weight). The reaction temperature is determined by compound () or compound (
) and () may be determined as appropriate from the temperature at which the mixture exists in liquid form to about 120°C, preferably from about 80 to 100°C.

The melting point of compound () is as described below, but compound ()
Since the mixture of and () melts at a lower temperature, it is sufficient to react with hydrogen fluoride at a temperature higher than that temperature. The amount of hydrogen fluoride to be used can be appropriately determined from the theoretical amount to an excess amount of about 30% more than the theoretical amount.

One of the advantages of the method of the present invention is that it does not require a large excess of hydrogen fluoride. After the reaction is completed, the target product may be separated from the reactants according to a conventional method.

Such operations and conditions are similarly used when fluorinating mixtures of compounds () and ().

This will be explained below. Journal of the Chemical Society (J. Chem. SOc.), 1 Suyu, 2212 (1922) describes compound (V) at
It is stated that pure compound () with a melting point of 87°C can be obtained by purifying the oil obtained by carrying out a chlorination reaction at ~240°C for about 10 hours, but in reality, compound () has a boiling point of 120°C~240°C. Since it is an oily substance with a temperature of 130° C./0.5TnT1LHg, the description in this document is not accurate.

The intermediate chlorine substituted α·α-dichloro-0-toluic chloride (hereinafter referred to as the compound) was detected by examining the compound () under relatively mild temperature conditions using an appropriate method such as gas chromatography or nuclear magnetic resonance spectroscopy. If the photochlorination reaction is carried out sufficiently until it is no longer detected, a mixture of compounds () and () can be obtained in good yield. Usually, the mixture thus obtained contains compounds () and (JIl) in a weight ratio of approximately 6:4. Compound () has a melting point of 8
It is a white crystal with a temperature of 5 to 86°C. The conditions for the photochlorination reaction will be explained below. According to the findings of the present inventors, the photochlorination reaction of Compound (V) and Compound () proceeds relatively easily, but the subsequent progress is difficult when the conditions are harsh as in the above literature. Not only does decomposition proceed at the same time, causing problems such as browning of the contents, but it is also difficult to collect compound (1) with good purity even if the product thus obtained is reacted with hydrogen fluoride. I can't. Therefore,
In order to obtain a mixture of compounds () and () in a good yield, it is necessary to carry out the photochlorination reaction under relatively mild conditions, and the temperature of the reaction contents must be controlled so that it does not reach a temperature range that promotes decomposition. This is very important. Generally, the reaction may be carried out in the temperature range from room temperature to around 140°C, but preferably 70°C to 13°C.
It is around 0°C. The photochlorination reaction can be carried out without a solvent or in a solvent such as carbon tetrachloride. The light source can be any one commonly used in photochlorination reactions, such as ultraviolet rays, tungsten lamps, sunlight, etc. When the resulting mixture is continuously introduced into the reaction with hydrogen fluoride, it is convenient to carry out the reaction under conditions where the compound () is present in liquid form.

However, when reacting with hydrogen fluoride, the compound ()
must be in liquid form.

As described above, according to the method of the present invention, the compound (), which is a photochlorination reaction product of the compound (), is directly reacted with anhydrous hydrogen fluoride, thereby producing the compound in good yield. (1) can be synthesized, and is an extremely valuable method for producing compound (1) on an industrial scale.

Next, some examples will be shown. Reference Example Compound () -> Compound () 10 Compound () 0-Toluyzc chloride 43f (0.27 mol) is reacted at 110 to 120°C by passing dry chlorine under irradiation with an ultraviolet lamp.

From the reaction contents, a necessary amount for gas chromatography analysis is taken from time to time and α・α-dichloro-0-
Check for changes in the Toluyuk chloride peak, and stop blowing chlorine after the peak disappears. Gas chromatography analysis of a portion of the reaction contents reveals that approximately 1,1,3,3-tetrachloro-1,3-dihydroisobenzofuran and α,a,αtrichloro-0-toluic chloride are present. It can be confirmed that they are mixed and produced at a weight ratio of 6:4. Yield 671 (chlorination yield 93
．． 4%). This mixture is subjected to a reaction with anhydrous hydrogen fluoride after passing nitrogen gas through it to drive out dissolved chlorine gas. Example 1 Antimony pentachloride 1V (3.3X10-3 mol) was added to the mixture 1037 (0.4 mol) obtained by the method of Reference Example 9.
Anhydrous hydrogen fluoride was blown into the reactor at a rate of 0.277/min for 148 minutes while stirring at 0°C.

After the reaction was completed, the reaction contents were washed with an aqueous sodium bicarbonate solution, the reaction product was extracted with dichloromethane, and after washing with water,
The dichloromethane layer is separated, dehydrated and dried over sodium sulfate, and then dichloromethane is distilled off at normal pressure. The residue was distilled under reduced pressure to produce a colorless and transparent product with a boiling point of 86-89℃/26-27mmHg.
A fraction of 65f7 is obtained. Yield from mixture 80% o Example 2 Tantalum pentachloride 17 (27X10-3 mol) was added to 103 t (0.4 mol) of the mixture obtained by the method of Reference Example at 90°C.
While stirring, anhydrous hydrogen fluoride was blown into the reactor at a rate of 0.271/min for 178 minutes.

The following treatment was carried out in the same manner as in Example 1 to 86-89°C/26-2
59.6 f7 of a colorless and transparent liquid with 7 Hg was obtained. 77% yield from mixture. Example 3 1 t (5.2 x 10-3 mol) of titanium tetrachloride was added to 103 t (0.4 mol) of the mixture obtained by the method of Reference Example at 90°C.
While stirring, anhydrous hydrogen fluoride was blown into the reactor at a rate of 0.27 f7/min for 148 minutes.

The following treatment was carried out in the same manner as in Example 1, and the boiling point was 86-89℃/26.
A colorless transparent liquid 651 of ~2711 Hg is obtained. 74% yield from mixture. Example 4 Antimony pentachloride 17 (3.3 x 10-3 mol) was added to 1,1,3,3-tetra-chloro-1,3-dihydroisozone Zofuran 103V (0.4 mol) at 90°C. While stirring, anhydrous hydrogen fluoride was added at a rate of 0.27 t/min.
It was blown for 8 minutes.

After the reaction is completed, the reaction contents are washed with an aqueous sodium bicarbonate solution, and then the reaction product is extracted with dichloromethane. After washing the extract with water and dehydrating it with anhydrous sodium sulfate, dichloromethane is distilled off at normal pressure and the residue is distilled under reduced pressure to obtain a boiling point of 86.
A clear colorless liquid 68V of ~89°C/26-27 fin Hg is obtained. Yield 85% o Comparative Example 9 to the mixture 1037 (0.4 mol) obtained by the method of Reference Example
245 anhydrous hydrogen fluoride at a rate of 0.27y/min at 0°C.
It blew for a minute.

The following treatment was carried out in the same manner as in Example 1, but the yield of the target product was 22% (
(compared to mixture).

Claims (1)

[Claims] 1. α characterized in that 1,1,3,3-tetrachloro-1,3-dihydroisobenzofuran is reacted with hydrogen fluoride in a molten state under normal pressure in the presence of a fluorination catalyst.・α
- A method for producing α-trifluoro-o-Toluik fluoride. 2. A mixture of α・α・α-trichloro-o-toluic chloride and 1,1,3,3-tetrachloro-1,3-dihydroisobenzofuran was fluorinated in a molten state under normal pressure in the presence of a fluorination catalyst. A method for producing α·α·α-trifluoro-o-toluitsuk fluoride, which comprises reacting with hydrogen chloride. 3 Thoroughly chlorinate o-Toluyk chloride to obtain α・
α・α-Trichloro-o-toluic chloride and 1・
α・α characterized by mixing 1,3,3-tetrachloro-1,3-dihydroisobenzofuran and reacting this mixture with hydrogen fluoride in a molten state under normal pressure in the presence of a fluorination catalyst. - A method for producing α-trifluoro-o-Toluik fluoride.