JP5088254B2 - Method for producing fluoroalkyl halide - Google Patents

Description

  The present invention relates to a method for producing a fluoroalkyl halide useful as a raw material for various organic materials.

  Conventionally, as a method for producing a fluoroalkyl halide, for example, a method for producing pentafluoroethyl iodide, a method in which tetrafluoroethylene, iodine, and iodine pentafluoride are reacted in the presence of a catalyst is known. (See Patent Document 1 and Patent Document 2.)

  However, in this production method, tetrafluoroethylene and iodine react to generate 1,2-diiodotetrafluoroethane as a by-product, an expensive metal catalyst, a highly explosive gaseous raw material, Since a highly corrosive raw material has to be used, there has been a problem that the manufacturing process and equipment become complicated in consideration of safety, raw material recovery, purification process and the like.

In addition, as a method for producing a fluoroalkyl halide having a larger carbon number used as a raw material for water / oil repellent (usually having 4 or more carbon atoms), fluorine-based surfactant, etc., carbon such as pentafluoroethyl iodide is used. A production method in which a small number of fluoroalkyl halide and tetrafluoroethylene are reacted is generally performed (see Patent Document 3). In this reaction as well, raw materials that require attention such as tetrafluoroethylene must be used, and the same problem as described above has occurred.
Japanese Patent Laid-Open No. 9-309847 Japanese translation of PCT publication No. 2002-507979 JP 2006-298817 A

  An object of the present invention is to provide a method for producing a fluoroalkyl halide in a high yield by a simple method instead of the conventional production method.

  The present invention has been made in order to solve the above-mentioned problems. A fluorodiacyl peroxide represented by the following formula (1) and a halogen molecule represented by the following formula (2) are reacted to form the following formula (3): A process for producing a fluoroalkyl halide, characterized in that the fluoroalkyl halide shown is obtained.

{F (CF ₂ ) _m COO} ₂ (1)
X ¹ X ² (2)
F (CF ₂ ) _m X ¹ and F (CF ₂ ) _m X ² (3)
(However, in each formula, m is an integer of 1 to 14. X ¹ and X ² are independently F, Cl, Br or I, and X ¹ and X ² are the same or different. May be good.)

  According to the present invention, a fluoroalkyl halide having a desired chain length can be produced with good yield without using tetrafluoroethylene or an expensive metal catalyst that requires attention in handling. In addition, a high-purity fluoroalkyl halide can be obtained by simple purification with little generation of by-products. Various fluoroalkyl halides can be produced by combining with various halogen molecules.

Embodiments of the present invention will be described below.
In the present specification, the compound represented by the formula (1) is referred to as a compound (1). Similarly, the compounds represented by formula (2) and formula (3) are referred to as compound (2) and compound (3), respectively.

  In the production method of the present invention, the compound (1) and the compound (2) are reacted to produce a fluoroalkyl halide of the compound (3) which is the target substance.

<Compound (1)>
The compound (1) used in the production method of the present invention is a fluorodiacyl peroxide represented by the formula (1), and reacts with the compound (2) (halogen molecule) described later to produce a fluoroalkyl halide. one of.
{F (CF ₂ ) _m COO} ₂ (1)
(In the formula, m is an integer of 1 to 14.)

  Here, the m number of the compound (1) used as the raw material component determines the carbon number m of the fluoroalkyl halide obtained. In addition, 14 which is the upper limit of the numerical value of m is a numerical value of the upper limit of m which a compound (1) can isolate easily as a single compound. Moreover, as a compound (1), the thing whose m is an integer of 1-7 is preferable from a viewpoint of industrial utilization and an environmental problem of the fluoroalkyl halide obtained. Compound (1) can be used in the production method of the present invention as one kind or a mixture of two or more kinds according to the demand of the target substance.

Compound (1) can be produced, for example, using the following reaction formula (a), reaction formula (b) and the like. In reaction formulas (a) and (b), m is an integer of 1 to 14.
Scheme _{(a): 2F (CF 2} ) m COCl + Na 2 CO 3 + H 2 O 2 → {F (CF 2) m COO} 2 + 2NaCl + H 2 CO 3
Reaction formula (b): 2F (CF ₂ ) _m COCl + H ₂ O ₂ + 2KOH → {F (CF ₂ ) _m COO} ₂ + 2H ₂ O + 2KCl

  Both the reaction formula (a) and the reaction formula (b) are known, and the compound (1) used in the present invention can be produced by an ordinary production method according to the reaction formula.

For example, in order to obtain compound (1) according to reaction formula (b), halogenated hydrocarbons such as hydrochlorofluorocarbon, hydrofluorocarbon, etc. are added as an organic solvent to an aqueous potassium hydroxide solution having an appropriate concentration. H ₂ O ₂ aqueous solution and F (CF ₂ ) _m COCl are sequentially added to the mixture, and stirred while appropriately adjusting the temperature to obtain a reaction solution having an aqueous phase and an organic phase. Compound (1) contained in the organic phase : {F (CF ₂ ) _m COO} ₂ (fluorodiacyl peroxide) is produced by washing, dehydration, separation and purification. In addition, if the organic solvent used for this reaction is a solvent which does not inhibit the reaction process of a compound (1) and a compound (2) in the manufacturing method of this invention demonstrated below, a compound (1) will be from solution. It can also be used in the production method of the present invention as a solution of the organic solvent used above without separation and purification.

<Compound (2)>
In the production method of the present invention, the compound (2) used as a raw material component together with the compound (1) is a halogen molecule represented by the formula (2).
X ¹ X ² (2)
(In the formula, X ¹ and X ² are independently F, Cl, Br or I, and X ¹ and X ² may be the same or different.)

When X ¹ and X ² are the same, the resulting fluoroalkyl halide is one, but when different, it is produced as a mixture of the two. In many cases, the fluoroalkyl halide is used as a starting material for inducing various organic materials, but X ¹ and X ² can be made the same or different depending on the use and purpose. Moreover, a compound (2) can be used for the manufacturing method of this invention as a 1 type, or 2 or more types of mixture according to the request | requirement of the target product.

Among the fluoroalkyl halides obtained by the production method of the present invention, fluoroalkyl iodide can be easily derived into a more useful compound. Therefore, as a specific example of compound (2) (halogen molecule), X in the formula ^An iodine molecule (I ₂ ) in which ¹ and X ² are both I is preferably used. Further, since fluoroalkyl bromide is used as a raw material for pharmaceutical and agrochemical intermediates, a bromine molecule (Br ₂ ) in which X ¹ and X ² in the formula are both Br is also preferably used.

<Compound (3)>
By reacting the compound (1) and the compound (2) described above, the fluoroalkyl halide represented by the formula (3) and the compound (3) are obtained by the following radical reaction mechanism.
First stage of reaction: {F (CF ₂ ) _m COO} ₂ (compound (1)) (heating) → 2F (CF ₂ ) _m · + 2CO ₂
Second stage of reaction: 2F (CF ₂ ) _m · + X ¹ X ² (Compound (2)) → F (CF ₂ ) _m X ¹ + F (CF ₂ ) _m X ² (final product: compound (3))
(In the formula, m is an integer of 1 to 14. X ¹ and X ² are independently F, Cl, Br or I, and X ¹ and X ² may be the same or different. )

As in the above reaction formula, compound (3) is obtained as a mixture of F (CF ₂ ) _m X ¹ and F (CF ₂ ) _m X ² . Actually, if one compound (1) and compound (2) in which X ¹ and X ² are the same are used, F (CF ₂ ) _m I, F (CF ₂ ) _m Cl, F (CF ₂ ) _m Br, (in each compound, m is 1 to 14 integer) _{F (CF 2)} m F compound (3) obtained alone as the two or more compounds (1), and / or, ^{X 1} and If a compound (2) or the like having a different X ² is used as a raw material, the compound (3) can be obtained as a mixture of the compounds exemplified as being obtained as the simple substance.

  In many cases, the compound (3) is used as a starting material for inducing various organic materials, and a desired structure is appropriately designed depending on the application and purpose. In order to obtain the compound (3) having a desired structure, the compound (1) and the compound (2) may be appropriately selected and used as a raw material component in the reaction.

  Next, reaction conditions for obtaining the compound (3) by reacting the compound (1) and the compound (2) will be described.

<Reaction conditions>
In the production method of the present invention, the ratio of the compound (1) and the compound (2) used in the reaction is not particularly limited, but the molar ratio of the compound (2) to the compound (1) is 1 or more. This is preferable in terms of yield and selectivity improvement.

  In the production method of the present invention, the reaction between the compound (1) and the compound (2) proceeds even in the absence of a solvent, but from the viewpoint of stirring efficiency and reaction efficiency of the compound (1) and the compound (2) as raw material components, It is preferable to carry out the reaction in the presence of a solvent. Any solvent can be used without particular limitation as long as it can dissolve compound (1) and compound (2), which are raw material components.

  In addition, since the reaction of the compound (1) and the compound (2) is a radical reaction as described above, it is preferable to use a solvent that is difficult to chain transfer depending on the solvent, for example, a hydrocarbon solvent. If the reaction solvent is selected from such a viewpoint, a fluorine-based solvent can be preferably mentioned as the solvent used in the present invention in that chain transfer is difficult and the solubility of the raw material components is good. Moreover, it is also possible to use a target product (compound (3)) as a solvent as needed. The amount of the solvent to be used depends on each raw material component, but is not particularly limited as long as these raw material components are dissolved. Usually, 1000 to 200,000 parts by mass of the solvent is used with respect to 100 parts by mass of the raw material.

  Examples of the fluorine-based solvent preferably used in the production method of the present invention include perfluoroalkane, hydrofluorocarbon, perfluoropolyether, hydrochlorofluorocarbon, perfluoroalkyl iodide, and the like. In the present invention, one selected from these can be used alone, or a mixture of two or more can be used as a solvent.

Examples of the perfluoroalkane include C ₅ F ₁₂ , C ₆ F ₁₄ , C ₇ F ₁₆ , C ₈ F ₁₈ , C ₉ F ₂₀ , C ₁₀ F _{22 and the} like.
Examples of the hydrochlorofluorocarbon include CF ₃ CF ₂ CCl ₂ H (225ca: product name of Asahi Glass Co., Ltd.), ClCF ₂ CF ₂ CClFH (225cb: product name of Asahi Glass Co., Ltd.), and the like.

Examples of the perfluoroalkyl iodide include CF ₃ I, CF ₃ CF ₂ I, CF ₃ CF ₂ CF ₂ I, CF ₃ CF ₂ CF ₂ CF ₂ I, CF ₃ CF ₂ CF ₂ CF ₂ CF ₂ I, CF ₃ CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ I, CF ₃ CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ I, CF ₃ CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ I, CF _{3 CF 2 CF 2 CF 2 CF 2} CF 2 CF 2 CF 2 CF 2 I, CF 3 CF 2 CF 2 CF 2 CF 2 CF 2 CF 2 CF 2 CF 2 CF 2 I , and the like.

Examples of the hydrofluorocarbon include CF ₃ H, CF ₃ CF ₂ H, CF ₃ CF ₂ CF ₂ H, CF ₃ CF ₂ CF ₂ CF ₂ H, CF ₃ CF ₂ CF ₂ CF ₂ CF ₂ H, and CF ₃ CF. ₂ CF ₂ CF ₂ CF ₂ CF ₂ H, CF ₃ CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ H, CF ₃ CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ H, CF ₃ CF ₂ CF _{2 CF 2 CF 2 CF 2 CF} 2 CF 2 CF 2 H, CF 3 CF 2 CF 2 CF 2 CF 2 CF 2 CF 2 CF 2 CF 2 CF 2 H , and the like.
Preferred examples of the perfluoropolyether include CF ₃ (CF ₂ ) ₃ OCF ₂ CF ₃ , CF ₃ (CF ₂ ) ₃ O (CF ₂ ) ₃ CF _{3, and the} like.

  Among these, hydrochlorofluorocarbons and hydrofluorocarbons are particularly preferable in that chain transfer reaction hardly occurs.

Next, the reaction process of the production method of the present invention will be described.
First, a predetermined amount of raw material components (compound (1) and compound (2)) and a solvent are introduced into a reactor. The order is not particularly limited as long as it is easy to introduce depending on the properties of the raw material components. Usually, it is easier to introduce in the order of solid, liquid, and gas. Examples of the material for the reactor include metals such as resin, glass, stainless steel, nickel alloy, and composite materials thereof.

  After supplying the raw material components, the air in the reactor is replaced with an inert gas such as nitrogen as necessary, and then the reactor is heated. The heating temperature is adjusted according to the type of compound (1) that is a raw material component. Specifically, the temperature is preferably about 10 to 70 ° C. higher than the 10-hour half-life temperature of the compound (1) used in the reaction. The 10-hour half-life temperature is an index representing the decomposition temperature of the organic peroxide, and refers to a temperature at which the amount of active oxygen is reduced to 1/2 by decomposing the organic peroxide in 10 hours. When the reaction temperature is lower than the 10 hour half-temperature of the compound (1) by more than 10 ° C, it may take more time to complete the reaction than necessary, and when the reaction temperature is higher than 70 ° C, Many coupling reactions may occur.

For example, {F (CF ₂ ) _m COO} ₂ where m is 2 (C ₂ F ₅ COO) _{2 has} a 10-hour half-life temperature of 28 ° C., and uses (C ₂ F ₅ COO) ₂ as a raw material component In the case of the reaction, the reaction conditions at about 40 to 100 ° C. are preferred according to the above conditions. The 10-hour half-life temperature of the compound belonging to compound (1) is in the range of −30 to 50 ° C. Therefore, according to the above conditions, the reaction temperature in the production method of the present invention is generally in the range of −20 to 120 ° C. Will be implemented. The heating or cooling method varies depending on the size of the reactor. Usually, in the case of a jacketed reactor, water, oil, or refrigerant whose temperature is adjusted is passed through until the internal temperature reaches a predetermined temperature.

  The reactor is equipped with a stirring blade, and the type and structure are changed according to the properties of the ingredients. For example, in the case of a gaseous raw material, a stirring blade with good gas absorption is used, and in the case of a solid raw material, a stirring blade excellent in solid-liquid dispersibility is used. The number of rotations is not particularly limited. In the production method of the present invention, the reaction pressure is not particularly limited. Specifically, the reaction is allowed to proceed without particularly adjusting the reaction pressure.

  When the inner surface of the reactor is made of metal, it is better to be polished in order to prevent the compound (1) from being decomposed on the metal surface, but the degree of polishing is not particularly limited. The reactor may be a resin-lined or glass-lined reactor in order to prevent decomposition of the compound (1).

  The reaction may be carried out by either a batch reaction or a continuous reaction, but it is preferably carried out by a continuous reaction from the viewpoint of productivity. In the case of carrying out by continuous reaction, each raw material component is introduced into the reactor at a constant ratio and speed, and after a predetermined residence time, the same amount as the introduced raw material component is continuously extracted as a reaction crude liquid. You can take The residence time is not particularly limited within the above preferable temperature range where the compound (1) sufficiently reacts.

When the reaction is carried out in a batch reaction, the reaction time is not particularly limited as long as the compound (1) can be substantially decomposed at the preferable reaction temperature. For example, when (C ₂ F ₅ COO) ₂ is used as the compound (1), when it is reacted at 70 ° C., it is sufficiently decomposed in 1 hour to complete the reaction.

  In the case of a batch reaction, the reaction crude liquid after completion of the reaction is cooled, and in the case of a continuous reaction, the reaction crude liquid continuously extracted under predetermined conditions is cooled as necessary, and is subjected to a usual method such as distillation. The desired product is purified. In the case of batch distillation, the reaction crude liquid is usually transferred to the kettle of the distillation column, and in the case of continuous distillation, the distillation is carried out by introducing it into the kettle or column.

The distillation method is appropriately selected from pressure distillation, atmospheric distillation, vacuum distillation and the like depending on the physical properties of the target product. For example, when the target product is C ₂ F ₅ I, since the boiling point is about 12 ° C., which is lower than normal temperature, distillation under pressure is performed. Distillation is usually carried out using a distillation column packed with packing. The distillation apparatus is usually equipped with a cooling condenser, through which the target product is recovered. The packing is not particularly limited as long as the target product and the raw material components can be separated. In order to improve the separation, the distillation operation is carried out with a certain reflux ratio. Thus, the fluoroalkyl halide which is a compound (3) is manufactured as a reaction product by making a compound (1) and a compound (2) react by the manufacturing method of this invention.

  As described above, according to the present invention, a fluoroalkyl halide having an arbitrary chain length can be obtained without using a highly explosive tetrafluoroethylene or an expensive metal catalyst used as a raw material in a conventional fluoroalkyl halide production method. It can be produced with good yield. In addition, a high-purity fluoroalkyl halide can be obtained by simple purification with little generation of by-products. Various fluoroalkyl halides can be produced by combining with various halogen molecules.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not limited to these Examples.

<Adjustment Example> Adjustment of Compound (1): {F (CF ₂ ) ₂ COO} _{2 In} a three-necked flask equipped with a thermometer and a dropping funnel, 3.5 g of potassium hydroxide was dissolved in 120 g of distilled water, 61 g of CF ₂ ClCF ₂ CFClH solvent was added and the temperature was adjusted to about 0 ° C. with an ice bath. 9.2 g of a 30% by mass H ₂ O ₂ aqueous solution was introduced, and then 14.3 g of C ₂ F ₅ COCl was introduced.

The temperature in the flask was adjusted to about 2 ° C. and stirring was continued for 30 minutes to obtain a liquid having an aqueous phase and an organic phase. Since the target product fluorodiacyl peroxide: {F (CF ₂ ) ₂ COO} ₂ is contained in the organic phase, the organic phase is then separated by a separatory funnel and washed with an aqueous sodium bicarbonate solution and distilled water. And dehydrated with magnesium sulfate to obtain a solution of fluorodiacyl peroxide: {F (CF ₂ ) ₂ COO} ₂ . The yield determined by titration was 70%.

Example 1 Synthesis Example 1 of CF ₃ CF ₂ I
600 g of CF ₂ ClCF ₂ CFClH and 38.5 g of {F (CF ₂ ) ₂ COO} ₂ as solvents are introduced into an autoclave with a stirrer (made of stainless steel, volume: 1 L), and then 30 g of iodine (I ₂ ) is added. It was. The reactor was purged with nitrogen and heated to 50 ° C. Two hours later, the reaction crude liquid was quantitatively analyzed by gas chromatography, whereby CF ₃ CF ₂ I was produced (yield 80%).

Example 2 Synthesis Example 2 of CF ₃ CF ₂ I
Into an autoclave with a stirrer (made of stainless steel, volume: 1 L), 500 g of CF ₃ CF ₂ CF ₂ CF ₂ I and 38.5 g of {F (CF ₂ ) ₂ COO} ₂ were introduced as solvents, followed by iodine (I ₂ 30 g) was added. The reactor was purged with nitrogen and heated to 50 ° C. Two hours later, the reaction crude liquid was quantitatively analyzed by gas chromatography, whereby CF ₃ CF ₂ I was produced (yield 91%).

  According to the production method of the present invention, a fluoroalkyl halide having an arbitrary chain length can be produced in a high yield by a simple method. Various fluoroalkyl halides can be produced by combining with various halogen molecules. The fluoroalkyl halide thus obtained is useful as a raw material for various organic materials.

Claims (4)

A fluoroalkyl halide represented by the following formula (3) is obtained by reacting a fluorodiacyl peroxide represented by the following formula (1) with a halogen molecule represented by the following formula (2): Method.
{F (CF ₂ ) _m COO} ₂ (1)
X ¹ X ² (2)
F (CF ₂ ) _m X ¹ and F (CF ₂ ) _m X ² (3)
(However, in each formula, m is an integer of 1 to 14. X ¹ and X ² are independently F, Cl, Br or I, and X ¹ and X ² are the same or different. May be good.) The method for producing a fluoroalkyl halide according to claim 1, wherein the halogen molecule represented by the formula (2) is an iodine molecule (I ₂ ).   The method for producing a fluoroalkyl halide according to claim 1 or 2, wherein the reaction is carried out in the presence of a fluorinated solvent.   The reaction temperature of the fluoroalkyl halide according to any one of claims 1 to 3, wherein the reaction temperature is 10 to 70 ° C higher than the 10-hour half-life temperature of the fluorodiacyl peroxide represented by the formula (1). Production method.