JPH07126245A - Production of (perfluoroalkylseleno)biphenyl compound - Google Patents

Abstract

PURPOSE:To obtain the compound e.g. for a production intermediate of a fluorine-containing compound on an industrial scale at a low cost by reacting a specific selenocyanatobiphenyl compound with a (perfluoroalkyl)silane compound in the presence of a base. CONSTITUTION:The (perfluoroalkylseleno)biphenyl compound useful as an intermediate of a fluorine-containing compound is easily obtained in a high yield by reacting a selenocyanatobiphenyl compound (e.g. 2-selenocyanatobiphenyl) expressed by formula I [R<1> and R<2> are H or 1-4C alkyl; (m) and (n) are integer of 1-3] with a (perfluoroalkyl)silane compound (e.g. trifluoromethyltrimethylsilane) expressed by formula II (R<3> to R<5> are 1-8C alkyl, 6-10C aryl or 7-10C aralkyl; Rf is 1-10C perfluoroalkyl) in the presence of a base (e.g. potassium fluoride) in a reaction solvent, e.g. dimethyl sulfoxide at room temperature.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a process for producing a (perfluoroalkylseleno) biphenyl compound, which is a useful intermediate for the production of a fluorine-containing compound.

[0002]

2. Description of the Related Art (Perfluoroalkylseleno) biphenyl compounds are useful intermediates for the production of fluorine-containing compounds. Among them, 2- (perfluoroalkylseleno) biphenyl compounds are the production of perfluoroalkylating agents for organic compounds. It is particularly useful as an intermediate (for example, JP-A-3-197479; Tetrahedron Letters, Vol. 31, p. 3579 (1990); Journal.
Of American Chemical Society, Volume 115,
2156 (1993)).

As a method for synthesizing a 2- (perfluoroalkylseleno) biphenyl compound, conventionally, sodium borohydride is allowed to act on a 2-selenocyanate biphenyl compound to form a biphenylselenolate salt, and this is reacted with perfluoroalkyl iodide. There is known a method for making the above (see the above-mentioned document). However, these conventional methods
(1) A dangerous hydrogen gas is generated in the reaction of selenocyanate biphenyl with sodium borohydride in the first step which is a two-step reaction, and (2) a large amount of bis (biphenyl) diselenide as a by-product. To generate,
(3) In order to suppress the formation of by-product bis (biphenyl) diselenide and increase the yield of desired (perfluoroalkylseleno) biphenyl, a large excess of expensive perfluoroalkyl iodide must be used. 4) When the perfluoroalkyl iodide used is trifluoromethyl iodide, it has a low boiling point of −22 ° C. and is a gas at room temperature, and therefore a complicated operation such as liquefaction is required during the reaction.
There was a defect such as. Therefore, in terms of economical efficiency, safety, operability, etc., it is very inconvenient when the conventional method is industrially carried out. It must be said that these conventional methods are insufficient as industrial manufacturing methods.

[0004]

An object of the present invention is to provide a novel industrially useful process for producing a (perfluoroalkylseleno) biphenyl compound, which is a useful intermediate for fluorine-containing compounds.

[0005]

As a result of intensive studies to solve the above problems, the present inventors succeeded in finding a completely new reaction as described below, and completed the present invention. It is a thing. That is, the present invention has the general formula:

[Chemical 4] (In the formula, R ¹ and R ² are independently a hydrogen atom or a carbon number 1
~ 4 alkyl groups, m and n each represent an integer of 1 to 3. ) And a selenocyanatobiphenyl compound represented by the general formula:

[Chemical 5] (In the formula, R ³ , R ⁴ and R ⁵ independently represent an alkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 10 carbon atoms or an aralkyl group having 7 to 10 carbon atoms, and Rf represents the number of carbon atoms. 1-1
Represents 0 perfluoroalkyl groups. ) Is reacted with a (perfluoroalkyl) silane compound in the presence of a base to give a compound of the general formula:

[Chemical 6] (In the formula, R ¹ , R ² , m, n and Rf are as defined above.) A method for producing a (perfluoroalkylseleno) biphenyl compound.

R ¹ and R ² in the above general formula (I)
Is an alkyl group having 1 to 4 carbon atoms, straight-chain or branched alkyl groups such as methyl, ethyl, propyl, i-propyl, n-butyl, sec-butyl, ter-
A butyl group etc. can be illustrated.

The selenocyanatobiphenyl compound represented by the general formula (I) is a known compound, or a compound which can be easily synthesized in the same manner as in the known method for producing a selenocyanatobiphenyl compound (for example, Kaihei 3-19
No. 7479; Tetrahedron Letters, Volume 31,
3579 (1990); Journal of American Chemical Society, 115, 2156 (1
993). ).

R ³ , R ⁴ in the above general formula (II),
And R ⁵ is independently a straight chain or branched alkyl group having 1 to 8, preferably 1 to 4 carbon atoms, 6 to 10
An aryl group having 6, preferably 7 to 7 carbon atoms, or an aralkyl group having 7 to 10, preferably 7 to 8 carbon atoms. Specific examples of preferred alkyl groups include methyl, ethyl, propyl and butyl groups, specific examples of preferred aryl groups include phenyl and tolyl groups, and specific examples of preferred aralkyl groups include benzyl and phenethyl groups. be able to. In the general formula (II), Rf is CF
₃ , C ₂ F ₅ , C ₃ F ₇ , C ₄ F ₉ , C ₅ F ₁₁ , C ₆ F ₁₃ , C ₇ F
_15, as the _{C 8 F 17, C 9 F} 19, C 10 F 21, carbon atoms 1 to 1
There may be 0 linear or branched perfluoroalkyl groups.

The (perfluoroalkyl) silane compound represented by the general formula (II) is a known compound or a compound easily synthesized in the same manner as in the known method for producing a (perfluoroalkyl) silane compound (eg, ,
Journal of Organic Chemistry, 56
Volume, 984 pages (1991); 54, 2873 pages (1)
989); Tetrahedron Letters, Vol. 25, 219.
5 (1984); and Journal of Fluorine Chemistry, 42, 429 (1989). ).

The amount of the (perfluoroalkyl) silane compound represented by the general formula (II) used is usually 0.8 mol to 5 mol per 1 mol of the selenocyanatobiphenyl compound represented by the general formula (I). However, it is preferably 1 mol to 2 mol, and more preferably 1 mol to 1.5 mol from the viewpoint of economy and yield.

In the method of the present invention, the reaction is carried out in the presence of a base. Examples of the base include those usually used in synthetic organic chemistry, but potassium fluoride, cesium fluoride, sodium fluoride, and the like in order to promote the reaction in good yield.
Alkali metal fluorides such as lithium fluoride and rubidium fluoride; Cesium cyanide, potassium cyanide, sodium cyanide, lithium cyanide and other alkali metal cyanides; benzyltrimethylammonium fluoride, tetramethylammonium fluoride, tetrafluoride Quaternary ammonium fluoride such as butylammonium;
Quaternary ammonium cyanides such as benzyltrimethylammonium cyanide, tetramethylammonium cyanide, tetrabutylammonium cyanide, etc. are preferred.
The amount of the base used can be selected in the range of a catalytic amount to an excess amount with respect to 1 mol of the selenocyanatobiphenyl compound represented by the general formula (I), but it is economical, effective and in terms of yield. Therefore, it is usually 0.05 mol to 1.5 mol, preferably 0.1 mol to 1 mol, more preferably 0.1 mol to 1 mol.
It is in the range of 0.8 mol.

The reaction of the present invention is preferably carried out in a solvent. Examples of the solvent used include dimethyl sulfoxide, dimethyl sulfone, tetramethylene sulfoxide, tetramethylene sulfone, hexamethylphosphoric triamide (HMPA), hexaethylphosphoric triamide, dimethylformamide,
Illustrate aprotic solvents such as N-methylpyrrolidinone, 1,3-dimethyl-2-imidazolidinone, acetonitrile, propionitrile, tetrahydrofuran (THF), methylene chloride, chloroform, hexane, octane, benzene and toluene. However, an aprotic polar solvent such as dimethyl sulfoxide, hexamethylphosphoric triamide, or acetonitrile is particularly preferable in order to allow the reaction to proceed efficiently and in good yield. The solvent is usually used in an amount of 1 to 100 parts by weight with respect to 1 part by weight of the selenocyanatobiphenyl compound represented by the general formula (I).

The reaction temperature can be selected in the range of -50 ° C to + 100 ° C, but it is preferably in the range of -10 ° C to + 50 ° C for the reaction to proceed in good yield. The reaction time varies depending on the reaction temperature and the like, but is usually in the range of 0.1 to 100 hours.

[0014]

According to the method of the present invention, a selenocyanatobiphenyl compound represented by the general formula (I), which is industrially available or easily synthesized, and a perfluoroalkylsilane compound represented by the general formula (II). Thus, the desired (perfluoroalkylseleno) biphenyl compound represented by the general formula (III) can be easily produced in a high yield by a one-step reaction using an inexpensive base. This makes it possible to remarkably suppress the production of the by-product bis (diphenyl) diselenide compound. In addition, since dangerous hydrogen gas is not generated in this reaction, it can be safely operated. Furthermore, since the (perfluoroalkyl) silane compound of the above general formula (II) used in this reaction has a boiling point of room temperature or higher, complicated operations such as liquefaction are required. Does not need The (perfluoroalkylseleno) biphenyl compound produced by the present invention is useful as an intermediate raw material for producing a perfluoroalkylating agent.

[0015]

EXAMPLES The present invention will be described in more detail below with reference to examples. Example 1

[Chemical 7] Fully dried potassium fluoride under argon atmosphere 1.
16 g (20 mmol) of dimethyl sulfoxide (60
ml), 2-selenocyanatobiphenyl (10.3 g, 40 mmol) and trifluoromethyltrimethylsilane (7.2 ml, 48 mmol) were added, and the mixture was stirred at room temperature for 0.5 hours. Water and ether were added to the reaction solution, the organic layer was extracted, washed with water and saturated saline, and then dried over anhydrous magnesium sulfate. After the desiccant was filtered off, the product was concentrated under reduced pressure to give an oily product. This was purified by column chromatography on silica gel using n-hexane as a developing solvent to obtain 10.9 g (yield 91%) of 2- (trifluoromethylseleno) biphenyl. The physical properties of the product are shown below. Melting point: 44-45 ° C. ¹ H-NMR (ppm, in CDCl ₃ ): 7.17-7.5
2 (8H, m), 7.87 (1H, br.d, J = 6Hz,
3-H), ¹⁹ F-NMR (ppm, in CDCl ₃ , CFCl ₃ internal standard): 36.0 (s), mass spectrum (m / e):
301 (M ⁺ ), 232 (M ⁺ -CF ₃ ), 69 (C
F ₃ ⁺ ) Elemental analysis: Found, C, 51.85%; H, 3.09% Calculated (C ₁₃ H ₉ F ₃ Se); C, 51.85%; H, 3.
01%

Examples 2 to 5 In the same manner as in Example 1, the reactants, the amounts of the reactants shown in Table 1,
And the reaction was carried out under the reaction conditions. The results are shown in Table 1. In Example 3, the extract was purified by vacuum distillation. The boiling point was 113 to 116 ° C / 5 to 6 mmHg. The results of Example 1 are also shown in Table 1.

[0017]

[Table 1]

Claims (2)

[Claims] 1. A general formula: (In the formula, R ¹ and R ² are independently a hydrogen atom or a carbon number 1
~ 4 alkyl groups, m and n each represent an integer of 1 to 3. ) And a general formula: (In the formula, R ³ , R ⁴ and R ⁵ independently represent an alkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 10 carbon atoms or an aralkyl group having 7 to 10 carbon atoms, and Rf represents carbon. Number 1 to 1
Represents 0 perfluoroalkyl groups. )
By reacting with a (perfluoroalkyl) silane compound in the presence of a base, a compound of the general formula: (Wherein R ¹ , R ² , m, n and Rf are as defined above) to obtain a (perfluoroalkylseleno) biphenyl compound represented by the formula (perfluoroalkylseleno) biphenyl compound Production method. 2. As a base, an alkali metal fluoride, an alkali metal cyanide, a quaternary ammonium fluoride,
Alternatively, the manufacturing method according to claim 1, wherein a quaternary ammonium cyanide is used.