JPH0686418B2 - Manufacturing method of perfluoroalkyl aryl sulfide - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a perfluoroalkylaryl sulfide.

2. Description of the Related Art Conventionally, perfluoroalkyl sulfide is known to be produced by reacting perfluoroalkyl iodide (RfI) with an alkali salt of benzenethiol or an alkali salt of alkylthiol (“Journal Fluorine Chemistry” 24 , 191-203 (1984)). This method requires production of a perfluoroalkyl iodide once, which is troublesome. There is also known a method of obtaining a perfluoroalkenylaryl thioether by reacting a perfluoroolefin with an aromatic having a mercapto group in the presence of a basic catalyst (Japanese Patent Application No. 51-4441). Perfluoroalkyl sulfide cannot be obtained by this method. Also known is a method of synthesizing perfluoroalkyl polysulfide by reacting perfluoroalkyl iodo (RfI) with sulfur in a sealed tube at 200 to 300 ° C. (G.V.D.Tears, “Journal of Organs”). Nick chemistry "26, 3515 (196
1): GVDTiers.Journal of Organic Chemistry).

Further, there is known a method of reacting a copper perfluoroalkyl thiolate with a halogeno-substituted aromatic compound (JP-A-50-123609). This method also requires high temperature and high pressure, and the synthesis is complicated.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The present invention provides a method for synthesizing perfluoroalkylaryl sulfides from a perfluoroolefin, which is relatively inexpensive as a perfluorocarbon, as a raw material at room temperature, atmospheric pressure and in a one-step reaction. is there.

Means for Solving the Problems The present invention provides a compound represented by the general formula (I): XS-φ [wherein X represents halogen and φ represents an aromatic group] and a perfluoroolefin in a non-aqueous solvent. Of the general formula [II] Rf-S-φ [II] [wherein Rf is a perfluoroalkyl group and φ is the same as defined above] characterized by reacting with alkali fluoride. It relates to a method for producing sulfide.

In the arylthio halide represented by the general formula [I]: XS-φ in the present invention, X is halogen, particularly chlorine,
Bromine is suitable. The aromatic group φ is phenyl, naphthyl, anthryl or the like which may have a substituent, and the substituent is not particularly limited as long as it does not have active hydrogen such as a hydroxyl group, an amino group and a carboxyl group. is not. Specific examples of the substituent include an alkyl group (methyl, ethyl, propyl, etc.), a halogen (chloro, bromine, iodine, etc.), an alkoxy group (methoxy, ethoxy, etc.) and the like. The present invention can be applied to an arylthiohalide having any substituent to obtain a perfluoroalkylaryl sulfide. The substitution position and the number of the substituents of the compound having the above-mentioned substituents are not limited, but the yield is large when the substituent is large at the o-position with respect to the thio group (for example, one having an alkyl substituent having 3 or more carbon atoms). Is reduced.

As the perfluoroolefin used in the present invention, tetrafluoroethylene or an oligomer thereof, particularly one having a polymerization degree of 5 or less, or hexafluoropropene or an oligomer thereof, particularly one having a polymerization degree of 3 or less is suitable.

In the method of the present invention, a non-aqueous solvent, particularly an aprotic solvent is used as a solvent. Typically, glymes, ethers such as THF, or DMF are suitable. The solvent should always be sufficiently dried.

The alkali fluoride used in the present invention is KF, CsF, NaF or the like.

The amount of alkali fluoride used is appropriately 1 to 2 mol, particularly 1 to 1.5 mol of perfluoroalkene per 1 mol of alkali fluoride.

The reaction between the perfluoroalkene and the aryl thiohalogenide can be carried out at room temperature and atmospheric pressure. The reaction temperature can be room temperature, for example, 20 ° C. or higher, but it is preferable to raise the temperature in order to carry out the reaction at a higher speed, but if it exceeds 100 ° C., a large amount of diphenyl disulfide is by-produced as a side reaction. Therefore, the reaction is preferably carried out in the range of 50 ° C to 60 ° C. The reaction pressure may be normal pressure.

The present invention will be described below with reference to examples.

Example 1 CsF (10 mmol), perfluoro (2-methyl-2-pentene) (15 mmol) and DMF (4 ml) were placed in a three-necked flask equipped with a dropping funnel and a Dimroth condenser, and the temperature was 50 to 60 ° C.
It was stirred for 1 hour. Benzenesulfenyl chloride A DMF solution (4 ml) of (10 mmol) was slowly added dropwise, and after completion of the addition, the mixture was further stirred at 50 to 60 ° C for 12 hours. After adding water to the reaction mixture, the oil layer was recovered and purified by silica gel chromatography to give perfluorohexylphenyl sulfide. 2.2 g (yield 52%) was obtained.

The physical properties of the product are shown in Table 1.

Under these conditions, the by-product diphenyl disulfide Rarely produces.

Column chromatography was performed under the following conditions.

Filler: Silica gel (Wakogel C-200) Column: φ15 mm × 200 mm Developer: Hexane Table 1 Boiling point: 108 ° C / 27 mmHg (Wagel roll) Refractive index: 1.4059 (25 ° C) ¹ H-NMR (CDCl ₃ ) 7.3 to 7.9 ( Phenyl ring H: m) ¹⁹ F-NMR (internal standard CFCl ₃ , solvent, CFCl ₃ ) δ61.1 (6F, q, CF ₃ ), 80.2 (3F, t, CF ₃ ), 104.3 (2F, m,
CF ₂ ), 121.3 (2F, m, CF ₂ ) IR analysis: 1336,1200-1260,1114,964,818,754,734,708cm
^-1 MS analysis (m / e): 476 (M ⁺ ), 157 (M ⁺ -Rf) Example 2 Example 1 except that benzenesulfenyl bromide generated in situ was used instead of benzenesulfenyl chloride. In the same manner, 0.293 g (yield about 17%) of perfluorohexylphenyl sulfide was obtained.

EFFECTS OF THE INVENTION According to the present invention, perfluoroalkylaryl sulfides can be obtained by using perfluoroalkenes, which are relatively inexpensive as perfluorocarbons, at room temperature and atmospheric pressure. This perfluoroalkylaryl sulfide has a low viscosity at low temperature and is useful as a working medium,
Expected as a raw material for medicines and agricultural chemicals.

Claims (7)

[Claims] 1. A compound represented by the general formula (I): XS-φ [I] [wherein, X represents a halogen and φ represents an aromatic group] and a perfluoroolefin in a non-aqueous solvent in a fluorine-containing solvent. A method for producing a perfluoroalkylaryl sulfide represented by the general formula [II] Rf-S-φ [wherein Rf is a perfluoroalkyl group and φ is as defined above], characterized by reacting with an alkali metal halide. 2. The process according to claim 1, wherein Rf is tetrafluoroethylene or an oligomer thereof or hexafluoropropene or an oligomer thereof. 3. The method according to claim 1, wherein Rf is a hexafluoropropene dimer. 4. The method according to claim 3, wherein the non-aqueous solvent is selected from glyme-based solvents, ethers such as THF, and DMF. 5. The method according to claim 1, wherein the alkali fluoride is selected from KF, CsF and NaF. 6. The method according to claim 1, wherein the reaction temperature is 10 to 100 ° C. 7. The method according to claim 1, wherein the reaction is carried out at atmospheric pressure.