JPH09173856A - Organic compound conversion catalyst - Google Patents

Abstract

(57) Abstract: A catalyst composed of bis (perfluoroalkylsulfonyl) imide. [Effect] It is effective for the acid-catalyzed conversion reaction, has high activity, and is effective when used in a small amount. There are few by-products of the waste catalyst, which makes a great contribution to environmental conservation.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a bis (perfluoroalkylsulfonyl) imide catalyst used in the conversion reaction of organic compounds. More particularly, it relates to a bis (perfluoroalkylsulfonyl) imide catalyst represented by the following formula, which is used in an acid-catalyzed conversion reaction of an organic compound.

[0002]

Embedded image (RfSO ₂ ) ₂ NH (wherein Rf is a perfluoroalkyl group having 1 to 8 carbon atoms).

[0003]

2. Description of the Related Art Conventionally, Friedel-Crafts catalysts such as aluminum chloride, iron chloride and tin chloride have been used as acid catalysts used for the conversion reaction of organic compounds, and general mineral acids such as sulfuric acid and phosphoric acid and solid acids. Well-known are silica-alumina and zeolite. Further, aluminum chloride and iron chloride are used industrially for alkylating and acylating aromatic hydrocarbons. However, these catalysts do not show sufficient activity, particularly aluminum chloride and the like used in the acylation reaction require a catalyst amount of equimolar amount or more of the reaction product, and it is difficult to reuse the catalyst,
It has a big environmental problem such as the generation of a large amount of waste catalyst.

[0004]

An object of the present invention is to provide a catalyst which is widely and effectively used as an acid catalyst useful for conversion of organic compounds and which is environmentally friendly.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that bis (perfluoroalkylsulfonyl) imide is extremely effective as an acid catalyst for the conversion reaction of organic substances in the liquid phase. . In particular, the inventors have found that the catalyst has an extremely high activity and is effective as an acylation reaction catalyst, which has many problems in the past, and completed the present invention.

Hereinafter, the present invention will be described in detail. Bis (perfluoroalkylsulfonyl) imide, which is the catalyst of the present invention, has recently been used as an intermediate raw material for fluorinating agents for organic compounds.
Alternatively, it has been reported to be used as an electrolyte of a fuel cell, but its use as a catalyst is not known.

The perfluoroalkylsulfonylimide of the present invention is a compound represented by the following formula, and specific examples thereof include a trifluoromethanesulfonyl group, a pentafluoroethanesulfonyl group, a heptafluoropropanesulfonyl group and a nonafluorobutanesulfonyl group. , Undecafluoropentanesulfonyl group, tridecafluorohexanesulfonyl group, pentadecafluoroheptanesulfonyl group, heptadecafluorooctanesulfonyl group and the same or different perfluoroalkyl group-substituted bissulfonylimide can be mentioned. .

[0008]

Embedded image (RfSO ₂ ) ₂ NH (wherein Rf is a perfluoroalkyl group having 1 to 8 carbon atoms)

A method for synthesizing the catalyst of the present invention will be described below, but the method is not limited thereto. The catalyst of the present invention is converted to a bis (perfluoroalkylsulfonyl) imide alkali metal salt by the reaction (1) of a perfluoroalkylsulfonyl halide with an alkali metal-bis (trimethylsilyl) amide, and then the alkali salt is converted to a hydrogen acid type such as a strongly acidic ion exchange resin. It can be synthesized by treating (2) with a solid acid or concentrated sulfuric acid.

As specific reaction conditions, (1) the reaction is usually carried out by using an excess amount of sulfonyl halogenide with respect to the silylimide, and the reaction temperature is from -10 ° C to 130 ° C, 10-
React for 120 hours. Furthermore, it is preferable to control the reaction temperature at -10 ° C to room temperature in the first stage and 80 to 130 ° C in the second stage. (2) When the reaction is carried out with concentrated sulfuric acid, the reaction is carried out under an excessive amount of sulfuric acid at a reaction temperature of 0 ° C to 100 ° C for 1 to 10 hours, and when carried out by ion exchange, a column packed with an ion exchanger is used. Usually at room temperature 0.5 to 5 cc / cm ² / m
It can be converted to an imide by ion exchange treatment at a flow rate of about in.

[0011]

Embedded image (However, X is a halogen atom and M is an alkali metal atom.)

The acid-catalyzed conversion reaction of organic compounds includes, for example, Friedel-Crafts reaction, Diels-Alder reaction, isomerization, disproportionation, hydration of olefins, dehydration reaction of alcohols, O-glycosidation, etc. The dehydration condensation reaction, polycondensation reaction, etc. The Friedel-Crafts reaction includes alkylation, acylation, transalkylation, haloalkylation, cycloalkylation, Guttermann aldehyde synthesis, sulfonylation, sulfonation, nitration, halogenation, and the like. Examples of the polycondensation reaction include polymerization of olefins, polyketone synthesis using diacyl halide, and polyoxymethylene synthesis reaction. In particular, the catalyst of the present invention has a high activity and a small amount of the catalyst used as compared with aluminum chloride, which has been conventionally used in the Friedel-Crafts reaction, and the aromatic acylation reaction and the like proceed under mild conditions.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. The infrared spectrum in the examples is made by Perkin Elma,
Using a 1600 type infrared spectrophotometer, NMR data was measured using a JEOL JNN-EX400 type nuclear magnetic resonance apparatus.

Reference Example 1: Preparation of catalyst. Synthesis of bis (trifluoromethanesulfonyl) imide lithium salt Lithium bis (trimethylsilyl) amide / THF solution (Aldrich 1mo) in a 500 ml three-necked flask.
(1 solution) (200 ml) and stirred under ice cooling while stirring trifluoromethanesulfonyl chloride (manufactured by Tokyo Kasei) 6
After gradually adding 7.4 g, the temperature was raised to room temperature for reaction. After completion of the reaction, the reaction solution is filtered, and the filtrate is dried up by a rotary evaporator (40-70 ° C / 15mmH
g), followed by vacuum drying at 120 ° C for 6 hours and then ethanol 50
Add 0 ml, stir at 78 ° C. for 1 hour, then filter,
The filtrate was dried up and vacuum dried at 120 ° C. for 6 hours to obtain 37 g of white powdery bis (trifluoromethanesulfonyl) imide lithium salt. Yield 64
It was mol%.

[0015] Imidization of imide lithium salt 30 g of bis (trifluoromethanesulfonyl) imide lithium salt synthesized in a 200 ml three-necked flask and 36 g of 35% sulfuric acid were put, set in an oil bath with a stirrer, and heated to 60 ° C. with stirring. And reacted for 6.5 hours. After the reaction was completed, the reaction solution was cooled and then extracted twice with 100 ml of diethyl ether each time.

Ether was removed from the ether extraction layer using an evaporator (95 mmHg, 40 ° C., 30 minutes), and then volatile matter was sufficiently removed for 2 hours at 30 ° C., 3 mmHg using a vacuum dryer. As a result, 26.6 g of colorless was obtained. A liquid product of was obtained. The yield was about 90 mol%. As a result of recrystallization purification using fluorotrichloromethane at -50 ° C, 1
8.3 g of white powder product was obtained. The purification yield was about 70%.

The infrared absorption spectrum of the synthesized bis (trifluoromethanesulfonyl) imide was 3508 cm ^-1.
(Caused by N-H), 1197 cm ^-1 (caused by C-F), 13
Absorption peaks were observed at 38, 1140, 1060 cm ^-1 (due to SO ₂ group). Further, in the ¹⁹ F-NMR spectrum (CF ₃ COOH standard), CF ₃ was found to be -80.6 ppm.
An absorption peak attributed to fluorine was observed. ¹ H-
In the NMR spectrum (TMS standard), an absorption peak attributed to the NH proton was observed at 10.8 ppm.

Reference Example 2: Synthesis of bis (perfluorobutanesulfonyl) imide. Synthesis of N-trimethylsilylperfluorobutanesulfonylamide Na salt (A) After replacing with nitrogen in a 300 ml beaker equipped with a dropping funnel, 36.2 g of perfluorobutanesulfonyl fluoride (120 g) was added.
(60 mmol), and stirred and ice-cooled, 60 ml of a 1 molar solution of bis (trimethylsilyl) amide sodium salt in tetrahydrofuran was added dropwise over 30 minutes, and the mixture was reacted for 3 hours under ice-cooling and then overnight at room temperature. Unreacted nonafluorobutanesulfonyl fluoride, THF solvent and the like were removed from the reaction solution under reduced pressure (60 ° C., 30 mmHg-> 1 mmHg) to obtain crude N-trimethylsilylperfluorobutanesulfonylamide sodium salt (A).

[0019] Synthesis of bis (perfluorobutanesulfonyl) imide Na salt (B) Next, 27 g (90 mmol) of this A and perfluorobutanesulfonyl fluoride and 35 ml of dioxane were put in a nitrogen atmosphere in a 200 ml autoclave (containing Teflon inner cylinder). Charge to 120 ° C with stirring,
The reaction was performed for 8 hours. Unreacted perfluorobutanesulfonyl fluoride, dioxane solvent and the like were removed from this reaction solution under reduced pressure (80 ° C., 40 mmHg-> 1 mmHg) to obtain 25 g of a light brown solid (B). The yield was 69 mol%. Infrared absorption spectrum of solid (B) is 1358 cm
^-1, 1140 cm ^-1, absorption peaks attributable to an SO ₂ group were observed near 1083cm ^-1.

[0020] Conversion to bis (perfluorobutanesulfonyl) imide (C) 10 g of this solid B was dissolved in 500 ml of water to give a strongly acidic ion exchange resin (Amberlite IR-120B) 20.
The resulting solution was passed through an ion-exchange column (20 mmφ glass column) packed with 100 ml of water to obtain a crude imide aqueous solution. P of this effluent
H showed 2.4. This aqueous solution was heated at a water bath temperature of 80 ° C. and 160 mmHg using a rotary evaporator.
The water was distilled off under reduced pressure of 6 OmmHg to obtain 8.6 g of a light brown solid (C). When 0.1 g of C was used as an aqueous solution and titrated with an aqueous 0.1 N sodium hydroxide solution, the strong acid component was 1.7 × 10 ^-1 meq.

[0021] High Purity Purification Solid C was treated with a vacuum dryer at 60 ° C. under 1 mmHg for 1 hour and then under high vacuum (105 ° C., 6 × 10 ⁻² m
mHg) to obtain white crystals. The infrared absorption spectrum of this crystal shows 1358 cm ^-1 , 1140 cm ^-1 ,
An absorption peak due to the SO ₂ group was observed around 1083 cm ⁻¹ . H-N of deuterated dioxane solution of this crystal
MR measurement result shows a chemical shift to the high frequency side of 12.8.
Absorption attributed to the imide proton was observed in ppm (TMS standard). Also, ¹⁹ F-NMR measurement results, -4.
_{9ppm (CF 3), - 37.8ppm} (3 -position of the C
F ₂ ), -45 ppm (CF _{2 at the} 2nd position), -49.9 p
An absorption peak of F was confirmed in pm (CF _{2 at the} 1st position).
(CFCl ₃ standard)

Reference Example 3: Synthesis of bis (perfluorooctanesulfonyl) imide. Synthesis of N-trimethylsilylperfluorooctanesulfonylamide Na salt (A) Instead of perfluorobutanesulfonyl fluoride, 40 g of perfluorooctanesulfonyl fluoride (80 mmo
In the same manner as in Example 1 except that 1) was used, 30 ml of a 1 molar solution of bis (trimethylsilyl) amide sodium salt in tetrahydrofuran was added dropwise over 30 minutes with stirring and ice cooling, and the mixture was cooled with ice for 3 hours and then at room temperature. The reaction was performed overnight. Unreacted perfluorooctanesulfonyl fluoride, THF solvent, and the like from the reaction solution under reduced pressure (60 ° C., 30 mmHg-
> 1 mmHg) to remove crude N-trimethylsilylperfluorooctanesulfonylamide sodium salt (A)
I got

[0023] Synthesis of bis (perfluorooctanesulfonyl) imide Na salt (B) Next, 20 g (40 mmol) of this A and perfluorononanesulfonyl fluoride and 25 ml of dioxane were put into a 200 ml autoclave (in a Teflon inner cylinder) under a nitrogen atmosphere using a dry box. Charge to 120 ° C with stirring,
The reaction was performed for 8 hours. Unreacted perfluorooctanesulfonyl fluoride, dioxane solvent and the like were removed from this reaction solution under reduced pressure (80 ° C., 40 mmHg-> 1 mmHg) to obtain 21 g of a light brown solid (B). The yield was 70 mol%. The infrared absorption spectrum of this solid shows 1343c
An absorption peak due to the SO ₂ group was observed near m ⁻¹ , 1150 cm ⁻¹ .

[0024] Conversion to bis (perfluorooctanesulfonyl) imide (C) 5 g of this solid B was added to 150 ml of water and 150 m of ethanol.
1c of a mixed solvent and placed in an ion exchange column (20 mmφ glass column) filled with 20 ml of a hydrogen type strongly acidic ion exchange resin (Amberlite IR-120B).
An aqueous solution of crude imide was obtained by flowing at a rate of c / min. The pH of this effluent was 2.0. This aqueous solution was placed on a rotary evaporator at a water bath temperature of 80 ° C, 16
The solvent was distilled off under reduced pressure of 0 mmHg to 60 mmHg,
Then, it was vacuum dried at 80 ° C. under 1 mmHg to obtain 2.4 g of a light brown solid (C).

An inflection point of an aqueous solution prepared by dissolving 54 mg of C in 10 ml of distilled water with an aqueous solution of 0.01N caustic soda is based on a strong acid, and only one point is found.
It was c. In addition, the solid C was added to the deuterated acetone solvent in ¹
As a result of 1 H-NMR and ¹⁹ F-NMR measurements, 10.5
ppm peak corresponding to protons of (TMS basis) _{imide, -4.9ppm (CF 3), -} 36.9ppm
(1st place CF ₂ ), from -43.7 to TO-46.5 pp
m (CF _{2 at} position 2-6), -50 ppm (C at position 7
An absorption peak attributed to F ₂ ) was observed. (CFCl
₃ standards)

[0026]

EXAMPLES In the examples, Shimadzu Corporation GC-7A was used as the gas chromatograph, and silicon DC-550 was used as the FID detection and column packing material.

Example 1 Acylation Reaction Using the bis (trifluoromethanesulfonyl) imide synthesized in Reference Example 1 as a catalyst, an acetylation reaction of anisole with acetic anhydride was carried out. 3.16 g of anisole and acetic anhydride in a 50 ml three-necked flask equipped with a cooling tube.
12 g and 20 ml of acetonitrile as a solvent were added, and the mixture was placed in an oil bath equipped with a stirrer. When the oil bath was heated to reach a predetermined temperature (70 ° C.), 20 mol% of the catalyst was added to anisole to carry out an acetylation reaction. The reaction solution at the reaction temperature of 70 ° C. for 2 hours was analyzed using a gas chromatograph. As a result, the conversion of anisole was 95% and the selectivity of methoxyacetophenone was 98% (based on anisole).

Example 2 The reaction was carried out under the same conditions as in Example 1 except that the reaction conditions were 70 ° C. and the catalyst ratio was 2 mol%. As a result of the 1-hour reaction, the conversion of anisole was 54% and the selectivity was 100%.

Example 3 The reaction was carried out under the same conditions as in Example 1 except that the reaction conditions were 30 ° C. and the catalyst ratio was 5 mol%. As a result of the 1-hour reaction, the conversion of anisole was 44% and the selectivity was 100%.

Example 4 The reaction was carried out in the same manner as in Example 1 except that the bis (perfluorobutanesulfonyl) imide synthesized in Reference Example 2 was used as a catalyst, the reaction temperature was 30 ° C., and the catalyst ratio was 5 mol%. 1
As a result of the time reaction, the conversion rate of anisole is 42 and the selectivity is 1.
00%.

Example 5 The reaction was carried out in the same manner as in Example 1 except that the bis (perfluorobutanesulfonyl) imide synthesized in Reference Example 2 was used as a catalyst, the reaction temperature was 70 ° C., and the catalyst ratio was 5 mol%. 1
As a result of the time reaction, the conversion of anisole was 62% and the selectivity was 99%.

Example 6 Using the bis (perfluorooctanesulfonyl) imide synthesized in Reference Example 3 as a catalyst, the reaction temperature was 30 ° C., and the catalyst ratio was 5 mo%. 1
As a result of the time reaction, the conversion of anisole was 43% and the selectivity was 99%.

Example 7 The reaction was carried out in the same manner as in Example 1 except that the bis (perfluorooctanesulfonyl) imide synthesized in Reference Example 3 was used as the catalyst, the reaction temperature was 70 ° C., and the catalyst ratio was 5 mo%. 1
As a result of the time reaction, the conversion of anisole was 60% and the selectivity was 99%.

Example 8 Using the bis (perfluorobutanesulfonyl) imide synthesized in Reference Example 2 as a catalyst, acetylation reaction of anisole with acetic acid was performed. The reaction was carried out in the same manner as in Example 1 except that acetic anhydride was replaced by 2.4 g of acetic acid, the reaction temperature was 70 ° C., and the catalyst ratio was 20 mol%. As a result of the 1-hour reaction, the conversion of anisole was 20% and the selectivity of methoxyacetophenone was 99% (based on anisole).

Comparative Example 1 The reaction was carried out under the same conditions as in Example 1 except that 20 mol% of anhydrous aluminum chloride conventionally used as a catalyst was used. The conversion rate of anisole at a reaction temperature of 70 ° C. and a reaction time of 2 hours was less than 1%, which was a very low conversion rate.

Comparative Example 2 The reaction was carried out under the same conditions as in Comparative Example 1 except that the addition amount of the catalyst was equimolar to that of anisole. When the reaction temperature is 70 ° C and the reaction time is 2 hours, the conversion rate of anisole is 60% and the selectivity is 9
8%.

[0037]

EFFECT OF THE INVENTION It is an extremely highly active catalyst and is effective even when used in a small amount. Furthermore, there are few by-products of the waste catalyst, which contributes significantly to environmental protection.

Claims (2)

[Claims] 1. A bis (perfluoroalkylsulfonyl) represented by the following formula, which is used in an acid-catalyzed conversion reaction of an organic compound.
Imide catalyst. Embedded image (RfSO ₂ ) ₂ NH (wherein Rf is a perfluoroalkyl group having 1 to 8 carbon atoms). 2. The bis (perfluoroalkylsulfonyl) imide catalyst according to claim 1, wherein the acid-catalyzed conversion reaction is a Friedel-Crafts reaction.