JPH07316127A - Production of 2,2,4,6,6-pentamethylheptane-4-thiol - Google Patents

Abstract

PURPOSE:To obtain 2,2,4,6,6-pentamethylheptane-4-thiol in high purity and yield by using recovered triisobutylene having poor reactivity. CONSTITUTION:Isobutylene of formula I or a mixture of triisobutylenes of formulas I and II having a component ratio of (formula I/formula II) of >=1 is reacted with hydrogen sulfide in the presence of a boron trifluoride complex with an carboxylic acid or in the coexistence of a Lewis acid and a protonic acid at 2-30atm, especially at 3-15atm and -100 to +50 deg.C, especially -40 to +10 deg.C to produce 2,2,4,6,6-pentamethylheptane-4-thiol of formula III. It is especially preferable to use 0.01-0.5mol of boron trifluoride complex with a carboxylic acid, and 0.01-0.5mol of Lewis acid and 0.005-0.5mol of protonic acid in the cocatalyst system. The yield of the objective compound can be improved by contacting the reaction liquid with a reaction stopper after the reaction to stop the reaction.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing 2,2,4,6,6-pentamethylheptane-4-thiol.

[0002]

2. Description of the Related Art 2, 2, 4, represented by the following formula (3)
6,6-Pentamethylheptane-4-thiol has been favored as a chain transfer agent in emulsion polymerization.

[Chemical 5]

As a method for producing such 2,2,4,6,6-pentamethylheptane-4-thiol, for example, triisobutylene and hydrogen sulfide are combined with boron trifluoride phosphate complex or boron trifluoride diethyl ether complex. Of reacting in the presence of a Lewis acid catalyst (Neftechimiya,
Vol. 2, No. 5, pp. 735-738, 1962
A method of continuously reacting triisobutylene and hydrogen sulfide in the presence of a boron trifluoride phosphate complex in the presence of a Lewis acid catalyst (US Pat. No. 2,426,647) and the like.

[0004]

DISCLOSURE OF THE INVENTION The inventors of the present invention studied the above method and found that unreacted triisobutylene remained in a large amount of 20 to 80% after the completion of the reaction, and the triisobutylene had the above formula (1) and Among the isomers of the formula (2), the component (1) is biased, and the use of the recovered triisobutylene containing a large amount of the component (1) is not preferable because the yield of the target substance is significantly decreased. understood.

The inventors of the present invention have made extensive studies using recovered triisobutylene containing a large amount of the component of the formula (1). As a result, the carboxylic acid complex of boron trifluoride is used as the acid catalyst, or trifluoride is used. It was found that the target product can be obtained in a high yield even if a raw material containing a large amount of the formula (1) is used by using a Lewis acid such as various boron complexes in combination with a protonic acid, and the present invention has been completed. .

[0006]

According to the present invention, the formula (1) is thus obtained.

[Chemical 6] Triisobutylene represented by:

[Chemical 7] A triisobutylene mixture represented by the formula (1) / (2) of triisobutylene represented by the formula (1) is reacted with hydrogen sulfide in the presence of a carboxylic acid complex of boron trifluoride. Method for producing 2,4,6,6-pentamethylheptane-4-thiol, and formula (1)

[Chemical 8] Triisobutylene represented by:

[Chemical 9] A triisobutylene mixture represented by the formula (1) / (2) of triisobutylene represented by the formula (1) is reacted with hydrogen sulfide in the presence of a Lewis acid and a protic acid. A method of making 4,6,6-pentamethylheptane-4-thiol is provided.

The composition ratios of the above formulas (1) and (2), which are isomers of triisobutylene, can be determined by analysis by gas chromatography or hydrogen nuclear magnetic resonance spectrum. For example, in the case of analysis by hydrogen nuclear magnetic resonance spectrum, it can be determined by quantifying the vinyl proton signal of each triisobutylene.

In the present invention, the triisobutylene of the formula (1) is used alone or the component ratio of the formula (1) / formula (2) is 1 or more, further 1.2 or more, and particularly 1.5 or more. 1)
And a triisobutylene mixture of formula (2) is used. The triisobutylene containing a large amount of the component of the formula (1) can be obtained by recovering or distilling the unreacted raw material of the reaction.

As the acid catalyst used in the present invention, a carboxylic acid complex of boron trifluoride or a Lewis acid and a protic acid are used in combination.

Examples of the carboxylic acid complex of boron trifluoride used in the present invention include acetic acid, propionic acid, butyric acid,
Examples thereof include carboxylic acid complexes such as valeric acid, and acetic acid complexes and propionic acid complexes are preferred. These are used alone or in combination of two or more, and the amount used is
Usually, 0.001-5 relative to 1 mol of triisobutylene
The molar amount is preferably 0.005 to 1 mol, and more preferably 0.01 to 0.5 mol.

The Lewis acid used in the combined system of the present invention is one that is used in ordinary olefin addition reaction, for example, boron trifluoride; various complexes of boron trifluoride;
Examples thereof include fluoroboric acid ether complexes; aluminum halides; and alkyl-substituted aluminum halides.

Concretely, various complexes of boron trifluoride include phosphoric acid complexes; dimethyl ether, diethyl ether, dinormal propyl ether, diisopropyl ether, dinormal butyl ether, methyl ethyl ether, methyl tertiary butyl ether, dipentyl ether. , Ether complexes such as anisole and phenetole; nitrile complexes such as acetonitrile, propionitrile and benzonitrile; ketone complexes such as acetone, methyl ethyl ketone, diethyl ketone, acetophenone and acetylacetone; aldehyde complexes such as trimethylacetaldehyde and benzaldehyde; acetamide,
Amide complexes such as N-phenylacetamide; amine oxide complexes such as trimethylamine oxide; phosphine oxide complexes such as trimethylphosphine oxide;
Examples thereof include ester complexes such as methyl acetate, ethyl acetate, butyl acetate and ethyl propionate; complexes derived from carboxylic acid anhydrides such as acetic anhydride, propionic anhydride and butyric anhydride, and the above carboxylic acid complexes. Examples of the ether complex of fluoroboric acid include ether complexes such as dimethyl ether, diethyl ether, dinormal propyl ether, dinormal butyl ether, anisole and phenetole. Examples of the aluminum halide compound include aluminum iodide, aluminum fluoride, aluminum bromide, aluminum chloride and the like. Examples of alkyl-substituted aluminum halide compounds include diethyl aluminum chloride and ethyl aluminum dichloride.

The above Lewis acids may be used alone or in combination of two or more, and the amount thereof used is usually 0.001 to 5 mol, preferably 0.1% to 1 mol of triisobutylene.
The amount is 005 to 1 mol, and more preferably 0.01 to 0.5 mol.

The protonic acid used in the combination system of the present invention is not particularly limited as long as it is a Bronsted acid capable of releasing free protons, and examples thereof include organic acids, inorganic acids and acidic ion exchange resins. Used. Examples of the organic acid include benzenesulfonic acid, monofluoroacetic acid, difluoroacetic acid, trifluoroacetic acid, trifluoromethanesulfonic acid and the like. Examples of the inorganic acid include hydrogen chloride, sulfuric acid, perchloric acid, phosphoric acid and the like. Examples of the acidic ion exchange resin include sulfonic acid type ion exchange resin, phenolsulfonic acid type ion exchange resin, perfluorinated ion exchange resin and the like. Among these protic acids, preferred are inorganic acids, and particularly preferred are phosphoric acid and sulfuric acid.

The amount of the protic acid used is usually 0.0005 to 5 mol, preferably 0.001 to 1 mol, and more preferably 0.005 to 1 mol of triisobutylene.
It is in the range of 0.5 mol. In the case of an acidic ion exchange resin, it is used so that the acid point falls within this range.

The amount of hydrogen sulfide used in the present invention is
The amount is usually equimolar or more, preferably 1 to 30 mol, and more preferably 2 to 10 mol with respect to 1 mol of triisobutylene.

A solvent may be present in the reaction. The solvent is not particularly limited as long as it is inert to the reaction, and examples thereof include aliphatic hydrocarbons such as n-pentane and n-hexane, alicyclic hydrocarbons such as cyclopentane and cyclohexane, benzene and toluene. Examples thereof include aromatic hydrocarbons such as and halogenated hydrocarbons such as dichloromethane and dichloroethane.

The reaction method in the present invention is not particularly limited, but it is usually carried out in an autoclave with stirring. The reaction pressure varies depending on the reaction temperature and the type of solvent, but is usually in the range of 2 to 30 atm, preferably 2 to 20 atm, more preferably 3 to 15 atm. The reaction temperature is generally -100 to + 50 ° C, preferably -60 to +
It is in the range of 20 ° C, preferably -40 to + 10 ° C. If the reaction temperature is excessively high, the yield of the desired product will decrease, and if it is excessively low, the reaction will proceed extremely slowly, which is not preferable. The reaction time is generally 10 minutes to 20 hours, preferably 30 minutes to 10 hours.

After the completion of the reaction, the treatment can be carried out by a conventional method. After the above reaction, the reaction product is brought into contact with a reaction terminator to terminate the reaction to obtain the desired product in a higher yield. You can When contacting the reaction terminator, it is preferable to contact the reaction terminator with the reaction solution before returning to normal pressure. As a method of bringing the reaction solution into contact with the reaction terminator before returning to normal pressure, after the reaction is completed, a method of adding the reaction terminator to the reaction solution under the same reaction pressure, a reaction pressure or a pressure lower than that is set. Examples thereof include a method of adding a reaction solution to a reaction terminator. When the reaction solution is brought into contact with the reaction terminator after returning to normal pressure, it is important to make the contact as quickly and as promptly as possible in order to minimize the decrease in yield.

The reaction terminator used in the present invention is
There is no particular limitation as long as it can significantly reduce or deactivate the activity of the acid catalyst used, and examples thereof include alkalis, alcohols and water.

Specifically, examples of the alkalis include amines such as ethylamine, diethylamine, triethylamine, benzylamine, aniline and ethylenediamine; sodium carbonate, potassium carbonate, lithium carbonate, magnesium carbonate, calcium carbonate, barium carbonate and the like. Carbonates; sodium hydrogencarbonates, potassium hydrogencarbonates, etc .; sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, magnesium hydroxide, etc. hydroxides; sodium hydride, potassium hydride, etc. Examples thereof include hydrides; ammonia, etc., and these alkalis may be used in the state of an aqueous solution. When the carbonate or hydrogen carbonate is used as a solid, it is preferably used in a finely crushed state. Examples of alcohols include methanol, ethanol, normal propanol, isopropanol, benzyl alcohol, ethylene glycol and the like. Examples of water include water alone or water dissolved in an inert solvent such as water-containing tetrahydrofuran or water-containing dioxane.

Among the above reaction terminators, preferred are carbonates, hydrogencarbonates, hydroxides, hydrides, inorganic alkalis such as ammonia, or aqueous solutions thereof, water, etc., and particularly preferred are carbonates. Examples thereof include salt, hydrogen carbonate, an aqueous solution thereof, water and the like.

The amount of the reaction terminator used is usually 1 equivalent or more with respect to 1 equivalent of the acid of the acid catalyst, and the preferable range varies depending on the kind of the terminator. For example, alcohols, amines, carbonates, hydrogen carbonates, hydroxides and the like are 1 to 10 equivalents, hydrides are 1 to 1.1 equivalents, and water is 1 to 100 equivalents.

From the reaction solution, the desired product, 2, 2, 4, 6,
As a method for isolating 6-pentamethylheptane-4-thiol, for example, after removing the residual hydrogen sulfide from the reaction solution to the outside of the system, the reaction terminator layer is subjected to solid-liquid separation, or the organic layer-
A method of separating the organic layer by separating the aqueous layer and distilling it under reduced pressure can be mentioned.

The preferred embodiments of the present invention are shown below. Expression (1)

[Chemical 10] Triisobutylene represented by:

[Chemical 11] A triisobutylene mixture represented by the formula (1) / (2) of triisobutylene represented by the formula (1) is reacted with hydrogen sulfide in the presence of a carboxylic acid complex of boron trifluoride. A method for producing 2,4,6,6-pentamethylheptane-4-thiol. (2) The carboxylic acid complex of boron trifluoride is at least one selected from acetic acid complex, propionic acid complex, butyric acid complex, and valerian complex. (3) The carboxylic acid complex of boron trifluoride is an acetic acid complex or a propionic acid complex. (4) The amount of the boron trifluoride carboxylic acid complex used is 0.001 to 5 mol, preferably 0.005 to 1 mol, and more preferably 0.01 to 1 mol based on 1 mol of triisobutylene.
It is in the range of 0.5 mol. Expression (1)

[Chemical 12] Triisobutylene represented by:

[Chemical 13] A triisobutylene mixture represented by the formula (1) / (2) of triisobutylene represented by the formula (1) is reacted with hydrogen sulfide in the presence of a Lewis acid and a protic acid. A method for producing 4,6,6-pentamethylheptane-4-thiol. (6) The Lewis acid is at least one selected from boron trifluoride, various boron trifluoride complexes, fluoroboric acid ether complexes, aluminum halide compounds, and alkyl-substituted aluminum halide compounds. (7) Various complexes of boron trifluoride include phosphoric acid complexes, ether complexes, nitrile complexes, ketone complexes, aldehyde complexes,
It is at least one selected from an amide complex, an amine oxide complex, a phosphine oxide complex, an ester complex, a complex derived from a carboxylic acid anhydride, and a carboxylic acid complex. (8) The amount of Lewis acid used is in the range of 0.001 to 5 mol, preferably 0.005 to 1 mol, and more preferably 0.01 to 0.5 mol, based on 1 mol of triisobutylene. (9) The protonic acid is at least one selected from organic acids, inorganic acids and acidic ion exchange resins. (10) The protic acid is an inorganic acid. (11) The inorganic acid is at least one selected from sulfuric acid, hydrogen chloride, perchloric acid and phosphoric acid. (12) The inorganic acid is phosphoric acid or sulfuric acid. (13) The amount of protonic acid catalyst used is triisobutylene 1
0.0005 to 5 mol, preferably 0.1.
001 to 1 mol, more preferably 0.005 to 0.5
It is in the molar range. (14) The component ratio of triisobutylene of formula (1) / formula (2) is 1.2 or more, and particularly 1.5 or more. (15) The amount of hydrogen sulfide used is equal to or more than 1 mol of triisobutylene, preferably 1 to 30 mol, and more preferably 2 to 10 mol. (16) Reaction pressure is 2 to 30 atm, preferably 2 to 20
Atmospheric pressure, more preferably in the range of 3 to 15 atmospheric pressure. (17) Reaction temperature is −100 to + 50 ° C., preferably −
It is in the range of 60 to + 20 ° C, preferably -40 to + 10 ° C. (18) Reaction time is 10 minutes to 20 hours, preferably 30
Minutes to 10 hours. (19) After completion of the reaction, the reaction solution and the reaction terminator are contacted with each other. (20) The reaction terminator is at least one selected from alkalis, alcohols and water. (21) The reaction terminator is carbonate, hydrogen carbonate, hydroxide,
It is a hydride, an inorganic alkali such as ammonia, an aqueous solution thereof, or water. (22) The amount of the reaction terminator used is 1 equivalent or more per 1 equivalent of the acid of the acid catalyst. (23) The reaction solution comes into contact with the reaction solution before the reaction solution returns to normal pressure.

Thus, according to the present invention, the above formula (1)
Even if triisobutylene containing many components is used, the desired 2,2,4,6,6-pentamethylheptane-4-thiol can be obtained in good yield and purity.

[0027]

EXAMPLES The present invention will be described in more detail with reference to the following examples. Unless otherwise specified, the parts and% in the examples and comparative examples are based on the weight of the reaction reagents and the yield is based on the moles of triisobutylene. The yield, purity, and triisobutylene isomer composition ratio of the target product are
Gas chromatography analysis was performed under the following measurement conditions to calculate. (Apparatus: Shimadzu GC-14B, column: GL Science TC-1701 glass capillary 0.
25 mmI. D. × 30 m (df = 0.1 μm), carrier gas; helium 1.0 ml / min, column temperature 1
00 → 200 ° C (temperature rise 5 ° C / min), detector; FI
D).

Example 1 (1) Triisobutylene (P0 manufactured by Tokyo Chemical Industry Co., Ltd.
456-FHB01; formula (1) / formula (2) component ratio = 0.
89) 77 g, hydrogen sulfide 103 g, and boron trifluoride diethyl ether complex 5.6 ml were reacted in an autoclave under stirring at 5 atm and -20 ° C for 6 hours. After the completion of the reaction, 73 ml of a 10% aqueous solution of sodium carbonate was added, the hydrogen sulfide was depressurized, washed with a 10% aqueous sodium carbonate solution until it became alkaline, and then distilled under reduced pressure to recover 26 g of triisobutylene.

(2) Recovered triisobutylene (formula (1) / formula (2) component ratio = 1.86) 7.7 g, hydrogen sulfide 10.3 g, boron trifluoride diethyl ether complex 0.56 ml And 0.49 ml of concentrated sulfuric acid in an autoclave with stirring at 10 atm and -20 ° C.
After 6 hours of reaction and post-treatment according to (1) above, the reaction product was analyzed and the yield of 2,2,4,6,6-pentamethylheptane-4-thiol was 61%. .
The residual rate of triisobutylene as a raw material was 34%. No formation of mercaptans having 4 or 8 carbon atoms or polymers was observed.

Example 2 The reaction product was analyzed in the same manner as in (2) of Example 1 except that 224 mg of phosphoric acid was used instead of concentrated sulfuric acid. The yield of -pentamethylheptane-4-thiol was 61%. The residual rate of triisobutylene as a raw material was 34%.

Example 3 The same operation as in (2) of Example 1 was repeated except that 4.7 ml of a hexane solution containing 1 mol of diethylaluminum chloride was used in place of the boron trifluoride diethyl ether complex, The reaction product was analyzed and found to be 2,2,4,6,6-pentamethylheptane-4
-The yield of thiol was 61%. The residual rate of triisobutylene as a raw material was 33%.

Comparative Example 1 The procedure of (2) of Example 1 was repeated, except that only boron trifluoride diethyl ether complex was used as the acid catalyst and concentrated sulfuric acid was not used. When the reaction product was analyzed,
The content of 2,4,6,6-pentamethylheptane-4-thiol was 30% and the content of unreacted raw material triisobutylene was 68%.

EXAMPLE 4 Boron trifluoride acetic acid complex (BF ₃ .2AcOH) 0.1 was used as the acid catalyst instead of the boron trifluoride diethyl ether complex.
The same operation as in Comparative Example 1 was performed using only 3 ml.
When the reaction products were analyzed, 2,2,4,6,6-pentamethylpeptane-4-thiol was 57% and unreacted raw material triisobutylene was 40%.

Example 5 The same as (2) of Example 1 except that 7.7 g of triisobutylene adjusted so that the component ratio of the formula (1) / the formula (2) was 2.33 by distillation was used. To the operation. The reaction products were analyzed and found to be 2, 2, 4, 6,
The yield of 6-pentamethylheptane-4-thiol is 56.
%Met. Residual rate of raw material triisobutylene is 40%
Met.

Claims (2)

[Claims] 1. Formula (1): Triisobutylene represented by the following formulas alone or in formulas (1) and (2) A triisobutylene mixture represented by the formula (1) / (2) of triisobutylene represented by the formula (1) is reacted with hydrogen sulfide in the presence of a carboxylic acid complex of boron trifluoride. A method for producing 2,4,6,6-pentamethylheptane-4-thiol. 2. Formula (1): Triisobutylene represented by the following formulas alone or in formulas (1) and (2) A triisobutylene mixture represented by the formula (1) / (2) of triisobutylene represented by the formula (1) is reacted with hydrogen sulfide in the presence of a Lewis acid and a protic acid. A method for producing 4,6,6-pentamethylheptane-4-thiol.