JP2003055386A - METHOD FOR PRODUCING 1,3-DI-tert-BUTYL-1,1,3,3- TETRAHYDROXYDISILOXANE - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for obtaining 1,3-di-tert-butyl-1,1,3,3- tetrahydroxydisiloxane in high yield. SOLUTION: Tert-Butyltrichlorosilane is hydrolyzed in a two-phase system unreactive and incompatible with 1,3-di-tert-butyl-1,1,3,3-tetrahydroxydisiloxane and comprising a water-insoluble organic solvent and water. A water-soluble organic solvent and a basifying agent are not contained in the two-phase system.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to 1,3-di-ter.
It relates to a method for obtaining t-butyl 1,1,3,3-tetrahydroxydisiloxane (= [t-BuSi (OH) ₂ ] ₂ O) in high yield. 1,3-di-t thus obtained
ert-Butyl 1,1,3,3-tetrahydroxydisiloxane is expected to be used as a raw material for a siloxane polymer having a highly ordered structure.

[0002]

2. Description of the Related Art Si-C of trichlorosilane having a tert-butyl group (ie, t-BuSi (Cl) ₃ )
The l bond is easily converted into a Si—OH group (silanol group) by hydrolysis. Tert-Butyltrihydroxysilane (ie, t-
BuSi (OH) ₃ ) has been isolated as a stable compound. This is a characteristic not found in general organic silanol compounds, and is considered to be due to the steric bulkiness of the butyl group.

However, since the Si-OH group of tert-butyltrihydroxysilane is very stable against the condensation reaction, a reported example that a generally known silicone resin was synthesized using this as a starting material. There is no.

Although there is no case where all the silanol groups of t-BuSi (OH) ₃ are reacted by condensation, 1,3-di-t which is a condensed dimer of tert-butyltrihydroxysilane.
An example of the synthesis of ert-butyl 1,1,3,3-tetrahydroxydisiloxane is Lickiss, PD; Lister, SA: Redhous.
e, AD; Wisener, CJJChem.Soc., Chem.Commun.1991,
173-174. “Isolation of a Tetrahydroxydisiloxane fo
rmed during Hydrolysis of an Alkyltrichlorosilane:
^{Crystal and Molecular Structure of [Bu t} (OH) 2 Si]
₂ O ”. In this reference, tert-butyltrichlorosilane (ie,
t-BuSi (Cl) ₃ ) was added to a mixed solution containing KOH, water, and methanol for hydrolysis, and finally recrystallized from tetrahydrofuran (THF) to give 1,3-di-tert- Crystals of butyl 1,1,3,3-tetrahydroxydisiloxane are obtained.

In this synthetic example, KOH is tert
-Used to accelerate the hydrolysis of butyltrichlorosilane and to control the pH of the reaction system. In this example, the final reaction solution is made alkaline by adding 4 equivalents of KOH in total to 1 equivalent of tert-butyltrichlorosilane. The yield of the final product 1,3-di-tert-butyl 1,1,3,3-tetrahydroxydisiloxane according to this synthesis example is reported to be 65%.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the current state of the art as described above.
An object of the present invention is to provide a method for obtaining -di-tert-butyl-1,1,3,3-tetrahydroxydisiloxane in a higher yield.

[0007]

The present invention is directed to 1,3-di-t.
A method for producing ert-butyl-1,1,3,3-tetrahydroxydisiloxane, which is non-reactive with 1,3-di-tert-butyl-1,1,3,3-tetrahydroxydisiloxane It is characterized in that tert-butyltrichlorosilane is hydrolyzed in a two-phase system of a water-soluble and water-insoluble organic solvent and water. The two-phase system preferably does not include a water-soluble organic solvent and a basifying agent.

In this method, the amount of water in the two-phase system is t
1. For 1 mol of ert-butyltrichlorosilane, 2.
It is preferably 5 mol or more, and more preferably 3 mol or more. The organic solvent is an aliphatic saturated hydrocarbon having 5 to 10 carbon atoms, an aromatic hydrocarbon having 6 to 9 carbon atoms, and 4 to 10 carbon atoms.
And a C4-10 ether.

In another embodiment, tert-butyltrihydroxysilane is dimerized to give 1,3-di-tert.
It is also possible to produce -butyl 1,1,3,3-tetrahydroxydisiloxane. In this case, the dimerization reaction is non-reactive and incompatible with 1,3-di-tert-butyl-1,1,3,3-tetrahydroxydisiloxane and is water-insoluble. It is preferable to carry out the reaction in the presence of the organic solvent, and in the absence of an effective amount of the basifying agent. Furthermore, in this embodiment, it is preferable that an acidic catalyst be present in the reaction system.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the production method of the present invention, tert-butyltrichlorosilane is hydrolyzed in an organic solvent having specific properties, and t produced by the hydrolysis is
The basic idea of the technical idea is to dimerize ert-butyltrihydroxysilane in situ.

In the present invention, as the organic solvent,
A non-reactive, incompatible, and water-insoluble one is used for 1,3-di-tert-butyl-1,1,3,3-tetrahydroxydisiloxane.

Here, "1,3-di-tert-butyl-
“Non-reactive with 1,1,3,3-tetrahydroxydisiloxane” means 1,3-di-tert-butyl-1,
[T-BuSi (OH) _m (OR) _{2 -m} ] ₂ O (m = 0 or 1 by reacting with 1,3,3-tetrahydroxydisiloxane, R is other than hydrogen derived from an organic solvent) Group) does not form a by-product. The production of such by-products is not preferable because it leads to a reduction in the yield of the intended final product 1,3-di-tert-butyl-1,1,3,3-tetrahydroxydisiloxane. . Therefore, not to mention lower alcohols,
The organic solvent which can react with 1,3-di-tert-butyl-1,1,3,3-tetrahydroxydisiloxane to produce the above-mentioned by-product is a “non-reactive” organic solvent of the present invention. Does not apply to

Further, "1,3-di-tert-butyl-1,1,
"Incompatible with 1,3,3-tetrahydroxydisiloxane" means 1,3-di-tert-butyl-1,1,
It means that 3,3-tetrahydroxydisiloxane is not substantially dissolved. Such properties are particularly useful for efficiently recovering the final product 1,3-di-tert-butyl-1,1,3,3-tetrahydroxydisiloxane as a precipitate.

Furthermore, "water-insoluble" means that the organic solvent under consideration is substantially incompatible with water and, when mixed with water, a two-phase system consisting of an organic phase and an aqueous phase. Is formed. As such a water-insoluble organic solvent, one that is less likely to dissolve water than a lower alcohol (methanol, ethanol, etc.) is usually used. Further, more preferably, for example, one that is less likely to dissolve water than diethyl ether is useful.

The amount of such a non-reactive, incompatible and water-insoluble organic solvent used in the production method of the present invention is not particularly limited, but from a practical point of view, water is used. For 100 parts by weight, 100 parts by weight or more,
A range of preferably 200 parts by weight or more, more preferably 300 parts by weight or more is recommended.

Examples of such non-reactive, incompatible and non-water-soluble organic solvents include aliphatic saturated hydrocarbons having 5 to 10 carbon atoms, aromatic hydrocarbons having 6 to 9 carbon atoms, and 4 to carbon atoms. 10
And the ether having 4 to 10 carbon atoms.

Examples of preferred non-reactive, incompatible and water-insoluble organic solvents include: saturated aliphatic hydrocarbons such as pentane, hexane, heptane, octane, nonane, decane, benzene, toluene, xylene. , Ethylbenzene,
Aromatic hydrocarbons such as trimethylbenzene, ethyltoluene, propylbenzene, isopropylbenzene, -methylethylketone, methylpropylketone, methylisopropylketone, methylbutylketone, methylisobutylketone, methyl-sec-butylketone, methyl-te.
rt-Butyl ketone, methyl pentyl ketone, methyl isopentyl ketone, methyl neopentyl ketone, methyl hexyl ketone, methyl heptyl ketone, methyl octyl ketone, diethyl ketone, ethyl propyl ketone, ethyl isopropyl ketone, ethyl butyl ketone, ethyl isobutyl ketone, ethyl -sec-butyl ketone, ethyl-te
rt-butyl ketone, ethyl pentyl ketone, ethyl isopentyl ketone, ethyl neopentyl ketone, ethyl hexyl ketone, ethyl heptyl ketone, dipropyl ketone, propyl isopropyl ketone, diisopropyl ketone, propyl butyl ketone, propyl isobutyl ketone, propyl-sec-butyl ketone, Propyl-tert-butyl ketone, propyl pentyl ketone, propyl isopentyl ketone, propyl neopentyl ketone, propyl hexyl ketone, dibutyl ketone, butyl isobutyl ketone, butyl-sec-butyl ketone, butyl-tert-butyl ketone, diisobutyl ketone, di-sec- Butyl ketone, di-
tert-butyl ketone, butyl pentyl ketone, isobutyl pentyl ketone, sec-butyl pentyl ketone, tert-
Butyl pentyl ketone, butyl isopentyl ketone, isobutyl isopentyl ketone, sec-butyl isopentyl ketone, tert-butyl isopentyl ketone, butyl neopentyl ketone, isobutyl neopentyl ketone, sec-
Butyl neopentyl ketone, ketones such as tert-butyl neopentyl ketone, -methyl propyl ether, methyl isopropyl ether, methyl butyl ether, methyl isobutyl ether, methyl-sec-butyl ether, methyl tert-butyl ether, methyl pentyl ether, methyl iso Pentyl ether, methyl neopentyl ether, methyl hexyl ether, methyl heptyl ether, methyl octyl ether, methyl nonyl ether, ethyl propyl ether, ethyl isopropyl ether, ethyl butyl ether, ethyl isobutyl ether, ethyl sec-butyl ether, ethyl tert-butyl ether , Ethyl pentyl ether, ethyl isopentyl ether, ethyl neopentyl ether, ethyl hexyl ether, ethyl hepti Ether, ethyl octyl ether, dipropyl ether, propyl isopropyl ether, diisopropyl ether, propyl butyl ether, propyl isobutyl ether, propyl-sec-butyl ether, propyl-tert-butyl ether, propyl pentyl ether, propyl isopentyl ether, propyl neopentyl ether, Propylhexyl ether, propylheptyl ether, dibutyl ether, butyl isobutyl ether, butyl-sec-butyl ether, butyl-tert-
Butyl ether, diisobutyl ether, di-sec-butyl ether, di-tert-butyl ether, butyl pentyl ether, isobutyl pentyl ether, sec-butyl pentyl ether, tert-butyl pentyl ether, butyl isopentyl ether, isobutyl isopentyl ether, sec-butyl Isopentyl ether, tert-butyl isopentyl ether, butyl neopentyl ether,
Such as isobutyl neopentyl ether, sec-butyl neopentyl ether, tert-butyl neopentyl ether, dipentyl ether, pentyl isopentyl ether, pentyl neopentyl ether, diisopentyl ether, isopentyl neopentyl ether, dineopentyl ether Examples include ether.

In the production method of the present invention, tert-butyltrichlorosilane is hydrolyzed in a two-phase system consisting of the above-mentioned non-reactive, incompatible and water-insoluble organic solvent and water to produce tert-butyl. By carrying out the above equilibrium reaction without isolation of trihydroxysilane, the target 1,3-di-tert-butyl-
It is possible to obtain 1,1,3,3-tetrahydroxydisiloxane. In this case, the hydrolysis reaction formula for producing tert-butyltrihydroxysilane from tert-butyltrichlorosilane is: t-BuSi (Cl) ₃ + 3H ₂ O → t-BuSi (OH)
It can be represented by ₃ +3 HCl. Since the hydrolysis reaction of tert-butyltrichlorosilane is an exothermic reaction, it is desirable to carry out the reaction at around room temperature while cooling so that the reaction does not proceed rapidly.

The tert-butyltrihydroxysilane thus produced is dehydrated and condensed between the two molecules as it is to form 1,3-di-tert-butyl-1,1,3,3-tetrahydroxydisiloxane. . This reaction theoretically follows the following equilibrium reaction equation. 2t-BuSi (OH) ₃ ⇔ [t-BuSi (OH) ₂ ] ₂
O ↓ + H ₂ O In this case, _{2 of} tert-butyltrihydroxysilane
Due to the dimerization reaction of the molecule, a precipitate of 1,3-di-tert-butyl-1,1,3,3-tetrahydroxydisiloxane is produced, which is in equilibrium with water present in the reaction system. Dependent.

By the way, it is preferable that the two-phase system contains no "water-soluble organic solvent". "Water-soluble" means that the organic solvent under consideration is substantially compatible with water and, when mixed with water, does not form a two-phase system consisting of an organic phase and an aqueous phase Is formed. When such a water-soluble organic solvent is present in a two-phase system, the water-soluble organic solvent is
The phase separation state of the phase system is destroyed and the final product 1,3-
This is a particular disadvantage in that the yield of di-tert-butyl-1,1,3,3-tetrahydroxydisiloxane is significantly reduced.

Examples of such water-soluble organic solvents include lower alcohols such as methanol, ethanol and propyl alcohol, acetone, diethyl ether and the like.

In the above equilibrium reaction system, the presence of a strong basifying agent such as KOH advances the equilibrium to the left.
The final product, 1,3-di-tert-butyl-1,1,
It is not preferable in terms of yield of 3,3-tetrahydroxydisiloxane. Therefore, in the production method of the present invention, the dimerization reaction is not performed in the presence of the "basifying agent".

The term "basifying agent" as used herein refers to an inorganic or organic compound having the property of making the pH of the aqueous phase in the reaction system basic, and specifically, in the reaction system. Sodium hydroxide, which can make the water phase of
Examples of the compound include potassium hydroxide and ammonia.

The basifying agent is limited to use in an "effective amount" or more. Here, the "effective amount" means an amount of the basifying agent sufficient to make the aqueous phase in the reaction system alkaline, and a specific amount is the basifying agent used. Depending on the particular type of reaction and the type of reaction system. Therefore, even if the basifying agent is added to the reaction system of the present invention, if the addition amount is less than the above-mentioned effective amount and the water phase in the reaction system is not alkaline, The basifying agent may be present in the reaction system in the production method of the present invention.

In order to advantageously proceed the production method of the present invention, it is preferable to proceed the above equilibrium reaction in the forward direction, that is, to the right. However, the presence of a catalytic amount of acid in this equilibrium reaction causes the equilibrium reaction to proceed. It can be shifted in the positive direction. As such an acid, an inorganic or organic compound capable of making the aqueous phase in the reaction system acidic can be used, and specifically, an inorganic acid such as hydrochloric acid, sulfuric acid, nitric acid or a carboxylic acid. Examples thereof include organic acids such as carboxylic acid anhydride. However, in order to suppress excessive acidification of the aqueous phase in the reaction system due to the presence of excess acid, an appropriate amount of acid scavenger may be added.

In the case of the present invention, t-BuSi (Cl) ₃ + 3H ₂ O → t-BuSi (OH)
Hydrochloric acid is generated as a by-product of the reaction of ₃ + 3HCl, and this hydrochloric acid is 2t-BuSi (OH) ₃ → [t-BuSi (OH) ₂ ] ₂
Since it acts as a condensation catalyst that pushes the reaction of O ↓ + H ₂ O in the forward direction (right), it is advantageous in improving the yield of the target product.

If necessary, by-product hydrochloric acid is removed from the reaction system to obtain t-BuSi (Cl) ₃ + 3H ₂ O → t-BuSi (OH).
_It may promote the positive reaction of ₃ + 3HCl. To remove hydrochloric acid, use normal H
Cl scavengers can be used. But tert-
Since butyltrihydroxysilane is very stable against condensation, it is desirable that HCl remains in the reaction system to some extent. Therefore, when an HCl scavenger is used, it is desirable that HCl is not completely removed from the reaction system.

The theoretical reaction formula of the manufacturing method of the present invention is as follows: 2t-BuSi (Cl) ₃ + 5H ₂ O → [t-BuSi (O
H) ₂ ] ₂ O + 6HCl. Therefore, the amount of water required for this reaction is theoretically 2.5 mol or more per 1 mol of tert-butyltrichlorosilane. As long as more water is used, the desired substance can be produced. Therefore, there is no particular upper limit to the amount of water, and for example, 3 mol of water may be used per 1 mol of tert-butyltrichlorosilane.

By the way, as another mode other than the above, 1,
In the presence of an organic solvent which is non-reactive and incompatible with 3-di-tert-butyl-1,1,3,3-tetrahydroxydisiloxane and is insoluble in water, a further effective amount of It is also possible to dimerize tert-butyltrihydroxysilane in the absence of a basifying agent to form 1,3-di-tert-butyl 1,1,3,3-tetrahydroxydisiloxane. .

As already mentioned, the starting material in this case, tert-butyltrihydroxysilane, is tert-butyltrihydroxysilane.
By using butyltrichlorosilane as a precursor and hydrolyzing it as a precursor, it is possible to isolate it as a stable compound. Therefore, in this embodiment, tert-butyltrihydroxysilane that has been previously synthesized and isolated in a separate step is used.

The reaction formula in this case theoretically follows the following equilibrium reaction formula. 2t-BuSi (OH) ₃ ⇔ [t-BuSi (OH) ₂ ] ₂
O ↓ + H ₂ O In this case, in order to push the equilibrium reaction in the forward direction (right), the reaction system is provided with an inorganic acid such as hydrochloric acid, sulfuric acid, nitric acid or an acidic catalyst such as an organic acid such as carboxylic acid or carboxylic acid anhydride. Is preferably added.

The manufacturing method according to the present invention can be carried out, for example, according to the following steps.

When tert-butyltrichlorosilane is used as a starting material, t-BuSi (Cl) ₃ + 3H ₂ O → t-BuSi (OH)
₃ + 3HCl 2t-BuSi (OH) ₃ → [t-BuSi (OH) ₂ ] ₂
A two-step reaction of O ↓ + H ₂ O was continuously carried out to obtain 1,3-di-tert-butyl-1,1,3,3-tetrahydroxydisiloxane directly from tert-butyltrichlorosilane. To generate.

Therefore, in this case, first, water and the organic solvent are mixed and stirred, and tert-butyltrichlorosilane dissolved in the organic solvent is added dropwise. At this time, effective amounts of the water-soluble organic solvent and the basifying agent are not added. Here, tert-butyltrihydroxysilane is produced as a product (intermediate) of the first step reaction. Since the hydrolysis reaction of tert-butyltrichlorosilane is an exothermic reaction, the above reaction is preferably carried out near room temperature while cooling so that the reaction does not proceed rapidly. Further, it is desirable that the above reaction be carried out in an inert gas atmosphere so that tert-butyltrichlorosilane does not react with moisture in the air.

Then, by continuing stirring of the reaction system as it is at a predetermined temperature for a predetermined time, the obtained tert-butyltrihydroxysilane is directly transferred to the second-stage two-molecule dehydration condensation reaction without isolation. 1,3-
A precipitate of di-tert-butyl-1,1,3,3-tetrahydroxydisiloxane is obtained.

Next, the obtained 1,3-di-tert-butyl-1,1,3,3-tetrahydroxydisiloxane is purified. A known method can be applied to the purification. For example, after dropping, continue stirring at room temperature for several hours,
The precipitate generated during stirring and the supernatant are separated using a filter or the like. The precipitate obtained at this time is washed with the above organic solvent and ether, and then the solvent is removed by a method such as leaving it in vacuum. In this way, 1,3-di-tert-butyl-1,1,3,3-
Tetrahydroxydisiloxane can be obtained. On the other hand, if necessary, the supernatant may also be used at room temperature for 2
By leaving it for 3 days to deposit a precipitate and treating it in the same manner as above, 1,3-di-tert-butyl-1,1,3,3-tetrahydroxydisiloxane can be obtained as a white solid. it can.

In this embodiment, there is no need to add an acidic catalyst, and tert-butyltrichlorosilane is directly separated from tert-butyltrichlorosilane without separating and purifying tert-butyltrihydroxysilane as an intermediate. -tert
Since it is possible to obtain -butyl-1,1,3,3-tetrahydroxydisiloxane, it is possible to simplify the manufacturing equipment and reduce the manufacturing cost in addition to the high yield.

On the other hand, when tert-butyltrihydroxysilane is used as a starting material, the above-mentioned organic solvent solution of tert-butyltrihydroxysilane is stirred in the presence of water. Next, an appropriate amount of acid is added, if necessary, without adding a basifying agent. Then, by continuing stirring as it is, 1,3-di-tert-butyl-
Produces 1,1,3,3-tetrahydroxydisiloxane. Finally, the same purification operation as above is performed to obtain a purified solid of 1,3-di-tert-butyl-1,1,3,3-tetrahydroxydisiloxane.

In this embodiment, a specific organic solvent is used,
In addition, 1,3-di-tert-butyl-1, by adding the required amount of acidic catalyst without using a basifying agent
1,3,3-Tetrahydroxydisiloxane can be obtained in high yield.

Further, as preferable aspects of the present invention to be noted, there are the following. 1,3-di-tert-
In a two-phase system of water and a water-insoluble organic solvent which is non-reactive and incompatible with butyl-1,1,3,3-tetrahydroxydisiloxane, the amount of water is tert.
1,3-di-tert-butyl-1,1,3,3, characterized in that tert-butyltrichlorosilane is hydrolyzed to 2.5 mol or more per 1 mol of -butyltrichlorosilane. -Method for producing tetrahydroxydisiloxane. 1,3-di-tert-butyl-1,1,3,3
-Amount of water in a two-phase system of water, which is non-reactive and incompatible with tetrahydroxydisiloxane and is insoluble in water, and is limited to a water-insoluble organic solvent. To 2.5 mol or more with respect to 1 mol of tert-butyltrichlorosilane to hydrolyze tert-butyltrichlorosilane.
A method for producing 1,3-di-tert-butyl-1,1,3,3-tetrahydroxydisiloxane. Group: a saturated aliphatic hydrocarbon having 5 to 10 carbon atoms, b aromatic hydrocarbon having 6 to 9 carbon atoms, and hydrocarbon having a ketone structure having 4 to 10 carbon atoms.

[0041]

EXAMPLES Below, 1,3-di-tert in the present invention is described.
The method for producing -butyl 1,1,3,3-tetrahydroxydisiloxane will be specifically described with reference to an example using tert-butyltrichlorosilane as a starting material. Two
17 g of water and 350 g of methyl isobutyl ketone (hereinafter referred to as “MIBK”) are vigorously stirred under ice-cooling with ice water.
g of tert-butyltrichlorosilane in 350 ml of MIBK was added dropwise. As a result, tert-butyltrichlorosilane is hydrolyzed and t-BuSi (O
H) ₃ was obtained.

After the completion of the dropping, the reaction solution was allowed to stand at room temperature for 7 hours.
Stir for hours. The precipitate formed during stirring was separated from the supernatant using a glass filter and washed with MIBK and diethyl ether. The precipitate was left to stand overnight at room temperature to naturally dry, and the solvent was removed by further degassing in vacuum overnight to obtain a white solid (yield 58.9).
g). On the other hand, the supernatant was left at room temperature for 2-3 days,
The precipitate deposited at the interface between the organic phase and the aqueous phase was separated with a glass filter and washed with MIBK and diethyl ether. Then, the solvent was removed by the same method as described above to obtain a white solid (yield 4.2 g). The white solid obtained, namely 1,3-di-tert-butyl 1,1,
The total yield of 3,3-tetrahydroxydisiloxane is 6
The amount was 3.1 g, and the yield was 99.5%. ²⁹ Si CP-MAS NMR (59.6 MHz) (δ
ppm): -49 GC-MS (EI, 70 eV) (m / z): 239 [M
-CH ₃ ] ⁺

[0043]

According to the manufacturing method of the present invention, 1,3-di-t
It is possible to produce ert-butyl-1,1,3,3-tetrahydroxydisiloxane in high yield. 1,
3-di-tert-butyl 1,1,3,3-tetrahydroxydisiloxane is useful as a raw material for a siloxane polymer having a highly ordered structure.

Claims (2)

[Claims] 1. 1,3-Di-tert-butyl-1,1,
Characterized by hydrolyzing tert-butyltrichlorosilane in a two-phase system of water and a water-insoluble organic solvent that is non-reactive and incompatible with 3,3-tetrahydroxydisiloxane Let's say 1,3-di-ter
Process for producing t-butyl-1,1,3,3-tetrahydroxydisiloxane. 2. The method of claim 1, wherein the two-phase system is free of water-soluble organic solvent and basifying agent.