JP2001151705A - Method for producing adamantane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing adamantine (tricyclo [3.3.1.13,7] decane) by the isomerization reaction of tetrahydrodicyclopentadiene (tricyclo [5.2.1.02,6] decane) in the presence of a superacid catalyst, whereby the high purity adamantane is industrially advantageously produced in a high yield. SOLUTION: The isomerization reaction is carried out in a halogen-containing methane as a solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention uses the super acid catalyst, tetrahydrodicyclopentadiene (tricyclodecane [5.2.1.0 ^2,6]) isomerization reaction by adamantane (tricyclodecane [3.3.1.1 ^{3 , 7} ]). Adamantane derivatives are pharmaceuticals, special fuels, lubricating oils, engineering polymers, functional polymers, pesticides,
It is applied to specialty chemicals such as surfactants and fine chemicals.

[0002]

2. Description of the Prior Art Adamantane is generally obtained by isomerizing tetrahydrodicyclopentadiene. Conventionally, as a catalyst used in the production of adamantane, aluminum halide, alumina, zeolite,
HF and BF ₃ series are known.

An acid catalyst is required to obtain adamantane by isomerizing tetrahydrodicyclopentadiene, but the adamantane yield varies greatly depending on the strength of the acid strength (Hammett's acidity function (= H ₀ )). That is,
If the acid strength is low (H ₀ is large), an industrially sufficient space-time yield cannot be obtained. For example, HF known for its strong acid strength
Is also not enough to produce adamantane because H ₀ is -10.2.

AlCl ₃ -HCl, AlBr ₃ -t-BuBr, AlCl ₃ -t
Aluminum halide based catalysts such as -BuCl must use a large amount of the catalyst with respect to the raw material, and the compound by-produced in the reaction tends to form a strong complex with the catalyst. Therefore, there are drawbacks in that the activity decreases rapidly and the regeneration of the catalyst is difficult.

Chlorinated platinum-alumina, silica treated with sulfuric acid
An alumina-supported catalyst such as alumina has a low activity and a short life. Further, the mixed rare earth exchanged zeolite catalyst has a disadvantage that the space-time yield is low although the catalyst can be easily regenerated. Further, in order to obtain a high selectivity, it is necessary to modify with an expensive noble metal, and there is a disadvantage that the preparation of the catalyst is complicated and the price is high.

[0006] Super strong acid catalysts (H ₀ <-11.93), such as HF B
The F ₃ based catalyst, in U.S. Patent No. 2,937,211, adamantane is obtained at 32.2% yield. Furthermore, Tokiko Sho 55
In -38935, adamantane is obtained in a high yield of 60% or more, and HF.BF ₃ catalyst can be recovered.

[0007]

SUMMARY OF THE INVENTION Tetrahydrodicyclopentadiene (tricyclodecane [5.2.
1.0 ^2,6 ]) When adamantane (tricyclodecane [3.3.1.1 ^3,7 ]) is produced by the isomerization reaction of adamantane, the melting point of adamantane produced is extremely high at 269 ° C, so it is recovered by heating and melting. Is difficult to do.

As described above, a catalyst having a strong acid strength is desirable in order to obtain an industrially sufficient space-time yield. However, when a super-strong acid catalyst and adamantane coexist for a long time,
The transformation reaction of adamantane proceeds to lower the yield. An object of the present invention is to provide a method for industrially advantageously obtaining high-purity adamantane in a high yield in producing adamantane by isomerization reaction of tetrahydrodicyclopentadiene using a super strong acid catalyst.

[0009]

Means for Solving the Problems The present inventors have conducted intensive studies on a method for producing adamantane having the above-mentioned problems, and as a result, when performing an isomerization reaction using a super strong acid catalyst, a halogen-containing methane, specifically, Contains CCl ₄ , CHCl ₃ , CH ₂ Cl ₂ , C
By adding HBr ₃ , CH ₂ Br ₂ , CH ₂ I ₂ , and CH ₃ I as a solvent, a high-purity adamantane can be obtained in a high yield, the produced adamantane can be easily transferred, and the solvent is deteriorated. It has been found that adamantane can be advantageously produced from the fact that it does not occur, and the present invention has been achieved.

That is, in the present invention, tetrahydrodicyclopentadiene (tricyclodecane [5.2.
1.0 ^2,6 ]), in the production of adamantane (tricyclodecane [3.3.1.1 ^3,7 ]) by the isomerization reaction, a halogenated methane is used as a solvent in the isomerization reaction. It is.

[0011]

The superacid catalyst in DETAILED DESCRIPTION OF THE INVENTION The present invention has like _{HF · SbF 5, HF · BF} 3, TFA ( trifluoroacetic acid), HF · BF ₃ is preferably used. The reaction conditions when using HF.BF ₃ are 0.5 to 10 parts by weight of HF based on 1 part by weight of tetrahydrodicyclopentadiene, preferably
₃ to 4.5 parts by weight are used and BF3 is used at 0.25 to 1.5 parts by weight, preferably 0.5 to 1.3 parts by weight. Reaction temperature is 0 ~
120 ° C, preferably 40 to 80 ° C, and the reaction pressure is 0.6 to
It is 5.0 MPa, preferably 1.1 to 3.5 MPa.

The physical properties required for the solvent used in the method of the present invention are that it does not deteriorate even when reacted under heating conditions in the presence of a super strong acid catalyst, that the solubility of by-product high boiling compounds is low,
· BF ₃ and that it does not become a homogeneous solution. Halogenated methane is used as a solvent satisfying this condition, and CCl ₄ , CH
Cl ₃ , CH ₂ Cl ₂ , CHBr ₃ , CH ₂ Br ₂ , CH ₂ I ₂ , and CH ₃ I are applicable. Further, a mixture thereof may be used. The amount of the solvent to be used is 5 to 30 parts by weight, preferably 10 to 20 parts by weight, per 1 part by weight of tetrahydrodicyclopentadiene. If the amount of the solvent used is too large, the reaction rate becomes extremely slow and the size of the reaction apparatus becomes large. If the amount of the solvent is too small, the reaction temperature for dissolution must be increased, and the pressure will be increased. Therefore, the amount of the solvent used may be an amount necessary for dissolving adamantane formed at the temperature.

In the present invention, adamantane produced is dissolved in the solvent layer by performing isomerization reaction of tetrahydrodicyclopentadiene using HF.BF ₃ as a catalyst and methane containing halogen as a solvent. After the completion of the reaction, when left to stand, the two layers of the catalyst layer and the solvent layer are separated. Adamantane, unreacted raw material tetrahydrodicyclopentadiene,
Trans - decalin, and a relatively low boiling point by-products mainly distributed in the solvent layer, by-products of high boiling point is distributed to the catalyst layer to form a HF · BF ₃ complexes. By fractionating only the lower solvent layer, a solution in which most of the dissolved organic matter is adamantane can be obtained. By heating the catalyst layer containing high-boiling by-products, HF.BF ₃ and high-boiling by-products can be separated, and the catalyst can be recovered and reused.

In the present invention, by using a halogen-containing methane as a solvent, no alteration occurs even in the presence of a super strong acid catalyst, for example, HF.BF ₃ catalyst. Further, by using a halogen-containing methane as a solvent, a super-strong acid catalyst such as HF
_{(3) Since the} catalyst and the catalyst do not dissolve each other, the solvent layer containing the product is easily separated from the catalyst layer, and purification and separation can be simplified. In addition, since adamantane is selectively dissolved in a solvent, a solution having a high adamantane concentration can be obtained.

[0015] The reaction for isomerizing tetrahydrodicyclopentadiene using an acid catalyst gives a product via a carbocation. Due to this mechanical problem, side reactions occur sequentially or in parallel, and adamantane selectivity generally does not increase. In the present invention, by using a solvent that selectively dissolves adamantane, the selectivity in the process is improved, and the purification / separation step is simplified.

In the present invention, the reaction rate is controlled by selecting an appropriate amount or type of solvent. By controlling the reaction rate, application to existing equipment is possible. For acid catalysts, it is necessary to control the reaction rate to obtain the maximum adamantane yield. Also, in industrial production methods that often use existing equipment, controlling the reaction rate itself has great advantages. That is, specifically, it can be used for a device whose residence time cannot be changed, or used for a device with limited temperature control.

The acid catalyst is also known as a hydrocarbon isomerization catalyst. For example, an acid catalyst is used in a reaction for isomerizing a straight-chain aliphatic hydrocarbon into an isomer having a higher octane number. In the method described in JP-A-8-268925, isobutylene is produced from paraffin by using a super strong acid. Further, in the method described in US Pat. No. 5,457,257, an alkylation reaction between isoparaffin and olefin is performed using an HF.BF ₃ catalyst. Therefore, when a straight-chain aliphatic hydrocarbon is used as a solvent regardless of the strength of the acid, an isomerization reaction of the solvent itself occurs. Furthermore, when a super strong acid catalyst is used, degradation such as a decomposition reaction and a polymerization reaction occurs, and it is practically difficult to use an aliphatic hydrocarbon as a solvent in this system (see Comparative Example 2).

If a catalyst having a weak acid strength is used, reactions such as decomposition and polymerization of aliphatic hydrocarbons can be reduced. However, there is a problem that the activity of the catalyst is not sufficient and the space-time yield is low. In addition, as the solvent is recovered and reused, an alteration reaction such as decomposition and polymerization proceeds stepwise. If an aromatic hydrocarbon is used as a solvent, degradation such as decomposition and polymerization does not occur even in the presence of a super-strong acid catalyst, but the reaction rate is extremely slow, so the apparatus must be enlarged to obtain a sufficient residence time. (See Comparative Example 3).

[0019]

The method of the present invention will be described in more detail with reference to the following examples. However, the present invention is not limited by the following examples.

Example 1 A 300 mL Hastelloy autoclave equipped with an electromagnetic stirrer, a baffle plate, a gas injection port and a liquid supply port was prepared.
Tetrahydrodicyclopentadiene 10 g, CCl ₄ 102 g, HF
47 g of the mixture was charged and heated with flowing hot water to the outside (jacket) of the autoclave while stirring, and the temperature of the inside liquid was raised to 50 ° C. with stirring. After that, stop stirring BF
The ₃ 8 g was introduced into the autoclave, the reaction was initiated by restarting the stirring. After 45 minutes, stirring was stopped and the mixture was allowed to stand. Lower CCl ₄
The HF in the layer and the upper layer were separated, and the organic matter in the HF layer was extracted with a solvent. As a result of analyzing each layer by gas chromatography, the conversion of tetrahydrodicyclopentadiene was 7
The selectivity for adamantane was 7.5% and 7.5%. The proportion of the produced adamantane dissolved in the CCl ₄ layer was 99.7%. The proportion of adamantane in the product dissolved in the CCl ₄ layer was 93.2%.

Example 2 Example 2 was carried out in the same manner as in Example 1 except that CH ₂ Cl ₂ was used as a solvent instead of CCl ₄ and the reaction time was 60 minutes. The conversion of tetrahydrodicyclopentadiene is 62.3%, the selectivity for adamantane is 60.5%, and in the produced adamantane, C
The proportion dissolved in the Cl ₄ layer was 98.2%. Also, CH ₂ C
l The proportion of adamantane in the product dissolved in the _two layers is 9
0.4%. Compared to using CCl ₄ as the solvent, CH
_{When 2} Cl ₂ is used as a solvent, the reaction rate becomes slow.

Comparative Example 1 Comparative Example 1 was carried out in the same manner as in Example 1 except that 1,2-dichloroethane was used instead of CCl ₄ as the solvent, and the reaction temperature was 90 ° C. and the reaction time was 30 minutes. The conversion of tetrahydrodicyclopentadiene was 25.2%, and the selectivity for adamantane was 38.2%. This shows that the results obtained with halogen-containing ethane are not industrially sufficient.

Comparative Example 2 The reaction was carried out at a reaction temperature of 80 ° C. and a reaction time of 30 minutes without using CCl ₄ as the solvent and without adding tetrahydrodicyclopentadiene. Other charging amounts were the same as in Example 1. The rate of alteration of hexane was 73.6%, and the rate of the recovered amount to the charged weight was 38.3%. This indicates that the aliphatic hydrocarbon solvent cannot be used industrially.

Comparative Example 3 Comparative Example 3 was carried out in the same manner as in Example 1 except that fluorobenzene was used as a solvent instead of CCl ₄ , and the reaction temperature was 100 ° C. and the reaction time was 40 minutes. The conversion of tetrahydrodicyclopentadiene was 17.2%, and the selectivity for adamantane was 10.8%. From this, it can be seen that an aromatic hydrocarbon solvent can provide industrially unsatisfactory results.

[0025]

As is clear from the above examples, the method of the present invention produces adamantane by isomerization reaction of tetrahydrodicyclopentadiene using a superacid catalyst in high yield and high purity. Adamantane can be easily obtained. Further, in the present invention, the produced adamantane is obtained in a solution of halogen-containing methane, so that the transfer is easy and no deterioration occurs. Furthermore, in the present invention, the reaction rate can be controlled by performing the reaction using a stable solvent, so that the maximum adamantane yield can be obtained, and the conversion to existing equipment becomes possible. Therefore, according to the present invention, adamantane can be produced very advantageously, and the present invention has great industrial significance.

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Claims (3)

[Claims] 1. An adamantane (tricyclodecane [3.3.1.1]) obtained by an isomerization reaction of tetrahydrodicyclopentadiene (tricyclodecane [5.2.1.0 ^2,6 ]) using a super strong acid catalyst.
^3,7 ]), wherein a halogenated methane is used as a solvent in the isomerization reaction. 2. A method for producing adamantane according to claim 1 superacid catalyst is a HF · BF _3. 3. The method according to claim 1, wherein the solvent is CCl ₄ , CHCl ₃ , CH ₂ Cl ₂ , CHBr ₃ , CH ₂ B
_{r 2, CH 2 I 2,} CH 3 method for producing adamantane according to claim 1 or claim 2 is one or more compounds selected from I.