JPH026855A - Production of 1,3-dimethyladamantane, catalyst for production thereof and production of the same catalyst - Google Patents

Abstract

PURPOSE:To produce 1,3-dimethyladamantane in a high yield by supporting one or more kinds of metals such as Al, Ni, Cu and Cd on zeolite to form a catalyst for production of 1,3-dimethyladamantane. CONSTITUTION:Zeolite is subjected to ion exchange with ions of at least one kind of metal selected among Al, Ni, Ca, Co, Cr, Ti and Sn or at least one kind of metal salt selected among salts of Al, Ni, Ca, Co, Cr, Ti and Sn is impregnated and supported on zeolite to produce a catalyst for production of 1,3-dimethyladamantane by isomerization of perhydroacenaphthene. The pref. reaction temp. of isomerization of perhydroacenaphthene is 150-300 deg.C, especially 200-270 deg.C.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a catalyst for producing 1,3-dimethyladamantane, which is useful as a raw material for high-grade functional polymers and pharmaceuticals, and a method for producing 1,3-dimethyladamantane using the present catalyst. , relates to a method for producing 3-dimethyladamantane.

(Prior art) As a method for producing adamancune without a methyl group, 19
In 1956, Sch Ieyer et al. described a method for isomerizing endo-tetrahydrodicyclopentadiene using an anhydrous aluminum chloride (^1c13) catalyst (J
, Am, Chem, Soc,, 79.3292
(1957)), attempts have been made to isomerize tricyclic hydrocarbons having 10 or more carbon atoms using various acid catalysts.

The yield of adamantane obtained by the isomerization of endo-tetrahydrodicyclopentadiene using an initial AlCl3 catalyst is as low as 15-20%, and an extremely large amount of by-products are produced, making it difficult to produce adamantane industrially. It could not be said that it was advantageous.

After that, various improvements were made, among which
In the isomerization of tetrahydrodicyclopentadiene to adamantane using a 1C13 catalyst, the reaction is specifically promoted by using 1,2-dichloroethane as a solvent, improving the yield to 50% and reducing by-products such as resin. It is reported that the formation of
08) and is worthy of attention.

On the other hand, a catalyst using a normal solid acid such as zeolite is a catalyst (abbreviated as M/REV) in which metals such as platinum elements are supported on Y-type zeolite that has been ion-exchanged with rare earth ions and alkaline earth ions. There are some using (Japanese Patent Publication No. 53-35944, etc.). The advantage of this method is that the catalyst is non-corrosive and easy to handle, but the yield of adamancune is as low as 20-40%, and 11□
Disadvantages include that the reaction is carried out under pressure with a mixed gas of 1101 and 1101, and that the composition of the catalyst is complex and difficult to prepare.

(Problems to be Solved by the Invention) However, there is currently no known method for selectively producing 1,3-dimethyladamantane in a high yield, which is particularly useful as a raw material for fine chemicals among adamuncnes. Chlorinated (sequential treatment with hydrogen, hydrogen chloride, and thionyl chloride) Pt-Al□0. It has been reported that the catalyst is effective as a catalyst for isomerizing tricyclic hydrocarbons (J, 8m, Chem, Soc.

93, 2798 (1971)), but in this case Itch
There are problems in industrial implementation, such as the need for a pretreatment device that resists corrosion of the catalyst due to 5OCIz, the life of the catalyst being extremely short and the need for repopulation of the catalyst being large, and the handling of toxic gases. .

Furthermore, it is said that when perhydroacenaphthene is isomerized using the above M/REV catalyst, 1,3-dimethyladamantane is produced with a yield of 19% (Japanese Patent Publication No. 52427
06), perhydroacenaphthene conversion rate 39%, 1.
Not only is the selectivity of 3-dimethyladamantane as low as 28%, but 19% of decomposition products are produced, which is not at a level that can be used industrially. Furthermore, this method uses HC during the reaction.
Since I gas is used, there are many problems such as corrosion of the equipment.

The present inventors have already discovered that Al as a catalyst for isomerizing perhydroacenaphthene to obtain 1,3-dimethyladamantane.
It was discovered that the complex formed from Cl3 and 1,2-dichloroethane is very valuable and that 1,3-dimethyladamantane can be obtained with a high yield of 70 to 80% (Japanese Patent Application No. 61-305290). Although this catalyst system has much higher activity than conventional ones and is satisfactory as an industrial production method, it is not economical because the catalyst is disposable, and the reaction method is limited to a batch method, making production difficult. It also had the disadvantage of being inferior in gender.

In order to obtain 1,3-dimethyladamantane in high yield and with high selectivity, the present inventors used zeolite to improve the activity and selectivity of solid acid catalysts such as zeolite, and to reduce decomposition products as much as possible. As a result of intensive studies on the types of 13-dimethyladamane, the effects of adding various metal ions, and the reaction conditions, we discovered a power insect medium system that provides an excellent yield of 13-dimethyladamane and produces few decomposition products, and completed the present invention. did.

Therefore, an object of the present invention is to provide an economically efficient catalyst which can produce 1,3-dimethyladamantane in high yield and with high selectivity, and which produces few decomposition products.

(Another means to solve the problem) That is, the present invention solves the following problems: ^L Ni, Cu, Co, Cr
A catalyst for producing 1,3-dimethyladamantane by perhydroacenaphthene isomerization, comprising at least one metal selected from XTi and Sn supported on zeolite;
and a method for producing 1,3-dimethyladamantane using the present catalyst.

In addition, in the method of the present invention, in producing this catalyst, the zeolite is 8L Ni, Cu, Co, CrXTi.
and/or ion exchange with at least one metal ion selected from Sn and/or impregnating and supporting the zeolite with at least one metal salt selected from the above element group. It is characterized by

In addition, the present invention uses AI, Ni, Cu, Co, Cr, T as a catalyst in producing 1,3-dimethyladamantane by isomerizing perhydroacenaphthene.
It is characterized by using zeolite which is ion-exchanged with at least one metal ion selected from i and Sn and/or impregnated and supported with at least one metal salt selected from the above element group. 1, 3
- Provides a method for producing dimethyladamantane.

The metal salt used for impregnation and support may be any water-soluble salt such as sulfate, chloride, nitrate, etc., and is not limited in any way. Furthermore, when supporting two or more metal ions by an ion exchange method, the order of ion exchange may be arbitrary;
Furthermore, two or more metal ions may be simultaneously supported on the zeolite using a solution containing two or more metal ions.

In the present invention, when producing a catalyst by combining the ion exchange method and the impregnation support method, metal ions are supported on zeolite by the ion exchange method, and then other metal salts are supported by the impregnation method. There is no practical problem in reversing the order. Further, the impregnating and supporting method of the present invention includes known methods such as a method of dipping into an aqueous metal salt solution and a method of spraying an aqueous metal salt solution.

The raw material perhydroacenaphthene used in the present invention is usually obtained by hydrogenating acenaphthene contained in coal tar, but perhydroacenaphthene obtained by other methods can also be used.

The catalyst used in the present invention is a specific zeolite metal ion exchanger and/or metal salt impregnated support in air.
Alternatively, it is activated by firing in an inert gas.

It is generally known that the acid properties of zeolite are such that as the silica/alumina ratio decreases, the acid strength decreases, but the acid site density increases. Since this reaction is a skeletal isomerization reaction, a catalyst having a high acid site density is preferable, and a zeolite having a silica/alumina ratio of not so large, preferably 10 or less, is used as a catalyst. However, if such type II zeolite is used as it is in the reaction, it does not exhibit sufficient activity because of its weak acid strength. Therefore, with the aim of increasing the acid strength of zeolite, various metal ion exchangers and/or metal salt-impregnated supports were prepared and their catalytic activities and selectivities were investigated.
It has been found that those carrying at least one metal ion and/or metal salt selected from Cu, Go, Cr, Ti, and Sn exhibit particularly high activity.

In the present invention, it is essential to support at least one metal ion and/or metal salt selected from these seven types of metals. For example, in zeolite exchanged with alkali metal ions, perhydroacenaphthene isomerization It showed almost no reaction activity. Although the exchange rate of metal ions is not limited, it is preferably 10% or more. In the case of supporting a metal salt, it is preferable to carry the metal salt in an amount of 1.5 to 15% by weight, although this is not limited. In addition, the zeolite to be used can be any of the tl-Y type, Na-Y type, and is good.

The shape of the catalyst may be arbitrary, such as powder or granules.

The catalyst used in the present invention must be subjected to appropriate activation treatment, and the reaction will not proceed at all if no activation treatment is performed. As the activation treatment, normal heating and firing may be used, but the firing temperature is 300-700°C and the firing time is 1-100°C.
IO time is preferred. The atmosphere during firing may be air or an inert gas.

The catalyst has a weight ratio of 1/4 to perhydroacenaphthene.
It may be used in an amount of ~4/1 times, but from the viewpoint of productivity and economy, an amount of 172 to 2/1 times is particularly preferred. The reaction is carried out under pressure of 3 to 50 atm, preferably 5 to 30 atm, in an inert gas or hydrogen gas so that perhydroacenaphthene does not vaporize.

If the pressure is less than 3 atm or more than 50 a Lm, the reaction rate will decrease, which is not preferable. In addition, H
Since 1,3-dimethyladamantane is produced in a sufficiently high yield even without the coexistence of gases such as CI and 11Br, it is not only economical but also practical without problems such as equipment corrosion.

The reaction temperature for isomerization is 150 to 300°C, especially 200 to 2
70°C is preferred. If the temperature is lower than 150°C, the reaction rate is extremely slow; if it exceeds 300°C, a large amount of decomposition products will be produced, which is not economical. The reaction time is preferably 1 to 10 hours, although it depends on the reaction temperature. For example, at a reaction temperature of 250°C, 2 to 4 hours is appropriate.

Although the activity of this catalyst is maintained for a long time, coke-like substances gradually adhere to the surface with long-term use. The resulting catalyst can be heated at 200-600°C in air or under an H2 gas atmosphere diluted with an inert gas.
By heating for 20 hours, the attached coke-like substance is completely removed and the catalyst activity is completely regenerated.

In the present invention, 1,3-dimethyladamantane is produced with high selectivity by selecting appropriate reaction conditions, so the target product, 1,3-dimethyladamantane, can be easily separated with high purity by vacuum distillation. can do.

Next, typical examples will be shown to clarify the effects of the present invention. Examples 1 to 21 are cases in which the catalyst according to the present invention is used, Comparative Example 1.2 is a case in which the metal according to the present invention is not supported, and Comparative Example 3 is a case in which a zeolite with a high silica/alumina ratio is used as the zeolite. Indicate the case.

The firing conditions for preparing the catalysts in Examples 2 to 21 of the present invention and Comparative Examples 1 to 3 were the same as in Example 1.

(Example) 8 ICl3'6 tlzO aqueous solution 4 with a soil concentration of 0.5N
5iO273.7% by weight in 30ml, Δ120321.
H with a composition of 8% by weight, Nazo 3.6% by weight
-Y type zeolite (silica/alumina ratio 5.7) 30
g and stirred at 70 to 80°C for 2.5 hours. Then, this slurry was filtered, and the resulting cake-like material was IA'
Washed with pure water. Furthermore, the above operation was repeated twice to obtain AI ion exchanged tAHY zeolite. Next, put this entire amount into a porcelain evaporating dish, use a manful furnace, and immerse it in air for 4 hours.
It was baked at 50°C for 2 hours.

5 g of the calcined catalyst and 5 g of perhydroacenaphthene (hereinafter abbreviated as P)IA) were placed in a stainless steel autoclave with an internal volume of 30 cc, and after being purged with nitrogen and pressurized to 15 atm with If gas, the following steps were taken: The reaction container was placed in a sand bath heated to about 250°C, and shaking was started. The reaction was carried out for 2.5 hours while maintaining the temperature inside the autoclave at 250±5°C.

After the reaction was completed, the reaction vessel was put into water and rapidly cooled, and then residual gas was purged and the pressure was returned to normal pressure. After removing the catalyst from the reaction product by filtration, the product was analyzed by gas chromatography, and the results showed that the conversion rate of pH/l was 100%, 1.
The selectivity of 3-dimethyladamantane (hereinafter abbreviated as 1.3-Kano) was 50.5%.

The selectivity for other products was 44.1% in total for dimethyladamancune and ethyladamancune (hereinafter referred to as R-Ad+n) other than 1.3-DMA. was 5.4%.

1 test ■↓ When the PIIA isomerization reaction was carried out in the same manner as in Example 1 except that N2 was used as the reaction atmosphere gas and pressurized, I
100% to 'll 8 conversion, selectivity is 9.5% to 1.3-DM 8, R-8 dm 44.3%, decomposition products 6.2
%Met.

Deputy Director - Example - Ion exchange of zeolite is carried out using N1 (NO
3) Ni ion exchange H-Y type zeolite prepared using z・611□0 aqueous solution (silica/alumina ratio 5.7)
The isomerization reaction was carried out in the same manner as in Example 1 except that . P II A conversion rate 100%, selectivity 1.3-
D? 8% for I84, 53.7% for DM, and 3.5% for decomposition products.

Tenkawa L Bot Ion exchange of zeolite is carried out at a concentration of 0.5N(7)Cu(
Circular μ isomerization reaction was carried out in the same manner as in Example 1, except that C u t + ion exchange H-Y type zeolite prepared using C1laCOO) 2 .lho aqueous solution was used.

PIIA conversion rate 100%, selectivity 1.3-DMA
50.8%, R-Adm 45.7%, decomposition products 3.
It was 5%.

Ion exchange of zeolite was carried out using Co (No.
:l) Co prepared using z ・611zO aqueous solution
A circular IA isomerization reaction was carried out in the same manner as in Example 1 except that ion exchange 11-Y type zeolite was used.

PIIA conversion rate 100%, selectivity 1.3-DMA
37°1%, R-Adm 59.8%, decomposition products 3.
It was 1%.

Ion exchange of Ten1's zeolite was carried out using Cr(N() with a concentration of 0.5N.
h) Cr3 prepared using 3' 9 tlzO aqueous solution
+Ion Exchange 1] A PIIA isomerization reaction was carried out in the same manner as in Example 1 except that -Y type zeolite was used.

P11A conversion rate 100%, selectivity 1.3-DMA4
2.1%, R-hedm 52.2%, decomposition products 5.7
%Met.

Jiku M↑ Ti(SO4)z with concentration 0.15N ・411z058
Ti" ion exchange H-Y type prepared by adding 30 g of H-Y type zeolite with a silica/alumina ratio of 5.7 to an aqueous solution in which 5 ml of concentrated hydrochloric acid was added to 0 ml of Ti4+ ion exchange operation. A circular 1^ isomerization reaction was carried out in the same manner as in Example 1 except that zeolite was used.P
IIA conversion rate 100%, selectivity 1.3-DMA 4
4.2%, R-8dm 52.2%, decomposition products 3.6%
Met.

51 (SO,) with a concentration of 0.15N, ・nf1,o (average value n-2) 580 ml with a silica/alumina ratio of 5.
Add 30g of 11-Y type zeolite which is 7.Sn'+
Sn 4 + prepared by performing only one ion exchange operation
A PIIA isomerization reaction was carried out in the same manner as in Example 1 except that ion exchange H-Y type zeolite was used. Yen 1 conversion rate 100%, selectivity 1.3-DMA 50.9%,
P-8dm was 44.7%, and decomposition products were 4.4%.

AICh・611゜0 aqueous solution 820-
The silica/alumina ratio is 4.8! PIIA isomerization reaction was carried out in the same manner as in Example 1 except that old ion exchange H-Y type zeolite prepared by adding 30 g of -Y type zeolite was used. PIIA conversion rate 100%, selectivity 1.3-DMA 56.4%, P-8dm 38.9
%, and the decomposition products were 4.7%.

Ni (NO3) t 611zO with a concentration of 0.5 N on the top side
Ni prepared by adding 30 g of H-Y type zeolite with a silica/alumina ratio of 4.8 to 820 mff1 of an aqueous solution.
The isomerization reaction to circle 1 was carried out in the same manner as in Example 1 except that ion exchange Y-type zeolite was used. P) IA conversion rate 100%, selectivity 1.3-DMA 52.6%
, R-^dm 43.3%, and decomposition products 4.1%.

Sour can - Ida 1≦1≦1 Concentration 0. IN^lcl+ ・61120 aqueous solution 43M
The AI ion exchange operation was performed only once by adding 30 g of H-Y type zeolite with a silica/alumina ratio of 5.7 to the helium, and the hel exchange rate was 40%.
Example 1 except that ion exchange H-Y type zeolite was used.
PIIA isomerization reaction was carried out in the same manner as described above. PIIA conversion rate 100%, selectivity 1.3-DMA 50.0%,
The R-8dIl content was 146.1%, and the decomposition products were 3.9%.

Next ml its concentration 0.15N N1(NO:+)z ・611! The PIIA isomerization reaction was carried out in the same manner as in Example 1, except that Ni ion exchange Na-Y type zeolite prepared by adding 30 g of Na-Y type zeolite with a silica/alumina ratio of 5.6 to 5901 nl of O aqueous solution was used. went. PIIA conversion rate 100%, selectivity 1.3-DMA 34.1%, P-
8 dm was 61.9%, and decomposition products were 4.0%.

↓ 1 sentence] Column ↓ The PH^ isomerization reaction was carried out in the same manner as in Example 1, except that H-Y type zeolite (silica/alumina ratio 5.7) without any metal ion exchange operation was used. Ta. Pl+8 turn rate 71.8%, selection rate is 1.3-DMA14.4
%, R-8 dm 2 (i, 4%, decomposition products 4.2%).

几士■ Ikukai MCI aqueous solution with a concentration of 0.5N and a silica/alumina ratio of 5
．． The process was repeated in the same manner as in Example 1, except that ion-exchanged 11-Y type zeolite, which was prepared by adding 1-1-Y type zeolite (7) and ion-exchange operation three times, was used. An isomerization reaction was carried out. The PIIA conversion rate was 0.1%.

P) IA was carried out in the same manner as in Example 1 except that ultra-stable H-Y zeolite with a silica/alumina ratio of 14.0 was used.
An isomerization reaction was performed. PHA conversion rate 52.4%, selectivity 1.3-DMA 6.4%, R-Adm 30.1%
, decomposition products were 2.1%.

Implementation U Ion exchange of zeolite was carried out at a concentration of 0. IN 8 ICI:
l ・6 HzO aqueous solution 210mff1 to 13
H-Y type zeolite with an exchange rate of +'' ions of 20% was prepared, and after drying, CO(NO3) with a concentration of 0.IN was prepared.
) t ・611zO aqueous solution 860 ml T: Co
A bimetallic ion exchanger was prepared by carrying out ion exchange so that the ion exchange rate of H-Y type zeolite was 20% for 8I and 80% for Co. A pHA isomerization reaction was carried out in the same manner as in Example 1 except that this was used. P11
Eight conversion rate: 100%, selectivity: 1.3-DMA 54.
9%, R-Adm 41.5%, and decomposition products 4.6%.

Ion exchange of old bile zeolite was carried out at a concentration of 0. 5n(S
O4) t・n 1120 (average value n-2) Using an aqueous solution of 210 mZ, H-Y type zeolite was prepared with a Sn" ion exchange rate of 20%, and after drying,
．． IN 8ICh・611□0 aqueous solution 860- Δ13
+ ion exchange was performed to prepare a bimetallic ion exchanger in which the ion exchange rate of 11-Y type zeolite was 20% for Sn and 80% for AI. Example 1 except for using this
A pH^isomerization reaction was carried out in the same manner as above. The pH conversion rate was 100%, the selectivity was 57.2% for 1.3-DMA, 41.0% for R-8dm, and 4.4% for decomposition products.

■ A 14-Y type zeolite prepared in the same manner as in Example 13 with an exchange rate of 13゛ ions of 20% was prepared, and after drying, the concentration was reduced to 0. Perform N12+ ion exchange with 860ml of IN N1(NO3)z・611□0 aqueous solution, +1-
A bimetal ion exchanger was prepared in which the ion exchange rate of Y-type zeolite was 20% for AI and 80% for 2.PIIA isomerization reaction was carried out in the same manner as in Example 1 except that this was used. PIIA conversion rate was 100%, selectivity was 1.3.
-DMA was 44.4%, R-Adm was 49.1%, and decomposition products were 4.0%.

The order of ion exchange was reversed from that of Example 15, and ■1 Y-type zeolite was ion-exchanged first with Ni! After drying the ion exchange rate of 20% with +, AI''-(on exchange was performed, and the ion exchange rate of 11- Y type zeolite was Ni!''20% and Al''80%. A metal ion exchanger was prepared.Example 1 except that this was used.
PIIA isomerization reaction was carried out in the same manner as described above. pH conversion rate 100%, selectivity 1.3-DMA 55.1%, R
-Adm was 39.5%, and decomposition products were 4.4%.

Using an aqueous solution in which 9.42 g of charcoal N1 (N(h)z 6 HzO and 1.74 g of 8ICl3 611□0 were dissolved in 810 ml of water, the ion exchange rate of ■1Y type zeolite was Ni" A dual metal ion simultaneous exchanger containing 60% and 20% AI was prepared.

r'llA in the same manner as in Example 1 except that this was used.
An isomerization reaction was performed. Enyu conversion rate is 100%, selection rate is
1.3-DMA 47.5%, R-Adm 47.3%
, the decomposition products were 3.9%.

Senpai box concentration 0. IN Ti(S04)z・41120 aqueous solution 2
After adding H-Y type zeolite to 80- and stirring this slurry at room temperature for one hour, stirring was stopped. Next, it was heated in an oil bath to evaporate the water, and then calcined to form Ti of 11-Y type zeolite with a loading rate of 5.6% by weight.
(504) A v-impregnated support was prepared. PIIA isomerization reaction was carried out in the same manner as in Example 1 except that this was used. PIIA conversion rate 100%, selectivity 1.3-DMA
29.4%, R-hedm 58.3%, decomposition products 3.
It was 2%.

Leftover currency - phosphorus agricultural index 0. IN＾ICI+・611□0 aqueous solution 380
A catalyst was prepared in the same manner as in Example 18, except that - was used, and an AICh-impregnated support of H-Y type zeolite with a supporting rate of 12.8% by weight was obtained. PIIA isomerization reaction was carried out in the same manner as in Example 1 except that this was used.

PIIA conversion rate 100%, selectivity 1.3-DMA3
2.9%, P-Adm 60.5%, decomposition products 2.8
%Met.

After drying H-Y type zeolite with an exchange rate of 20% of AI" ions prepared in the same manner as in Example 13, the concentration was 0, IN
Using the 7i(SO4)z・4H30 aqueous solution 280-, the exchange rate of AI'° ions was set to 2 in the same manner as in Example 18.
A catalyst was obtained by combining the ion exchange method and the impregnation method in which Ti (SO4) was supported at 5.6% by weight on 0% H-Y type zeolite. A pHA isomerization reaction was carried out in the same manner as in Example 1 except that this was used. PI (A conversion rate 100
%, selectivity is 1.3-DMA 51.4%, t^dm
44.8%, and decomposition products 3.7%.

The same Ti (SO4
) Example 1 except that a three-element supported catalyst obtained by a combination of ion exchange method and impregnation method obtained by performing Z impregnation treatment was used.
PIIA isomerization reaction was carried out in the same manner as described above. Yen 18 conversion rate 100%, selectivity 1.3-DMA60.6%, R
-Adm was 30.9%, and decomposition products were 5.4%.

The above examples and comparative examples of the present invention are collectively shown in Tables 1 and 2.

(Effect of the invention) It is known that dicarboxylic acids and diols such as 1.3-dimethyladamantane are suitable as raw materials for high-grade functional polymers such as polyester and polyimide, and that they are useful as raw materials for various fine chemicals such as pharmaceuticals and fragrances. ing.

However, since there was no industrially advantageous method for producing 1,3-dimethyladamantane, it is currently very expensive, and as a result, the development of derivatives and the like has not made much progress. The present invention provides a catalyst for producing 1,3-dimethyladamantane that exhibits high activity and selectivity, is easy to handle, and is recyclable, and a method for producing 1,3-dimethyladamantane using the present catalyst. This makes it possible to provide 1,3-dimethyladamantane in a relatively large amount at a high yield, safely, and at low cost, which has great industrial significance.

Claims (4)

[Claims] (1) 1,3 by perhydroacenaphthene isomerization in which zeolite supports at least one metal selected from Al, Ni, Cu, Co, Cr, Ti, and Sn.
-Catalyst for producing dimethyladamantane. (2) Zeolite is Al, Ni, Cu, Co, Cr, T
Ion exchange with at least one metal ion selected from i and Sn and/or at least one metal salt selected from Al, Ni, Cu, Co, Cr, Ti and Sn on the zeolite 1. A method for producing a catalyst for producing 1,3-dimethyladamantane by perhydroacenaphthene isomerization, which comprises impregnating and supporting a metal salt. (3) By isomerizing perhydroacenaphthene, 1,3-
A method for producing 1,3-dimethyladamantane, which comprises using the catalyst according to claim 1 in producing dimethyladamantane. (4) By isomerizing perhydroacenaphthene, 1,3-
In producing dimethyladamantane, ion exchange and/or Al, Ni, Cu, Co, Cr
, Ti, and Sn.