JPS58150534A - Preparation of cyclopentanone - Google Patents

Abstract

PURPOSE:To obtain the titled compound which is an intermediate for solvents, perfumes, etc. in a high space-time yield, per-pass yield and selectivity, by using easy unit operations to bring cyclopentanol into contact with a palladium catalyst having improved durability. CONSTITUTION:Cyclopentanol is brought into contact with a catalyst and dehydrogenated to give cyclopentanone. In the process, a palladium catalyst is used as a catalyst to carry out the reaction at 150-400 deg.C and 0.2-5kg/cm<2>. A catalyst prepared by supporting palladium ions or palladium amine complex, etc. on a carrier, e.g. silica, alumina or silica alumina, by the ion exchange or ligand exchange method is suitable for preparing the cyclopentanone in large amounts with a small amount of the palladium. USE:An intermediate for chemicals.

Description

Detailed Description of the Invention The present invention relates to a method for producing cyclopentanone, and more specifically, cyclopentanone t-m is produced by subjecting cyclopentanol to a strong catalytic reaction with palladium-catalyzed koji to cause a dehydrogenation reaction. Cyclopentanone is a very useful substance as a layering agent, a fragrance, and an intermediate between chemicals, and its mass production has recently been desired. Therefore, as a method for producing such cyclopentanone, jl! A method of dehydrogenating cyclopentanol using a lead-copper catalyst is known (for example, U.
．． 577.412, Special Publication No. 55-5579, etc.).

However, this method does not necessarily provide a sufficient yield of spatiotemporal insects (and the activity of the insects deteriorates over time, so it cannot be said that it is a method suitable for industrialization).

On the other hand, a method of dehydrogenating secondary alcohols such as iso-10panol, benzyl alcohol, cyclohexanol, etc. using a platinum metal element is also known. For example, British Patent No. 824,514 describes a method for dehydrogenating secondary alcohols using a platinum metal element supported on a non-acidic carrier. An experimental example of the process is shown. According to the description, octagon and ruthenium, which are the same white metal elements, have extremely high activity, whereas tetradium has low activity, and palladium has even lower activity. has been done.

Also R@act, Kin@t, 0ata1. Lett
@r 1 (2) 121 (1974) and Kem, Kog
1, 44 (1-2) 35 (1975), it is reported that when cyclohexanol is treated with octane, phenol is directly produced without passing through cyclohexone, and UNK cyclohexone, benzene, etc. are produced as by-products. . In contrast, this description contradicts the description in the British guidebook, and there was not always a clear understanding of the dehydrogenation of alicyclic alcohols by elements of the genus Elus.

Therefore, based on the knowledge of the prior art, the present inventors have devised an efficient method for synthesizing cyclopentanone. It was discovered that palladium, which had exhibited only low activity, had extremely excellent performance, and the present invention was completed.

Thus, according to Superposition@, a method for producing cyclopentanone is provided II, which involves dehydrogenating cyclopentanol by contacting it with palladium metal or a palladium compound to form a 'kIIIl mold'.

The present invention is industrially useful! The purpose is to produce cyclopentanone V in a simple unit operation of bringing the raw material cyclopentanol into contact with a palladium catalyst, resulting in high space-time yields and impressive single-stream yields.
This is a method for producing cyclopentanone that exhibits high selectivity and excellent durability.

The cyclopentanol used as a raw material in the present invention may be sown by any manufacturing method (
Further, it does not necessarily have to be highly pure as long as it does not essentially impede the effects of the present invention. Specific examples of such industrial methods for obtaining cyclopenteinol include, for example, cyclopentene water utilization method, cyclopentane liquid phase air amelioration method,
Cyclopentanol is present in the raw sea bream fraction during the production of adipine #1, and is used after being purified in a uniform manner if necessary.

At this time, along with cyclopentanol, water, alcohol,
Ketones, ethers, esters, and vertical water ratios may coexist (if a compound such as an alcohol that is easily dehydrogenated is included, a dehydrogenation reaction will occur concurrently, and ketones, unsaturated vertical water volume, etc.) may coexist. When the catalyst contains a compound that easily bulks up water, a hydrogenation reaction occurs simultaneously.The catalyst used in the present invention is palladium metal or a palladium compound, and can be prepared according to a known catalyst preparation method. However, industrially, it is advantageous to use cyclopentanone supported on a carrier material in order to produce large amounts of cyclopentanone with small amounts of palladium.

Examples of the carrier material include silica, silicate, vertical bulky palpebrium, Takeshun salt, magnesia, alumina, aluminate, titania, titanate, diatomaceous earth, zirconia, silica aluna and its metal salts, pumice, etc. can give. When carrying ions such as palladium ions, palladium ammine complex ions, and their ions by ion-exchange or ligand-exchange methods, the carrier must have an anchor point or a coordination horse that can exchange these ions in several layers. It is preferable to have.

The amount of palladium supported is selected depending on the purpose based on the target reaction rate, reaction density, etc., reactor size, product distribution, etc. (11 to 10% by weight, 11 degrees is the ideal range). Examples of methods for supporting Km include ion exchange method, ligand exchange method, impregnation method, deposition method, coating method, coprecipitation method,
Examples include the crosstalk method, but it is preferable to support the palladium by an ion exchange method or a ligand exchange flow. Combining with the impregnating coating method, carrying the exchange support near the surface of the carrier is also an effective way to utilize palladium atoms. This is the preferred method.

Palladium may be in any state before the reaction, such as ionic state, cluster state, metal state, oxide, complex compound, etc., but palladium is preferably kept in a state with a high degree of dispersion. is preferred. It is also possible to apply not only palladium but also known methods for surface modification in which compounds known as 10 motors, such as alkali metals, alkaline earth metals, etc., are present, or compounds that do not poison the catalyst are present. Furthermore, if the acidity of the carrier is too strong, the carrier can be neutralized after supporting palladium. The shape of the tip 1 may be any known shape, such as a powdered shape or a molded nose shape. The catalyst can be used as it is, but prior to one reaction, it may be subjected to heat treatment, oxidation treatment, reduction treatment, etc. alone or in combination by a known method.

The overuse form of the reaction can be either liquid phase or gas phase, but
Industrially, it is common to carry out the process in a gas phase and use a fixed bed or fluidized bed, and the fixed bed system is more convenient because it is easier to operate. The reaction #IA degree can be selected from a wide range depending on the reaction pressure and reaction time, but it can be selected from 100 to 450.
C, preferably 150C to 400C. In addition, the reaction pressure can be selected from reduced pressure to high pressure, but it is economical to carry out the reaction using a L2 to 5# tank.The reaction time is not necessarily constant depending on the reaction type, the method of preparation of the reactor, and the loading force, but it is fixed. When using a bed flow type gas phase reactor with α5! It may be diluted with an inert gas such as the following.

Thus book 111! According to IK, cyclopentanone can be produced from cyclopentanol in high yield, selectivity, and durability.

The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the following examples.

Note that parts and saliva in Examples are based on weight unless otherwise specified, and analysis of products in Examples was performed using a combination of gas chromatography and mass spectrometry needles.

Example t 10 to 20 meshes of silica gel (manufactured by Davison Co., Ltd., Davison 1 gel) 5001 was mixed with 10 ml of ammonia water 1500
After degassing with an aspirator, soak in IJi overnight. After washing with water and drying, amminepalladium chloride (P
It was immersed in an aqueous solution in which 115 parts of d(MHs)h 107s was dissolved in 1500 parts of water for 1 star night to perform ion exchange.

After washing with water and drying, use a Matsufuru furnace! A firing process was performed for 5OOtl' for 2 hours. This catalyst contains palladium 11&.

Next, a stainless steel reactor with an inner diameter of 20 mm was filled with 10- and 10-20% carbon, and hydrogen reduction was performed so that the 1-layer mesh was 250C, and then cyclopentanol was added to the gas phase for a predetermined contact time. After the activity became constant, the product was analyzed to determine the yield*1 selectivity. The results are shown in Table 1.

gt* Example 2 After mixing 100 parts of heat II & post-treatment in Example 1, 1 s of sodium carbonate, and 150 parts of water and degassing under reduced pressure, 1
The star was double dipped and evaporated to dryness.

Next, this 1 Ω tube was filled into a stainless steel reactor with an inner diameter of 20 mm, and after pretreatment by supplying cyclopentanol in a gas phase instead of water 1/A 1 l, the reaction pressure was controlled at vm. The reaction was carried out in the same manner as in Example 1 except for the following. Since then, the yield and selectivity of cyclopentanone were as shown in Table 2. Also, the reaction of Experimental Qiaogo (2-2)! t1
Although the treatment was continued for 0 days, no decrease in activity was observed.

In the same manner as in Table 2, oxidation treatment was carried out to create proton acid sites (2 parts of palladium were supported by ion exchange on activated carbon). As a result, the cyclopentanone yield and selectivity 5 hours after the start of the reaction were 6α8 and 857s, respectively.

Claims (1)

[Claims] 1. A method for producing cyclopentanone, which comprises dehydrogenating 1-cyclopentanol by contacting it with a palladium catalyst.