JP2010173965A - Method for producing 2-alkyl-2-cycloalkenone - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method which efficiently and industrially advantageously produces a 2-alkyl-2-cycloalkenone by a simple method using a 2-alkylidenecycloalkanone as a raw material. <P>SOLUTION: The method for producing a 2-alkyl-2-cycloalkenone comprises continuously bringing a 2-alkylidenecycloalkanone into contact with a supporting-type solid catalyst obtained by supporting at least one platinum group metal on a carrier to perform isomerization. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a process for continuously producing 2-alkyl-2-cycloalkenone by contacting 2-alkylidenecycloalkanone with a solid catalyst.
2-Alkyl-2-cycloalkenone is a useful compound as a fragrance, a pharmaceutical intermediate for producing agricultural chemicals, and the like.

  Conventionally, 2-alkyl-2-cycloalkenone synthesizes 2- (1-hydroxyalkyl) cycloalkanone by aldol condensation reaction using cycloalkanone and saturated aliphatic aldehyde as raw materials, and then dehydration reaction 2 -Alkylidene cycloalkanone, and further synthesized through a three-step reaction to form 2-alkyl-2-cycloalkanone by double bond isomerization reaction.

  For example, when 2-n-pentyl-2-cyclopentenone, which is useful as a synthetic intermediate for perfume methyl jasmonate, is industrially produced, first as a first step, cyclopentanone and valeraldehyde are used as raw materials. 2- (1-hydroxy-n-pentyl) cyclopentanone is synthesized by the aldol condensation reaction. Next, as a second step, the reaction of dehydrating the obtained 2- (1-hydroxy-n-pentyl) cyclopentanone and the reaction of isomerizing the carbon-carbon double bond formed thereby are performed simultaneously. A method of obtaining the object is employed.

  In each step of this method, the reaction is carried out in the liquid phase, and the target product can be obtained with a relatively high reaction yield. However, when this method is employed, since the operation involves collecting unreacted substances and purifying reaction products in each step, the total yield of the target substance based on the starting material is low at present. Moreover, since each process is performed by batch type (batch) reaction, there existed a problem that manufacturing equipment became complicated, reaction operation became complicated and cycle time became long. In particular, in the second step, it is common to use a liquid inorganic acid such as hydrochloric acid as a catalyst (Patent Document 1). However, due to the problem of corrosion of the reactor material by acid, the use of high-grade materials or glass Lining is essential, the capital investment increases, and a neutralization process is required, so a large amount of waste is generated.

  On the other hand, a method in which a dehydration reaction and an isomerization reaction are performed separately in separate steps is also known (Patent Documents 2 to 4). However, in this method, the isomerization reaction step is a homogeneous catalyst reaction using an amine hydrogen halide salt as a catalyst, and it is difficult to recover the used catalyst, so that a large amount of waste is generated. There's a problem.

Patent Documents 5 and 6 disclose a method of obtaining 2-n-pentyl-2-cyclopentenone by isomerizing 2-pentylidenecyclopentanone in the presence of a transition metal catalyst.
However, in the method described in Patent Document 5, 2-alkylcyclopentanone is by-produced by the hydrogen gas used for activating the catalyst, and the desired 2-alkyl-2-cyclopentenone is highly purified. There is a disadvantage that cannot be obtained. Also. The method described in Patent Document 6 has a drawback that it is difficult to recover the catalyst because a soluble transition metal catalyst is used. Furthermore, since all of these production methods are batch-type reactions, when producing 2-alkyl-2-cyclopentenone on an industrial production scale, a large reactor is required. It cannot be said that this is advantageous.

JP 56-147740 A JP 2004-217620 A JP 2005-126445 A JP 2004-203844 A Japanese Examined Patent Publication No. 58-42175 Japanese Patent Publication No.59-29051

  The present invention has been made in view of the above-described problems of the prior art, and the object of the present invention is to use 2-alkylidenecycloalkanone as a raw material in an efficient and industrially advantageous manner. It is to provide a method for producing an alkyl-2-cycloalkenone.

  In order to achieve the above-mentioned object, the present inventors have intensively studied on a method for producing 2-alkyl-2-cycloalkenone in an industrially advantageous manner. As a result, it has been found that by adopting a specific manufacturing process, the target product can be obtained efficiently and industrially advantageously by a simple method, and the present invention has been completed.

Thus, according to the present invention, the following (1) and (2) 2-alkyl-2-cycloalkenone production methods are provided.
(1) 2-alkyl-2, wherein 2-alkylidenecycloalkanone is continuously contacted with a supported solid catalyst in which at least one platinum group metal is supported on a carrier to carry out an isomerization reaction. -Method for producing cycloalkenone.
(2) The solid catalyst is a supported solid catalyst in which at least one metal selected from metals other than the platinum group is supported in addition to at least one platinum group metal. The manufacturing method as described.

  According to the production method of the present invention, 2-alkyl-2-cycloalkenone can be produced from a 2-alkylidenecycloalkanone as a raw material in a simple and efficient manner and industrially advantageously.

It is a conceptual diagram of the apparatus which manufactures continuously 2-pentylidenecyclopentanone used by this invention from 2- (1-hydroxy- n-pentyl) cyclopentanone. It is a conceptual diagram of the manufacturing apparatus for enforcing the manufacturing method of this invention.

Hereinafter, the present invention will be described in detail.
In the present invention, 2-alkylidenecycloalkanone is subjected to an isomerization reaction by continuously contacting 2-alkylidenecycloalkanone with a supported solid catalyst in which at least one platinum group metal is supported on a carrier. This is a method for producing 2-cycloalkenone.

(1) 2-Alkylidenecycloalkanone The 2-alkylidenecycloalkanone used in the present invention is a 2-alkylidenecycloalkanone having a cyclic saturated aliphatic ketone skeleton.

  The cyclic saturated aliphatic ketone skeleton usually has a 4- to 10-membered ring, preferably a 5- to 7-membered ring, more preferably a 5-membered ring. Moreover, the said cyclic saturated aliphatic ketone skeleton may have a substituent in arbitrary positions other than 2-position, unless the isomerization reaction is prevented.

Specific examples of the cyclic saturated aliphatic ketone skeleton include a cyclobutanone skeleton; a cyclopentanone skeleton such as cyclopentanone, 3-methylcyclopentanone, 3-ethylcyclopentanone, and 3-n-propylcyclopentanone;
Cyclohexanone skeletons such as cyclohexanone, 3-methylcyclohexanone, 4-methylcyclohexanone, 3-ethylcyclohexanone, 4-ethylcyclohexanone, 3-n-propylcyclohexanone, 4-n-propylcyclohexanone;
Cycloheptanone skeletons such as cycloheptanone, 3-methylcycloheptanone, 4-methylcycloheptanone;
Cyclooctanone skeletons such as cyclooctanone, 3-methylcyclooctanone, 4-methylcyclooctanone, 5-methylcyclooctanone, 3,4-dimethylcyclooctanone;
Cyclononanone skeletons such as cyclononanone, 3-methylcyclononanone, 4-methylcyclononanone, 5-methylcyclononanone, 3,4-dimethylcyclononanone, 3,4,5-trimethylcyclononanone;
Cyclodecanone, 3-methylcyclodecanone, 4-methylcyclodecanone, 5-methylcyclodecanone, 6-methylcyclodecanone, 3-ethylcyclodecanone, 3,4-dimethylcyclodecanone, 4,5- And cyclodecanone skeletons such as dimethylcyclodecanone and 3,4,5,6-tetramethylcyclodecanone.

  Among these cyclic saturated aliphatic ketone skeletons, cyclopentanone, cyclohexanone, and cycloheptanone are preferable, and cyclopentanone is most preferable.

  The number of carbon atoms of the alkylidene group of the 2-alkylidenecycloalkanone used in the present invention is not particularly limited, but is usually 1 to 10, preferably 2 to 8, more preferably 3 to 7, still more preferably 4 to 6, particularly Preferably it is 5.

  Specific examples of such alkylidene groups include methylidene groups, ethylidene groups, propylidene groups, butylidene groups, pentylidene groups, hexylidene groups, heptylidene groups, octylidene groups, nonylidene groups, decylidene groups and the like;

  2-methylpropylidene group, 2-methylbutylidene group, 3-ethylbutylidene group, 2,2-dimethylbutylidene group, 2,3-dimethylbutylidene group, 2,2,3-trimethylbutylidene group, 2-methylpentylidene group, 3-methylpentylidene group, 4-methylpentylidene group, 2,2-dimethylpentylidene group, 3,4-dimethylpentylidene group, 2,2,3-trimethylpentylidene group, 2-methylhexylidene group, 3-methylhexylidene group, 4-methylhexylidene group, 5-methylhexylidene group, 2-methylheptylidene group, 3-methylheptylidene group, 2-ethyl Heptylidene group, 2-methyloctylidene group, 3-methyloctylidene group, 4-methyloctylidene group, 2-ethyloctylidene group, 3-methylnonylidene group, 4-methyloctylidene group Alkylidene group having a branched such Runoniriden group;

  Cyclobutylmethylidene group, cyclopentylmethylidene group, (2-methylcyclopentyl) methylidene group, (3-methylcyclopentyl) methylidene group, cyclohexylmethylidene group, (2-methylcyclohexyl) methylidene group, (3-methylcyclohexyl) methylidene Group, (2-ethylcyclohexyl) methylidene group, cycloheptylmethylidene group, (2-methylcycloheptyl) methylidene group, (3-methylcycloheptyl) methylidene group, (4-methylcycloheptyl) methylidene group, cyclooctylmethylidene And an alkylidene group having a cyclic structure such as a lidene group, (2-methylcyclooctyl) methylidene group, cyclononylmethylidene group, 2-cyclopentylethylidene group, and 2-cyclohexylethylidene group.

  Among these, methylidene group, ethylidene group, propylidene group, butylidene group, pentylidene group, hexylidene group, heptylidene group, octylidene group, 2-methylbutylidene group, 3-methylbutylidene group, 2-methylpentylidene group, 3 -Methylpentylidene group, 4-methylpentylidene group, cyclobutylmethylidene group, cyclopentylmethylidene group, cyclohexylmethylidene group, cycloheptylmethylidene group are preferable, butylidene group, pentylidene group, hexylidene group, heptylidene group are more Preferably, a pentylidene group is particularly preferable.

  Specific examples of 2-alkylidenecycloalkanone used in the present invention include 2-butylidenecyclopentanone, 2-pentylidenecyclopentanone, 2-hexylidenecyclopentanone, 2-heptylidenecyclopentanone, Examples include 2-pentylidene-5-methylcyclopentanone, 2-butylidenecyclohexanone, 2-pentylidenecyclohexanone, 2-hexylidenecyclohexanone, and 2-heptylidenecyclohexanone. Among these, 2-pentylidenecyclopentanone is particularly preferable.

  2-alkylidenecycloalkanone can be produced and obtained by a conventionally known method. For example, it can be easily obtained by hydrolyzing the reaction product of cycloalkanone enamine and alkyl aldehyde with an acid (hydrochloric acid or the like).

  In addition, 2-alkylidenecycloalkanone is a dehydration reaction by continuously contacting 2- (hydroxyalkyl) cycloalkanone synthesized by an aldol condensation reaction using cycloalkanone and aliphatic aldehyde as raw materials with a solid catalyst. At the same time, it can be obtained by a method of removing the generated water from the reaction system.

(2) Solid catalyst In the present invention, a supported solid catalyst in which at least one platinum group metal is supported on a carrier is used.
The platinum group metal is a general term for Group 8 to 10 elements (Ru, Rh, Pd, Os, Ir, Pt) of the fifth and sixth periods of the periodic table (long period type). A platinum group metal can be used 1 type or in combination of 2 or more types. Among these, Pd is particularly preferable.

  In the present invention, as the solid catalyst, it is preferable to use a supported solid catalyst in which at least one metal selected from metals other than the platinum group is supported in addition to at least one platinum group metal.

Examples of metals other than the platinum group include at least one element selected from Group 2 to 7 elements of the periodic table, Group 11 to 14 elements of the periodic table, and Group 3 elements of Groups 8 to 10 of the periodic table. Can be mentioned. Of these, Group 2 elements and Group 7 elements of the Periodic Table are preferable, and calcium and rhenium are particularly preferable.
The ratio of the platinum group metal to the metal other than the platinum group is 0.05 to 100 parts by weight, preferably 0.1 to 10 parts by weight, with respect to 100 parts by weight of the platinum group metal.

The carrier for supporting a platinum group metal and optionally a metal other than the platinum group is not particularly limited. For example, activated carbon, metal oxide, metal sulfate, metal carbonate, metal phosphate, heteropoly acid, zeolite, diatomaceous earth. , Hydroxyapatite, hydrotalcite, montmorillonite, ion exchange resin and the like. These can be used alone or in combination of two or more. Among these, activated carbon and metal oxide are preferable.
The ratio of the support to the platinum group metal and the metal other than the platinum group used as desired is 0.1 to 60 parts by weight of the platinum group metal and the metal other than the platinum group used as desired with respect to 100 parts by weight of the support. Is 0.5 to 40 parts by weight.

  Specific examples of the metal oxide include silicon oxide (silica), aluminum oxide (alumina), magnesium oxide, calcium oxide, zirconium oxide, niobium oxide, titanium oxide, tin oxide, molybdenum trioxide, and tungsten oxide. Silica, alumina, zirconium oxide and niobium oxide are preferred.

Examples of a method for supporting a platinum group metal and optionally a metal other than the platinum group on the carrier include known methods such as a coprecipitation method, a kneading method, an impregnation method, and an ion exchange method.
For example, a solution of at least one metal salt selected from a platinum group metal salt and, if desired, a metal other than the platinum group metal is added to the support, left to stand for a certain period of time, impregnated in the support, dried, and then reduced. The supported solid catalyst in which a platinum group metal and, if desired, a metal other than the platinum group are supported in a metal state can be prepared by the activation by.

  The platinum group metal salt used here is not particularly limited, and examples thereof include platinum group metal hydrochloride, bromate, nitrate, sulfate, acetate, and the like. Examples of salts of metals other than the platinum group include hydrochlorides, bromates, nitrates, sulfates, acetates and perrhenates of metals other than the platinum group.

  As the reduction method, either a dry method using hydrogen gas or a wet method using a reducing agent solution can be employed. When the former method is employed, hydrogen gas diluted with an inert gas such as nitrogen gas or argon gas can be used.

  The reduction temperature of the catalyst may be appropriately selected depending on the combination of a platinum group metal that is a catalytically active component, a carrier, and another metal that is a promoter component, and is not particularly limited, but is preferably in the range of 100 to 900 ° C.

  The shape of the supported solid catalyst to be used is not particularly limited, and any form such as a powder or a molded product can be used. The molding method of the catalyst is not particularly limited, and a known method such as tableting, compression, rolling granulation or the like can be adopted. Examples of the external shape of the granular molded product include a spherical shape, a disk shape, a columnar shape, and a cylindrical shape.

  The average particle size of the supported solid catalyst is not particularly limited and is appropriately selected according to the inner diameter of the reaction tube described later, but is usually 1 to 40 mm, and preferably 2 to 20 mm. If the effective average particle size is too small, pressure loss increases in continuous reaction, making operation difficult. If the effective average particle size is too large, the geometric surface area per reaction tube unit volume (cylinder standard) Due to the decrease, it becomes difficult to obtain sufficient reaction results.

The specific surface area of the supported solid catalyst is not particularly limited, but is usually appropriately selected from the range of 1 to 100 m ² / g. If the specific surface area is too small, sufficient catalytic activity cannot be obtained, and if the specific surface area is too large, the catalytic activity becomes too high, the production rate of by-products increases, and the target product selectivity decreases. .

(3) Isomerization reaction In the present invention, 2-alkylidenecycloalkanone is continuously brought into contact with a supported solid catalyst in which at least one platinum group metal is supported on a carrier to perform an isomerization reaction. .

  In the present invention, “continuously” means a continuous reaction as a synonym of a batch (batch) reaction. That is, in the reaction operation, the reaction is performed in a state where the supply of the raw material and the extraction of the reaction mixture are continuously performed without interruption while maintaining consistency with respect to the mass balance.

  In the continuous reaction of the present invention, an appropriate method may be used depending on the case regardless of the gas phase or the liquid phase. The shape and material of the reactor to be used are not particularly limited, and examples include a stirred tank type continuous reactor, a fixed bed flow type continuous reactor, and the like. From the viewpoint of reactor efficiency, a fixed bed flow type continuous reactor is used. preferable.

The form of the fixed bed flow type continuous reactor is not particularly limited, and may be either a single pipe type or a multi-pipe type. The temperature control method of the reactor is not particularly limited, and either a heat exchange type or an adiabatic type can be used.
These reactors may be one, or a plurality of reactors may be connected in series.

  For example, stainless steel is suitable as the material of the reactor. A preheater for preheating the raw material mixture and a vaporizer for vaporizing the raw material mixture may be used together with such a reactor. The preheater, the vaporizer, and the reactor do not necessarily need to be separate, and the same reactor and the temperature of each part may be set to a temperature suitable for each purpose.

  When employing the multi-tube fixed bed flow type continuous reactor, the inner diameter of the reaction tube is not particularly limited, but is usually 5 to 500 mm, preferably 7 to 300 mm, more preferably 10 to 200 mm. The length of the reaction tube is not particularly limited, but is usually 0.1 to 10 m, preferably 0.2 to 7 m.

  When the reaction is carried out in a stirred tank type continuous reactor, the residence time is usually 0.05 to 100 hours, preferably 0.2 to 5 hours. When it is carried out in a fixed bed flow type continuous reactor, it is usually 1 to 500 seconds, preferably 2 to 300 seconds.

  The reaction pressure (gauge pressure) is usually −0.1 to 1 MPaG, preferably −0.1 to 0.5 MPaG, more preferably −0.1 to 0.1 MPaG.

  Further, the 2-alkylidenecycloalkanone to be contacted with the supported solid catalyst may be the 2-alkylidenecycloalkanone as it is, or it may be one obtained by diluting 2-alkylidenecycloalkanone with an appropriate diluent. Good.

  The diluent to be used is not particularly limited as long as it is an inert substance that does not interfere with the reaction, and may be liquid or gas. For example, aromatic hydrocarbons such as benzene, toluene and ethylbenzene; alicyclic hydrocarbons such as cyclohexane, cycloheptane and cyclooctane; alcohols such as n-butanol and n-pentanol; gases such as nitrogen gas; It is done. These diluents can be used alone or in combination of two or more.

  When 2-cycloalkylidenecycloalkanone which is a raw material is diluted with a diluent, the amount used is usually 5 to 2000 parts by weight with respect to 100 parts by weight of the raw material.

In the present invention, 2-alkylidenecycloalkanone and, if desired, a diluent, a value obtained by dividing the space velocity (total flow rate per hour of the liquid reference raw material by the catalyst filling volume (cylinder reference)). the same.) at "hereinafter. hereinafter, usually 0.001～100Hr ^-1, preferably introduced onto the catalyst in 0.01～20Hr ^-1. If the LHSV is too large, sufficient reaction results cannot be obtained. If the LHSV is too small, the production rate of by-products increases, causing a decrease in the target product selectivity and at the same time promoting the deterioration of the catalyst. There is a risk.

  The temperature at which the 2-alkylidenecycloalkanone and optionally the diluent are brought into contact with the catalyst is usually 20 to 400 ° C, preferably 50 to 300 ° C, more preferably 80 to 280 ° C. Specifically, 2-alkylidenecycloalkanone and, optionally, a diluent are introduced onto a catalyst that is usually maintained at 20 to 400 ° C., preferably 50 to 300 ° C. If the temperature when the 2-alkylidenecycloalkanone and optionally the diluent are contacted with the catalyst is too low, sufficient reaction results cannot be obtained, and if the reaction temperature is too high, the rate of by-product formation increases. In addition, the target product selectivity may be lowered, and at the same time, deterioration of the catalyst may be promoted.

  The 2-alkyl-2-cycloalkenone obtained according to the present invention can be isolated with high purity by subjecting it to purification means such as vacuum distillation, if necessary. .

  The cyclic part of 2-alkyl-2-cycloalkenone obtained by the present invention is a 4- to 10-membered ring, preferably a 5- to 7-membered ring, particularly preferably a 5-membered ring. Moreover, carbon number of the 2-position alkyl group of 2-alkyl-2-cycloalkenone is 1-10 normally, Preferably it is 2-8, More preferably, it is 3-7, More preferably, it is 4-6, Most preferably, it is 5 It is. Moreover, 2-alkyl-2-cycloalkenone may have an arbitrary substituent at a site other than the 2-position of the cyclic portion.

Specific examples of 2-alkyl-2-cycloalkenone obtained from the present invention include 2-n-butylcyclopentenone, 2-n-pentyl-2-cyclopentenone, 2-n-hexyl-2-cyclopene. Tenon, 2-n-heptyl-2-cyclopentenone, 2-n-pentyl-5-methyl-2-cyclopentenone, 2-n-butyl-2-cyclohexenone, 2-n-pentyl-2-cyclohex Examples include cenone, 2-n-hexyl-2-cyclohexenone, 2-n-heptyl-2-cyclohexenone. Among these, 2-n-pentyl-2-cyclopentenone is particularly preferable.
2-n-pentyl-2-cyclopentenone is useful as an intermediate for the production of the perfume methyl jasmonate.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the following examples.
In the following examples and comparative examples, the conversion rate, selectivity, and reactor efficiency are defined as follows.

Conversion (%) = (moles of reacted 2-alkylidenecycloalkanone / moles of fed 2-alkylidenecycloalkanone) × 100
Selectivity (%) = (number of moles of 2-alkyl-2-cycloalkenone produced / number of moles of reacted 2-alkylidenecycloalkanone) × 100
Yield (%) = (number of moles of 2-alkyl-2-cycloalkenone produced / number of moles of 2-alkylidenecycloalkanone fed) × 100
Reactor efficiency (kg / (m ³ · hr)) = production amount of 2-alkyl-2-cycloalkenone per hour (kg / hr) / reactor volume (m ³ )

  In the following Production Example 1, production of 2-pentylidenecyclopentanone was performed using the production apparatus shown in FIG. Moreover, in the following Examples 1-5, manufacture of 2-n-pentyl-2-cyclopentenone was performed using the manufacturing apparatus shown in FIG. The manufacturing apparatus shown in FIG. 2 is a manufacturing apparatus for carrying out the manufacturing method of the present invention.

(Production Example 1) Synthesis of 2-pentylidenecyclopentanone (1) Step 1 A reactor equipped with a stirrer was charged with 151.2 g (1.8 mol) of cyclopentanone and 1.5% by weight of hydroxylation. 80 g of sodium aqueous solution and 86 g (1 mol) of valeraldehyde were added and stirred at room temperature for 3 hours. After completion of the reaction, hydrochloric acid was added dropwise to the reaction solution for neutralization. As a result of analyzing the oil layer separated into oil and water by gas chromatography (GC), 2- (1-hydroxy-n-pentyl) cyclopentanone was produced in a yield of 90%. By distilling off unreacted cyclopentanone from this composition organism, 170.2 g of 2- (1-hydroxy-n-pentyl) cyclopentanone having a purity of 90% was obtained.

(2) Second Step 76 ml of a strongly acidic ion exchange resin (RCP160M, manufactured by Mitsubishi Chemical Corporation) is charged into the stainless steel reactor 31 (inner diameter 22.4 mm, length 200 mm) shown in FIG. Was held at 85 ° C. The 2- (1-hydroxypentyl) cyclopentanone obtained in the first step is heated to 85 ° C., and the pressure inside the reactor 31 is reduced to −0.05 MPaG from the bottom of the reactor 31. 1-Hydroxypentyl) cyclopentanone was continuously circulated with LHSV0.8Hr- ¹ . As a result of GC analysis of the crude product obtained at the outlet of the reactor 31, the conversion was 96%, the selectivity was 87%, and the yield was 84%. The crude product was distilled under reduced pressure to obtain 2-pentylidenecyclopentanone having a purity of 97%.

Example 1 Production of 2-n-pentyl-2-cyclopentenone using activated carbon-supported palladium catalyst (1) Preparation of activated carbon-supported palladium catalyst 70 g of activated carbon (Shirakaba G2X, manufactured by Nippon Enviro Chemical Co., Ltd.) in a 500 ml eggplant flask To this, 200 ml of distilled water and 70 ml of concentrated hydrochloric acid (special grade reagent, manufactured by Wako Pure Chemical Industries, Ltd.) were added and allowed to stand at room temperature for 8 hours. After standing, the content was suction filtered, and the filtrate was distilled and washed with 150 ml. The obtained filtrate was put into a 300 ml eggplant flask, and a solution prepared by mixing 31.3 g of concentrated hydrochloric acid, 5.3 g of palladium chloride (special grade reagent, manufactured by Wako Pure Chemical Industries, Ltd.) and 200 ml of distilled water was added. This was allowed to stand at room temperature for 12 hours, and then water was removed using an evaporator. The obtained solid content was dried in air at 120 ° C. for 5 hours to obtain a catalyst precursor.

  The obtained catalyst precursor was filled in a stainless steel filling tube (inner diameter 23 mm, length 18 cm) and set in an electric furnace. The tube was dried at 350 ° C. for 3 hours while flowing nitrogen gas at a flow rate of 40 ml / min, and then reduced at 350 ° C. for 5 hours while flowing a mixed gas of hydrogen / nitrogen = 4 (volume ratio). Thus, an activated carbon-supported palladium catalyst (a solid catalyst in which 4.5% by weight of palladium was supported on activated carbon) was obtained.

(2) Production of 2-n-pentyl-2-cyclopentenone

The supported solid catalyst obtained above was charged into the stainless steel reactor 32 (inner diameter 10.7 mm, length 200 mm) shown in FIG. 2, and the reactor 32 was kept at 220 ° C. The 2-pentylidenecyclopentanone obtained in Production Example 1 was heated to 220 ° C. in the catalyst packed tower 42 and continuously passed from the lower part of the reactor 32 under normal pressure with LHSV 0.8 Hr ⁻¹ . As a result of quantitative analysis of the crude product obtained at the outlet of the reactor 32, the conversion was 73%, the selectivity was 74%, and the yield was 54%. In addition, the reactor efficiency at this time was 405.

Example 2 Production of 2-n-pentyl-2-cyclopentenone using activated carbon-supported palladium / calcium catalyst (1) Preparation of activated carbon-supported palladium / calcium catalyst 70 g of activated carbon (Shirakaba G2X, manufactured by Nippon Enviro Chemical Co., Ltd.) Was weighed into a 500 ml eggplant flask, and 200 ml of distilled water and 70 ml of concentrated hydrochloric acid (special grade reagent, manufactured by Wako Pure Chemical Industries, Ltd.) were added thereto and allowed to stand at room temperature for 8 hours. After standing, the content was suction filtered, and the filtrate was distilled and washed with 150 ml. The filtrate after washing was put into a 300 ml eggplant flask, 29.45 g of calcium nitrate (special grade reagent, manufactured by Wako Pure Chemical Industries, Ltd.) dissolved in 200 ml of distilled water was added, and the water was evaporated using an evaporator. . The obtained solid was put into a 300 ml eggplant flask, and a solution prepared by mixing 31.3 g of concentrated hydrochloric acid, 5.3 g of palladium chloride (special grade reagent, manufactured by Wako Pure Chemical Industries, Ltd.) and 200 ml of distilled water was added. This was allowed to stand at room temperature for 12 hours, and then water was removed using an evaporator. The obtained solid content was dried in air at 120 ° C. for 5 hours to obtain a catalyst precursor.

  The obtained catalyst precursor was filled in a stainless steel filling tube (inner diameter 23 mm, length 18 cm) and set in an electric furnace. The tube was dried at 350 ° C. for 3 hours while flowing nitrogen gas at a flow rate of 40 ml / min, and then reduced at 350 ° C. for 5 hours while flowing a mixed gas of hydrogen / nitrogen = 4 (volume ratio). Then, an activated carbon-supported palladium / calcium catalyst (a solid catalyst in which 4.5% by weight of palladium and 5% by weight of calcium were supported on activated carbon) was prepared.

(2) Production of 2-n-pentyl-2-cyclopentenone The reaction was performed in the same manner as in Example 1 except that the activated carbon-supported palladium / calcium catalyst obtained by the method (1) was used. The conversion was 84%, the selectivity was 84%, and the yield was 71%. Further, the reactor efficiency at this time was 524.

(Example 3) Production of 2-n-pentyl-2-cyclopentenone using an alumina-supported palladium catalyst (1) Preparation of alumina-supported palladium catalyst In the method for preparing an activated carbon-supported palladium catalyst of Example 1, instead of activated carbon An alumina-supported palladium catalyst was prepared in the same manner as in Example 1 except that γ-alumina (N612N, manufactured by JGC Chemical Co., Ltd.) was used.

(2) Production of 2-n-pentyl-2-cyclopentenone 2-Pentylidenecyclopentanone is heated to 240 ° C., diluted with a nitrogen stream at LHSV 0.8 Hr ⁻¹ at a flow rate of 110 Ncm ³ / min, and gas phase In this state, it was circulated under normal pressure from the bottom of the reaction tube. As a result of quantitative analysis of the crude product obtained at the outlet of the reaction tube, the conversion was 88%, the selectivity was 68%, and the yield was 60%. Further, the reactor efficiency at this time was 444.

Example 4 Production of 2-n-pentyl-2-cyclopentenone using an alumina-supported palladium / calcium catalyst (1) Preparation of an alumina-supported palladium / calcium catalyst Preparation of an activated carbon-supported palladium / calcium catalyst of Example 2 In this method, alumina-supported palladium / calcium catalyst (4.5 wt% palladium, 5 wt% calcium was used in the same manner as in Example 2 except that γ-alumina (N612N, manufactured by JGC Chemical Co., Ltd.) was used instead of activated carbon. Was prepared on a solid catalyst).

(2) Production of 2-n-pentyl-2-cyclopentenone A reaction was carried out in the same manner as in Example 3 except that the alumina-supported palladium / calcium catalyst obtained in (1) above was used. The conversion was 91%, the selectivity was 70%, and the yield was 63%. The reactor efficiency at this time was 472.

(Example 5) Production of 2-n-pentyl-2-cyclopentenone using activated carbon-supported palladium / rhenium catalyst (1) Preparation of activated carbon-supported palladium / rhenium catalyst Activated carbon (Shirakaba G2X, manufactured by Nippon Enviro Chemical Co., Ltd.) 70 g Was weighed into a 500 ml eggplant flask, and 200 ml of distilled water and 70 ml of concentrated hydrochloric acid (special grade reagent, manufactured by Wako Pure Chemical Industries, Ltd.) were added thereto and allowed to stand at room temperature for 8 hours. After standing, the content was suction filtered, and the filtrate was distilled and washed with 150 ml. The filtrate after washing is put into a 300 ml eggplant flask, 31.3 g of concentrated hydrochloric acid, 5.3 g of palladium chloride (special grade reagent, manufactured by Wako Pure Chemical Industries, Ltd.), 0.22 g of potassium perrhenate (manufactured by Wako Pure Chemical Industries, Ltd.) , And a mixed solution of 200 ml of distilled water was added. After leaving this to stand at room temperature for 12 hours, water was removed using an evaporator. The obtained solid content was dried in air at 120 ° C. for 5 hours to obtain a catalyst precursor.

  The obtained catalyst precursor was filled in a stainless steel filling tube (inner diameter 23 mm, length 18 cm) and set in an electric furnace. The tube was dried at 350 ° C. for 3 hours while flowing nitrogen gas at a flow rate of 40 ml / min, and then reduced at 350 ° C. for 5 hours while flowing a mixed gas of hydrogen / nitrogen = 4 (volume ratio). An activated carbon-supported palladium / rhenium catalyst was obtained.

(2) Production of 2-n-pentyl-2-cyclopetenone Reaction was carried out in the same manner as in Example 1 except that the activated carbon-supported palladium / rhenium catalyst obtained by the method (1) was used and the reaction temperature was 200 ° C. Went. The conversion was 93%, the selectivity was 84%, and the yield was 78%. Further, the reactor efficiency at this time was 568.

Comparative Example 1 Production of 2-n-pentyl-2-cyclopentenone by a batch method (1)
To a 200 ml four-necked flask, 100 g of 2-pentylidenecyclopentanone obtained in Production Example 1 and 5 g of an activated carbon-supported palladium catalyst containing 4.5% by weight of palladium obtained in Example 1 (1) were added, A reflux condenser was attached, and the mixture was heated and stirred at 150 ° C. for 6.5 hours under a nitrogen stream under normal pressure. After the reaction, the reaction solution was quantitatively analyzed by GC. As a result, the raw material conversion was 86%, the selectivity was 92%, and the yield was 79%. Further, the reactor efficiency at this time was 61.

Comparative Example 2 Production of 2-n-pentyl-2-cyclopentenone by a batch method (2)
In Comparative Example 1, the reaction was performed in the same manner as Comparative Example 1 except that a γ-alumina catalyst was used instead of the activated carbon-supported palladium catalyst. When the reaction solution was quantitatively analyzed by GC, the raw material conversion was 94.6%, the selectivity was 2.5%, and the yield was 2.4%. The reactor efficiency at this time was 18.

From the above results, Comparative Example 1 in which the production method is a batch method has low reactor efficiency, and γ-alumina is further used as the solid catalyst, and Comparative Example 2 in which the production method is a batch method, the selectivity, yield, and The reactor efficiency was low.
Compared with the present, Examples 1-5 which are the manufacturing methods of this invention have high selectivity, a yield, and reactor efficiency, and it turned out that 2-n-pentyl-2-cyclopentenone can be manufactured efficiently. .

11, 12 ... Raw material tanks 21, 22 ... Liquid feed pumps 31, 32 ... Reactors 41, 42 ... Catalyst packed towers 51, 52 ... Coolers 61, 62 ... Reaction liquids tank

Claims (2)

  2-alkyl-2-cycloalkenone characterized in that 2-alkylidenecycloalkanone is continuously brought into contact with a supported solid catalyst in which at least one platinum group metal is supported on a carrier to carry out an isomerization reaction. Manufacturing method.   2. The production according to claim 1, wherein the solid catalyst is a supported solid catalyst obtained by supporting at least one metal selected from metals other than the platinum group in addition to at least one platinum group metal. Method.

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