JP2001240569A - Preparation method of compound having -ch2-chf- group - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a preparation method of a 4C or higher compound containing-CH2-CHF- group that is low in deactivation of a hydrogenation catalyst in hydrogenation, also high in selectivity and yield and industrially advantageous. SOLUTION: The 4C or higher compound containing the -CH2-CHF- group is prepared by gas-phase hydrogenation of a 4C or higher compound containing a -CCl=CF- group in the presence of the hydrogenation catalyst in which this preparation method is characterized by dividing a reaction zone to be packed the above hydrogenation catalyst into at least two zones and (1) packing the hydrogenation catalyst lower in activity than the rear zone catalyst in the former reaction zone or (2) keeping the external heating temperature of the former reaction zone lower than the rear zone.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention has a carbon number containing -CH ₂ -CHF- group such useful 1,1,2,2,3,3,4-heptafluoro cyclopentane as a cleaning agent or solvent It relates to a method for producing four or more compounds.

[0002]

2. Description of the Related Art 1,1,2,2,3,3,4-heptafluorocyclopentane (hereinafter sometimes abbreviated as HFCPA) is a known substance having a boiling point of 82.5 ° C. (under normal pressure). There is conventionally known a manufacturing method thereof.

[0003] As a method for producing HFCPA, for example, perfluorocyclopentene is reacted with hydrogen in the presence of a hydrogenation catalyst such as palladium to make 1,1,2,2,3,1.
It has been reported that 3,4,4-octafluorocyclopentane is obtained as a by-product when synthesizing (JCS (C)., 548 (1968)). However, there is no description that this HFCPA was isolated,
Since these two compounds have almost the same boiling point, separation from the main product by distillation is difficult.

In addition, perfluorocyclopentene is added to 0.1.
175-20 using 1% palladium on alumina as a catalyst
Hydrogenation at 0 ° C. with hydrogen allows H, as a minor component, with 1,2-dihydrooctafluorocyclopentane.
A method for obtaining FCPA is described in GB 1046095.

Japanese Patent Application Laid-Open No. H11-322644 proposes a method for producing HFCPA by hydrogenating and reducing chlorononafluorocyclopentane as a starting material in the presence of palladium-supported activated carbon and sodium hydrogen carbonate. HFCPA (target substance) in the product obtained by this method is 35%, and it is described that 56.8% of the unreacted raw material remains, so it cannot be said that the production method is industrially satisfactory.

Further, WO 99/33771 proposes a method for producing HFCPA by hydrogenating 1-chloroheptafluorocyclopentene as a raw material in the presence of a noble metal catalyst such as palladium. Also,
This publication also describes a method in which a noble metal catalyst is used by being supported on activated carbon, alumina, silica gel, titania, zirconia, and those obtained by treating these with hydrogen fluoride.

The method for producing HFCPA using 1-chloroheptafluorocyclopentene as a raw material has a conversion of the raw material of 99%, which is significantly improved as compared with the above-mentioned conventional production method.

[0008]

However, this manufacturing method has the following problems. That is, in this production method, 1-chloroheptacyclopentene is continuously dechlorinated by passing a reducing gas containing hydrogen through a reaction section (reaction column) filled with a noble metal hydrogenation catalyst such as palladium. In this reaction, the reaction heat is large and the reaction part becomes partially hot (generation of hot spots), causing catalyst sintering and catalyst poisoning substances. (Catalyst poison) may increase. In such a case, the life of the catalyst is shortened, and undesired by-products are obtained, which has been a problem in industrial mass production.

[0009] The present invention is to solve the problems of the prior art, less deterioration of the hydrogenation catalyst of the hydrogenation reaction, yet industrially advantageously high selectivity and in high yield, -CH ₂ -CHF
It is an object of the present invention to provide a method for producing a compound having 4 or more carbon atoms containing a group.

[0010]

Means for Solving the Problems The present inventors have proposed -CCl
Reaction conditions for producing a compound having 4 or more carbon atoms containing a —CH ₂ —CHF— group by a gas-phase hydrogenation reaction using a compound having 4 or more carbon atoms containing a = CF— group as a raw material, As a result of intensive studies on the reaction temperature, this gas-phase hydrogenation reaction was roughly divided into two, and the reaction conditions in the former stage were changed to milder conditions (using a less active hydrogenation catalyst, lower reaction temperature, That the above-mentioned issues can be achieved.
The present invention has been completed.

That is, the present invention provides a method for hydrogenating a compound having a carbon number of 4 or more containing a —CCl ＝ CF— group in the presence of a hydrogenation catalyst in the gas phase to obtain a carbon number containing a —CH ₂ —CHF— group. A method for producing four or more compounds, wherein the reaction part charged with the hydrogenation catalyst is divided into at least two parts,
(1) -CH characterized by filling the active low hydrogenation catalyst than subsequent to the reaction unit of the preceding stage, or (2) external heating temperature in the reaction section of the preceding stage lower than subsequent ₂ -CHF-
This is a method for producing a compound having a group and having 4 or more carbon atoms.

In the present invention, the above-mentioned -CCl = CF-
It is preferable to use 1-chloroheptafluorocyclopentene as the compound having 4 or more carbon atoms having a group.

Further, in the present invention, a hydrogen gas and a compound having a carbon number of 4 or more containing a -CCl = CF- group are mixed in a reaction section at a flow rate molar ratio of 2: 1 to 10: 1 (hydrogen gas: -C
Cl = CF-group-containing compound having 4 or more carbon atoms) to give -CCl = CF-group-containing 4 carbon atoms.
More preferably, the above compounds are subjected to gas phase hydrogenation.

According to the present invention, there is little deterioration of the hydrogenation catalyst in the hydrogenation reaction, and it is industrially advantageous in high selectivity and high yield and has a --CH ₂ --CHF-- group containing 4 or more carbon atoms. Can be manufactured.

[0015]

DETAILED DESCRIPTION OF THE INVENTION The present invention is, -CCl = CF- the number 4 or more compounds the carbon containing group is hydrogenated in the presence of a hydrogenation catalyst, carbon atoms containing -CH ₂ -CHF- group 4
The present invention relates to a method for producing the compound. The starting compound used in the present invention contains a —CCl ＝ CF— group in the molecule,
It is a chain or alicyclic compound having 4 or more carbon atoms. −
The carbon number of the basic skeleton of the compound containing a CCl = CF- group is usually 4 to 10, preferably 4 to 6, and particularly preferably 5.

The general formula of a compound having a carbon number of 4 or more containing a —CCl ＝ CF— group is shown in the following formula (1).

[0017]

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In the formula, the substituents R ¹ and R ² each independently represent a hydrogen atom, a fluorine atom or an alkyl group having 1 to 8 carbon atoms. All or a part of the alkyl group having 1 to 8 carbon atoms may be fluorinated. Where R
^At least one of ¹ and R ² is an optionally fluorinated alkyl group having 1 to 8 carbon atoms, and the sum of the carbon numbers of both R ¹ and R ² is at least 2. Also, R ¹ and R ² are
Both are united and have ² to ² carbon atoms together with C ¹ and C 2.
8 may form an alicyclic skeleton.

The substituents R ¹ and R ² are selected from a hydrogen atom, a fluorine atom, an alkyl group having 1 to 8 carbon atoms and an alkyl group substituted by a fluorine atom. Carbon number 1
As the alkyl group of 8, methyl, ethyl, propyl,
Isopropyl, n-butyl, sec-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, n-
Hexyl, isohexyl, n-heptyl, n-octyl and the like can be mentioned.

Further, a compound having 1 to 1 carbon atoms substituted by a fluorine atom
Examples of the alkyl group of 8 include a fluoroalkyl group in which part or all of the hydrogen atoms of the above alkyl having 1 to 8 carbon atoms has been substituted with a fluorine atom.

Among these, a fluorine atom and a perfluoroalkyl group having 1 to 8 carbon atoms are preferred. For example,
Trifluoromethyl group, pentafluoroethyl group, heptafluoro-n-propyl group, heptafluoroisopropyl group, perfluoro-n-butyl group, perfluoro-
A linear or branched perfluoroalkyl group having 1 to 8 carbon atoms such as a sec-butyl group, a perfluoro-t-butyl group, a perfluoropentyl group, a perfluorohexyl group, a perfluoroheptyl group, and a perfluorooctyl group. No.

The compound represented by the formula (1) may have stereoisomers (E isomer and Z isomer) derived from a carbon-carbon double bond, and both isomers are present. It can be used for the invention.

In the formula (1), R ¹ and R ² are bonded to each other to form C ¹
And alicyclic compounds with C ² by forming a ring of 2-8 carbon atoms, the compound represented by formula (2).

[0024]

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In the above formula (2), the divalent hydrocarbon group -R ¹ -R ^2- has 2 to 8, preferably 2 to 4 carbon atoms. Further, all or a part of the hydrogen atom of the divalent hydrocarbon group -R ¹ -R ^2- may be fluorinated.

Of these, a perfluoroalkylene group having 2 to 8 carbon atoms and all of the hydrogen atoms of the hydrocarbon group -R ¹ -R ^2- being fluorinated is particularly preferred. For example, perfluoroethylene group, perfluoro-n-propylene group, perfluoroisopropylene group, perfluoro-n
Linear or branched such as -butylene group, perfluoro-sec-butylene group, perfluoro-tert-butylene group, perfluoropentylene group, perfluorohexylene group, perfluorohepthiolen group, perfluorooctylene group, etc. Perfluoroalkylene group.

The alicyclic compound represented by the above formula (2) includes, for example, cyclobutene compounds, cyclopentene compounds, cyclohexene compounds, cycloheptene compounds,
And cyclooctene compounds. Among these, a cyclobutene compound, a cyclopentene compound, and a cyclohexene compound are preferred, and a cyclopentene compound is more preferred.

Specific examples of the compound having a carbon number of 4 or more containing a —CClＣＦCF— group include 1-chloroheptafluorobutene, 2-chloroheptafluorobutene and 1-chloroheptafluorobutene.
Chlorononafluoropentene, 2-chloroheptafluoropentene, 3-chlorononafluoro-2-pentene,
1-chloroundecafluorohexene, 2-chloroundecafluorohexene, 3-chloroundecafluoro-2
Chlorofluoroalkenes such as hexene,

1-chloropentafluorocyclobutene,
Alicyclic chlorofluoroalkenes such as 1-chloroheptafluorocyclopentene, 1-chlorononafluorocyclohexene, 1-chloro-5-trifluoromethyloctafluorocyclohexene, and 1-chloroundecafluorocycloheptene are exemplified.

Of these, 1-chlorononafluoropentene, 2-chlorononafluoropentene, 3-chlorononafluoro-2-pentene and 1-chloroheptafluorocyclopentene are preferred, and 1-chloroheptafluorocyclopentene is most preferred.

The compounds having 4 or more carbon atoms containing the -CCl = CF- group can be prepared by a known production method, for example, WO99 /
Those manufactured by the method described in, for example, Japanese Patent No. 33771 can be used.

The hydrogen used in the hydrogenation reaction may be in a gaseous state, and a diluent such as nitrogen, a hydrocarbon gas, a hydrofluorocarbon gas or a rare gas may be used in combination. As hydrocarbon gas, methane gas, ethane gas,
Propane gas, butane gas, and the like, pentafluoroethane, pentafluoropropane, hexafluorobutane, decafluoropentane, and the like, as the hydrofluorocarbon gas, and helium, argon, and the like, as the rare gas, can be given.

These diluents may be used alone,
Alternatively, two or more kinds may be used in combination. Although the amount of the diluent used is not particularly limited, for example, -CCl = CF-
Usually, 0 to 100 parts by weight of the compound containing a group.
500 parts by weight, preferably 0 to 200 parts by weight.

The proportions of hydrogen and raw materials used can vary greatly. However, enough hydrogen is needed to effect hydrogenolysis of carbon-chlorine bonds and hydrogenation of carbon-carbon double bonds using at least a stoichiometric amount of hydrogen. The amount of hydrogen used is usually 2 mol or more per 1 mol of the starting material, and may be appropriately selected in the range of 2 mol to 50 mol. Preferably it is 2 to 10 mol. Before flowing the hydrogen gas, it is preferable to completely remove air from the reaction system by, for example, sufficiently flowing a nitrogen gas or the like.

The hydrogenation catalyst used in the present invention includes:
For example, the periodic table VI of palladium, rhodium, ruthenium, rhenium, platinum, iridium, osmium, etc.
A simple substance of a group II element or a compound thereof is exemplified. Among these, palladium, rhodium, ruthenium or a compound thereof is preferable, and palladium or a palladium compound is particularly preferable. Examples of the metal compound include compounds of Group VIII elements of the periodic table, such as palladium acetate, palladium sulfate, palladium nitrate, palladium chloride, and platinum oxide.

These metal catalysts may be those composed of a single metal, or may be used as an alloy of two or more metals, a so-called bimetallic catalyst. As such an alloy, an alloy mainly containing palladium is preferable.

Further, the hydrogenation catalyst of the present invention may contain a metal component (addition metal component) other than the above-mentioned metals. Examples of the added metal component include silver, copper, gold, tellurium, zinc, chromium, molybdenum, thallium, tin, bismuth, and lead. The amount of the added metal component is 0.01 to 500 parts by weight, preferably 0.1 to 30 parts by weight, per 100 parts by weight of the metal.
0 parts by weight is preferable from the viewpoint of utilizing the properties of the metal. Generally, in an alloy catalyst, the characteristics of the component elements can be made to appear or the catalytic activity can be varied according to the alloy composition.

As the carrier for supporting the hydrogenation catalyst, if the specific surface area is large and the heat resistance is high, the type,
The shape, size and the like are not particularly limited. Examples of the type of the carrier include activated carbon, alumina, silica gel, titania, zirconia, and those obtained by treating these with hydrogen fluoride. As the shape of the carrier, powder, spherical,
It may be a granular material such as a pellet. The granular material may be a processed compact or a crushed product. A preferred shape is a granular material. The amount of the hydrogenation catalyst carried on the carrier is usually 0.05 to 20% by weight, preferably 0.1 to 10% by weight, more preferably 0.5 to 7% by weight.
% By weight.

In general, changing the amount of hydrogenation catalyst carried changes the catalytic activity. That is, the catalytic activity can be increased by increasing the supported amount of the hydrogenation catalyst, and conversely, the catalytic activity can be reduced by decreasing the supported amount.

The pressure of the reaction system of the present hydrogenation reaction is usually from normal pressure to about 50 kg / cm ² , preferably from normal pressure to ² kg / cm 2.
It is about 0 kg / cm ² . The reaction temperature is usually from ordinary temperature to about 350 ° C, preferably from ordinary temperature to about 200 ° C. In this reaction, the reaction system is stirred or shaken as necessary.

In general, the higher the pressure in the reaction system, the more easily the hydrogenation reaction proceeds. However, since there is a possibility that an undesired side reaction may also proceed, it is necessary to select conditions under which the desired product can be obtained with the highest yield. There is. Also, the higher the reaction temperature, the easier the hydrogenation reaction proceeds, but if the reaction temperature is too high, by-products are obtained as described later, sintering of the hydrogenation catalyst occurs due to heat, and catalyst poisoning occurs. May be generated. Therefore, it is necessary to appropriately control the reaction temperature.

The hydrogenation reaction of the present invention is preferably a continuous reaction in which a raw material and hydrogen gas are continuously supplied to a reaction section filled with a hydrogenation catalyst, and a reaction product is continuously extracted from the reaction section. . The reaction vessel used was 1 connected in series.
One or more reactors can be used, for example a cascade reactor.

As a material for the reaction vessel, for example, stainless steel is suitable. It is also preferred that the stainless steel reactor be conditioned before use, for example by nitric acid treatment.

In the present invention, a compound having a carbon number of 4 or more containing a —CH ₂ —CHF— group is produced from a compound having a carbon number of 4 or more containing a —CCl ＝ CF— group as a raw material by a gas phase hydrogenation reaction. This method is characterized in that the gas-phase hydrogenation reaction is roughly divided into two, and the reaction conditions in the former stage are made milder in the latter stage. That is, the present invention aims at controlling the initial stage of the gas phase hydrogenation reaction.

As a method for making the reaction conditions in the former stage more mild, the reaction conditions in the latter stage include, for example, 1) using a relatively low-activity catalyst in the former stage of the reaction, A method using a relatively high activity, 2) a method in which the reaction temperature in the preceding step is relatively lower than the reaction temperature in the subsequent step, and the like. In the present invention, the pre-stage and the post-stage are for convenience only, and do not precisely regulate the reaction stage.

As a method for reducing the catalytic activity of 1),
(A) increasing the particle diameter of the metal catalyst particles used,
(B) reducing the specific surface area of the support, (c) reducing the amount of the metal catalyst supported on the support, and (d) adding bismuth to a simple substance of Group VIII element of the periodic table such as palladium or these compounds. For example, there is a method of adding another metal. In order to increase the catalytic activity, (a) reducing the particle diameter of the metal catalyst particles used, (b) increasing the specific surface area of the carrier, or (c) increasing the amount of the metal catalyst supported on the carrier. It depends on the method.

For example, a metal catalyst is filled in the reaction section,
In the case where the gaseous hydrogenation reaction is continuously performed by feeding the raw material and the hydrogen gas into the reaction part, the reaction part is divided into at least two parts, and the front part (the side where the raw material and the hydrogen are sent)
May be filled with a metal catalyst having relatively low catalytic activity, and the rear portion (a side from which a reaction product is taken out) may be filled with a metal catalyst having relatively high catalytic activity. In this case, the reaction part is not limited to two parts, but may be divided into three parts, four parts, or the like, or a metal catalyst may be provided in the reaction part so that the catalytic activity gradually (continuously) increases. It can also be filled.
Further, the number of reaction units is not limited to one.
It is also preferable to fill the reaction tube with a metal catalyst having relatively low catalytic activity, and fill the second reaction tube with a metal catalyst having relatively high catalytic activity.

2) As a method of controlling the reaction temperature, for example, the reaction temperature in the preceding stage (the external heating temperature of the reaction section) is set to 3
0 to 130 ° C., preferably 50 to 110 ° C., and the reaction temperature in the subsequent stage (external heating temperature of the reaction section) is 100 to 200 ° C.
° C, preferably 100 to 150 ° C. Further, in the present invention, the above methods 1) and 2) can be used in combination, and more preferable effects can be obtained by using the methods in combination.

In the gas phase reaction of the present invention, a mixed gas of hydrogen gas and a gas of a compound containing a —CCl ＝ CF— group (in the case of a liquid, in a gaseous state) is fed into a reaction section filled with a metal catalyst. Is preferred. In this case, when the flow rate ratio between the hydrogen gas and the compound containing a —CCl ＝ CF— group is changed, the conversion, the selectivity of the reaction, and the location of the hot spot are changed. Therefore, in actually carrying out the present invention, a compound containing a hydrogen gas and a —CClＣＦCF— group so as to have the highest conversion rate, excellent selectivity, and so as not to generate a hot spot in a stage before the reaction section. It is necessary to optimize the gas flow ratio. The flow ratio of the hydrogen gas and the gas of the compound containing a —CCl ＝ CF— group can be appropriately set depending on the raw material, the reaction temperature, the metal catalyst used, and the like.
Compound containing a group = 2: 1 to 50: 1 (molar ratio);
Preferably it is 2: 1 to 10: 1 (molar ratio). It is preferable that the flow ratios of these gases are experimentally obtained in advance and set.

In the present invention, acidic components such as hydrogen chloride gas are generated as by-products. This acidic component is preferably removed by absorption or neutralization during or after the reaction. Examples of the removal method include a method in which an additive is added to the system, and a method in which the reaction product is washed with water or alkaline water. Examples of additives and alkalis used for washing include hydroxides, oxides, weak acid salts, and organic acid salts of alkali metals or alkaline earth metals. For example,
Examples include soda lime, quicklime, alkali carbonate, and alkali acetate. These additives can be used alone or in combination of two or more. These are used in an amount of 1 mol or more based on 1 mol of a compound containing a —CCl ＝ CF— group as a raw material.

After completion of the reaction, the desired product can be isolated by a conventional purification method such as distillation after absorbing or neutralizing the acidic component, if necessary.

The compound obtained by the production method of the present invention is
It is a chain or alicyclic compound having 4 or more carbon atoms containing a CH ₂ —CHF— group. In particular, the method of the present invention can be suitably applied to the synthesis of alicyclic compounds. -CH ₂ -CHF-
The carbon number of the basic skeleton of the compound containing a group is usually 4 to 1
0, preferably 4 to 6, and particularly preferably 5. The structural formula of a compound having 4 or more carbon atoms having a —CH ₂ —CHF— group is shown in the following formula (3).

[0053]

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Where R^ThreeAnd R^FourIs R in the above formula (1)
¹And R^TwoIs the same as Also, R ^ThreeAnd R^FourAt least
Alkyl having 1 to 8 carbon atoms, one of which may be fluorinated
R^ThreeAnd R^FourAnd the sum of the carbon numbers of both
Is also 2; and R^ThreeAnd R^FourAnd coalesced together
A divalent hydrocarbon group of -2 to 8 -R^Three-R^Four-And C
^ThreeAnd C^FourMay form an alicyclic compound together with
The same is true for

The above R^ThreeAnd R^FourPreferred number of carbon atoms is 1 to 8
Specific examples of the perfluoroalkyl group of the formula (1)
R¹And R^TwoAnd -R^Three-R^Four-
Preferred C2-8 Perfluoroalkylene Group Tool
A specific example is -R of the formula (1). ¹-R^TwoSame as-
You.

The alicyclic compound having 2 to 8 carbon atoms formed by combining R ³ and R ⁴ together in the formula (3) includes a compound represented by the formula (4).

[0057]

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In the above formula (4), the divalent hydrocarbon group -R ³ -R ^4- has 2 to 8, preferably 2 to 4 carbon atoms. The divalent hydrocarbon group -R ³ -R ⁴ - hydrogen atoms, in whole or in part may be fluorinated.

[0059] Specific examples of the compound containing the -CH ₂ -CHF- group, 1,1,1,2,4,4,4, -
Heptafluoro-n-pentane, 1,1,1,2,2
3,5,5,5-nonafluoro-n-pentane, 1,
1,1,2,2,4,5,5,5-nonafuluoro-n
-Pentane, 1,1,1,2,2,3,3,4,6
6,6-undecafluoro-n-hexane, 1,1,
Chain compounds such as 1,2,2,3,3,5,6,6,6-undecafluoro-n-hexane,

1,1,2,2,3-pentafluorocyclobutane, 1,1,2,2,3,3,4-heptafluorocyclopentane, 1,1,2,2,3,3,4 4,
Alicyclic compounds such as 5-nonafluorocyclohexane;

Of these compounds, 1,1,1,2,2
2,3,5,5,5-nonafluoro-n-pentane,
1,1,2,2,3,3,4-heptafluorocyclopentane is preferred, and 1,1,2,2,3,3,4-heptafluorocyclopentane is particularly preferred.

[0062]

EXAMPLES The present invention will be described below in detail with reference to examples, but the scope of the present invention is not limited by these examples. The following embodiment and the first embodiment
The meanings of the abbreviations used in Tables 1 to 3 are as follows. MCL: 1-chloroheptafluorocyclopentene F7E: 1,3,3,4,4,5,5-heptafluorocyclopentene F7A: 1,1,2,2,3,3,4-heptafluorocyclopentane F6A: 1 , 1,2,2,3,3-hexafluorocyclopentane

Example 1 1, 1, 2, 2, 3, 3, 4-
Synthesis of heptafluorocyclopentane 1 Inner diameter 2.54 cm, length 4 wrapped with a ribbon heater
Prepare a 0cm SUS tube (stainless steel reaction tube)
In the SUS tube, a metal catalyst supporting 2% by weight of palladium and 0.2% by weight of bismuth with respect to the carbon carrier (2%
70 g of Pd 0.2% Bi / C (Chemcat) was used as the first reactor. As a second reaction tube, an inner diameter of 2.54 cm provided with an electric furnace outside,
A SUS tube having a length of 40 cm was filled with 70 g of a metal catalyst (5% Pd / C catalyst, manufactured by Degussa Co., Ltd.) supporting 5% by weight of palladium with respect to the carbon carrier. The first and second reactors were connected as reactors.

Before starting the reaction, the temperature was raised while flowing nitrogen gas from the first reactor. Nitrogen gas was set at 100 ° C. in the first reactor and 130 ° C. in the second reactor at a flow rate of 1360 sccm for 2 hours to completely remove the air inside the reactor. Then, hydrogen gas was supplied at a flow rate of 13
The catalyst was reduced with hydrogen by flowing at 60 sccm for 2 hours.

Thereafter, the MCL was heated to 100 ° C. at a flow rate of 2.3 g / min (flow rate molar ratio of H ₂ / MCL = 6/1) from the first reaction tube while keeping the temperature setting and the hydrogen flow rate unchanged. A gas phase hydrogenation reaction was performed by flowing.
The contact time between the raw material and the catalyst was 80 seconds. Two hours after the start of the reaction, the gas (reaction product) flowing out of the second reactor was washed with an aqueous potassium carbonate solution and analyzed by gas chromatography. The results of the analysis are shown in Table 1. Table 1 also shows the results of measuring the temperature inside the reaction tube at 2 hours after the start of the reaction (the temperature in the first reactor was HS1, and the temperature in the second reactor was HS2. Notation.) As a result, both the conversion and the selectivity of the reaction were good.

[0066]

[Table 1]

Example 2 1,1,2,2,3,3,4-
Synthesis of heptafluorocyclopentane 2 An experiment was conducted using the same catalyst and reaction temperature as in Example 1.
However, in this embodiment, the flow rate ratio between the hydrogen gas and the raw material MCL is changed (the flow rate molar ratio of H ₂ / MCL is changed to 3 /
1, 4/1, 5/1, 6/1, 7/1, 8/1 and 1
It was changed to 0/1. ), The state of the reaction was tracked. The results are shown in Table 2.

[0068]

[Table 2]

From the results shown in Table 2, it can be seen that when the flow ratio of the hydrogen gas to the raw material is changed, the conversion of the reaction, the selectivity, and the position of the hot spot move. In the present example, it was found that the optimum flow ratio (molar ratio) between the hydrogen gas and the raw material MCL gas was 6/1.

Comparative Example 1 1,1,2,2,3,3,4-
Synthesis of heptafluorocyclopentane 3 Internal diameter 2.54 cm, equipped with an electric furnace outside, length 40 cm
Metal catalyst (A) (0.5% Pd) with carbon as a carrier and 0.5% by weight of palladium supported on the SUS tube
A reactor was prepared by charging 70 g of C catalyst (manufactured by Degussa Co., Ltd.). Next, the temperature was raised while flowing nitrogen into the reactor. At 150 ° C., a nitrogen flow rate of 1360
After flowing at 2 sccm for 2 hours to completely remove the air inside the reactor, the catalyst was hydrogen reduced by flowing hydrogen at 150 ° C. at a flow rate of 1360 sccm for 2 hours.

Next, the reaction temperature was set to 60 ° C., and the hydrogen flow rate was kept as it was, and the raw material MCL was 2.3 g / mi.
It was continuously introduced into the reactor while heating to 100 ° C. at a flow rate of n. The contact time between the MCL and the metal catalyst was 40 seconds. The gas flowing out of the reaction tube at 2 hours after the start of the reaction was washed with an aqueous potassium carbonate solution and analyzed by gas chromatography. The results are shown in Table 3. Also,
The results of measuring the temperature inside the reaction tube at 2 hours after the start of the reaction are also shown in Table 3 (indicated by HS in the table).

From Table 3, the selectivity of the reaction was inferior to the result of Example 1 (Table 1). In addition, despite the generation of hot spots, the conversion of the reaction was inferior to that of Example 1.

Comparative Example 2 1,1,2,2,3,3,4-
Synthesis of heptafluorocyclopentane As a four- metal catalyst, a metal catalyst (B) (1% Pd / C, in which 1% by weight of palladium is supported on carbon as a carrier).
The reaction was carried out in the same manner as in Comparative Example 1 except that Chemcat (manufactured by Chemcat) was used. The results are shown in Table 3. From Table 3, it was found that the conversion and selectivity of the reaction were inferior to those of Example 1.

Comparative Example 3 1,1,2,2,3,3,4-
Synthesis of heptafluorocyclopentane As a 5- metal catalyst, a metal catalyst (C) (2% Pd 0.2% Bi / C) using carbon as a carrier and supporting 2% by weight of palladium and 0.2% by weight of bismuth thereon , Chemc
The reaction was carried out in the same manner as in Comparative Example 1 except that at) was used. The results are shown in Table 3. In this comparative example, no generation of a hot spot was observed, but the result was that the conversion of the reaction was significantly inferior to that of Example 1.

[0075]

[Table 3]

[0076]

As described in the foregoing, according to the production method of the present invention, less deterioration of the hydrogenation catalyst of the hydrogenation reaction, yet industrially advantageously high selectivity and in high yield, -CH ₂ - C
A compound having 4 or more carbon atoms containing an HF-group can be produced.

In particular, the present invention relates to a compound having 4 carbon atoms containing a --CH ₂ --CHF-- group such as 1,1,2,2,3,3,4-heptafluorocyclopentane which is useful as a detergent or a solvent.
The present invention can be suitably applied to a method for producing the above compounds on an industrial scale.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenfumi Suzuki 1-2-1 Nightlight, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Inside the Zeon Corporation General Development Center (72) Inventor Toshiro Yamada 1 Nightlight, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Chome No.2-1 F-term in the Zeon Corporation General Development Center (reference) 4H006 AA02 AC11 AC13 BA05 BA07 BA09 BA11 BA13 BA14 BA15 BA16 BA22 BA23 BA24 BA25 BA26 BA30 BA32 BA34 BA36 BA37 BC10 BC13 BC31 BD60 BE20 4H039 CA10 CB10 CD20 CE40

Claims (3)

[Claims] 1. A gas-phase hydrogenation of a compound having 4 or more carbon atoms containing a —CCl ＝ CF— group in the presence of a hydrogenation catalyst,
A method for producing a compound having 4 or more carbon atoms containing a CH ₂ —CHF— group, wherein a reaction section filled with the hydrogenation catalyst is divided into at least two sections, and -CH ₂ -C, wherein a hydrogenation catalyst having a low activity is charged, or (2) the external heating temperature of the former reaction section is lower than that of the latter.
A method for producing a compound having 4 or more carbon atoms containing an HF-group. Wherein said -CCl = CF- group as having 4 or more compounds carbon containing, using 1-chloro-heptafluorocyclopentene, -CH ₂ -CH according to claim 1
A method for producing a compound having 4 or more carbon atoms containing an F-group. 3. A hydrogen gas and -CCl = C in said reaction section.
By passing an F-group-containing compound having 4 or more carbon atoms at a flow rate molar ratio of 2: 1 to 10: 1, -CCl = CF-
Gas-phase hydrogenating a compound having 4 or more carbon atoms containing a group,
Production method of 4 or more compounds carbon containing -CH ₂ -CHF- group of claim 1.