JP2001261594A - Method for producing 1-chloroheptafluorocyclopentene - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for producing 1-chloroheptafluorocyclopentene which is industrially suitable and has high selectivity. SOLUTION: 1,1-Dichlorooctafluorocyclopentane is reduced with hydrogen in the presence of a catalyst comprising a metal of Group VIII of the periodic table.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a reduction reaction
The present invention relates to a method for producing -chloro-2,3,3,4,4,5,5-heptafluorocyclopentene (hereinafter may be referred to as "1-chloroheptafluorocyclopentene"). 1-Chloroheptafluorocyclopentene is a raw material for producing heptafluorocyclopentane, which is a compound useful as a refrigerant, a blowing agent, and a solvent.

[0002]

2. Description of the Related Art As a method for obtaining 1-chloroheptafluorocyclopentene, a method is known in which 1,2-dichlorohexafluorocyclopentene is subjected to chlorine-fluorine exchange with potassium fluoride in an organic solvent.

[0003]

However, in this method, since solid potassium fluoride is used together with an organic solvent, an equimolar amount of these mixed by-products is generated, so that the treatment is a serious problem.

Accordingly, the present invention provides a method for producing clean 1-chloroheptafluorocyclopentene without generating waste that is difficult to treat.

[0005]

Means for Solving the Problems As a result of repeated studies to solve the above problems, the inventors found that reducing 1,1-dichlorooctafluorocyclopentane with hydrogen in the presence of a specific catalyst merely required the reduction. It has been found that one chlorine atom can be selectively reduced to obtain the desired 1-chloroheptafluorocyclopentene, and the present invention has been completed.

That is, the present invention relates to a method for producing 1-chloroheptafluorocyclopentene by reducing 1,1-dichlorooctafluorocyclopentane with hydrogen in the presence of a catalyst, wherein the catalyst is a Group VIII metal of the periodic table. A process for producing 1-chloroheptafluorocyclopentene.

[0007] 1,1-Dichlorooctafluorocyclopentane may be produced by any method. For example, 1,1-dichlorooctafluorocyclopentane described in US Pat. No. 5,416,246 may be used. Is obtained by isomerization with chlorofluorinated aluminum (Aluminum chlorofluoride), and as described in Japanese Patent Application No. 10-314661 filed by the present applicant,
It can also be obtained by reacting 2-dichlorohexyfluorocyclopentene simultaneously with chlorine and hydrogen fluoride in the presence of a fluorination catalyst.

Examples of Group VIII metals of the periodic table include iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium, platinum and the like. Palladium and platinum are preferred, and selectivity for 1-chloroheptafluorocyclopentene is preferred. Is high, and palladium is most preferred.

Further, as the metal of the catalyst, VI of the periodic table
Two or more selected from Group II metals, for example, Pd-P
They may be used simultaneously as t, Pd-Fe, and the like. Also in that case, it is preferable to use palladium as the main active ingredient.

[0010] The catalyst used in the present invention may contain components other than the Group VIII metal of the periodic table. Such components include silver, copper, gold, tellurium, zinc, chromium, molybdenum, thallium, tin, bismuth, lead, and the like. Generally, in alloy catalysts, it is said that the characteristics of the component elements appear depending on the alloy composition, and the amount of the added metal component is 0.01 to 500 parts by weight with respect to 100 parts by weight of Group VIII metal of the periodic table. Parts, especially 0.1-3
00 parts by weight is preferable from the viewpoint of utilizing the properties of Group VIII metal of the periodic table.

Specifically, Pd-Cu, Pd-Bi, P
Combinations of d-Mo, Pd-Sn, Pd-Zn, Pd-Ag and the like are preferable, and Pd-Cu, Pd-Bi, Pd-
Combinations such as Sn are particularly preferred.

[0012] The concentration of the Group VIII metal of the periodic table or other metals supported on various carriers may be selected from carrier 100
A wide range of 0.05 to 20 parts by weight per part by weight can be used, but usually 0.5 to 10 parts by weight is recommended. In the present invention, as the carrier of the catalyst, for example, activated carbon, alumina, zirconia, titania and the like are suitable. The particle size of the carrier has almost no effect on the reaction, but is preferably 0.1 to 100 mm.

In the reduction reaction of 1,1-dichlorooctafluorocyclopentane, the ratio between hydrogen and 1,1-dichlorooctafluorocyclopentane can be varied greatly. However, chlorine atoms are usually replaced with hydrogen atoms using at least a stoichiometric amount of hydrogen. For 1 mol of 1,1-dichlorooctafluorocyclopentane,
Significantly more than the stoichiometric amount can be used, for example 3 moles or more of hydrogen. Specifically, it is used in a range of about 1 to 100 mol. Excessive hydrogen gas is not problematic in terms of reaction, but is not preferable because it leads to an increase in the size of the reactor. As for the reaction pressure, normal pressure or a pressure higher than normal pressure can be used.

The reaction temperature is 0 to 450 ° C., preferably 50
To 300 ° C., more preferably 50 to 150 ° C. The reaction can be carried out in the liquid or gas phase. The contact time is usually 0.1 to 300 when the reaction is carried out in a gas phase.
Seconds, especially 1 to 30 seconds.

[0015]

Next, the present invention will be described with reference to examples, but the embodiments are not limited thereto. The analysis of the organic substance is performed by gas chromatography, and the composition of the organic substance is indicated by area%.

[Preparation Example 1] Palladium chloride (PdC)
l ₂ : N. E. FIG. Chemcat (25 g) was diluted to 312 g with 5.3% hydrochloric acid to prepare a 4.8% palladium solution. This palladium solution was used as the palladium solution in all the following preparation examples.

In a 200 ml Erlenmeyer flask, cupric chloride (C
uCl ₂ ) 3.71 g and 4.8% palladium solution 7.3
7 g was weighed, and a solution prepared by adding 110 ml of 30% hydrochloric acid thereto was poured into a 500 ml eggplant flask containing 35 g of activated carbon (granular Shirasagi G2X-4 / 6 manufactured by Takeda Pharmaceutical Co., Ltd.) and shaken well. . Activated carbon is allowed to settle for 3 days and nights, and then liquid components are distilled off using an evaporator.
It was dried to obtain a metal-impregnated activated carbon.

Next, a pretreatment of the catalyst was performed. Dried metal-impregnated activated carbon was placed in a stainless steel reaction tube (inner diameter 16 mm
φ × length 660mm) and fill with nitrogen 200ml / m
The temperature of the reaction tube was raised to 85 ° C. while flowing in, and then the flow rate of nitrogen was reduced to 50 ml / min, and hydrogen was added at the same time.
It started flowing at 8 ml / min. Then, the temperature was raised to 150 ° C., further raised to 300 ° C. at a rate of 60 ° C./hr, and maintained for 4 hours. After that, the reaction tube
Hydrogen was continued to flow until the temperature became below, and the catalyst was prepared to obtain a copper-palladium activated carbon-supported catalyst. This catalyst has a loading of 5% copper and 1% palladium based on the weight of activated carbon.

[Preparation Example 2] Cupric chloride (CuCl ₂ )
1. Bismuth chloride (BiCl ₂ ) instead of 3.71 g
A catalyst was prepared in the same manner as in Preparation Example 1 using 64 g. The pretreatment was performed at 150 ° C. for 4 hours. This catalyst has a loading of 5% bismuth and 1% palladium based on the weight of activated carbon.

[Preparation Example 3] Cupric chloride (CuCl ₂ )
Bismuth chloride (BiCl ₂ ) instead of 3.71 g
A catalyst was prepared in the same manner as in Preparation Example 1 using 58 g. The pretreatment was performed at 150 ° C. for 4 hours. This catalyst has a loading of 3% bismuth and 1% palladium based on the weight of activated carbon.

[Preparation Example 4] Cupric chloride (CuCl ₂ )
Bismuth chloride (BiCl ₂ ) instead of 3.71 g.
A catalyst was prepared in the same manner as in Preparation Example 1 using 53 g. The pretreatment was performed at 150 ° C. for 4 hours. This catalyst has a loading of 1% palladium and 1% palladium based on the weight of activated carbon.

[Preparation Example 5] Cupric chloride (CuCl ₂ )
Molybdenum pentachloride (MoCl ₅ ) instead of 3.71 g
A catalyst was prepared in the same manner as in Preparation Example 1 using 4.99 g. This catalyst has a loading of 5% molybdenum and 1% palladium based on the weight of activated carbon.

[Preparation Example 6] Cupric chloride (CuCl ₂ )
Instead of 3.71 g, tin chloride dihydrate (SnCl _2.
A catalyst was prepared in the same manner as in Preparation Example 1 using 3.32 g of (2H ₂ O). The pretreatment was performed at 210 ° C. for 4 hours.
This catalyst has a loading of 5% tin and 1% palladium based on the weight of activated carbon.

[Preparation Example 7] Cupric chloride (CuCl ₂ )
5.08 g of iron chloride (FeCl ₃ ) instead of 3.71 g
Was used to prepare a catalyst in the same manner as in Preparation Example 1. This catalyst has a loading of 5% iron and 1% palladium based on the weight of activated carbon.

[Preparation Example 8] Cupric chloride (CuCl ₂ )
3.66 g of zinc chloride (ZnCl ₂ ) instead of 3.71 g
Using g, a catalyst was prepared in the same manner as in Preparation Example 1. This catalyst has a loading of 5% zinc and 1% palladium based on the weight of activated carbon.

[Preparation Example 9] In a 200 ml Erlenmeyer flask, 2.75 g of silver nitrate (AgNO ₃ ) and a palladium nitric acid solution (24.49% Pd nitric acid solution: NE Chemcat)
1.42 g), 30% nitric acid 110 m there
of a solution prepared by adding 1 g of activated carbon (granular Shirasagi G2X-4 / 6 manufactured by Takeda Pharmaceutical Co., Ltd.) in 50 g.
The mixture was poured into a 0 ml eggplant flask and shaken well. The activated carbon was allowed to stand still for three days and nights, and then the liquid component was distilled off using an evaporator and dried to obtain a metal-impregnated activated carbon.

Next, a pretreatment of the catalyst was performed in the same manner as in Preparation Example 1. This catalyst has a loading of 5% silver and 1% palladium based on the weight of activated carbon.

[Preparation Example 10] Silver nitrate (AgNO ₃ )
Copper nitrate trihydrate in place of _{75g (Cu (NO 3) 2} · 3
A catalyst was prepared in the same manner as in Preparation Example 9 using 6.62 g of (H ₂ O). This catalyst has a loading of 5% copper and 1% palladium based on the weight of activated carbon.

[Preparation Example 11] In a 200 ml Erlenmeyer flask
Hexachloroplatinic acid hexahydrate (H_TwoPtCl₆・ 6H
_TwoO) Weigh 0.4649 g and add 30% hydrochloric acid 1
Activated carbon (Takeda Pharmaceutical Co., Ltd.)
5 containing 35 g of Granulated Shirasagi G2X-4 / 6 manufactured by Sangyo Co., Ltd.
The mixture was poured into a 00 ml eggplant flask and shaken well. Activated carbon
Is settled for three days and nights, and then liquid
The body component was distilled off and dried to obtain a metal-impregnated activated carbon.

Next, the catalyst was pretreated in the same manner as in Preparation Example 1. This catalyst has a loading of 1% of platinum based on the weight of activated carbon.

[Preparation Example 12] Activated carbon (Granular Shirasagi G2X-4 / Takeda Pharmaceutical Co., Ltd.) was placed in a 300 ml eggplant-shaped flask.
6) was weighed out, and then hexachloroplatinum (I
V) acid hexahydrate _{(H 2 PtCl 6 · 6H 2} O) 0.79
A solution of 6 g dissolved in 100 ml of 30% hydrochloric acid was injected,
Let stand for 2 days.

The metal-impregnated activated carbon that had been allowed to stand for 2 days was dried under reduced pressure by elevating the bath temperature to 150 ° C. using an evaporator.
Next, the dried metal-impregnated activated carbon was placed in a reaction tube (25 mm).
(φ × 400mm capacity about 200ml)
While flowing at 00-300ml / min,
The temperature was raised to 00 ° C in steps of 50 ° C and fired. 1 at 300 ° C
Bake for an hour, lower the set temperature to 150 ° C and 100ml of nitrogen
/ Min, 300 ° C while flowing hydrogen at 300 ml / min
The temperature was raised again in steps of 30 ° C. until the temperature was reduced to prepare a catalyst. Platinum is 0.5% of the activated carbon weight.

All the catalysts were subjected to the reaction of the example while being filled in the reaction tube.

Example 1 A stainless steel reaction tube filled with the catalyst prepared in Preparation Example 1 (inner diameter 16 mmφ × length 6
A vaporizer is provided on the upstream side of 50 mm / min, and 50 ml / min of nitrogen and 178 m of hydrogen are passed through the vaporizer set at 110 ° C.
The reaction tube temperature was set at 85 ° C. while introducing 1 / min, and the temperature was raised. 30 minutes after the temperature reached the set temperature, the raw material organic substance 1,1-dichlorooctafluorocyclopentane vaporized by the vaporizer was introduced into the reaction tube at a flow rate of 0.2 g / min. After a while the reaction stabilized. When the reaction product gas was analyzed by gas chromatography 6 hours after the start of the supply of the organic material, 95.6% (area%, the same applies hereinafter) of 1-chloroheptafluorocyclopentene and 1-chloro-2,2,3,3 , 4,4,5,5-
3.1% of octafluorocyclopentane and 1,1-dichloro-2,2,3,3,4,4,5,5- unreacted
Octafluorocyclopentane was 0.3%. The results are shown in Table 1.

[0035]

[Table 1]

Examples 2 to 11 The same reaction as in Example 1 was carried out on the catalysts prepared in Preparation Examples 2 to 11. In Example 6, a reaction was performed in which only the reaction temperature was changed to 100 ° C and 120 ° C. The results are shown in Table 1.

Example 12 A SUS304 reaction tube (25 mm) filled with 120 ml of the catalyst prepared in Preparation Example 12 was used.
φ × 400mm capacity about 200ml) and nitrogen 100ml
The reaction tube temperature was set to 85 ° C. while introducing 340 ml / min of hydrogen and 340 ml / min of hydrogen, and the temperature was raised. 0.2 g of the raw material organic substance 1,1-dichlorooctafluorocyclopentane gasified by an organic substance vaporizer (18 mmφ × 300 mm) set at 110 ° C. horizontally set on the upper part of the reaction tube in the reaction tube which has reached the set temperature. / Min flow rate.
The reaction product gas was analyzed by gas chromatography. The results are shown in Table 1.

[0038]

The process of the present invention is a process for producing 1-dichlorooctafluorocyclopentane from 1,1-dichlorooctafluorocyclopentane with extremely high selectivity.
The effect is that chloro-2,3,3,4,4,5,5-heptafluorocyclopentene can be produced.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B01J 23/644 B01J 23/89 X 23/652 C07C 23/08 23/89 C07B 61/00 300 C07C 23 / 08 B01J 23/64 101X // C07B 61/00 300 103X (72) Inventor Naoto Takada 2805 Imafukunakadai, Kawagoe-shi, Saitama Central Glass Co., Ltd. 2805 Imafukunakadai Central Glass Co., Ltd. Chemical Research Laboratory F-term (reference) 4H006 AA02 AC13 BA05 BA07 BA11 BA13 BA14 BA15 BA17 BA25 BA55 BE20 4H039 CA40 CG20

Claims (4)

[Claims] 1. A method for producing 1-chloroheptafluorocyclopentene by reducing 1,1-dichlorooctafluorocyclopentane with hydrogen in the presence of a catalyst, wherein the catalyst is a Group VIII metal of the periodic table. A method for producing 1-chloroheptafluorocyclopentene, which is characterized in that: 2. The process for producing 1-chloroheptafluorocyclopentene according to claim 1, wherein the metal of Group VIII of the periodic table is palladium. 3. The catalyst according to claim 1, wherein the catalyst is obtained by adding at least one metal selected from the group consisting of silver, copper, gold, tellurium, zinc, chromium, molybdenum, thallium, tin, bismuth and lead to palladium. Item 1. The method for producing 1-chloroheptafluorocyclopentene according to Item 1. 4. The method for producing 1-chloroheptafluorocyclopentene according to claim 1, wherein the catalyst is a supported catalyst having a metal component supported on a carrier. [0001]