Preparation method of dichlorohexafluorocyclopentene

Abstract

The invention provides a preparation method of dichlorohexafluorocyclopentene. Perhalogenated cyclopentene or / and perhalogenated cyclopentadiene is used as a raw material and reacts with HF and Cl2 in a tubular reactor filled with a catalyst to generate dichlorohexafluorocyclopentene, the catalyst needs to be used after being activated for 2-12 h in a mixed gas of HF and F2 at the temperature of 200-600 DEG C, and the catalyst is one or more of molybdenum fluoride, nickel fluoride, cobalt fluoride or molybdenum fluoride; the reaction conditions are as follows: the molar ratio of HF to Cl2 to octachlorocyclopentene or hexachlorocyclopentadiene is (4-10): (1-5): 1, the reaction temperature is 200-500 DEG C, the reaction pressure is 0-2.0 MPa, and the catalyst contact time is 5-90 seconds. According to the method, the reaction process is simple, the needed target object is prepared through one-step gas-phase catalytic fluorination, the method is suitable for large-scale production of dichlorohexafluorocyclopentene, the requirement for equipment is low, and the catalyst activity and stability are high.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical synthesis, and particularly relates to a method for preparing dichloropentafluorocyclopentene, and more particularly to a method for reacting perhalocyclopentene or / and perhalocyclopentadiene with HF or / and Cl2 in the presence of a catalyst to produce dichloropentafluorocyclopentene. Background Art

[0002] Dichloropentafluorocyclopentene is an important intermediate with high industrial value, and can be used to prepare etching agent octafluorocyclopentene, cleaning agent 1,2,2,3,3,4,4-heptafluorocyclopentane, etc.

[0003] Up to now, many literatures have reported the preparation methods of 1,2-dichloropentafluorocyclopentene. Most of them are synthesized starting from hexachlorocyclopentadiene or octachlorocyclopentene, and the fluorination reagents used can be SbF5 (see literature US2459783), SbF3Cl2, SbFxCl5-x (0 < x < 5) or a mixture of SbF3 and SbF3Cl2, and can also be anhydrous hydrogen fluoride. When using anhydrous hydrogen fluoride as the fluorination reagent, the reaction must be carried out in the presence of a fluorination catalyst such as SbCl5 catalyst (see literatures WO9743233, WO9600707 and US6218586) or a catalyst containing bismuth and iron (see literature US5180861).

[0004] The above preparation processes have the following disadvantages: First, the reaction process is complex and the total yield is low. Second, when the fluorination reagent is a fluorine- and / or chlorine-containing antimony compound, such fluorination reagents are highly corrosive and easily hydrolyze to release hydrogen fluoride or hydrogen chloride gas, making it difficult to operate and control during use; at the same time, a liquid fluorinating agent is required. When the fluorination reagent is anhydrous hydrogen fluoride, the activity of the fluorination catalyst is low and it is easily deactivated. Summary of the Invention

[0005] The technical problem to be solved by the present invention is aimed at the deficiencies of the above-mentioned prior art. The object of the present invention is to provide a method for preparing dichloropentafluorocyclopentene. The reaction process of this invention is simple, and the required target product is prepared by one-step gas-phase catalytic fluorination, which is suitable for large-scale production of dichloropentafluorocyclopentene. To achieve the above object, the technical solution of the present invention is as follows:

[0006] A method for preparing dichloropentafluorocyclopentene, using perhalocyclopentene or / and perhalocyclopentadiene as raw materials, and reacting with HF and Cl2 in a tubular reactor equipped with a catalyst to produce dichloropentafluorocyclopentene.

[0007] Preferably, the perhalocyclopentene is octachlorocyclopentene, and the perhalocyclopentadiene is hexachlorocyclopentadiene.

[0008] Preferably, the catalyst is one or more of nickel fluoride, cobalt fluoride or molybdenum fluoride.

[0009] Preferably, the reaction temperature is 200 °C to 500 °C, the reaction pressure is 0 MPa to 2.0 MPa, and the catalyst contact time is 5 s to 90 s.

[0010] Preferably, the tube reactor cylinder is made of nickel, stainless steel or Monel.

[0011] Preferably, the molar ratio of HF, Cl2 to octachlorocyclopentene or / and hexachlorocyclopentadiene is 4 - 10:1 - 5:1.

[0012] Preferably, the catalyst is activated in a HF / N2 mixed gas with a molar ratio of 5:1 at 200 °C to 600 °C for 2 h to 12 h.

[0013] The chemical reaction equation of the present invention is:

[0014]

[0015] The beneficial effects of the present invention are:

[0016] 1. The reaction process is simple. The desired target product is prepared by one-step gas-phase catalytic fluorination, which is suitable for large-scale production of dichloropentafluorocyclopentene.

[0017] 2. High-corrosive and easily hydrolyzed fluorination reagents are not used during the reaction process, and the requirements for equipment are low.

[0018] 3. A method for producing dichloropentafluorocyclopentene with high catalyst activity and high stability is provided. Specific Embodiments

[0019] The technical solutions in the embodiments of the present invention are further described in detail. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0020] The tube reactor has a specification of Φ50×500 mm. 100 ml of the catalyst is filled into the tube reactor. A 2 L collection cold trap is connected behind the tube reactor, and a -20 °C ethylene glycol aqueous solution is used as the refrigerant to cool the collection cold trap. The tube reactor cylinder is made of nickel, stainless steel or Monel.

[0021] Example 1

[0022] Fill the catalyst nickel fluoride into a tubular reactor and heat it to 300 °C. Introduce a HF / N2 mixed gas with a molar ratio of 5:1 into the reactor for activation for 2 h. Control the reaction temperature at 350 °C. Simultaneously introduce HF, Cl2 and hexachlorocyclopentadiene into the reactor. Control the molar ratio of the introduced HF, Cl2 and hexachlorocyclopentadiene to be 4:1:1, the contact time to be 20 s, and the reaction pressure to be 0.5 MPa. The reaction product is collected and analyzed by gas chromatography, and the results are shown in Table 1.

[0023] Example 2

[0024] Fill the catalyst nickel fluoride into a reactor and heat it to 300 °C. Introduce a HF / N2 mixed gas with a molar ratio of 5:1 into the reactor for activation for 2 h. Control the reaction temperature at 200 °C. Simultaneously introduce HF, Cl2 and hexachlorocyclopentadiene into the reactor. Control the molar ratio of the introduced HF, Cl2 and hexachlorocyclopentadiene to be 10:1:1, the contact time to be 5 s, and the reaction pressure to be 0.5 MPa. The reaction product is collected and analyzed by gas chromatography, and the results are shown in Table 1.

[0025] Example 3

[0026] Fill the catalyst nickel fluoride into a reactor and heat it to 300 °C. Introduce a HF / N2 mixed gas with a molar ratio of 5:1 into the reactor for activation for 2 h. Control the reaction temperature at 500 °C. Simultaneously introduce HF, Cl2 and hexachlorocyclopentadiene into the reactor. Control the molar ratio of the introduced HF, Cl2 and hexachlorocyclopentadiene to be 4:5:1, the contact time to be 20 s, and the reaction pressure to be 0.5 MPa. The reaction product is collected and analyzed by gas chromatography, and the results are shown in Table 1.

[0027] Example 4

[0028] Fill the catalyst nickel fluoride into a reactor and heat it to 200 °C. Introduce a HF / N2 mixed gas with a molar ratio of 5:1 into the reactor for activation for 2 h. Control the reaction temperature at 350 °C. Simultaneously introduce HF, Cl2 and hexachlorocyclopentadiene into the reactor. Control the molar ratio of the introduced HF, Cl2 and hexachlorocyclopentadiene to be 10:5:1, the contact time to be 55 s, and the reaction pressure to be 0.5 MPa. The reaction product is collected and analyzed by gas chromatography, and the results are shown in Table 1.

[0029] Example 5

[0030] Fill the catalyst nickel fluoride into a reactor and heat it to 600 °C. Introduce a HF / N2 mixed gas with a molar ratio of 5:1 into the reactor for activation for 2 h. Control the reaction temperature at 350 °C. Simultaneously introduce HF, Cl2 and hexachlorocyclopentadiene into the reactor. Control the molar ratio of the introduced HF, Cl2 and hexachlorocyclopentadiene to be 4:1:1, the contact time to be 90 s, and the reaction pressure to be 0.5 MPa. The reaction product is collected and analyzed by gas chromatography, and the results are shown in Table 1.

[0031] Example 6

[0032] Fill the reactor with nickel fluoride catalyst and heat it to 300 °C. Pass a HF / N2 mixed gas with a molar ratio of 5:1 into the reactor for activation for 2 h. Control the reaction temperature at 350 °C. Simultaneously pass HF, Cl2 and hexachlorocyclopentadiene into the reactor. Control the molar ratio of HF, Cl2 and hexachlorocyclopentadiene passed in to be 4:1:1, the contact time is 20 s, the reaction pressure is 0.1 MPa. The reaction products are collected and analyzed by gas chromatography. The results are shown in Table 1.

[0033] Example 7

[0034] Fill the reactor with nickel fluoride catalyst and heat it to 300 °C. Pass a HF / N2 mixed gas with a molar ratio of 5:1 into the reactor for activation for 2 h. Control the reaction temperature at 350 °C. Simultaneously pass HF, Cl2 and octachlorocyclopentene into the reactor. Control the molar ratio of HF, Cl2 and hexachlorocyclopentadiene passed in to be 4:1:1, the contact time is 20 s, the reaction pressure is 2.0 MPa. The reaction products are collected and analyzed by gas chromatography. The results are shown in Table 1.

[0035] Example 8

[0036] Fill the reactor with nickel fluoride catalyst and heat it to 300 °C. Pass a HF / N2 mixed gas with a molar ratio of 5:1 into the reactor for activation for 2 h. Control the reaction temperature at 350 °C. Simultaneously pass HF, Cl2 and hexachlorocyclopentadiene into the reactor. Control the molar ratio of HF, Cl2 and hexachlorocyclopentadiene passed in to be 4:5:1, the contact time is 20 s, the reaction pressure is 0.5 MPa. The reaction products are collected and analyzed by gas chromatography. The results are shown in Table 1.

[0037] Example 9

[0038] Fill the reactor with nickel fluoride catalyst and heat it to 300 °C. Pass a HF / N2 mixed gas with a molar ratio of 5:1 into the reactor for activation for 2 h. Control the reaction temperature at 350 °C. Simultaneously pass HF, Cl2 and hexachlorocyclopentadiene into the reactor. Control the molar ratio of HF, Cl2 and hexachlorocyclopentadiene passed in to be 8:5:1, the contact time is 20 s, the reaction pressure is 0.5 MPa. The reaction products are collected and analyzed by gas chromatography. The results are shown in Table 1.

[0039] Example 10

[0040] Fill the reactor with molybdenum fluoride catalyst and heat it up to 300 °C. Introduce a HF / N2 mixed gas with a molar ratio of 5:1 into the reactor for activation for 2 h. Control the reaction temperature at 350 °C. Simultaneously introduce HF, Cl2 and hexachlorocyclopentadiene into the reactor. Control the molar ratio of HF, Cl2 and hexachlorocyclopentadiene introduced to be 4:1:1, the contact time to be 20 s, and the reaction pressure to be 0.5 MPa. The reaction products are collected and analyzed by gas chromatography, and the results are shown in Table 1.

[0041] Example 11

[0042] Fill the reactor with cobalt fluoride catalyst and heat it up to 300 °C. Introduce a HF / N2 mixed gas with a molar ratio of 5:1 into the reactor for activation for 2 h. Control the reaction temperature at 350 °C. Simultaneously introduce HF, Cl2 and hexachlorocyclopentadiene into the reactor. Control the molar ratio of HF, Cl2 and hexachlorocyclopentadiene introduced to be 4:5:1, the contact time to be 20 s, and the reaction pressure to be 0.5 MPa. The reaction products are collected and analyzed by gas chromatography, and the results are shown in Table 1.

[0043] Example 12

[0044] Fill the reactor with nickel fluoride catalyst and heat it up to 200 °C. Introduce a HF / N2 mixed gas with a molar ratio of 5:1 into the reactor for activation for 2 h. Control the reaction temperature at 350 °C. Simultaneously introduce HF, Cl2 and hexachlorocyclopentadiene into the reactor. Control the molar ratio of HF, Cl2 and hexachlorocyclopentadiene introduced to be 10:5:1, the contact time to be 20 s, and the reaction pressure to be 0.5 MPa. The reaction products are collected and analyzed by gas chromatography, and the results are shown in Table 1.

[0045] Example 13

[0046] Fill the reactor with nickel fluoride catalyst and heat it up to 400 °C. Introduce a HF / N2 mixed gas with a molar ratio of 5:1 into the reactor for activation for 2 h. Control the reaction temperature at 350 °C. Simultaneously introduce HF, Cl2 and hexachlorocyclopentadiene into the reactor. Control the molar ratio of HF, Cl2 and hexachlorocyclopentadiene introduced to be 4:1:1, the contact time to be 20 s, and the reaction pressure to be 0.5 MPa. The reaction products are collected and analyzed by gas chromatography, and the results are shown in Table 1.

[0047] Example 14

[0048] Fill the reactor with nickel fluoride catalyst and heat it up to 300 °C. Introduce a HF / N2 mixed gas with a molar ratio of 5:1 into the reactor for activation for 6 h. Control the reaction temperature at 350 °C. Simultaneously introduce HF, Cl2 and hexachlorocyclopentadiene into the reactor. Control the molar ratio of HF, Cl2 and hexachlorocyclopentadiene introduced to be 4:1:1, the contact time to be 20 s, and the reaction pressure to be 0.5 MPa. The reaction products are collected and analyzed by gas chromatography, and the results are shown in Table 1.

[0049] Example 15

[0050] Fill the reactor with nickel fluoride catalyst and heat it to 300 °C. Pass a HF / N2 mixed gas with a molar ratio of 5:1 into the reactor for activation for 12 h. Control the reaction temperature at 350 °C. Simultaneously pass HF, Cl2 and hexachlorocyclopentadiene into the reactor. Control the molar ratio of HF, Cl2 and hexachlorocyclopentadiene passed in to be 4:1:1, the contact time is 20 s, and the reaction pressure is 0.5 MPa. The reaction product is collected and analyzed by gas chromatography. The results are shown in Table 1.

[0051] Example 16

[0052] Fill the reactor with nickel fluoride catalyst and heat it to 300 °C. Pass a HF / N2 mixed gas with a molar ratio of 5:1 into the reactor for activation for 12 h. Control the reaction temperature at 350 °C. Simultaneously pass HF, Cl2 and octachlorocyclopentene into the reactor. Control the molar ratio of HF, Cl2 and octachlorocyclopentene passed in to be 4:1:1, the contact time is 20 s, and the reaction pressure is 0.5 MPa. The reaction product is collected and analyzed by gas chromatography. The results are shown in Table 1.

[0053] Table 1 Statistical table of experimental data

[0054]

[0055]

[0056] As mentioned above, it is only the preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and all should be covered within the protection scope of the present invention.

Claims

1. A preparation method of dichloropentafluorocyclopentene, characterized in that: Using perhalocyclopentene or / and perhalocyclopentadiene as raw materials, reacting with HF and Cl2 in a tubular reactor equipped with a catalyst to produce dichloropentafluorocyclopentene.

2. The preparation method of 1,2-dichlorohexafluorocyclopentene according to claim 1, characterized in that: The perhalocyclopentene is octachlorocyclopentene, and the perhalocyclopentadiene is hexachlorocyclopentadiene.

3. The preparation method of 1,2-dichloro-3,4,5,5,5-pentafluorocyclopentene according to claim 1, wherein: The catalyst is one or several of nickel fluoride, cobalt fluoride or molybdenum fluoride.

4. The preparation method of 1,2-dichloro-3,4,5,5,5-pentafluorocyclopentene according to claim 1, characterized in that: The reaction temperature is 200°C to 500°C, the reaction pressure is 0 MPa to 2.0 MPa, and the catalyst contact time is 5 s to 90 s.

5. The preparation method of 1,2-dichlorohexafluorocyclopentene according to claim 1, characterized in that: The material of the tubular reactor cylinder is nickel, stainless steel or Monel.

6. The preparation method of 1,2-dichloro-3,4,5,5,5-pentafluorocyclopentene according to claim 2, characterized in that: The molar ratio of HF, Cl2 to octachlorocyclopentene or / and hexachlorocyclopentadiene is 4 to 10:1 to 5:

1.

7. The preparation method of 1,2-dichlorohexafluorocyclopentene according to claim 3, characterized in that: The catalyst is activated in a HF / N2 mixed gas with a molar ratio of 5:1 at 200°C to 600°C for 2 h to 12 h.

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