Method for synthesizing 1, 2-dichlorodifluoroalkoxy alkylene ethyl ether
By reacting the compound of formula (II) with dichlorodifluoroethylene under acidic conditions, 1,2-dichlorodifluoroalkoxyalkylene ethyl ether is prepared, which solves the problem of low-temperature rubber modification selectivity in the prior art, achieves high yield and selectivity preparation, and promotes the development of low-temperature rubber.
Patent Information
- Application Number
- CN202311762772.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-20
- Publication Date
- 2025-06-20
AI Technical Summary
The prior art has little selectivity in the modification of low-temperature rubber, and the synthesis route is single, which limits the development of low-temperature rubber.
A new synthetic route is provided to prepare 1,2-dichlorodifluoroalkoxyalkylene ethyl ether by contacting the compound of formula (II) with dichlorodifluoroethylene under acidic conditions. The method includes controlling the reaction conditions at a temperature of 20-50°C for at least 2 hours, controlling the reaction conditions to improve selectivity and reduce the occurrence of side reactions.
The stable preparation of 1,2-dichlorodifluoroalkoxyalkylene ethyl ether, especially 1,2-dichlorodifluoromethoxymethylene ethyl ether, was achieved. The entire process only requires 2 steps of reaction, and the yield can reach more than 40%, enriching the selectivity of low-temperature modified monomers.
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Abstract
Description
Technical Field
[0001] The present invention relates to the field of chemistry and chemical engineering, and in particular to a method for synthesizing 1,2-dichlorodifluoroalkoxyalkylene ethyl ether, its products and applications. Background Art
[0002] 1,2-Dichlorodifluoroalkoxyalkylene ethyl ether is an important intermediate monomer, which can be used to prepare fluorine monomers with double ethers. The fluorine monomers with double ethers can be widely used in the modification of rubber, especially for the modification of rubber elasticity at low temperatures. At present, the main low-temperature modification monomers are PMVE (perfluoromethyl vinyl ether), ether, perfluoromethoxyethyl vinyl perfluoromethoxymethylene vinyl ether. The selectivity of modification monomers is not much, and the synthesis route is single, which greatly limits the development of low-temperature rubber. Summary of the Invention
[0003] The purpose of the present invention is to provide a new synthesis route for developing a series of intermediate monomers for modification monomers and enriching the selectivity of low-temperature modification monomers.
[0004] In a first aspect, the present invention provides a method for synthesizing a compound of formula (I):
[0005] R1-O-CFR2-O-CA1A2-CHA3A4 (I)
[0006] The method comprises contacting a compound of formula (II) with dichlorodifluoroethylene,
[0007] R1-O-CFR2-OH (II)
[0008] wherein R1 is selected from perfluorosubstituted C1-5 alkyl groups in which one or more fluorines are optionally substituted, such as CF3-, CF3CF2- or CF3OCF2-, R2 is selected from H, F or perfluorosubstituted C1-3 alkyl groups, such as methyl, ethyl, propyl or isopropyl, and wherein A1 to A4 are each independently selected from F or Cl, provided that two of A1 to A4 are F.
[0009] In some embodiments, the method comprises contacting a compound of formula (II) with dichlorodifluoroethylene under acidic conditions, such as in the presence of concentrated sulfuric acid.
[0010] In some embodiments, the method comprises contacting a compound of formula (II) with dichlorodifluoroethylene at a temperature of 20 to 50 °C, such as at a temperature of 30 to 40 °C, such as at a temperature of 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50 °C or any value therebetween.
[0011] In some embodiments, the method includes contacting a compound of formula (II) with dichlorodifluoroethylene at a constant concentration, for example, introducing gaseous dichlorodifluoroethylene into the compound of formula (II) at a constant rate. In some embodiments, the method includes contacting a compound of formula (II) with dichlorodifluoroethylene at a constant concentration for at least 2 hours, for example, 2 to 14 hours, preferably 6 to 10 hours.
[0012] In some embodiments, the dichlorodifluoroethylene can be 1,2-dichloro-1,2-difluoroethylene or 1,1-dichloro-2,2-difluoroethylene.
[0013] In some embodiments, the method further includes the step of preparing a compound of formula (II) by subjecting R1OH and R2C(O)F to a nucleophilic addition reaction.
[0014] In some embodiments, the nucleophilic addition reaction is carried out in the presence of an acid catalyst, preferably in the presence of concentrated sulfuric acid and under anhydrous conditions.
[0015] In some embodiments, the nucleophilic addition reaction is carried out at a temperature of 60 to 120 °C, for example, at a temperature of 70 to 100 °C, for example, at a temperature of 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120 °C or any value therebetween.
[0016] In some embodiments, the nucleophilic addition reaction includes contacting R1OH with R2C(O)F at a constant concentration, for example, introducing gaseous R2C(O)F into R1OH at a constant rate. In some embodiments, the method includes preheating R1OH and then adding R2C(O)F. In some embodiments, the nucleophilic addition reaction is carried out for at least 6 hours, for example, 6 to 16 hours, preferably 8 to 14 hours, for example, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 hours or any value therebetween.
[0017] In some embodiments, the method further includes the step of washing the final reaction solution with an alkaline solution until it is neutral. Examples of the alkaline solution include but are not limited to aqueous NaOH solution, aqueous KOH solution, aqueous sodium carbonate solution or aqueous sodium bicarbonate solution.
[0018] In some specific embodiments, the method of the present invention includes the following steps:
[0019]
[0020]
[0021] Wherein R1 is selected from perfluoro-substituted C1-5 alkyl groups in which one or more fluorines are optionally substituted, such as CF3-, CF3CF2-, or CF3OCF2-, and R2 is selected from H, F, or perfluoro-substituted C1-3 alkyl groups, such as methyl, ethyl, propyl, or isopropyl.
[0022] In a specific embodiment, the method of the present invention comprises the following steps:
[0023]
[0024]
[0025] Specifically, the method comprises: (1) First, a certain amount of trifluoromethanol and a small amount of concentrated sulfuric acid are added to a nickel metal reactor with stirring, and it is kept dry. Then, the temperature is raised. When the temperature reaches 80°C, phosgene fluoride is introduced into the reactor, and the temperature is further raised to 100°C. The pressure is maintained at 0.8 MPa. After reacting for 10 hours, the reaction is terminated, the temperature of the reaction kettle is lowered to 20°C, and the gas phase in the reaction kettle is discharged. This reaction process is slow, and side reactions are likely to occur during the reaction to generate CF3OCOF and HF, which needs to be carried out while keeping dry in a nickel metal reactor and an acidic environment.
[0026] (2) Dichlorodifluoroethylene is slowly added to the reaction kettle, and the reaction temperature is controlled at 35°C. A certain amount of dichlorodifluoroethylene is introduced, and after stopping the introduction, the mixture is stirred and reacted for 2 h, and then the reaction is stopped.
[0027] (3) Then, a KOH solution is added to the product of the previous step for washing until neutral, and CF3OCF2OCFClCFHCl is separated out.
[0028] Furthermore, a dehalogenation reaction commonly used in the art can be employed to remove one molecule of HCl or Cl2 from 1,2-dichlorodifluoroalkoxyalkylene ethyl ether of formula I to prepare alkoxyalkylene vinyl ether (R1-O-CFR2-O-CF=CHF or R1-O-CFR2-O-CF=CFCl), which is an important modifying monomer for modifying rubber at low temperatures.
[0029] Therefore, in the second aspect of the present invention, there is provided a 1,2-dichlorodifluoroalkoxyalkylene ethyl ether having the structure of formula (I) and prepared by the method according to the first aspect of the present invention.
[0030] In the third aspect of the present invention, there is also provided the use of the 1,2-dichlorodifluoroalkoxyalkylene ethyl ether according to the second aspect of the present invention in the preparation of alkoxyalkylene vinyl ether.
[0031] Beneficial Effects
[0032] The present invention provides a new reaction route. According to the reaction steps and reaction conditions provided by the present invention, the reaction is easy to control, the selectivity of the reaction is improved, and the occurrence of side reactions is reduced. Therefore, according to the synthesis method of the present invention, 1,2-dichlorodifluoroalkoxyalkylidene ethyl ether, especially 1,2-dichlorodifluoromethoxymethylene ethyl ether, can be prepared stably. The whole process only requires two-step reactions, and the yield can reach more than 40%. Detailed Embodiments
[0033] To make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to embodiments. The specific embodiments described herein are only used to explain the present invention and do not constitute any limitation to the present invention. In addition, in the following description, the descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present disclosure. Such structures and technologies are also described in many publications.
[0034] Definition
[0035] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as commonly used in the field to which the present invention belongs. For the purpose of explaining this specification, the following definitions will be applied, and where appropriate, terms used in the singular form will also include the plural form, and vice versa.
[0036] Unless the context clearly indicates otherwise, the expressions "a" and "an" used herein include plural referents.
[0037] In the present disclosure, the expression "about" is as understood by those of ordinary skill in the art and varies within a certain range according to the context in which it is used. If those of ordinary skill in the art do not understand the use of this term according to the context in which it is used, "about" will mean at most plus or minus 10% of a specific value.
[0038] In the present disclosure, the term "alkyl" refers to a straight-chain or branched-chain saturated hydrocarbon group having a specified number of carbon atoms (i.e., C1-5 refers to a straight-chain or branched-chain saturated hydrocarbon group having one to five carbon atoms). Examples of C1-5 alkyl include but are not limited to methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, isobutyl, sec-butyl, n-pentyl and similar alkyl groups.
[0039] In some embodiments, one or more fluorine atoms in the perfluoro-substituted C1-5 alkyl can be replaced by a perfluoro-substituted C1-5 alkyl or a perfluoro-substituted C1-5 alkoxy group. In some embodiments, one or more fluorine atoms in the perfluoro-substituted C1-5 alkoxy group can be replaced by a perfluoro-substituted C1-3 alkyl or a perfluoro-substituted C1-3 alkoxy group.
[0040] In the present disclosure, the term "perfluoro-substituted" means that all hydrogen atoms therein are replaced by fluorine atoms.
[0041] In the present disclosure, the term "alkoxy" means a straight-chain or branched-chain alkyl group connected through an ether oxygen, and its free valence bond comes from this ether oxygen. Representative examples include, but are not limited to: methoxy, ethoxy, propoxy, isopropoxy, butoxy, or pentyloxy, etc., preferably C1-3 alkoxy.
[0042] The following specifically describes the process and conditions for the small-scale preparation of 1,2-dichlorodifluoromethoxymethylene ethyl ether. The examples are only used to illustrate the reaction steps, reaction conditions, and catalyst selection of the present invention, and do not limit the spirit and scope of the present invention.
[0043] Example 1
[0044] This example uses trifluoromethanol, phosgene fluoride, and dichlorodifluoroethylene as raw materials to generate 1,2-dichlorodifluoromethoxymethylene ethyl ether through two-step addition reactions.
[0045] Add 1000 g of trifluoromethanol to a 2 L nickel alloy reaction kettle, then add 50 ml of concentrated sulfuric acid, heat the reactor to 80 °C, then introduce phosgene fluoride, maintain the pressure of the reactor at about 0.8 Mpa, then raise the reaction temperature to 100 °C, react for 10 hours, stop introducing phosgene fluoride after the reaction is completed, lower the temperature of the reactor to 20 °C, then discharge the gas phase in the reactor, and purge the gas phase space with nitrogen. Then add 100 ml of concentrated sulfuric acid to the reaction, then control the temperature of the reactor at 35 °C, introduce gaseous dichlorodifluoroethylene, introduce it at 25 L / h for 8 h, maintain the pressure at about 0.2 Mpa, stop the reaction after reacting for 2 h after introducing dichlorodifluoroethylene for 8 h, lower the temperature of the reactor to 20 °C, add 10% KOH aqueous solution to wash until neutral, and then separate out CF3OCF2OCFClCFHCl.
[0046] Finally, 2154 g of the product is obtained, among which the content of (1,2-dichlorodifluoromethoxymethylene ethyl ether) is 72%, and the yield is 46.8%.
[0047] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, and these simple modifications all fall within the protection scope of the present invention.
Claims
1. Method for synthesizing the compound of formula (I): R1-O-CFR2-O-CA1A2-CHA3A4 (I) The method comprises contacting a compound of formula (II) with dichlorodifluoroethylene, R1-O-CFR2-OH (II) wherein R1 is selected from perfluorosubstituted C1-5 alkyl groups in which one or more fluorines are optionally substituted, such as CF3-, CF3CF2- or CF3OCF2-, R2 is selected from H, F or perfluorosubstituted C1-3 alkyl groups, such as methyl, ethyl, propyl or isopropyl, and wherein A1 to A4 are each independently selected from F or Cl, provided that two of A1 to A4 are F.
2. The method of claim 1, wherein the method comprises contacting the compound of formula (II) with dichlorodifluoroethylene under acidic conditions and / or at a temperature of 20 to 50 °C, and / or the method comprises contacting the compound of formula (II) with dichlorodifluoroethylene at a constant concentration for at least 2 hours.
3. The method of claim 1 or 2, wherein the dichlorodifluoroethylene is 1,2-dichloro-1,2-difluoroethylene or 1,1-dichloro-2,2-difluoroethylene.
4. The method of claim 1 or 2, wherein the method further comprises the step of preparing the compound of formula (II) by subjecting R1OH and R2C(O)F to a nucleophilic addition reaction.
5. The method of claim 4, wherein the nucleophilic addition reaction is carried out in the presence of an acid catalyst and / or, the nucleophilic addition reaction is carried out at a temperature of 60 to 120 °C and / or, the nucleophilic addition reaction comprises contacting R1OH with R2C(O)F at a constant concentration and / or the method comprises preheating R1OH and then adding R2C(O)F and / or the nucleophilic addition reaction is carried out for at least 6 hours.
6. The method of claim 1 or 2, wherein the method further comprises the step of washing the final reaction solution with an alkaline solution until it is neutral. Preferably, the alkaline solution is selected from aqueous NaOH solution, aqueous KOH solution, aqueous sodium carbonate solution or aqueous sodium bicarbonate solution.
7. The method of claim 1 or 2, wherein the method comprises the following steps: 1) 2) wherein R1 is selected from perfluorosubstituted C1-5 alkyl groups in which one or more fluorines are optionally substituted, and R2 is selected from H, F, or perfluorosubstituted C1-3 alkyl groups.
8. A 1,2-dichlorodifluoroalkoxyalkyleneethyl ether having the structure of formula (I) and prepared by the method according to any one of claims 1 to 7 R1-O-CFR2-O-CA1A2-CHA3A4 (I) wherein R1 is selected from perfluorosubstituted C1-5 alkyl groups in which one or more fluorines are optionally substituted, such as CF3-, CF3CF2-, or CF3OCF2-, R2 is selected from H, F, or perfluorosubstituted C1-3 alkyl groups, such as methyl, ethyl, propyl, or isopropyl, and wherein A1 to A4 are each independently selected from F or Cl, provided that two of A1 to A4 are F.
9. Use of the 1,2-dichlorodifluoroalkoxyalkyleneethyl ether of claim 8 in the preparation of an alkoxyalkylene vinyl ether, wherein the alkoxyalkylene vinyl ether is represented by the following formula: R1-O-CFR2-O-CF=CHF or R1-O-CFR2-O-CF=CFCl.