CN109485541B - Method for preparing 1H,1H, 2H-perfluoro-1-octene - Google Patents
Method for preparing 1H,1H, 2H-perfluoro-1-octene Download PDFInfo
- Publication number
- CN109485541B CN109485541B CN201710817253.1A CN201710817253A CN109485541B CN 109485541 B CN109485541 B CN 109485541B CN 201710817253 A CN201710817253 A CN 201710817253A CN 109485541 B CN109485541 B CN 109485541B
- Authority
- CN
- China
- Prior art keywords
- reaction
- alkali metal
- perfluorohexyl
- ethane
- iodo
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C17/00—Preparation of halogenated hydrocarbons
- C07C17/25—Preparation of halogenated hydrocarbons by splitting-off hydrogen halides from halogenated hydrocarbons
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention relates to a method for preparing 1H,1H, 2H-perfluoro-1-octene, which takes 2-perfluorohexyl-1-iodo-ethane as a raw material and prepares the 1H,1H, 2H-perfluoro-1-octene through elimination reaction under the action of alkali metal alkoxide. The method of the invention can greatly improve the yield and purity of the product. The method has the advantages of cheap and easily-obtained raw materials, short synthetic route, simple method, mild reaction conditions, simple operation and good industrial application prospect.
Description
Technical Field
The invention relates to the field of chemical synthesis, in particular to a method for preparing 1H,1H, 2H-perfluoro-1-octene by base catalysis dehydroiodination.
Background
The fluorine-containing olefin is a very economic intermediate, has certain chemical activity, can derive a plurality of fluorine-containing organic matters, is a basic raw material for producing fluorine-containing fine chemicals and high polymer materials, and can meet special purposes and special purposes which can not be replaced by common organic matters in advanced industry and the like.
Dehydrohalogenation of halogenated fluoroalkanes is the main method for synthesizing fluorinated olefins, and can be divided into high-temperature method, liquid-alkali method and gas-phase catalysis method. The high-temperature method is to directly carry out thermal cracking dehydrohalogenation on halogenated fluorine-containing alkane under the high-temperature condition, the method has the advantages of high energy consumption, strict requirements on reaction equipment, more byproducts and low yield, and reaction materials are easy to polymerize and coke at high temperature, and are easy to block pipelines and damage equipment; the liquid alkali method adopts strong base to carry out intermittent dehydrohalogenation reaction in a liquid phase environment, the reaction condition is mild, and the conversion rate is high; the gas phase catalysis method is to carry out dehydrohalogenation reaction in the presence of a gas phase catalyst, has the advantages of simple process, economy, high efficiency, small environmental pollution, easy continuous production and the like, and has good industrial prospect. Most of the catalysts reported in the literature at present are metal catalysts, and are generally supported on carriers such as activated carbon, alumina and the like, and the carriers have high reactivity for some kinds of reaction and can also be used as the catalysts independently.
At present, the literature reports of the preparation of 1H,1H, 2H-perfluoro-1-octene by directly utilizing 2-perfluorohexyl-1-iodo-ethane dehydroiodination are less, and similar Chinese patent application CN105732295A discloses a method for preparing 1H,1H, 2H-perfluoro-1-octene by hydrohalogenation of C3-7Preparation of C from fluoroalkanes by base-mediated dehydrohalogenation3-7A method for preparing fluoroolefin, which relates to a method for preparing CF3CF＝CHX、CHX2CX＝CX2Or a straight or branched chain C4-7A process for (hydro) fluoroolefins, wherein each X is independently H or F, with the proviso that in CHX2CX＝CX2At least one X is F, the method has requirements on the chemical structure of the raw materials, and the raw materials with specific special structures need to be synthesized by operations such as chlorination and the like. In addition, chinese patent application CN102838445A discloses a method for preparing fluorine-containing olefin by selectively dehydrohalogenating halogenated hydrocarbon, which uses halogen-fluorine alkane containing three or more carbon atoms and having at least one hydrogen atom and at least one halogen atom on adjacent carbon atoms as raw material, and in the presence of composite catalyst, the fluorine-containing olefin product is formed by high temperature gas phase dehydrohalogenation reaction. The adopted gas phase method has a plurality of byproducts, and the required composite catalyst needs to be prepared by a relatively complex coprecipitation-impregnation method, so that the wide application of preparing fluorine-containing olefin by an industrial production method is limited.
Disclosure of Invention
The invention aims to provide a preparation method of 1H,1H, 2H-perfluoro-1-octene, which has the advantages of simple process, high selectivity of target products and industrial application prospect.
The method specifically comprises the following steps: 2-perfluorohexyl-1-iodo-ethane is taken as a raw material, and 1H,1H, 2H-perfluoro-1-octene is prepared through elimination reaction under the action of alkali metal alkoxide.
generally, as a result of electron withdrawing from a halogen atom in an alkyl halide molecule, not only the α carbon atom carries a partial positive charge, but also the β carbon atom is somewhat affected, and carries a smaller amount of partial positive charge, so that the electron cloud density on β -C-H is biased toward the carbon atom, and thusthe beta hydrogen atom shows certain activity and is easy to leave under the attack of strong alkaline reagent, while in 2-perfluorohexyl-1-iodine-ethane molecule, the electron-withdrawing effect of iodine atom on α carbon atom is weakened to a certain extent due to the electron-withdrawing induction effect of fluorine atom in perfluorohexyl2And the like. If conventional caustic is used to remove hydrogen iodide from 2-perfluorohexyl-1-iodo-ethane, the yield tends to be low or even non-reactive.
Based on the above, the invention adopts alkali metal alkoxide with higher alkalinity, wherein the alkali metal alkoxide is alkali metal salt of alcohol with 1-4 carbon atoms;
preferably, the alkali metal salt is one of sodium salt, potassium salt or lithium salt;
the invention further provides that the alkali metal alkoxide is selected from one or more of sodium methoxide, sodium ethoxide, potassium methoxide, potassium ethoxide or sodium tert-butoxide; the boiling point of the product is 102-104 ℃, compared with other alkyl alcohol, the boiling point of methanol is only 64.7 ℃, and the methanol does not generate azeotropy with water, so that the corresponding alcohol can be prevented from being introduced into a target product in the distillation process, and then high-purity 1H,1H, 2H-perfluoro-1-octene can be obtained through simple distillation, and therefore, the preferred boiling point is sodium methoxide or potassium methoxide.
The invention further provides that the reaction is carried out in an organic solvent; the organic solvent can further increase the solubility of the raw materials, so that the reaction is more complete. In addition, the organic solvent is more beneficial to the strong exothermic reaction of hydrogen iodide removal, so that the heat transfer is better; the control of the reaction temperature is facilitated; meanwhile, a large amount of halide salt is generated in the dehydrohalogenation reaction, a polar solvent with certain solubility to the salt is selected in consideration of the polarity of the raw material, and the amount of the used solvent also needs to ensure that the raw material and the by-product are fully dissolved, so that the stirring is smooth, and the heat transfer and mass transfer are better carried out. The organic solvent may be used in an amount conventionally used in the art by experimental or industrial methods.
The organic solvent is selected from twoOne or more of methyl chloride, methanol, acetonitrile or tetrahydrofuran; for bimolecular elimination due to reduced solvent polarity (E)2) Advantageously, less polar dichloromethane (polarity 3.4) is preferred as the solvent in the present invention in order to reduce the formation of substitution products and increase the yield of olefins.
Typically, the reaction is initiated by the dehydroiodination with a slight amount of heat required to initiate the reaction, and once the reaction has been initiated, enhanced heat transfer is required to control the reaction temperature. When the reaction temperature is high enough to ensure the reaction, the higher the reaction temperature is, the more side reactions are likely to occur, which is favorable for the generation of substitution products. Therefore, the reaction temperature is reduced, which is beneficial to controlling the increase of the content of the by-products, and the invention further provides that the reaction temperature is 30-80 ℃, and preferably 35-50 ℃; further preferably 40 ℃; .
When the organic solvent is dichloromethane, the reaction temperature is preferably 40 ℃; since the boiling point of methylene chloride is 39.75 ℃, this reaction temperature of 40 ℃ is highly advantageous in view of the formation of substitution-elimination products.
The molar ratio of the 2-perfluorohexyl-1-iodo-ethane to the alkali metal alkoxide is 1:1 to 2, preferably 1:1.1 to 1.5, and more preferably 1:1.1 to 1.3.
The invention further provides that after the elimination reaction is finished, the pH value of the reaction system is adjusted to 6-8, and then the product is purified.
The method specifically comprises the following steps: and adjusting the pH value of the reaction system to 6-8 after the elimination reaction is finished, taking an organic phase, distilling at normal pressure, and collecting fractions at 102-104 ℃ to obtain the catalyst.
Preferably, after the elimination reaction is finished, washing the mixture with water until the pH value is 6.5-7.5, standing for layering, separating out an organic phase, further extracting a water phase with an organic solvent, and combining all the organic phases; distilling at normal pressure, and collecting the fraction at 102-104 ℃ to obtain the product.
Wherein, in the purification process, the adopted organic solvent is one or more of diethyl ether, dichloromethane, ethyl acetate and cyclohexane; preferably dichloromethane.
The volume of the organic solvent is 1/2-1/3 of that of the water phase.
As a preferred scheme of the present invention, the method specifically comprises: adding 2-perfluorohexyl-1-iodo-ethane and an alkali metal salt of alcohol with 1-4 carbon atoms into an organic solvent according to a molar ratio of 1: 1-2, reacting at the temperature of 35-50 ℃, adjusting the pH value of a reaction system to 6-8 after the elimination reaction is finished, taking an organic phase, distilling at normal pressure, and collecting a fraction at 102-104 ℃ to obtain the product.
Further provides a preferable scheme, and the method specifically comprises the following steps: adding 2-perfluorohexyl-1-iodo-ethane and sodium methoxide into dichloromethane according to the molar ratio of 1: 1.1-1.3, reacting at the temperature of 35-50 ℃, adjusting the pH value of a reaction system to 6-8 after elimination reaction is finished, taking an organic phase, distilling at normal pressure, and collecting fractions at 102-104 ℃ to obtain the product.
Still further preferred embodiments provide the method comprising the steps of:
1) adding 2-perfluorohexyl-1-iodo-ethane and sodium methoxide into dichloromethane according to the molar ratio of 1:1.2, stirring, reacting at the temperature of 40 ℃ for 24 hours, and cooling;
2) washing the mixture after the reaction until the pH value is 6.5-7.5, standing for layering, and separating out an organic phase; extracting the water phase part with dichloromethane with the volume of the water phase being 1/3, and combining the organic phases; distilling at normal pressure, and collecting the fraction at 102-104 ℃ to obtain the product.
In the present invention, the order of addition of 2-perfluorohexyl-1-iodo-ethane, alkali metal alkoxide and organic solvent is not particularly limited.
The invention has at least the following beneficial effects:
1. the method adopts alkali metal alkoxide with stronger alkalinity to carry out elimination reaction to prepare the 1H,1H, 2H-perfluoro-1-octene, thereby greatly improving the synthetic yield of preparing the 1H,1H, 2H-perfluoro-1-octene from the 2-perfluorohexyl-1-iodo-ethane. The yield is more than 75 percent, and the purity can reach 98 percent;
2. in the reaction, the consumption of alkali metal alkoxide is less, and the reaction is carried out in an organic solvent; the organic solvent is beneficial to the heat transfer of the strong exothermic reaction of hydrogen iodide removal, so that the control of the reaction temperature is more stable; the used organic solvent can be repeatedly used;
3. compared with the traditional method that the alkali metal hydroxide participates in the reaction in the form of aqueous solution, the method adopts the alkali metal alkoxide as the dehydrohalogenation reagent, and does not need a phase transfer catalyst to promote the mutual contact of the reactants;
4. the method has the advantages of cheap and easily-obtained raw materials, short synthetic route, simple method, mild reaction conditions, simple operation and good industrial application prospect.
Detailed Description
The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.
In the following examples, the purity of the product (carrier gas N) was measured by a gas chromatograph analyzer model GC-4000A of Beijing east west analytical instruments Ltd2(ii) a Detector FID), quantitating by area normalization; the product was determined in combination with a nuclear magnetic resonance apparatus of model AvanceIII HD400M from Bruker, Germany1H NMR,CDCl3As a solvent.
The raw material 2-perfluorohexyl-1-iodo-ethane used in the invention is industrial grade, and other reagents such as alkali metal alkoxide and organic solvent are analytically pure and can be obtained commercially.
The following examples were conducted in a 1000mL three-necked flask equipped with a reflux condenser and a thermometer, which was placed on a thermal-arrest thermostatically-heated magnetic stirrer.
Example 1
This example is a process for making 1H, 2H-perfluoro-1-octene, comprising the steps of:
1) 355.5g (0.75mol) of 2-perfluorohexyl-1-iodo-ethane, 48.6g (0.9mol) of sodium methoxide and 500ml of dichloromethane are added in succession; stirring, heating in oil bath to 40 deg.C, reacting for 24 hr, and cooling;
2) transferring the mixture after the reaction into a separating funnel, washing with water until the pH value is 6.5-7.5, standing for layering, and separating out an organic phase; extracting the water phase part with dichloromethane with the volume of the water phase being 1/3, and combining the organic phases; distilling under normal pressure, heating by oil bath under controlled temperature, and collecting distillate at 102-104 ℃ to obtain 218.7g of 1H,1H, 2H-perfluoro-1-octene.
The purity of the obtained product was checked and, by gas chromatography analysis, the purity was 99.2%, the calculated total yield was 83.6%.
The prepared product is subjected to nuclear magnetic resonance analysis, and the 1H NMR data is as follows: deltaH：5.949～6.019ppm(m，-CH＝，1H)；δH：5.800～5.838ppm(m，＝CH2And 2H) is in agreement with the relevant literature.
Example 2
This example is a process for the preparation of 1H, 2H-perfluoro-1-octene, the preparation and testing procedures described in this example being the same as in example 1 except that sodium methoxide was used in an amount of 60.8g (1.125 mol);
the product of the reaction was 221.9g, with a purity of 99.1% and a calculated overall yield of 84.7%.
Example 3
This example is a process for the preparation of 1H, 2H-perfluoro-1-octene, which is the same as example 1 except that the basic metal salt used is replaced with sodium ethoxide in an amount of 61.2g (0.9 mol); the product of the reaction was 212.3g, purity was 98.4%, and the calculated total yield was 80.5%.
Example 4
This example is a method for preparing 1H, 2H-perfluoro-1-octene, and the preparation method and detection method described in this example are the same as those described in example 1, except that the organic solvent used is replaced by methanol, and the amount of methanol used is 500 mL;
the product of the reaction was 202g, purity was 98.67%, calculated as a total yield of 76.8%.
Comparative example 1
This comparative example is a process for producing 1H, 2H-perfluoro-1-octene, which is the same as example 1 except that potassium carbonate (124.4 g (0.9 mol)) is used in place of the alkali metal alkoxide in the reaction, and no product peak is observed by gas chromatography.
Comparative example 2
This comparative example is a process for producing 1H,1H, 2H-perfluoro-1-octene, the production and detection procedures described in this example are the same as in example 1 except that potassium hydroxide is used in place of the alkali metal alkoxide in the reaction, the amount of potassium hydroxide being 50.4g (0.9 mol);
the product of the reaction was 34.5g, purity 96.4%, calculated total yield 12.8%.
Although the invention has been described in detail hereinabove by way of general description, specific embodiments and experiments, it will be apparent to those skilled in the art that many modifications and improvements can be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.
Claims (9)
1. A method for preparing 1H,1H, 2H-perfluoro-1-octene is characterized in that 2-perfluorohexyl-1-iodo-ethane is used as a raw material, and 1H,1H, 2H-perfluoro-1-octene is prepared through elimination reaction under the action of alkali metal alkoxide; the alkali metal alkoxide is an alkali metal salt of an alcohol with 1-4 carbon atoms; the molar ratio of the 2-perfluorohexyl-1-iodo-ethane to the alkali metal alkoxide is 1: 1.1-1.5; the reaction is carried out in an organic solvent; the organic solvent is dichloromethane; the reaction temperature is 30-80 ℃.
2. The method of claim 1, wherein the alkali metal salt is one of a sodium salt, a potassium salt, or a lithium salt.
3. The process of claim 1, wherein the alkali metal alkoxide is selected from one or more of sodium methoxide, sodium ethoxide, potassium methoxide, potassium ethoxide, or sodium tert-butoxide.
4. The process according to claim 1, wherein the temperature of the reaction is between 35 ℃ and 50 ℃.
5. The process according to claim 1, wherein the molar ratio of the 2-perfluorohexyl-1-iodo-ethane to the alkali metal alkoxide is 1:1.1 to 1.3.
6. The method according to any one of claims 1 to 5, wherein the pH of the reaction system after the completion of the elimination reaction is adjusted to 6 to 8, and then the product is purified.
7. The preparation method of claim 6, wherein the pH value of the reaction system after the elimination reaction is adjusted to 6.5-7.5, and the organic phase is taken, distilled at normal pressure, and collected at 102-104 ℃ to obtain the final product.
8. The method according to claim 1, characterized in that the method is in particular: adding 2-perfluorohexyl-1-iodo-ethane and an alkali metal salt of alcohol with 1-4 carbon atoms into an organic solvent according to a molar ratio of 1: 1-2, reacting at the temperature of 35-50 ℃, adjusting the pH value of a reaction system to 6-8 after the elimination reaction is finished, taking an organic phase, distilling at normal pressure, and collecting a fraction at 102-104 ℃ to obtain the product.
9. The method according to claim 1, characterized in that the method is in particular: adding 2-perfluorohexyl-1-iodo-ethane and sodium methoxide into dichloromethane according to the molar ratio of 1: 1.1-1.3, reacting at the temperature of 35-50 ℃, adjusting the pH value of a reaction system to 6.5-7.5 after elimination reaction, taking an organic phase, distilling at normal pressure, and collecting 102-104 ℃ fractions.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710817253.1A CN109485541B (en) | 2017-09-12 | 2017-09-12 | Method for preparing 1H,1H, 2H-perfluoro-1-octene |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710817253.1A CN109485541B (en) | 2017-09-12 | 2017-09-12 | Method for preparing 1H,1H, 2H-perfluoro-1-octene |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109485541A CN109485541A (en) | 2019-03-19 |
| CN109485541B true CN109485541B (en) | 2020-05-19 |
Family
ID=65688610
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710817253.1A Active CN109485541B (en) | 2017-09-12 | 2017-09-12 | Method for preparing 1H,1H, 2H-perfluoro-1-octene |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109485541B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115872833A (en) * | 2021-08-13 | 2023-03-31 | 江苏正大清江制药有限公司 | Synthesis method of deuterated perfluorohexyl n-octane |
| CN114516781B (en) * | 2022-03-17 | 2023-09-19 | 山东大学 | Preparation method of perfluorooctyl ethyl iodide and perfluorooctyl ethylene |
-
2017
- 2017-09-12 CN CN201710817253.1A patent/CN109485541B/en active Active
Non-Patent Citations (1)
| Title |
|---|
| Study on preparation of 1H,1H,2H-Heptadecafluorodecene;Xiangcheng,Wang等;《Advanced Materials Research (Durnten-Zurich, Switzerland)》;20131231;第634-638卷;第2332-2335页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109485541A (en) | 2019-03-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN114763319B (en) | Method for co-producing valproamide and sodium valproate | |
| CN109485541B (en) | Method for preparing 1H,1H, 2H-perfluoro-1-octene | |
| CN110950776A (en) | Method for preparing 3-hydroxypropionitrile by catalyzing hydration of acrylonitrile with organic base | |
| EP2305626B1 (en) | Method for producing fluorine-containing ether | |
| CN104592030A (en) | Method for synthesizing phthalate compounds | |
| CN109020849B (en) | Preparation method of deuterated dimethyl sulfoxide | |
| US9487460B2 (en) | Method for producing allyl alcohol and allyl alcohol produced thereby | |
| CN114105727A (en) | Preparation method of perfluoroalkyl ethylene | |
| JP2008162902A (en) | Method for producing difluoroacetic acid ester | |
| CN107641067B (en) | Alpha-bromination method of o-diketone | |
| JP2010059071A (en) | Method for purifying trifluoromethanesulfonyl fluoride | |
| CN112723981B (en) | Method for preparing E-1,1,1,4,4, 4-hexafluoro-2-butene by gas phase fluorination | |
| CN104030922A (en) | Method for preparing dimethyl n-butyl malonate | |
| JP2019069922A (en) | Method of producing high-purity trifluoromethyl group-substituted aromatic ketone | |
| CN110734354B (en) | Method for preparing biaryl compound from alcohol compound | |
| CN109776281B (en) | Synthesis method of ethyl isoeugenol | |
| CN110003023B (en) | Preparation method of environment-friendly N, N-dimethylformamide dimethyl acetal | |
| CN102850270A (en) | Method for preparing hydroxy substituted-3,4-dihydro-2(1H)-quinolinone compound by one-pot method | |
| CN107602339B (en) | Method for synthesizing 4-hydroxymethyl biphenyl | |
| JP5317836B2 (en) | Method for producing alkyl sulfide compound | |
| CN115368217B (en) | Synthesis method of 3,4, 5-trimethoxytoluene | |
| CN116283504B (en) | Synthesis method of 2, 4-dicumyl phenol | |
| KR101212565B1 (en) | Process for producing monomer for fluorinated resist | |
| CN114163312B (en) | Synthesis method of fluorine-containing terephthalyl diether compound | |
| CN114516781B (en) | Preparation method of perfluorooctyl ethyl iodide and perfluorooctyl ethylene |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |