CN101085712A - Method for preparing alpha, omega-dibromoalkane - Google Patents
Method for preparing alpha, omega-dibromoalkane Download PDFInfo
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- CN101085712A CN101085712A CN 200710015262 CN200710015262A CN101085712A CN 101085712 A CN101085712 A CN 101085712A CN 200710015262 CN200710015262 CN 200710015262 CN 200710015262 A CN200710015262 A CN 200710015262A CN 101085712 A CN101085712 A CN 101085712A
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- dibromoalkane
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Abstract
The invention discloses a method for preparing alpha, omega- dibrom alkane. It comprises following steps: taking alpha, omega- diatomic alcohol and hydrobromic acid with the molar ratio between them being 1: 1- 8, dissolving them in reacting tank, adding inorganic aicd as catalyst and quaternary ammonium salt as phase- transferring catalyst, heating to 110- 130 Deg. C, stirring and refluxing hydrobromic acid, reacting for 1- 3 hours, removing hydrobromic acid through distillation, adding hydrobromic acid and keeping temperature being 100- 120 Deg. C, adding hydrobromic acid and removing hydrobromic acid through distillation at the same time, reacting for 1- 3 hours, getting rid of the lower part, adding alkali solution to the upper part to neutralize to neutral, extracting and getting omega- dibrom alkane. The invention is characterized by simple production method, high recovery rate and short reaction time.
Description
Technical Field
The invention relates to a production method of α, omega-dibromoalkane, in particular to a production method of long-chain (C8-C12) n-alkane dibromo compound.
Background
The long-chain alkane dibromo-compound plays an important role in national economy, and the demand of the long-chain alkane-dibromo-compound is continuously increased along with the development of economy and the continuous improvement of the living standard of people. The method has large demand in the fields of fine chemicals such as medicine synthesis, dye chemical industry, surfactants and the like, and dibromoalkane produced industrially in China is a dibromo-compound with less than six carbons generally, and has the defects of low yield, long reaction time and the like.
Disclosure of Invention
The invention aims to provide a method for producing α omega-dibromoalkane, which has the advantages of simple production method, high yield, short reaction time and the like.
The production method of α omega-dibromoalkane adopts α omega-dihydric alcohol and hydrobromic acid with a molar ratio of 1: 1-8 as raw materials, inorganic acid is added as a catalyst after the raw materials are dissolved in a reaction tank, quaternary ammonium salt is added as a phase change catalyst, the temperature is increased to 110 ℃ and 130 ℃, stirring is carried out, the hydrobromic acid reflux is kept, the reaction is carried out for 1-3 hours, the hydrobromic acid is distilled off, the hydrobromic acid is added, the reaction is kept at 100 ℃ and 120 ℃, the hydrobromic acid is distilled off while the addition is carried out, the lower layer is discarded after the reaction is carried out for 1-3 hours, the upper layer is added with an alkaline solution for neutralization to neutrality, and the α omega-dibromoalkane is obtained after purification.
The concentration of the hydrobromic acid is 30-60%.
The inorganic acid can adopt 98% sulfuric acid or 40% hydrochloric acid, and the molar ratio of the addition amount to the dihydric alcohol is 1-2.5: 1.
The phase-change catalyst can adopt benzyl trimethyl ammonium bromide or tetraethyl ammonium bromide or tetrapropyl ammonium bromide, and the molar ratio of the addition amount to the dihydric alcohol is 0.002-0.006: 1.
The environmental pressure is 0.02-0.1 MPa when the dihydric alcohol and the hydrobromic acid react, and the stirring speed is 50-400 r/min.
The purification can be carried out in a rectifying tower, and the α, omega-dibromoalkane can be obtained by collecting the fraction of 190-210 ℃/30 mmHg.
The reaction equation of the invention is as follows:
the invention has the beneficial effects that: the process is reasonable, the process is easy to control, the requirement on equipment is low, and the yield is high.
Drawings
FIG. 1 is a process flow diagram of the method of the present invention.
Detailed Description
The invention is further illustrated by the following examples:
the first embodiment is as follows:
a process for preparing 1, 8-dibromooctane includes such steps as proportionally mixing octanediol with 30% hydrobromic acid in 1: 1 ratio, dissolving, adding sulfuric acid as catalyst in 1: 1 ratio, adding benzyltrimethylammonium bromide as phase-change catalyst in 1: 0.002 ratio, gradually heating while stirring, reflux reacting at 110 deg.C for 1 hr under 0.02MPa while distilling out hydrobromic acid, reacting for 1 hr, laying aside, washing the upper layer with ammonium solution, neutralizing, purifying by rectifying tower, collecting 190-210 deg.C/30 mmHg fraction to obtain 1, 8-dibromooctane. The test shows that the content reaches 98 percent and the yield reaches 90 percent.
Example two:
a process for preparing 1, 10-dibromodecane from decanediol and 40% hydrobromic acid includes such steps as proportionally mixing decanediol with 40% hydrochloric acid in 1: 1.5, adding hydrochloric acid as catalyst, adding tetraethylammonium bromide as phase-change catalyst in 1: 0.004, gradually heating, stirring, reflux reaction while maintaining 120 deg.C for 2 hr, distilling to remove hydrobromic acid, adding hydrobromic acid, maintaining 110 deg.C while distilling, reacting for 2 hr, laying aside, removing lower layer, washing upper layer with ammonium solution, neutralizing, purifying, collecting the fraction at 190-210 deg.C/30 deg.C to obtain 1, 10-dibromodecane. The test shows that the content reaches 97 percent and the yield reaches 92 percent.
Example three:
a process for preparing 1, 10-dibromodecane from decanediol and 60% hydrobromic acid includes such steps as proportionally mixing decanediol with 98% sulfuric acid in 1: 2.5, adding sulfuric acid as catalyst, adding tetrapropylammonium bromide as phase-change catalyst in 1: 0.006, gradually heating while stirring, reflux reacting at 130 deg.C for 3 hr, distilling to remove hydrobromic acid, adding hydrobromic acid, distilling while adding hydrobromic acid, reacting for 3 hr, laying aside, discarding lower layer, adding ammonium solution to upper layer, washing, neutralizing, purifying by rectifying tower, collecting 190-210 deg.C/30 fraction to obtain 1, 10-dibromodecane. The test shows that the content reaches 98 percent and the yield reaches 91 percent.
Claims (6)
1.α, omega-dibromoalkane production method, which is characterized in that α, omega-dihydric alcohol and hydrobromic acid with a molar ratio of 1: 1-8 are used as raw materials, inorganic acid is added as a catalyst after being dissolved in a reaction tank, quaternary ammonium salt is added as a phase change catalyst, the temperature is raised to 110-.
2.α, the method for producing an omega-dibromoalkane according to claim 1, characterized in that the concentration of the hydrobromic acid is 30 to 60 percent.
3. α, the method for producing omega-dibromoalkane according to claim 1, characterized in that the inorganic acid can be sulfuric acid with a concentration of 98% or hydrochloric acid with a concentration of 40%, and the molar ratio of the inorganic acid to the dihydric alcohol is 1-2.5: 1.
4. α, the method for producing omega-dibromoalkane according to claim 1, characterized in that the phase-change catalyst can adopt benzyltrimethylammonium bromide or tetraethylammonium bromide or tetrapropylammonium bromide, and the molar ratio of the added amount to the diol is 0.002-0.006: 1.
5. The α, omega-dibromoalkane production method according to claim 1, characterized in that the ambient pressure at which the dihydric alcohol and the hydrobromic acid react is 0.02 to 0.1MPa, and the stirring speed is 50 to 400 rpm.
6. The α method for producing omega-dibromoalkane according to claim 1, wherein the purification can be carried out in a rectifying tower, and the α, omega-dibromoalkane is obtained by collecting the fraction of 190-210 ℃/30 mmHg.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2007100152625A CN101085712B (en) | 2007-07-10 | 2007-07-10 | Method for preparing alpha, omega-dibromoalkane |
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| Application Number | Priority Date | Filing Date | Title |
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| CN2007100152625A CN101085712B (en) | 2007-07-10 | 2007-07-10 | Method for preparing alpha, omega-dibromoalkane |
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| Publication Number | Publication Date |
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| CN101085712A true CN101085712A (en) | 2007-12-12 |
| CN101085712B CN101085712B (en) | 2012-05-30 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103864569A (en) * | 2014-03-27 | 2014-06-18 | 张家港威胜生物医药有限公司 | Simple preparation method for 1,4-dibromopentane |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1190398C (en) * | 2001-01-04 | 2005-02-23 | 汤俊明 | Process for preparing bromo-n-dodecane |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103864569A (en) * | 2014-03-27 | 2014-06-18 | 张家港威胜生物医药有限公司 | Simple preparation method for 1,4-dibromopentane |
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| CN101085712B (en) | 2012-05-30 |
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