CN102766028A - Method for preparing 2-bromine-4-methylphenol - Google Patents
Method for preparing 2-bromine-4-methylphenol Download PDFInfo
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- CN102766028A CN102766028A CN2012102899018A CN201210289901A CN102766028A CN 102766028 A CN102766028 A CN 102766028A CN 2012102899018 A CN2012102899018 A CN 2012102899018A CN 201210289901 A CN201210289901 A CN 201210289901A CN 102766028 A CN102766028 A CN 102766028A
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- bromo
- bromine
- methylphenol
- methyl chloride
- cresol
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Abstract
The invention provides a method for preparing 2-bromine-4-methylphenol, wherein p-cresol serves as the raw material. The method is characterized in that p-cresol and methyl chloride solvents are added into a reactor, methyl chloride solution added with bromine dropwise is subjected to bromination reaction, then the solvents are recovered through distilling, and finally the product of 2-bromine-4-methylphenol is obtained. By using the method to produce 2-bromine-4-methylphenol, purity and yield are high, consumption of the raw material and the solvents is low, and reaction conversion rate is high.
Description
Technical field
The invention belongs to the fine chemical technology field, especially relate to a kind of preparation method of 2-bromo-4-methylphenol.
Background technology
2-bromo-4-methylphenol (hereinafter to be referred as single bromine phenol) is the important intermediate of synthetic many medicines and broad spectrum type spices vanillin food grade,1000.000000ine mesh.At present, preparing the comparatively advanced method of single bromine phenol is to be that oxidation makes raw material through bromination with the p-cresol.This technology introduced in articles such as " the 2-bromo-4-methylphenol synthetic " that " chemical research and application " the 5th periodical in 2004 is stepped on.Can know that by above-mentioned article the key step of this technology is: in reactor drum, add p-cresol, methylene dichloride, after mixing; Add Hydrogen bromide, controlled temperature is under-5 ~-10 ℃ of conditions, drips ydrogen peroxide 50; After reaction was accomplished, through washing, underpressure distillation obtained single bromine phenol.The major defect of this technology is: (1) selects for use 40% Hydrogen bromide as bromizating agent, and equipment is had intensive corrodibility.(2) reaction process is easy to generate the dibrominated thing, is difficult to separate with single bromine phenol.(3) solvent load is big, and producing one ton of p-cresol needs 6.5 tons of solvents at least.(4) productive rate is up to 93%, and product gas purity does not obviously identify.Because above several reasons has limited the application of this method in industry.
Summary of the invention
The purpose of this invention is to provide a kind of is the novel process of the single bromine phenol of feedstock production with the p-cresol.Little during with the single bromine phenol of this explained hereafter to equipment corrosion, be difficult for producing the dibrominated thing, solvent load is little, and product yield is up to 99%, and purity reaches more than 98%, is convenient to realize suitability for industrialized production.
In order to realize above-mentioned target, the technical scheme that the present invention proposes is to prepare single bromine phenol according to the following steps:
A, in bromination reactor, add p-cresol and methyl chloride kind solvent; The mol ratio of p-cresol and methyl chloride kind solvent is that the ratio of 1.0 ~ 10.0:1 adds bromine and methyl chloride kind solvent in Dropping feeder; The mol ratio of bromine and methyl chloride kind solvent is 1.0 ~ 8.0:1, mixes; Wherein, the mol ratio of bromine and p-cresol is 1.0 ~ 1.1:1, and the chloromethane alkanes solution that drips bromine continuously carries out bromination reaction;
After B, above-mentioned reaction are accomplished, will accomplish liquid and wash; To accomplish behind the liquid elder generation normal pressure distillating recovering solvent under the reduced pressure then, solution can obtain 2-bromo-4-methylphenol finished product after steaming and desolventizing.
Said methyl chloride kind solvent is one or more in chloroform, tetracol phenixin, the methylene dichloride among the above-mentioned steps A; It is 50 ~ 80% that the methyl chloride kind solvent is diluted to mass percent concentration with p-cresol; Using the methyl chloride kind solvent that bromine is diluted to mass percent concentration is 50 ~ 80%; The temperature of bromination reaction is-5 ~ 10 ℃, and the time of reaction is 3 ~ 8 hours; Said washing is meant washing to neutral among the above-mentioned steps B, and the hydrogen bromide that produces in the removal bromination reaction is during distillating recovering solvent; Under condition of normal pressure, steam earlier to 100 ℃; Then-and 0.09MPa is following to be steamed to 55 ℃, reclaims the methyl chloride kind solvent, and solvent recovering rate reaches more than 95%; Single bromine phenolic product yield of this method preparation is more than 99%, and product purity is more than 98%.
Use the single bromine phenol of prepared of the present invention, less demanding to equipment, and can realize effectively reducing production costs the recycle of methyl chloride kind solvent.Generally speaking, technical characterstic of the present invention and excellent results are following:
(1) bromine has avoided using the high concentration of hydrogen bromic acid as the strong corrosion of bromizating agent to equipment as bromizating agent;
(2) adopt the mode that drips the bromination agent solution continuously, effectively avoided the generation of dibrominated thing;
(3) effectively reduced the consumption of solvent, producing 1 ton of single bromine phenol only needs 0.95 ton of solvent, and solvent can recycle, and the recovery reaches more than 95%;
(4) single bromine phenol yield is more than 99%, and purity is more than 98%.
Embodiment
Through concrete embodiment the present invention is done further elaboration below, but embodiment does not limit protection scope of the present invention.
Embodiment 1:
In the four-hole bottle of 1000mL, add p-cresol 220g (2.00 moles), chloroform 146.7g (1.23 moles) adds bromine 336.33g (2.10 moles) in constant pressure funnel, and chloroform 228.8g (1.91 moles) mixes.Open and stir, be cooled to 0 ~ 5 ℃, begin to drip the mixing solutions of bromine and chloroform, the control rate of addition, the dropping that remains a constant speed, and controlled temperature, the time is 7 hours, reaction finishes.In reaction flask, add water 400g and wash hydrogen bromide, divide water-yielding stratum, organic layer is washed once more, can be washed till neutrality general about 3 times.Organic layer distills, steam under the condition of normal pressure to 100 ℃, then-0.09MPa down steaming to 55 ℃; Reclaim chloroform, in order to experiment next time usefulness, organic layer can obtain finished product list bromine phenol 376.88g after steaming and desolventizing; Can know in the finished product that through the gas spectrum analysis except that chloroform, it consists of p-cresol 0.08%, single bromine phenol 98.54%; 2,6-two bromo-4-methylphenols 0.19%, single bromine phenol yield is 99.3%.
Embodiment 2:
In the four-hole bottle of 500mL, add p-cresol 110g (1.00 moles), methylene dichloride 52.11g (0.61 mole) adds bromine 168.24g (1.05 moles) in constant pressure funnel, and methylene dichloride 80.83g (0.95 mole) mixes.Open to stir, be cooled to-5 ~ 5 ℃, begin to drip the mixing solutions of bromine and methylene dichloride, the control rate of addition, about 1 second one, droppings that remain a constant speed, and controlled temperature, the time is 7.5 hours, reacts end.In reaction flask, add water 200g and wash hydrogen bromide, divide water-yielding stratum, organic layer is washed (washing altogether 3 times) once more.Organic layer distills, steam under the condition of normal pressure to 80 ℃, then-0.09MPa down steaming to 33 ℃; Reclaim methylene dichloride, in order to experiment next time usefulness, organic layer can obtain finished product list bromine phenol 189.39g after steaming and desolventizing; Can know in the finished product that through the gas spectrum analysis except that methylene dichloride, it consists of p-cresol 0.11%, single bromine phenol 97.68%; 2,6-two bromo-4-methylphenols 0.27%, single bromine phenol yield is 98.93%.
Embodiment 3:
In the four-hole bottle of 1000mL, add p-cresol 220g (2.00 moles), chloroform 300.11g (2.51 moles) adds bromine 368.69g (2.30 moles) in constant pressure funnel, and chloroform 448.17g (3.75 moles) mixes.Open and stir, be cooled to-5 ~ 0 ℃, begin to drip the mixing solutions of bromine and chloroform, the control rate of addition, the dropping that remains a constant speed, and controlled temperature, the time is 7 hours, reaction finishes.In reaction flask, add water 400g and wash hydrogen bromide, divide water-yielding stratum, organic layer is washed once more, can be washed till neutrality general about 3 times.Organic layer distills, steam under the condition of normal pressure to 100 ℃, then-0.09MPa down steaming to 55 ℃; Reclaim chloroform, in order to experiment next time usefulness, organic layer can obtain finished product list bromine phenol 376.76g after steaming and desolventizing; Can know in the finished product that through the gas spectrum analysis except that chloroform, it consists of p-cresol 0.05%, single bromine phenol 98.87%; 2,6-two bromo-4-methylphenols 0.09%, single bromine phenol yield is 99.6%.
Claims (8)
1. a method for preparing 2-bromo-4-methylphenol is a raw material with the p-cresol, and dripping bromine is carried out bromination reaction continuously, washing afterwards, and distillating recovering solvent obtains 2-bromo-4-methylphenol, it is characterized in that:
A, in bromination reactor, add p-cresol and methyl chloride kind solvent; The mol ratio of p-cresol and methyl chloride kind solvent is that the ratio of 1.0 ~ 10.0:1 adds bromine and methyl chloride kind solvent in Dropping feeder; The mol ratio of bromine and methyl chloride kind solvent is 1.0 ~ 8.0:1, mixes; Wherein, the mol ratio of bromine and p-cresol is 1.0 ~ 1.1:1, and the chloromethane alkanes solution that drips bromine continuously carries out bromination reaction;
After B, above-mentioned reaction are accomplished, will accomplish liquid and wash; To accomplish behind the liquid elder generation normal pressure distillating recovering solvent under the reduced pressure then, solution can obtain 2-bromo-4-methylphenol finished product after steaming and desolventizing.
2. the preparation method of 2-bromo-4-methylphenol according to claim 1 is characterized in that used methyl chloride kind solvent is one or more in chloroform, tetracol phenixin, the methylene dichloride.
3. the preparation method of 2-bromo-4-methylphenol according to claim 1; It is characterized in that: using the methyl chloride kind solvent that p-cresol is diluted to mass percent concentration is 50 ~ 80%, and using the methyl chloride kind solvent that bromine is diluted to mass percent concentration is 50 ~ 80%.
4. the preparation method of 2-bromo-4-methylphenol according to claim 1, it is characterized in that: the temperature of bromination reaction is-5 ~ 10 ℃.
5. the preparation method of 2-bromo-4-methylphenol according to claim 1 is characterized in that: the time of bromination reaction is 3 ~ 8 hours.
6. the preparation method of 2-bromo-4-methylphenol according to claim 1 is characterized in that: washing is removed the hydrogen bromide that produces in the bromination reaction to neutral.
7. the preparation method of 2-bromo-4-methylphenol according to claim 1 is characterized in that: during distillating recovering solvent, under condition of normal pressure, steams earlier to 100 ℃, then-0.09MPa steams down to 55 ℃, reclaims the methyl chloride kind solvent.
8. the preparation method of 2-bromo-4-methylphenol according to claim 1 is characterized in that: said preparing method's product yield is more than 99%, and product purity is more than 98%.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108218676A (en) * | 2018-01-18 | 2018-06-29 | 清华大学 | A kind of method for synthesizing the bromo- 3- methylanisoles of 4- |
| CN109134204A (en) * | 2018-11-16 | 2019-01-04 | 白银棓诺新材料有限公司 | The synthetic method of the fluoro- 5- chlorophenol of the bromo- 4- of intermediate 2- |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1863755A (en) * | 2003-08-28 | 2006-11-15 | 通用电气公司 | Bromination of hydroxyaromatic compounds |
| CN1874982A (en) * | 2003-08-28 | 2006-12-06 | 通用电气公司 | Selective catalytic oxybromination of hydroxyaromatic compounds |
| CN101037378A (en) * | 2006-03-16 | 2007-09-19 | 毕新民 | Method for preparing 2-bromine-4-methyl phenol and method for preparing vanillin |
| CN101279896A (en) * | 2008-05-26 | 2008-10-08 | 嘉兴市中华化工有限责任公司 | Preparation of 2-bromo-4-methylphenol |
-
2012
- 2012-08-15 CN CN2012102899018A patent/CN102766028A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1863755A (en) * | 2003-08-28 | 2006-11-15 | 通用电气公司 | Bromination of hydroxyaromatic compounds |
| CN1874982A (en) * | 2003-08-28 | 2006-12-06 | 通用电气公司 | Selective catalytic oxybromination of hydroxyaromatic compounds |
| CN101037378A (en) * | 2006-03-16 | 2007-09-19 | 毕新民 | Method for preparing 2-bromine-4-methyl phenol and method for preparing vanillin |
| CN101279896A (en) * | 2008-05-26 | 2008-10-08 | 嘉兴市中华化工有限责任公司 | Preparation of 2-bromo-4-methylphenol |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108218676A (en) * | 2018-01-18 | 2018-06-29 | 清华大学 | A kind of method for synthesizing the bromo- 3- methylanisoles of 4- |
| CN108218676B (en) * | 2018-01-18 | 2020-08-18 | 清华大学 | Method for synthesizing 4-bromo-3-methylanisole |
| CN109134204A (en) * | 2018-11-16 | 2019-01-04 | 白银棓诺新材料有限公司 | The synthetic method of the fluoro- 5- chlorophenol of the bromo- 4- of intermediate 2- |
| CN109134204B (en) * | 2018-11-16 | 2022-03-08 | 棓诺(苏州)新材料有限公司 | Synthesis method of intermediate 2-bromo-4-fluoro-5-chlorophenol |
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Application publication date: 20121107 |