CN105085403A - Preparation method of 1,2-dimethyl imidazole - Google Patents
Preparation method of 1,2-dimethyl imidazole Download PDFInfo
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- CN105085403A CN105085403A CN201510184981.4A CN201510184981A CN105085403A CN 105085403 A CN105085403 A CN 105085403A CN 201510184981 A CN201510184981 A CN 201510184981A CN 105085403 A CN105085403 A CN 105085403A
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- acetaldehyde
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- ammonia
- dimethylimidazole
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D233/00—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings
- C07D233/54—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings having two double bonds between ring members or between ring members and non-ring members
- C07D233/56—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings having two double bonds between ring members or between ring members and non-ring members with only hydrogen atoms or radicals containing only hydrogen and carbon atoms, attached to ring carbon atoms
- C07D233/58—Heterocyclic compounds containing 1,3-diazole or hydrogenated 1,3-diazole rings, not condensed with other rings having two double bonds between ring members or between ring members and non-ring members with only hydrogen atoms or radicals containing only hydrogen and carbon atoms, attached to ring carbon atoms with only hydrogen atoms or radicals containing only hydrogen and carbon atoms, attached to ring nitrogen atoms
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The present invention relates to a preparation method of 1,2-dimethyl imidazole, relates to a two-phase synthesis of method 1,2-dimethyl-imidazole, and particularly relates to a method for synthesizing 1,2-dimethyl-imidazole from methylamine, acetaldehyde, glyoxal and ammonia. The method is as below: first adding a glyoxal solution into a reaction vessel; controlling a certain temperature and pressure; introducing pure acetaldehyde, methylamine and ammonia in turn; heating and reacting for a period of time; reducing pressure to distill off most of the water, cooling, crystallizing, filtering and collecting the product. The method completely or partially uses ammonia; and acetaldehyde solution is replaced by pure acetaldehyde for participating reaction. The method improves product yield, also reduces energy consumption, and reduces waste or wastewater discharge.
Description
Technical field
The present invention relates to a kind of preparation method of 1,2 dimethylimidazole, belong to chemical intermediate synthesis technical field.
Background technology
Glyoxaline compound is the development in recent years heterogeneous ring compound that a class formation is special faster.The special performance in the numerous areas such as high performance composite, biological medicine, dyestuff and anti-corrosion of metal reality.1,2 dimethylimidazole is used for hard polyurethane foam and micro-pore elastomer, belongs to gel catalyst.Also can be used as epoxy curing agent simultaneously, be widely used in adhering with epoxy resin, application, cast, encapsulating, dipping and matrix material etc.1,2-methylimidazole is one of important intermediate of imidazoles, its traditional synthetic method adopts two-step approach to obtain, first oxalic dialdehyde is obtained glyoxal ethyline with acetaldehyde, ammoniacal liquor condensation, obtain 1,2 dimethylimidazole with methyl-sulfate methylation reaction further again, this method productive rate is lower, by product is many, and separation and purification is cumbersome.The people such as Qi Gang are pre-mixed with glyoxal water solution and acetaldehyde solution, drip the mixing solutions of methylamine and ammoniacal liquor, directly synthesis preparation 1,2 dimethylimidazole.This method raw material all adopts the aqueous solution, causes reaction volume comparatively large, and the process power consumption steaming water is comparatively large, and waste water is more.
Summary of the invention
The object of the invention is to the shortcoming existed in the method for existing synthesis 1,2 dimethylimidazole, provide that a kind of raw material is easy to get, equipment is simple, reduce energy consumption and the preparation method of the synthesis 1,2 dimethylimidazole of decreasing pollution.
The technical solution used in the present invention is: it is that raw material is formed by temperature-control pressure-control reaction by ammonia, methylamine, acetaldehyde, oxalic dialdehyde, and its synthetic route is as follows:
CH
3nH
2 (aq)+ CH
3cHO
(pure)+ NH
3 (gas)+ CHOCHO
(aq)→ 1,2 dimethylimidazole+3H
2o
Price according to ammoniacal liquor on market and ammonia determines, ammoniacal liquor low price and be easy to transport, then before the reaction partial ammonia water is steamed into ammonia.Because reaction front evaporator ammonia is more much easier than transpiring moisture after reaction, and the weak ammonia produced after evaporation ammonia, ammonial plant can be returned to and recycle.Its synthesis step is:
1) in the reactor of solution-air two-phase synthesis device, glyoxal solution is added;
2) control temperature and pressure, slowly once passes into pure acetaldehyde, methylamine, ammonia;
3) temperature rising reflux reaction certain hour is finished;
4) pressure reducing and steaming moisture after reacting completely, cooling, crystallization, filter and obtain product.
The present invention compared with prior art, tool has the following advantages: owing to using gas and liquid phase method, partly or entirely change the ammoniacal liquor of existing technique into ammonia, acetaldehyde solution changes pure acetaldehyde into, in sepn process, the more existing technique of water evaporation quantity reduces about 50%, reduces the production cost of 1,2 dimethylimidazole, can also discharge of wastewater be reduced, improve product yield.
Embodiment
According to following embodiment, the present invention may be better understood.But those skilled in the art will readily understand, concrete material proportion, processing condition and result thereof described by examples of implementation only for illustration of the present invention, and should can not limit the present invention described in detail in claims yet.
Embodiment 1:
The glyoxal solution 72.5 grams (0.5mol) of 40% is added in temperature automatically controlled reactor, under 16 DEG C of band stirrings, 0.1MPa condition, slowly pass into 22 grams, pure acetaldehyde (0.5mol) successively, 40% methylamine 38.8g (0.5mol), ammonia 34 grams (2mol); After reinforced, temperature control 80 DEG C, back flow reaction 6 hours; Reacted rear underpressure distillation removing moisture, cooling, crystallization obtain product.
Embodiment 2:
The glyoxal solution 72.5 grams (0.5mol) of 40% is added in temperature automatically controlled reactor, under 16 DEG C of band stirrings, tiny structure condition, slowly pass into 25% ammoniacal liquor 34 grams (0.5mol), 33 grams, pure acetaldehyde (0.75mol), 40% methylamine 38.8g (0.5mol), ammonia 8.5 grams (0.5mol); After reinforced, temperature control 80 DEG C, back flow reaction 6 hours; Reacted rear underpressure distillation removing moisture, cooling, crystallization obtain product.
Embodiment 3:
The glyoxal solution 72.5 grams (0.5mol) of 40% is added in temperature automatically controlled reactor, under 15 DEG C of band stirrings, tiny structure condition, slowly pass into 22 grams, pure acetaldehyde (0.5mol), 40% methylamine 38.8g (0.5mol), ammonia 17 grams (1mol); After reinforced, temperature control 85 DEG C, back flow reaction 6 hours; Reacted rear underpressure distillation removing moisture, cooling, crystallization obtain product.
Embodiment 1-3, owing to using gas and liquid phase method, partly or entirely change the ammoniacal liquor of existing technique into ammonia, acetaldehyde solution changes pure acetaldehyde into, in sepn process, the more existing technique of water evaporation quantity reduces about 50%, reduces the production cost of 1,2 dimethylimidazole, can also discharge of wastewater be reduced, improve product yield.
More than show and describe ultimate principle of the present invention and principal character and advantage of the present invention.The technician of the industry should understand; the present invention is not restricted to the described embodiments; what describe in above-described embodiment and specification sheets just illustrates principle of the present invention; without departing from the spirit and scope of the present invention; the present invention also has various changes and modifications, and these changes and improvements all fall in the claimed scope of the invention.Application claims protection domain is defined by appending claims and equivalent thereof.
Claims (5)
1. a preparation method for 1,2 dimethylimidazole, is characterized in that: synthetic route is as follows:
Its synthesis step is:
1) in the reactor of solution-air two-phase synthesis device, glyoxal solution is added;
2) control temperature and pressure, slowly once passes into pure acetaldehyde, methylamine, ammonia;
3) temperature rising reflux reaction certain hour is finished;
4) pressure reducing and steaming moisture after reacting completely, cooling, crystallization, filter and obtain product.
2. the preparation method of 1,2 dimethylimidazole according to claim 1, is characterized in that: in the process passing into substrate by pressure-controlling at minute-pressure or micro-vacuum state.
3. the preparation method of 1,2 dimethylimidazole according to claim 1, is characterized in that: the acetaldehyde passing into reactor is pure acetaldehyde but not acetaldehyde solution.
4. the preparation method of 1,2 dimethylimidazole according to claim 1, is characterized in that: what pass into reactor is ammonia, instead of ammoniacal liquor or liquefied ammonia.
5. the preparation method of 1,2 dimethylimidazole according to claim 1, is characterized in that: after adding reaction substrate, is warming up to 50-80 DEG C of reaction 5-10h.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510184981.4A CN105085403A (en) | 2015-04-20 | 2015-04-20 | Preparation method of 1,2-dimethyl imidazole |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510184981.4A CN105085403A (en) | 2015-04-20 | 2015-04-20 | Preparation method of 1,2-dimethyl imidazole |
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| CN105085403A true CN105085403A (en) | 2015-11-25 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510184981.4A Pending CN105085403A (en) | 2015-04-20 | 2015-04-20 | Preparation method of 1,2-dimethyl imidazole |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105732508A (en) * | 2016-03-28 | 2016-07-06 | 南京师范大学 | Continuous preparation method of N-methylimidazole |
| CN106905240A (en) * | 2017-03-20 | 2017-06-30 | 盐城卫生职业技术学院 | A kind of recovery method of 1,2 methylimidazole mother liquor |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101633642A (en) * | 2009-08-12 | 2010-01-27 | 曾舟华 | Preparation method of N-alkyl imidazole |
| JP2012211122A (en) * | 2011-03-22 | 2012-11-01 | Nippon Synthetic Chem Ind Co Ltd:The | Method for production of 1,2-dialkylimidazole, and 1,2-dialkylimidazole obtained thereby |
| CN102924381A (en) * | 2011-08-08 | 2013-02-13 | 曾舟华 | 2-methylimidazole preparation method |
-
2015
- 2015-04-20 CN CN201510184981.4A patent/CN105085403A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101633642A (en) * | 2009-08-12 | 2010-01-27 | 曾舟华 | Preparation method of N-alkyl imidazole |
| JP2012211122A (en) * | 2011-03-22 | 2012-11-01 | Nippon Synthetic Chem Ind Co Ltd:The | Method for production of 1,2-dialkylimidazole, and 1,2-dialkylimidazole obtained thereby |
| CN102924381A (en) * | 2011-08-08 | 2013-02-13 | 曾舟华 | 2-methylimidazole preparation method |
Non-Patent Citations (1)
| Title |
|---|
| 徐文清等人: "1,2-二甲基咪唑啉的合成及表征", 《有机化学》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105732508A (en) * | 2016-03-28 | 2016-07-06 | 南京师范大学 | Continuous preparation method of N-methylimidazole |
| CN106905240A (en) * | 2017-03-20 | 2017-06-30 | 盐城卫生职业技术学院 | A kind of recovery method of 1,2 methylimidazole mother liquor |
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Application publication date: 20151125 |