CN107556250A - The high-efficiency synthesis method of the methylpyrazine of 2 ethyl 3 - Google Patents
The high-efficiency synthesis method of the methylpyrazine of 2 ethyl 3 Download PDFInfo
- Publication number
- CN107556250A CN107556250A CN201710666130.2A CN201710666130A CN107556250A CN 107556250 A CN107556250 A CN 107556250A CN 201710666130 A CN201710666130 A CN 201710666130A CN 107556250 A CN107556250 A CN 107556250A
- Authority
- CN
- China
- Prior art keywords
- catalyst
- methylpyrazines
- synthesis method
- solution
- ethyls
- 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.)
- Withdrawn
Links
Landscapes
- Catalysts (AREA)
Abstract
The invention discloses the high-efficiency synthesis method of the methylpyrazine of 2 ethyl 3, following steps are specifically included：2,3 pentanediones are prepared using lactic acid as raw material first, use diammonium hydrogen phosphate and barium nitrate that porous carrier is made for raw material, it loads caesium as catalyst, effectively increases the conversion ratio of lactic acid；Then the methylpyrazine of 2 ethyl 3 is made by dehydrating condensation, dehydrogenation reaction successively as originally with obtained 2,3 pentanediones and ethylenediamine.The preparation method is simple, and cost is low, and product yield is high.
Description
Technical field：
The present invention relates to organic synthesis field, the high-efficiency synthesis method of 2- ethyl -3- methylpyrazines is specifically related to.
Background technology：
2- ethyl -3- methylpyrazines are naturally occurring in coffee, fibert, peanut, potato, nut, are colourless or faint yellow
Liquid, have nut perfume, peanut perfume, musty, cereal sample, bread fragrant.It can be by ethylenediamine and 2, and 3- pentanediones are raw material, dehydration
Condensation reaction, then dehydrogenation and obtain.
Current 2, it is that raw material is made by catalyzing and condensing that lactic acid is commonly used in the preparation of 3 pentanediones, but is made due to catalyst
With improper, usually make it that the conversion ratio of lactic acid is not high.
The content of the invention：
It is an object of the invention to provide the high-efficiency synthesis method of 2- ethyl -3- methylpyrazines, this method first using lactic acid as
2,3- pentanediones are made in raw material, by reasonable selection catalyst and preparation process condition, effectively improve the conversion ratio of lactic acid,
Then it is high as raw material, obtained product yield with obtained 2,3- pentanediones and ethylenediamine.
To achieve the above object, the present invention uses following technical scheme：
The high-efficiency synthesis method of 2- ethyl -3- methylpyrazines, comprises the following steps：
(1) barium sulfate and deionized water are mixed into solid dissolving, barium nitrate solution is made；By diammonium hydrogen phosphate and
Deionized water mixes to solid dissolving and ammonium dibasic phosphate solution is made；It is molten to barium nitrate under 1000 revs/min of stirring
Ammonium dibasic phosphate solution is added dropwise in liquid, while be added dropwise while stir, continue after completion of dropwise addition stirring 1h, then filter, solid spend from
8h is dried after sub- water washing, is finally placed in Muffle furnace and handles 3h at 500 DEG C, porous carrier is made；
(2) obtained porous carrier, cesium nitrate and deionized water are mixed into solid dissolving and mixed solution is made, so
Mixed solution is placed in oil bath pan into stirring at 80 DEG C afterwards to be evaporated, obtained solid is placed in Muffle furnace and handles 3h at 600 DEG C, system
Obtain catalyst；
(3) 0.3g catalyst obtained above is placed in quartz ampoule, length of the catalyst in quartz ampoule is 30mm, is urged
Agent both ends are blocked with silica wool, and lactic acid aqueous solution is carried by the quartz ampoule equipped with catalyst with nitrogen, and in silica wool
Surface vaporization, subsequent steam feed pass through the catalyst surface, and reaction temperature is 260-340 DEG C, lactic acid concn 10-
50wt%, charging rate 0.3-5.0mL/h, the flow velocity of carrier gas is 1-10mL/min, and 2,3- pentanediones are made；
(4) at -5~3 DEG C, obtained above 2,3- pentanediones, ethylenediamine and absolute ethyl alcohol are mixed in three-necked flask
Conjunction stirs, and reacts 5-7h, reacts and system is warming up into room temperature after terminating, and continues to stir 1-3h at room temperature, then heats to
65-70 DEG C, flow back 1-4h, backflow terminate after be quickly cooled to 30-40 DEG C, then sequentially added into three-necked flask dimethylbenzene,
Potassium hydroxide and catalyst, 65-70 DEG C, back flow reaction 5h being continuously heating to after addition, reaction is cooled to room temperature after terminating,
Filter, filtrate carries out air-distillation, and the concentrate after distillation is diluted with saturated aqueous common salt, extracts, and merges organic phase, with anhydrous sulphur
Sour copper is dried, and filtering, normal pressure steams extractant, and the cut for collecting 55-60 DEG C/1.33KMa obtains 2- ethyl -3- methylpyrazines.
As the preferred of above-mentioned technical proposal, in step (1), the mass concentration of barium nitrate solution is 20.5%.
As the preferred of above-mentioned technical proposal, in step (1), the mass concentration of the ammonium dibasic phosphate solution is
13.2%.
As the preferred of above-mentioned technical proposal, in step (1), barium nitrate, the mass ratio of diammonium hydrogen phosphate are 15.68:
6.34。
As the preferred of above-mentioned technical proposal, in step (1), the rate of addition of the ammonium dibasic phosphate solution is 1mL/
min。
As the preferred of above-mentioned technical proposal, in step (2), the mass ratio of the porous carrier and cesium nitrate is 111：
(19.5-48.75)。
As the preferred of above-mentioned technical proposal, in step (3), the mass concentration of the lactic acid aqueous solution is 26%.
As the preferred of above-mentioned technical proposal, in step (4), the catalyst is montmorillonite load manganese dioxide.
As the preferred of above-mentioned technical proposal, in step (4), the matter of 2, the 3- pentanediones, ethylenediamine and absolute ethyl alcohol
Amount is than being 1：(1-1.1)：70.
As the preferred of above-mentioned technical proposal, in step (4), 2, the 3- pentanediones, potassium hydroxide, catalyst, diformazan
The mass ratio of benzene is 1:0.8：(1.3-2.8)：1.
The invention has the advantages that：
The present invention uses lactic acid as obtained 2, the 3- pentanediones of raw material first, the preparation of each raw material of reasonable adjusting in preparation process
Condition, and being reacted using homemade catalyst, the catalyst can soda acid synergistic catalyst, the acid of porous carrier in catalyst
Property contribute to dehydration, its alkalescence of caesium loaded contributes to decarboxylic reaction, so as to effectively increase the conversion ratio of lactic acid；
Then the present invention is with homemade 2,3- pentanediones and ethylenediamine as raw material, and progress dehydrating condensation, dehydrogenation are anti-successively
2- ethyl -3- methylpyrazines should be made, the raw material of reasonable adjusting catalyst and various raw materials in preparation process, obtained product is received
Rate is high.
Embodiment：
In order to be better understood from the present invention, below by embodiment, the present invention is further described, and embodiment is served only for solving
The present invention is released, any restriction will not be formed to the present invention.
Embodiment 1
The high-efficiency synthesis method of 2- ethyl -3- methylpyrazines, comprises the following steps：
(1) barium sulfate and deionized water are mixed into solid dissolving, barium nitrate solution is made；By diammonium hydrogen phosphate and
Deionized water mixes to solid dissolving and ammonium dibasic phosphate solution is made；It is molten to barium nitrate under 1000 revs/min of stirring
Ammonium dibasic phosphate solution is added dropwise in liquid, while be added dropwise while stir, continue after completion of dropwise addition stirring 1h, then filter, solid spend from
8h is dried after sub- water washing, is finally placed in Muffle furnace and handles 3h at 500 DEG C, porous carrier is made；Wherein, barium nitrate solution
Mass concentration is 20.5%；The mass concentration of ammonium dibasic phosphate solution is 13.2%；Barium nitrate, the mass ratio of diammonium hydrogen phosphate are
15.68:6.34；The rate of addition of ammonium dibasic phosphate solution is 1mL/min；
(2) obtained porous carrier, cesium nitrate and deionized water are mixed into solid dissolving and mixed solution is made, so
Mixed solution is placed in oil bath pan into stirring at 80 DEG C afterwards to be evaporated, obtained solid is placed in Muffle furnace and handles 3h at 600 DEG C, system
Obtain catalyst；Wherein, the mass ratio of porous carrier and cesium nitrate is 111：19.5；
(3) 0.3g catalyst obtained above is placed in quartz ampoule, length of the catalyst in quartz ampoule is 30mm, is urged
Agent both ends are blocked with silica wool, and lactic acid aqueous solution is carried by the quartz ampoule equipped with catalyst with nitrogen, and in silica wool
Surface vaporization, subsequent steam feed pass through the catalyst surface, and reaction temperature is 260 DEG C, lactic acid concn 10wt%, charging
Speed is 0.3mL/h, and the flow velocity of carrier gas is 1mL/min, and 2,3- pentanediones are made；Wherein, the selection rate of lactic acid be 98.5% with
On；
(4) at -5~3 DEG C, obtained above 2,3- pentanediones, ethylenediamine and absolute ethyl alcohol are mixed in three-necked flask
Conjunction stirs, and reacts 5h, reacts and system is warming up into room temperature after terminating, and continues to stir 1h at room temperature, then heats to 65-70
DEG C, flow back 1h, and backflow is quickly cooled to 30-40 DEG C after terminating, dimethylbenzene, potassium hydroxide are then sequentially added into three-necked flask
And catalyst, 65-70 DEG C, back flow reaction 5h is continuously heating to after addition, reaction is cooled to room temperature after terminating, and filters, filter
Liquid carries out air-distillation, and the concentrate after distillation is diluted with saturated aqueous common salt, extracts, and merges organic phase, is done with anhydrous cupric sulfate
Dry, filtering, normal pressure steams extractant, and the cut for collecting 55-60 DEG C/1.33KMa obtains 2- ethyl -3- methylpyrazines；Product is received
Rate more than 93.5%；Wherein, the mass ratio of 2,3- pentanediones, ethylenediamine and absolute ethyl alcohol is 1：1：70；2,3- pentanediones, hydrogen-oxygen
It is 1 to change potassium, catalyst, the mass ratio of dimethylbenzene:0.8：1.3：1.
Embodiment 2
The high-efficiency synthesis method of 2- ethyl -3- methylpyrazines, comprises the following steps：
(1) barium sulfate and deionized water are mixed into solid dissolving, barium nitrate solution is made；By diammonium hydrogen phosphate and
Deionized water mixes to solid dissolving and ammonium dibasic phosphate solution is made；It is molten to barium nitrate under 1000 revs/min of stirring
Ammonium dibasic phosphate solution is added dropwise in liquid, while be added dropwise while stir, continue after completion of dropwise addition stirring 1h, then filter, solid spend from
8h is dried after sub- water washing, is finally placed in Muffle furnace and handles 3h at 500 DEG C, porous carrier is made；Wherein, barium nitrate solution
Mass concentration is 20.5%；The mass concentration of ammonium dibasic phosphate solution is 13.2%；Barium nitrate, the mass ratio of diammonium hydrogen phosphate are
15.68:6.34；The rate of addition of ammonium dibasic phosphate solution is 1mL/min；
(2) obtained porous carrier, cesium nitrate and deionized water are mixed into solid dissolving and mixed solution is made, so
Mixed solution is placed in oil bath pan into stirring at 80 DEG C afterwards to be evaporated, obtained solid is placed in Muffle furnace and handles 3h at 600 DEG C, system
Obtain catalyst；Wherein, the mass ratio of porous carrier and cesium nitrate is 111：48.75；
(3) 0.3g catalyst obtained above is placed in quartz ampoule, length of the catalyst in quartz ampoule is 30mm, is urged
Agent both ends are blocked with silica wool, and lactic acid aqueous solution is carried by the quartz ampoule equipped with catalyst with nitrogen, and in silica wool
Surface vaporization, subsequent steam feed pass through the catalyst surface, and reaction temperature is 340 DEG C, lactic acid concn 50wt%, charging
Speed is 5.0mL/h, and the flow velocity of carrier gas is 10mL/min, and 2,3- pentanediones are made；Wherein, the selection rate of lactic acid be 98.5% with
On；Wherein, the mass concentration of lactic acid aqueous solution is 26%；
(4) at -5~3 DEG C, obtained above 2,3- pentanediones, ethylenediamine and absolute ethyl alcohol are mixed in three-necked flask
Conjunction stirs, and reacts 7h, reacts and system is warming up into room temperature after terminating, and continues to stir 3h at room temperature, then heats to 65-70
DEG C, flow back 4h, and backflow is quickly cooled to 30-40 DEG C after terminating, dimethylbenzene, potassium hydroxide are then sequentially added into three-necked flask
And catalyst, 65-70 DEG C, back flow reaction 5h is continuously heating to after addition, reaction is cooled to room temperature after terminating, and filters, filter
Liquid carries out air-distillation, and the concentrate after distillation is diluted with saturated aqueous common salt, extracts, and merges organic phase, is done with anhydrous cupric sulfate
Dry, filtering, normal pressure steams extractant, and the cut for collecting 55-60 DEG C/1.33KMa obtains 2- ethyl -3- methylpyrazines；Product is received
Rate more than 93.5%；Wherein, the mass ratio of 2,3- pentanediones, ethylenediamine and absolute ethyl alcohol is 1：1.1：70；2,3- pentanediones, hydrogen
Potassium oxide, catalyst, the mass ratio of dimethylbenzene are 1:0.8：2.8：1.
Embodiment 3
The high-efficiency synthesis method of 2- ethyl -3- methylpyrazines, comprises the following steps：
(1) barium sulfate and deionized water are mixed into solid dissolving, barium nitrate solution is made；By diammonium hydrogen phosphate and
Deionized water mixes to solid dissolving and ammonium dibasic phosphate solution is made；It is molten to barium nitrate under 1000 revs/min of stirring
Ammonium dibasic phosphate solution is added dropwise in liquid, while be added dropwise while stir, continue after completion of dropwise addition stirring 1h, then filter, solid spend from
8h is dried after sub- water washing, is finally placed in Muffle furnace and handles 3h at 500 DEG C, porous carrier is made；Wherein, barium nitrate solution
Mass concentration is 20.5%；The mass concentration of ammonium dibasic phosphate solution is 13.2%；Barium nitrate, the mass ratio of diammonium hydrogen phosphate are
15.68:6.34；The rate of addition of ammonium dibasic phosphate solution is 1mL/min；
(2) obtained porous carrier, cesium nitrate and deionized water are mixed into solid dissolving and mixed solution is made, so
Mixed solution is placed in oil bath pan into stirring at 80 DEG C afterwards to be evaporated, obtained solid is placed in Muffle furnace and handles 3h at 600 DEG C, system
Obtain catalyst；Wherein, the mass ratio of porous carrier and cesium nitrate is 111：23.5；
(3) 0.3g catalyst obtained above is placed in quartz ampoule, length of the catalyst in quartz ampoule is 30mm, is urged
Agent both ends are blocked with silica wool, and lactic acid aqueous solution is carried by the quartz ampoule equipped with catalyst with nitrogen, and in silica wool
Surface vaporization, subsequent steam feed pass through the catalyst surface, and reaction temperature is 280 DEG C, lactic acid concn 20wt%, charging
Speed is 1mL/h, and the flow velocity of carrier gas is 3mL/min, and 2,3- pentanediones are made；Wherein, the selection rate of lactic acid is more than 98.5%；
Wherein, the mass concentration of lactic acid aqueous solution is 26%；
(4) at -5~3 DEG C, obtained above 2,3- pentanediones, ethylenediamine and absolute ethyl alcohol are mixed in three-necked flask
Conjunction stirs, and reacts 5.5h, reacts and system is warming up into room temperature after terminating, and continues to stir 1.5h at room temperature, then heats to
65-70 DEG C, flow back 2h, and backflow is quickly cooled to 30-40 DEG C after terminating, dimethylbenzene, hydrogen are then sequentially added into three-necked flask
Potassium oxide and catalyst, 65-70 DEG C, back flow reaction 5h is continuously heating to after addition, reaction is cooled to room temperature after terminating, and takes out
Filter, filtrate carry out air-distillation, and the concentrate after distillation is diluted with saturated aqueous common salt, extract, and merge organic phase, use anhydrous slufuric acid
Copper is dried, and filtering, normal pressure steams extractant, and the cut for collecting 55-60 DEG C/1.33KMa obtains 2- ethyl -3- methylpyrazines；Production
Product yield more than 93.5%；Wherein, the mass ratio of 2,3- pentanediones, ethylenediamine and absolute ethyl alcohol is 1：1.02：70；2,3- penta 2
Ketone, potassium hydroxide, catalyst, the mass ratio of dimethylbenzene are 1:0.8：1.6：1.
Embodiment 4
The high-efficiency synthesis method of 2- ethyl -3- methylpyrazines, comprises the following steps：
(1) barium sulfate and deionized water are mixed into solid dissolving, barium nitrate solution is made；By diammonium hydrogen phosphate and
Deionized water mixes to solid dissolving and ammonium dibasic phosphate solution is made；It is molten to barium nitrate under 1000 revs/min of stirring
Ammonium dibasic phosphate solution is added dropwise in liquid, while be added dropwise while stir, continue after completion of dropwise addition stirring 1h, then filter, solid spend from
8h is dried after sub- water washing, is finally placed in Muffle furnace and handles 3h at 500 DEG C, porous carrier is made；Wherein, barium nitrate solution
Mass concentration is 20.5%；The mass concentration of ammonium dibasic phosphate solution is 13.2%；Barium nitrate, the mass ratio of diammonium hydrogen phosphate are
15.68:6.34；The rate of addition of ammonium dibasic phosphate solution is 1mL/min；
(2) obtained porous carrier, cesium nitrate and deionized water are mixed into solid dissolving and mixed solution is made, so
Mixed solution is placed in oil bath pan into stirring at 80 DEG C afterwards to be evaporated, obtained solid is placed in Muffle furnace and handles 3h at 600 DEG C, system
Obtain catalyst；Wherein, the mass ratio of porous carrier and cesium nitrate is 111：30.5；
(3) 0.3g catalyst obtained above is placed in quartz ampoule, length of the catalyst in quartz ampoule is 30mm, is urged
Agent both ends are blocked with silica wool, and lactic acid aqueous solution is carried by the quartz ampoule equipped with catalyst with nitrogen, and in silica wool
Surface vaporization, subsequent steam feed pass through the catalyst surface, and reaction temperature is 300 DEG C, lactic acid concn 30wt%, charging
Speed is 2mL/h, and the flow velocity of carrier gas is 5mL/min, and 2,3- pentanediones are made；Wherein, the selection rate of lactic acid is more than 98.5%；
Wherein, the mass concentration of lactic acid aqueous solution is 26%；
(4) at -5~3 DEG C, obtained above 2,3- pentanediones, ethylenediamine and absolute ethyl alcohol are mixed in three-necked flask
Conjunction stirs, and reacts 6h, reacts and system is warming up into room temperature after terminating, and continues to stir 2h at room temperature, then heats to 65-70
DEG C, flow back 3h, and backflow is quickly cooled to 30-40 DEG C after terminating, dimethylbenzene, potassium hydroxide are then sequentially added into three-necked flask
And catalyst, 65-70 DEG C, back flow reaction 5h is continuously heating to after addition, reaction is cooled to room temperature after terminating, and filters, filter
Liquid carries out air-distillation, and the concentrate after distillation is diluted with saturated aqueous common salt, extracts, and merges organic phase, is done with anhydrous cupric sulfate
Dry, filtering, normal pressure steams extractant, and the cut for collecting 55-60 DEG C/1.33KMa obtains 2- ethyl -3- methylpyrazines；Product is received
Rate more than 93.5%；Wherein, the mass ratio of 2,3- pentanediones, ethylenediamine and absolute ethyl alcohol is 1：1.04：70；2,3- pentanediones,
Potassium hydroxide, catalyst, the mass ratio of dimethylbenzene are 1:0.8：2.0：1.
Embodiment 5
The high-efficiency synthesis method of 2- ethyl -3- methylpyrazines, comprises the following steps：
(1) barium sulfate and deionized water are mixed into solid dissolving, barium nitrate solution is made；By diammonium hydrogen phosphate and
Deionized water mixes to solid dissolving and ammonium dibasic phosphate solution is made；It is molten to barium nitrate under 1000 revs/min of stirring
Ammonium dibasic phosphate solution is added dropwise in liquid, while be added dropwise while stir, continue after completion of dropwise addition stirring 1h, then filter, solid spend from
8h is dried after sub- water washing, is finally placed in Muffle furnace and handles 3h at 500 DEG C, porous carrier is made；Wherein, barium nitrate solution
Mass concentration is 20.5%；The mass concentration of ammonium dibasic phosphate solution is 13.2%；Barium nitrate, the mass ratio of diammonium hydrogen phosphate are
15.68:6.34；The rate of addition of ammonium dibasic phosphate solution is 1mL/min；
(2) obtained porous carrier, cesium nitrate and deionized water are mixed into solid dissolving and mixed solution is made, so
Mixed solution is placed in oil bath pan into stirring at 80 DEG C afterwards to be evaporated, obtained solid is placed in Muffle furnace and handles 3h at 600 DEG C, system
Obtain catalyst；Wherein, the mass ratio of porous carrier and cesium nitrate is 111：40.15；
(3) 0.3g catalyst obtained above is placed in quartz ampoule, length of the catalyst in quartz ampoule is 30mm, is urged
Agent both ends are blocked with silica wool, and lactic acid aqueous solution is carried by the quartz ampoule equipped with catalyst with nitrogen, and in silica wool
Surface vaporization, subsequent steam feed pass through the catalyst surface, and reaction temperature is 320 DEG C, lactic acid concn 40wt%, charging
Speed is 4mL/h, and the flow velocity of carrier gas is 7mL/min, and 2,3- pentanediones are made；Wherein, the selection rate of lactic acid is more than 98.5%；
Wherein, the mass concentration of lactic acid aqueous solution is 26%；
(4) at -5~3 DEG C, obtained above 2,3- pentanediones, ethylenediamine and absolute ethyl alcohol are mixed in three-necked flask
Conjunction stirs, and reacts 6.5h, reacts and system is warming up into room temperature after terminating, and continues to stir 2.5h at room temperature, then heats to
65-70 DEG C, flow back 3h, and backflow is quickly cooled to 30-40 DEG C after terminating, dimethylbenzene, hydrogen are then sequentially added into three-necked flask
Potassium oxide and catalyst, 65-70 DEG C, back flow reaction 5h is continuously heating to after addition, reaction is cooled to room temperature after terminating, and takes out
Filter, filtrate carry out air-distillation, and the concentrate after distillation is diluted with saturated aqueous common salt, extract, and merge organic phase, use anhydrous slufuric acid
Copper is dried, and filtering, normal pressure steams extractant, and the cut for collecting 55-60 DEG C/1.33KMa obtains 2- ethyl -3- methylpyrazines；Production
Product yield more than 93.5%；Wherein, the mass ratio of 2,3- pentanediones, ethylenediamine and absolute ethyl alcohol is 1：1.06：70；2,3- penta 2
Ketone, potassium hydroxide, catalyst, the mass ratio of dimethylbenzene are 1:0.8：2.5：1.
Claims (10)
- The high-efficiency synthesis method of 1.2- ethyl -3- methylpyrazines, it is characterised in that comprise the following steps：(1) barium sulfate and deionized water are mixed into solid dissolving, barium nitrate solution is made；By diammonium hydrogen phosphate and go from Sub- water mixes to solid dissolving and ammonium dibasic phosphate solution is made；Under 1000 revs/min of stirring into barium nitrate solution Ammonium dibasic phosphate solution is added dropwise, is stirred when being added dropwise, continues to stir 1h after completion of dropwise addition, then filters, solid deionized water 8h is dried after washing, is finally placed in Muffle furnace and handles 3h at 500 DEG C, porous carrier is made；(2) obtained porous carrier and cesium nitrate and deionized water are mixed into solid dissolving and mixed solution is made, then Mixed solution is placed in oil bath pan into stirring at 80 DEG C to be evaporated, obtained solid is placed in Muffle furnace and handles 3h at 600 DEG C, is made Catalyst；(3) 0.3g catalyst obtained above is placed in quartz ampoule, length of the catalyst in quartz ampoule is 30mm, catalyst Both ends are blocked with silica wool, and lactic acid aqueous solution is carried by the quartz ampoule equipped with catalyst with nitrogen, and on silica wool surface Vaporization, subsequent steam feed pass through the catalyst surface, and reaction temperature is 260-340 DEG C, lactic acid concn 10-50wt%, Charging rate is 0.3-5.0mL/h, and the flow velocity of carrier gas is 1-10mL/min, and 2,3- pentanediones are made；(4) at -5~3 DEG C, obtained above 2,3- pentanediones, ethylenediamine and absolute ethyl alcohol is mixed in three-necked flask and stirred Mix uniformly, react 5-7h, react and system is warming up to room temperature after terminating, continue to stir 1-3h at room temperature, then heat to 65-70 DEG C, flow back 1-4h, and backflow is quickly cooled to 30-40 DEG C after terminating, dimethylbenzene, hydroxide are then sequentially added into three-necked flask Potassium and catalyst, 65-70 DEG C, back flow reaction 5h being continuously heating to after addition, reaction is cooled to room temperature after terminating, and filters, Filtrate carries out air-distillation, and the concentrate after distillation is diluted with saturated aqueous common salt, extracts, and merges organic phase, uses anhydrous cupric sulfate Dry, filtering, normal pressure steams extractant, and the cut for collecting 55-60 DEG C/1.33KMa obtains 2- ethyl -3- methylpyrazines.
- 2. the high-efficiency synthesis method of 2- ethyls -3- methylpyrazines as claimed in claim 1, it is characterised in that：In step (1), The mass concentration of barium nitrate solution is 20.5%.
- 3. the high-efficiency synthesis method of 2- ethyls -3- methylpyrazines as claimed in claim 1, it is characterised in that：In step (1), The mass concentration of the ammonium dibasic phosphate solution is 13.2%.
- 4. the high-efficiency synthesis method of 2- ethyls -3- methylpyrazines as claimed in claim 1, it is characterised in that：In step (1), Barium nitrate, the mass ratio of diammonium hydrogen phosphate are 15.68:6.34.
- 5. the high-efficiency synthesis method of 2- ethyls -3- methylpyrazines as claimed in claim 1, it is characterised in that：In step (1), The rate of addition of the ammonium dibasic phosphate solution is 1mL/min.
- 6. the high-efficiency synthesis method of 2- ethyls -3- methylpyrazines as claimed in claim 1, it is characterised in that：In step (2), The mass ratio of the porous carrier and cesium nitrate is 111：(19.5-48.75).
- 7. the high-efficiency synthesis method of 2- ethyls -3- methylpyrazines as claimed in claim 1, it is characterised in that：In step (3), The mass concentration of the lactic acid aqueous solution is 26%.
- 8. the high-efficiency synthesis method of 2- ethyls -3- methylpyrazines as claimed in claim 1, it is characterised in that：In step (4), The catalyst is montmorillonite load manganese dioxide.
- 9. the high-efficiency synthesis method of 2- ethyls -3- methylpyrazines as claimed in claim 1, it is characterised in that：In step (4), The mass ratio of the 2,3- pentanediones, ethylenediamine and absolute ethyl alcohol is 1：(1-1.1)：70.
- 10. the high-efficiency synthesis method of 2- ethyls -3- methylpyrazines as claimed in claim 1, it is characterised in that：In step (4), The 2,3- pentanediones, potassium hydroxide, catalyst, the mass ratio of dimethylbenzene are 1:0.8：(1.3-2.8)：1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710666130.2A CN107556250A (en) | 2017-08-07 | 2017-08-07 | The high-efficiency synthesis method of the methylpyrazine of 2 ethyl 3 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710666130.2A CN107556250A (en) | 2017-08-07 | 2017-08-07 | The high-efficiency synthesis method of the methylpyrazine of 2 ethyl 3 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN107556250A true CN107556250A (en) | 2018-01-09 |
Family
ID=60975041
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710666130.2A Withdrawn CN107556250A (en) | 2017-08-07 | 2017-08-07 | The high-efficiency synthesis method of the methylpyrazine of 2 ethyl 3 |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107556250A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20030134022A1 (en) * | 2000-05-08 | 2003-07-17 | Stefan Lambrecht | Production of 2-ethyl-3-methyl-1,4 diazine |
| CN106824236A (en) * | 2017-02-21 | 2017-06-13 | 西华师范大学 | Caesium or the hydroxyapatite catalyst of calcic of potassium doping and its preparation method and application |
| CN107051557A (en) * | 2017-06-05 | 2017-08-18 | 西华师范大学 | A kind of barium pyrophosphate load cesium-promoted catalyst and preparation method thereof, application |
-
2017
- 2017-08-07 CN CN201710666130.2A patent/CN107556250A/en not_active Withdrawn
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20030134022A1 (en) * | 2000-05-08 | 2003-07-17 | Stefan Lambrecht | Production of 2-ethyl-3-methyl-1,4 diazine |
| CN106824236A (en) * | 2017-02-21 | 2017-06-13 | 西华师范大学 | Caesium or the hydroxyapatite catalyst of calcic of potassium doping and its preparation method and application |
| CN107051557A (en) * | 2017-06-05 | 2017-08-18 | 西华师范大学 | A kind of barium pyrophosphate load cesium-promoted catalyst and preparation method thereof, application |
Non-Patent Citations (1)
| Title |
|---|
| CONGMING TANG等: "Catalytic dehydration of lactic acid to acrylic acid over dibarium pyrophosphate", 《CATALYSIS COMMUNICATIONS》 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106540726B (en) | A kind of catalyst and preparation method thereof for synthesizing isoprene | |
| CN104860802B (en) | The method that palladium Selective graphene catalytic hydrogenation prepares 1,3 cyclohexanediones | |
| CN102950014A (en) | Catalyst for production of 1,4-butynediol and preparation method of catalyst | |
| CN105693659B (en) | A kind of preparation method of tetrahydrofurfuryl alcohol | |
| CN106083596A (en) | A kind of continuous nitrification prepares the method for 2,5 dichloronitrobenzenes | |
| CN104817428A (en) | Method for production of cyclohexanol and cyclohexanone through selective oxidation of cyclohexane | |
| CN103819300A (en) | Method for preparing camphene from alpha-pinene | |
| CN103285888B (en) | A kind of Catalysts and its preparation method preparing acrylic acid reaction for propylene oxidation step | |
| CN101352688A (en) | Catalyst for producing acroleic acid by lactic acid dewatering and reaction technique | |
| CN102219665B (en) | Method for synthesizing 2,3,5-trimethylbenzoquinone and 2,3,5-trimethylhydroquinone | |
| CN105646153B (en) | A kind of support type Au/C3N4The method of the nanocatalyst catalytic oxidation of cyclohexane of@SBA 15 | |
| CN113402429B (en) | Synthetic method for generating 2-nitro-4-methylsulfonylbenzoic acid by oxidizing 2-nitro-4-methylsulfonyltoluene with oxygen | |
| CN104028300B (en) | Modified TS-1 molecular sieve as well as preparation method and application thereof | |
| CN107556250A (en) | The high-efficiency synthesis method of the methylpyrazine of 2 ethyl 3 | |
| CN105233860A (en) | Preparation method for denitration auxiliary agent for catalytically-cracked flue gas | |
| CN107282054B (en) | Catalyst for synthesizing acrolein and acrylic acid | |
| CN107262105A (en) | A kind of catalyst of methanol production formaldehyde and preparation method thereof | |
| CN108043421A (en) | A kind of preparation method of the nanometer cobalt-manganese catalyst of synthesis gas conversion preparing low carbon hydrocarbons | |
| CN107987041A (en) | A kind of method of synthesis 2,5- furandicarboxylic acids | |
| CN106582692B (en) | The ethylbenzene dehydrogenation catalyst with low water ratio of high activity | |
| CN114349973B (en) | Lanthanum-manganese bimetal quasi-organic framework material and preparation method and application thereof | |
| CN102728401A (en) | Post-processing modification method of Ti-Si molecular sieve | |
| CN104353443A (en) | Method for preparing styrene catalyst by ethylbenzene dehydrogenation | |
| CN105665005A (en) | Preparation method and application of catalyst used for asymmetric hydrogenation of pinene | |
| CN106582681A (en) | Low steam-to-oil ratio ethylbenzene dehydrogenation catalyst |
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 | ||
| WW01 | Invention patent application withdrawn after publication | ||
| WW01 | Invention patent application withdrawn after publication |
Application publication date: 20180109 |