Summary of the invention
In order to solve the deficiencies in the prior art, the invention provides a kind of synthetic method of N-ethylaniline, is the basic reaction raw material with aniline, acetaldehyde and hydrogen donor, adds catalyzer in reaction system, adopt alcohol-water mixed liquid to make solvent, in ultrasound reactor, prepare N-ethylaniline.This method is carried out under normal pressure and lesser temps, and as reaction solvent, its subsequent disposal is simple relatively with alcohol-water mixed liquid, and separating difficulty significantly reduces, and efficiently solves problems such as acid pollution, target product are not easily separated, High Temperature High Pressure.
The scheme that the present invention adopts is:
Be the basic reaction raw material with aniline, acetaldehyde and hydrogen donor, add catalyzer and alcohol in the reaction system, make solvent with alcohol-water mixed liquid, in ultrasound reactor, carry out;
Wherein hyperacoustic reaction parameter is: operating frequency: 21-23KHz, ultrasonic power: 200~800W, horn: Φ 10mm.
In ultrasound reactor, aniline and acetaldehyde react in alcohol-water solvent and generate imine intermediate, and the hydrogen that hydrogen donor provides is reduced into N-ethylaniline with imine intermediate under the effect of catalyzer, and reaction equation is as follows:
Its concrete preparation process is:
(1) in reactor, adds catalyzer and alcohol, stir-activating 20-40min under the normal temperature and pressure;
(2) add hydrogen donor and aniline in the above-mentioned reactor, opens ultrasonicly, stir the alcohol-water mixed liquid that drips acetaldehyde down, be incubated to reacting completely;
(3) with above-mentioned reaction solution suction filtration, evaporate to dryness filtrate adds organic solvent dissolution, washing, and separatory, solvent evaporated gets product.
Repeatedly experiment showed, among the present invention through the contriver raw materials used, with the molar ratio computing of pure substance, aniline: acetaldehyde: hydrogen donor: catalyzer=1:1-2:1-10:0.01-0.02, mol ratio meeting bigger than normal increases cost, causes waste; Mol ratio is less than normal will to reduce productive rate.
For selectivity and the yield that improves product, described hydrogen donor is hydrogen supply effect ammonium acetate or ammonium formiate or hydrogen or sodium borohydride preferably.Described catalyzer is palladium carbon and Ni-M/Al
2O
3Catalyst series, wherein M is one or more among Mo, Mn, Co, Pt, the Cr, because palladium carbon and Ni-M/Al
2O
3Catalyst series can have shortening effect preferably well as hydrogen carrier.Because the activation temperature of catalyzer is little to the activation effect influence, so catalyzer activates at normal temperatures and pressures and gets final product in the step (1), and soak time is 20-40min, and the time, too short activation effect was not good, and overlong time can be wasted resource.
For hydrogen donor, water is good solvent, and alcohol both can dissolve each other with aniline and also can dissolve each other with water, so adopts alcohol-water mixed liquid to make solvent among the present invention, can effectively solve dissolving and the contact reacts problem of raw material, and environmental pollution is little, and cost is low.For catalyzer is fully disperseed in alcoholic solvent, the consumption of alcohol is as the criterion fully to flood catalyzer in the step (1), repeatedly test through the contriver and to draw, the mass ratio optimum of catalyzer and alcohol is 1:50-250 in the step (1), and wherein said alcohol is methyl alcohol or ethanol or Virahol or butanols or propyl carbinol or its mixture; Consider that quantity of solvent total in the reaction system too much can cause waste, cross and react insufficient at least, the consumption of alcohol-water mixed liquid is in the step (2): the mass ratio of acetaldehyde and alcohol-water mixed liquid is 1:5-25, and wherein said alcohol is methyl alcohol or ethanol or Virahol or butanols or propyl carbinol or its mixture.Because the consumption of water is emitted hydrogen what and speed of response to hydrogen donor certain influence is arranged, therefore for improving reaction yield, reducing the reaction times, the contriver is through a large amount of experimental data optimizations, and the optimum quality ratio that obtains alcohol and water in alcohol-water mixed liquid is 2-6:1.
Owing to the process that adds acetaldehyde in reaction system is exothermic process, therefore, need slowly carry out when dripping acetaldehyde, when the alcohol-water mixed liquid of dropping acetaldehyde reacts, adopt routine techniques means hierarchy of control temperature all the time at 15-50 ℃, the product selectivity that all can make too high or too low for temperature reduces.After dropping acetaldehyde finishes, insulation reaction 1h-4h, the reaction times is too short, and it is maximum that the transformation efficiency of aniline can not reach; Reaction times is long, increases energy consumption, and cost is increased.Reaction can adopt high performance liquid chromatography to detect after finishing.
For the ease of aftertreatment, organic solvent described in the step (3) should be selected for use and can well dissolve N-ethylaniline, and its boiling point is lower than the solvent of N-ethylaniline boiling point, so organic solvent is toluene or benzene or ether, preferred toluene.Washing in the step (3) is in order to wash the hydrogen donor salt in the system off, to improve product purity.
Ultrasound reactor described in the present invention comprises that ultrasonic cleaning agent reactor or sound horn immerse reactor or cup type reactor or energy gathering type sound horn and immerse ultrasound reactor; Or other conventional ultrasound reactors.
Because cavitation effect of ultrasonic waves can be at high temperature and thousands of atmospheric high pressure of instantaneous generation hundreds of degree centigrade, and ultrasonic wave has specific heat effect and chemical effect, can impel the chemical reaction that under the popular response condition, can't realize or be difficult to finish smooth, therefore adopt the synthetic N-ethylaniline of ultrasonic wave among the present invention, under normal pressure and lesser temps, can finish chemical reaction, reduce production cost and to the requirement of conversion unit.The ultrasonic wave parameter is among the present invention: operating frequency: 21-23KHz, ultrasonic power: 200~800W, horn: Φ 10mm; Be because find that through a large amount of experiments of contriver in each conditional parameter scope of above-mentioned ultrasonic wave, reaction can obtain best effect, product selectivity and yield the best.
Stirring velocity of the present invention is 70~100r/min, and synthetic method of the present invention and workshop pilot scale for convenience and conversion are produced and integrated with, and stirring optimum described in the building-up process is magnetic agitation, and the stirring velocity optimum is 100r/min.
In sum, the present invention has following beneficial effect:
(1) the present invention adopts supersonic method to synthesize N-ethylaniline, can carry out under normal pressure and lesser temps, effectively reduces production cost and to the requirement of equipment.
(2) the present invention adopts the alcohol and water mixed solvent as reaction solvent, and environmental pollution is little, and cost is low, and its subsequent disposal is simple relatively, and separating difficulty significantly reduces, and product yield is higher.
(3) to adopt aniline, acetaldehyde, hydrogen donor be raw material in the present invention, avoided using the acid of severe corrosive, efficiently solves the problem of equipment corrosion and acid pollution.
Embodiment
Further specify the present invention below in conjunction with embodiment, can make those skilled in the art more fully understand the present invention, but not limit the present invention in any way.Except specified otherwise, described per-cent all is weight percentage among the present invention.
Embodiment 1
A kind of synthetic method of N-ethylaniline is the basic reaction raw material with aniline, acetaldehyde and hydrogen donor, adds catalyzer and alcohol in the reaction system, makes solvent with alcohol-water mixed liquid, carries out in the ultrasonic cleaning agent reactor;
Wherein each parameter of ultrasonic response is: operating frequency: 22KHz, ultrasonic power: 200W, horn: Φ 10mm.
Its concrete preparation process is:
(1) the 250mL four-hole boiling flask is fixed in the ultrasound reactor, in flask, adds 0.08g palladium carbon and 16.00g methyl alcohol, stir-activating 30min under the normal temperature and pressure, wherein stirring is magnetic agitation, stirring velocity is 70r/min;
(2) in above-mentioned reactor, add 4.41g ammonium formiate and 6.51g aniline, open ultrasonicly, drip under the 70r/min magnetic agitation and be dissolved with the 66.00g ethanol of 3.08g acetaldehyde and the mixed solution of 11.00g water, the dropping time is 30min, drip reacting temperature is 15 ℃, insulation reaction 4h under the normal pressure;
(3) with above-mentioned reaction solution suction filtration, evaporate to dryness filtrate adds the toluene dissolving, washing, and separatory keeps organic phase, and solvent evaporated, gets the 8.37g product, yield 98.8%, selectivity is 99.7%.
Embodiment 2
A kind of synthetic method of N-ethylaniline is the basic reaction raw material with aniline, acetaldehyde and hydrogen donor, adds catalyzer and alcohol in the reaction system, makes solvent with alcohol-water mixed liquid, immerses in the reactor in the sound horn and carries out;
Wherein each parameter of ultrasonic response is: operating frequency: 23KHz, ultrasonic power: 800W, horn: Φ 10mm.
Its concrete preparation process is:
(1) the 250mL four-hole boiling flask is fixed in the ultrasound reactor, in flask, adds 0.216gNi-Mn/Al
2O
3With 21.00g ethanol, stir-activating 20min under the normal temperature and pressure, wherein stirring is magnetic agitation, stirring velocity is 100r/min;
(2) in above-mentioned reactor, add 19.25g ammonium acetate and 4.65g aniline, open ultrasonicly, drip under the 100r/min magnetic agitation and be dissolved with the 33.00g methyl alcohol of 4.40g acetaldehyde and the mixed solution of 11.00g water, the dropping time is 29min, drip reacting temperature is 30 ℃, insulation reaction 1h under the normal pressure;
(3) with above-mentioned reaction solution suction filtration, evaporate to dryness filtrate adds the toluene dissolving, washing, and separatory keeps organic phase, and solvent evaporated, gets the 5.94g product, yield 98.2%, selectivity is 99.1%.
Embodiment 3
A kind of synthetic method of N-ethylaniline is the basic reaction raw material with aniline, acetaldehyde and hydrogen donor, adds catalyzer and alcohol in the reaction system, makes solvent with alcohol-water mixed liquid, carries out in cup type ultrasound reactor;
Wherein each parameter of ultrasonic response is: operating frequency: 24KHz, ultrasonic power: 500W, horn: Φ 10mm.
Its concrete preparation process is:
(1) the 250mL four-hole boiling flask is fixed in the ultrasound reactor, in flask, adds 0.33gNi-Co/Al
2O
3With 82.50g ethanol, stir-activating 40min under the normal temperature and pressure, wherein stirring is magnetic agitation, stirring velocity is 80r/min;
(2) in above-mentioned reactor, feed 0.6mol hydrogen, add 9.30g aniline, open ultrasonic, drip under the 80r/min magnetic agitation and be dissolved with the 22.00g Virahol of 6.60g acetaldehyde and the mixed solution of 11.00g water, the dropping time is 32min, and drip reacting temperature is 50 ℃, insulation reaction 3h under the normal pressure;
(3) with above-mentioned reaction solution suction filtration, evaporate to dryness filtrate adds the benzene dissolving, washing, and separatory keeps organic phase, and solvent evaporated, gets the 11.96g product, yield 98.7%, selectivity is 99.6%.
Embodiment 4
A kind of synthetic method of N-ethylaniline is the basic reaction raw material with aniline, acetaldehyde and hydrogen donor, adds catalyzer and alcohol in the reaction system, makes solvent with alcohol-water mixed liquid, immerses in the ultrasound reactor in energy gathering type sound horn and carries out;
Wherein each parameter of ultrasonic response is: operating frequency: 22KHz, ultrasonic power: 600W, horn: Φ 10mm.
Its concrete preparation process is:
(1) the 250mL four-hole boiling flask is fixed in the ultrasound reactor, in flask, adds 0.22gNi-Mo/Al
2O
3With the 11.00g Virahol, stir-activating 30min under the normal temperature and pressure, wherein stirring is magnetic agitation, stirring velocity is 90r/min;
(2) in above-mentioned reactor, add 15.20g sodium borohydride and 4.65g aniline, open ultrasonicly, drip under the 90r/min magnetic agitation and be dissolved with the 47.52g propyl carbinol of 3.96g acetaldehyde and the mixed solution of 11.88g water, the dropping time is 28min, drip reacting temperature is 25 ℃, insulation reaction 2h under the normal pressure;
(3) with above-mentioned reaction solution suction filtration, evaporate to dryness filtrate adds ether dissolution, washing, and separatory keeps organic phase, and solvent evaporated, gets the 5.96g product, yield 98.5%, selectivity is 99.2%.
Embodiment 5
A kind of synthetic method of N-ethylaniline is the basic reaction raw material with aniline, acetaldehyde and hydrogen donor, adds catalyzer and alcohol in the reaction system, makes solvent with alcohol-water mixed liquid, immerses in the ultrasound reactor in energy gathering type sound horn and carries out;
Wherein each parameter of ultrasonic response is: operating frequency: 23KHz, ultrasonic power: 700W, horn: Φ 10mm.
Its concrete preparation process is:
(1) the 250mL four-hole boiling flask is fixed in the ultrasound reactor, in flask, adds 0.178gNi-Pt/Al
2O
3With 26.70g methyl alcohol, stir-activating 30min under the normal temperature and pressure, wherein stirring is magnetic agitation, stirring velocity is 100r/min;
(2) in above-mentioned reactor, add 31.50g ammonium formiate and 4.65g aniline, open ultrasonicly, drip under the 100r/min magnetic agitation and be dissolved with the 45.11g butanols of 2.90g acetaldehyde and the mixed solution of 12.89g water, the dropping time is 29min, drip reacting temperature is 28 ℃, insulation reaction 2.5h under the normal pressure;
(3) with above-mentioned reaction solution suction filtration, evaporate to dryness filtrate adds ether dissolution, washing, and separatory keeps organic phase, and solvent evaporated, gets the 5.95g product, yield 98.3%, selectivity is 99.3%.
Embodiment 6
A kind of synthetic method of N-ethylaniline is the basic reaction raw material with aniline, acetaldehyde and hydrogen donor, adds catalyzer and alcohol in the reaction system, makes solvent with alcohol-water mixed liquid, carries out in the ultrasonic cleaning agent reactor;
Wherein each parameter of ultrasonic response is: operating frequency: 24KHz, ultrasonic power: 400W, horn: Φ 10mm.
Its concrete preparation process is:
(1) the 250mL four-hole boiling flask is fixed in the ultrasound reactor, in flask, adds 0.37gNi-Cr-Mo/Al2O3 and 37.00g ethanol, stir-activating 38min under the normal temperature and pressure, wherein stirring is magnetic agitation, stirring velocity is 75r/min;
(2) in above-mentioned reactor, add 11.40g sodium borohydride and 9.30g aniline, open ultrasonicly, drip under the 75r/min magnetic agitation and be dissolved with the 42.42g ethanol of 5.09g acetaldehyde and the mixed solution of 8.48g water, the dropping time is 31min, drip reacting temperature is 42 ℃, insulation reaction 3.7h under the normal pressure;
(3) with above-mentioned reaction solution suction filtration, evaporate to dryness filtrate adds the benzene dissolving, washing, and separatory keeps organic phase, and solvent evaporated, gets the 11.97g product, yield 98.9%, selectivity is 99.2%.