阅读说明：本技术 一种微通道反应器及利用该微通道反应器制备二甲氨基乙酸乙酯的方法 (Micro-channel reactor and method for preparing dimethylamino ethyl acetate by using same ) 是由 丁尊良 宋瑜 胡东云 叶山海 于 2021-08-16 设计创作，主要内容包括：本发明公开了一种种微通道反应器及利用该微通道反应器制备二甲氨基乙酸乙酯的方法,在微通道反应器内,以卤代乙酸酯、二甲胺和溶剂为原料合成二甲氨基乙酸酯的新工艺,将卤代乙酸酯、二甲胺和溶剂分别通入到微通道反应器后,经过预热、混合和反应,最后得到二甲氨基乙酸乙酯。本发明具有操作简单、使用安全、工艺环保的优点,二甲氨基乙酸乙酯的转化率达到95～99%,十分有利于工业化生产。(The invention discloses a microchannel reactor and a method for preparing dimethylamino ethyl acetate by using the same. The method has the advantages of simple operation, safe use and environment-friendly process, and the conversion rate of the dimethylamino ethyl acetate reaches 95-99%, so that the method is very favorable for industrial production.)

1. A microchannel reactor and a method for preparing dimethylaminoethyl acetate by using the microchannel reactor are characterized in that the microchannel reactor comprises a first straight channel module (1), a second straight channel module (2), a third straight channel module (3), a first heart-shaped channel module (4) and a second heart-shaped channel module (5), wherein the first straight channel module (1), the second straight channel module (2) and the third straight channel module (3) are sequentially arranged at the inlet end of the microchannel reactor, the second heart-shaped channel module (5) is arranged at the outlet end of the microchannel reactor, the first straight channel module (1) and the second straight channel module (2) are communicated with the first heart-shaped channel module (4) through pipelines, the third straight channel module (3) and the first heart-shaped channel module (4) are respectively communicated with the second heart-shaped channel module (5) through pipelines, the first straight-going channel module (1), the second straight-going channel module (2) and the third straight-going channel module (3) are respectively communicated with a first raw material tank (6), a second raw material tank (7) and a third raw material tank (8), and the second heart-shaped channel module (5) is communicated with a distillation reaction kettle (9);

the method for preparing the dimethylamino ethyl acetate by using the microchannel reactor comprises the following specific steps:

s1, storing the haloacetate, the solvent and the dimethylamine into a first raw material tank (6), a second raw material tank (7) and a third raw material tank (8) respectively;

s2, respectively introducing haloacetate, a solvent and dimethylamine into a first straight channel module (1), a second straight channel module (2) and a third straight channel module (3) of a microchannel reactor according to a certain ratio, and preheating;

s3, introducing the preheated haloacetate and the solvent into the first heart-shaped channel module (4) for mixing to obtain a mixture;

s4, introducing the mixture and dimethylamine into a second heart-shaped channel module (5) for reaction, and obtaining a reaction product from the outlet end of the microchannel reactor;

s5, introducing the reaction product into a distillation reaction kettle (9) for distillation, and collecting fractions at 114-118 ℃/-0.08MPa to obtain the dimethylamino ethyl acetate.

2. The microchannel reactor and the method for preparing dimethylaminoethyl acetate by using the same according to claim 1, wherein a metering pump (10) and a pressure gauge (11) are respectively arranged between the first straight channel module (1) and the first raw material tank (6), between the second straight channel module (2) and the second raw material tank (7) and between the third straight channel module (3) and the third raw material tank (8).

3. The microchannel reactor and the method for preparing ethyl dimethylaminoacetate using the same according to claim 1, wherein the solvent in step S1 is one of ethyl acetate, toluene, butyl acetate, methyl acetate and isopropyl acetate.

4. The microchannel reactor and the method for preparing ethyl dimethylaminoacetate using the microchannel reactor according to claim 1, wherein the halogenated acetate is one of ethyl chloroacetate, methyl chloroacetate, ethyl bromoacetate and methyl bromoacetate in step S1.

5. The microchannel reactor and the method for preparing dimethylamino ethyl acetate by using the microchannel reactor according to claim 1, wherein in the step S2, the molar ratio of the solvent to the haloacetate to the dimethylamine is (1-10): 1: (1-4).

6. The microchannel reactor and the method for preparing the dimethylaminoethyl acetate by using the microchannel reactor according to the claim 1, wherein the preheating setting stability is controlled by an external heat exchanger in the step S2, and the heat exchange medium is silicone oil.

7. The microchannel reactor and the method for preparing dimethylaminoethyl acetate by using the same according to claim 1, wherein the preheating temperature in step S2 is set to be 30-70 ℃.

8. The microchannel reactor and the method for preparing ethyl dimethylaminoacetate using the same according to claim 1, wherein in step S4, the reaction time is 30 to 180S, and the reaction pressure is 0 to 5 bar.

Technical Field

The invention belongs to the technical field of organic synthesis application, and particularly relates to a microchannel reactor and a method for preparing dimethylamino ethyl acetate by using the same.

Background

The dimethylamino ethyl acetate is an important chemical raw material for preparing raw material medicaments and veterinary medicaments, is an important organic intermediate, and has a plurality of problems of laggard production process, harsh conditions of high temperature and high pressure, further improved product quality, severe market competition and the like in the industrial production of the dimethylamino ethyl acetate. At present, the main industrial production process of dimethylamino ethyl acetate adopts a tank reaction mode, but because the difficulty of the synthesis process is high, pressure-resistant equipment is required in the general conventional preparation process, the operation is complicated, and the yield is low.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention aims to provide a microchannel reactor which can obviously improve the reaction efficiency, is simple to operate, safe to use, low in production cost and environment-friendly in process, and a method for preparing dimethylaminoethyl acetate by using the microchannel reactor.

In order to achieve the above object, the present invention adopts the following technical solutions:

a microchannel reactor and a method for preparing dimethylamino ethyl acetate by using the microchannel reactor are provided, the microchannel reactor comprises a first straight channel module, a second straight channel module, a third straight channel module, a first heart-shaped channel module and a second heart-shaped channel module, the first straight channel module, the second straight channel module and the third straight channel module are sequentially arranged at the inlet end of the microchannel reactor, the second heart-shaped channel module is arranged at the outlet end of the microchannel reactor, the first straight channel module and the second straight channel module are communicated with the first heart-shaped channel module through pipelines, the third straight channel module and the first heart-shaped channel module are respectively communicated with the second heart-shaped channel module through pipelines, the first straight channel module, the second straight channel module and the third straight channel module are respectively communicated with a first raw material tank, a second raw material tank and a third raw material tank, the second heart-shaped channel module is communicated with the distillation reaction kettle;

the method for preparing the dimethylamino ethyl acetate by using the microchannel reactor comprises the following specific steps:

s1, storing the haloacetate, the solvent and the dimethylamine into a first material tank, a second material tank and a third material tank respectively;

s2, respectively introducing haloacetate, a solvent and dimethylamine into a first straight channel module, a second straight channel module and a third straight channel module of the microchannel reactor according to a certain ratio, and preheating;

s3, introducing the preheated haloacetate and the solvent into the first heart-shaped channel module for mixing to obtain a mixture;

s4, introducing the mixture and dimethylamine into a second heart-shaped channel module for reaction, and obtaining a reaction product from the outlet end of the microchannel reactor;

s5, introducing the reaction product into a distillation reaction kettle for distillation, and collecting fractions at 114-118 ℃/-0.08MPa to obtain dimethylamino ethyl acetate.

Preferably, a metering pump and a pressure gauge are respectively arranged between the first straight channel module and the first raw material tank, between the second straight channel module and the second raw material tank and between the third straight channel module and the third raw material tank.

Still preferably, in the step S1, the solvent is one of ethyl acetate, toluene, butyl acetate, methyl acetate and isopropyl acetate.

More preferably, in step S1, the halogenated acetate is one of ethyl chloroacetate, methyl chloroacetate, ethyl bromoacetate and methyl bromoacetate.

Further preferably, in the step S2, the molar ratio of the solvent, the haloacetate and the dimethylamine is (1 to 10): 1: (1-4).

Specifically, in step S2, the setting of preheating is stably controlled by the external heat exchanger, and the heat exchange medium is silicone oil.

Preferably, in the step S2, the preheating temperature is set to be 30-70 ℃.

More preferably, in the step S4, the reaction time is 30 to 180S, and the reaction pressure is 0 to 5 bar.

The invention has the advantages that:

(1) the invention adopts a continuous flow microchannel reactor, greatly shortens the reaction time, ensures that the conversion rate of the dimethylamino ethyl acetate reaches 95-99 percent, obviously improves the reaction efficiency, reduces the unit consumption of raw materials, and has the advantages of simple operation, safe use, low production cost, environment-friendly process and avoidance of the risk of high pressure and high temperature;

(2) the mixing effect of the solvent, the halogenated acetate and the dimethylamine in the microchannel is excellent, the amplification effect is avoided, the reaction temperature is accurately controlled, the utilization rate of the dimethylamine and the halogenated acetate is improved, and the method is suitable for industrially producing the ethyl dimethylamino acetate;

(3) the microchannel reactor used in the invention is made of special glass, has excellent corrosion resistance, and is a continuous flow reaction in the processes of feeding, mixing, reacting and the like in the microchannel reactor, thereby effectively avoiding the serious problems of additional configuration and gas leakage in transfer in the conventional batch reaction, and being safe and environment-friendly.

Drawings

FIG. 1 is a flow diagram of the reaction process of the present invention.

The meaning of the reference symbols in the figures: 1. the device comprises a first straight channel module, a second straight channel module, a third straight channel module, a first heart-shaped channel module, a second heart-shaped channel module, a first raw material tank, a second raw material tank, a third raw material tank, a distillation reaction kettle, a metering pump, a pressure gauge and a control module, wherein the first straight channel module, the second straight channel module, the first heart-shaped channel module, the second heart-shaped channel module, the first raw material tank, the second raw material tank, the third raw material tank and the distillation reaction kettle are sequentially arranged from top to bottom.

Detailed Description

The invention is described in detail below with reference to the figures and the embodiments.

Referring to fig. 1, the microchannel reactor of the invention comprises a first straight channel module 1, a second straight channel module 2, a third straight channel module 3, a first heart-shaped channel module 4 and a second heart-shaped channel module 5, wherein the first straight channel module 1, the second straight channel module 2 and the third straight channel module 3 are sequentially arranged at the inlet end of the microchannel reactor, the second heart-shaped channel module 5 is arranged at the outlet end of the microchannel reactor, the first straight channel module 1 and the second straight channel module 2 are communicated with the first heart-shaped channel module 4 through pipelines, the third straight channel module 3 and the first heart-shaped channel module 4 are respectively communicated with the second heart-shaped channel module 5 through pipelines, the first straight channel module 1, the second straight channel module 2 and the third straight channel module 3 are respectively communicated with a first raw material tank 6, a second raw material tank 7 and a third raw material tank 8, the second heart-shaped channel module 5 is communicated with a distillation reaction kettle 9. A metering pump 10 and a pressure gauge 11 are respectively arranged between the first straight channel module 1 and the first raw material tank 6, between the second straight channel module 2 and the second raw material tank 7 and between the third straight channel module 3 and the third raw material tank 8. Each module in the microchannel reactor is composed of monocrystalline silicon, special glass, ceramics, corrosion-resistant alloy, Teflon and the like.

Example 1

The method for preparing the dimethylamino ethyl acetate by using the microchannel reactor comprises the following specific steps:

s1, respectively storing ethyl chloroacetate, ethyl acetate and dimethylamine in a first raw material tank 6, a second raw material tank 7 and a third raw material tank 8;

s2, respectively introducing 150g (1.22 mol) of ethyl chloroacetate, 480g (5.4 mol) of ethyl acetate and 124g (2.75 mol, 2.25 eq) of dimethylamine into a first straight channel module 1, a second straight channel module 2 and a third straight channel module 3 of a microchannel reactor through metering pumps, and preheating at 50 ℃;

s3, introducing the preheated ethyl chloroacetate and ethyl acetate into the first heart-shaped channel module 4 for mixing to obtain a mixture;

s4, introducing the mixture and dimethylamine into a second heart-shaped channel module 5 for reaction for 90S, and obtaining a reaction product from the outlet end of the microchannel reactor;

s5, introducing the reaction product into a distillation reaction kettle 9 for distillation, and collecting fractions at 114-118 ℃/-0.08MPa to obtain the dimethylamino ethyl acetate.

Example 2

The method for preparing the dimethylamino ethyl acetate by using the microchannel reactor comprises the following specific steps:

s1, respectively storing ethyl bromoacetate, methanol and dimethylamine in a first raw material tank 6, a second raw material tank 7 and a third raw material tank 8;

s2, respectively introducing 210g (1.71 mol) of ethyl bromoacetate, 400g (12.5 mol) of methanol and 82g (1.82 mol, 1.06 eq) of dimethylamine into a first straight channel module 1, a second straight channel module 2 and a third straight channel module 3 of a microchannel reactor through a metering pump 10, and preheating at the temperature of 40 ℃;

s3, introducing the preheated ethyl bromoacetate and methanol into the first heart-shaped channel module 4 for mixing to obtain a mixture;

s4, introducing the mixture and dimethylamine into a second heart-shaped channel module 5 for reaction for 120S, and obtaining a reaction product from the outlet end of the microchannel reactor;

s5, introducing the reaction product into a distillation reaction kettle 9 for distillation, and collecting fractions at 114-118 ℃/-0.08MPa to obtain the dimethylamino ethyl acetate.

Example 3

The method for preparing the dimethylamino ethyl acetate by using the microchannel reactor comprises the following specific steps:

s1, respectively storing ethyl chloroacetate, absolute ethyl alcohol and dimethylamine in a first raw material tank 6, a second raw material tank 7 and a third raw material tank 8;

s2, respectively introducing 135g (1.10 mol) of ethyl chloroacetate, 360g (7.83 mol) of absolute ethyl alcohol and 72g (1.60 mol, 1.45 eq) of dimethylamine into a first straight channel module 1, a second straight channel module 2 and a third straight channel module 3 of a microchannel reactor through a metering pump 10, and preheating at the temperature of 70 ℃;

s3, introducing the preheated ethyl chloroacetate and the anhydrous ethanol into the first heart-shaped channel module 4 for mixing to obtain a mixture;

s4, introducing the mixture and dimethylamine into a second heart-shaped channel module 5 for reaction for 30S, and obtaining a reaction product from the outlet end of the microchannel reactor;

s5, introducing the reaction product into a distillation reaction kettle 9 for distillation, and collecting fractions at 114-118 ℃/-0.08MPa to obtain the dimethylamino ethyl acetate.

Example 4

The method for preparing the dimethylamino ethyl acetate by using the microchannel reactor comprises the following specific steps:

s1, storing methyl bromoacetate, toluene and dimethylamine in a first raw material tank 6, a second raw material tank 7 and a third raw material tank 8 respectively;

s2, respectively introducing 190g (1.14 mol) of ethyl bromoacetate, 540g (5.87 mol) of toluene and 61.6g (1.37 mol, 1.2 eq) of dimethylamine into a first straight channel module 1, a second straight channel module 2 and a third straight channel module 3 of a microchannel reactor through a metering pump 10, and preheating at the temperature of 70 ℃;

s3, introducing the preheated ethyl bromoacetate and toluene into the first heart-shaped channel module 4 for mixing to obtain a mixture;

s4, introducing the mixture and dimethylamine into a second heart-shaped channel module 5 for reaction for 180S, and obtaining a reaction product from the outlet end of the microchannel reactor;

s5, introducing the reaction product into a distillation reaction kettle 9 for distillation, and collecting fractions at 114-118 ℃/-0.08MPa to obtain the dimethylamino ethyl acetate.

Comparative example

Adding 100g (0.816 mol) of ethyl chloroacetate and 350g of ethyl acetate into a reaction bottle, stirring and mixing uniformly, introducing 147g (3.26 mol, 4 eq) of dimethylamine gas under heating at 50 ℃, distilling after introducing the dimethylamine gas, and collecting fractions at 114-118 ℃/-0.08MPa to obtain dimethylamino ethyl acetate.

And (3) analyzing an experimental result:

(1) the products obtained in examples 1-4 and comparative example were weighed respectively, and the yield was calculated, the calculation results are shown in table 1.

TABLE 1 quality and yield of Ethyl Dimethylaminoacetate in examples 1-4 and comparative examples

As can be seen from Table 1, the yield of the product obtained in examples 1-3 is significantly higher than that of the conventional preparation method in the comparative example, which shows that the preparation method of the invention can improve the yield of dimethylaminoethyl acetate.

(2) 1000g of dimethylaminoethyl acetate product was produced by the method of example 1 and comparative example respectively, and the consumption of dimethylamine and ethyl chloroacetate was calculated, and the calculation results are shown in Table 2.

TABLE 2 consumption of dimethylamine and ethyl chloroacetate

As can be seen from table 2, the consumption of dimethylamine and ethyl chloroacetate in example 1 is much less than that of the comparative example, because in the comparative example, part of dimethylamine enters the tail gas absorption system due to volatilization of dimethylamine gas, which results in significant increase of consumption, and the dimethylamine gas and ethyl chloroacetate are not uniformly mixed, which easily causes gas overflow, thus resulting in incomplete reaction conversion of ethyl chloroacetate, and thus, the consumption of ethyl chloroacetate is also increased. In the embodiment 1, the fluid mixing effect of the microchannel reactor ensures that the dimethylamine gas and the ethyl chloroacetate are fully mixed, and the gas cannot overflow in a closed pipeline, so that the reaction conversion is complete, and the utilization rate of the dimethylamine and the ethyl chloroacetate is improved.

The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It should be understood by those skilled in the art that the above embodiments do not limit the present invention in any way, and all technical solutions obtained by using equivalent alternatives or equivalent variations fall within the scope of the present invention.