Method for synthesizing 3-butyne-2-ol with high yield

文档序号:1884048 发布日期:2021-11-26 浏览:40次 中文

阅读说明:本技术 一种高收率合成3-丁炔-2-醇的方法 (Method for synthesizing 3-butyne-2-ol with high yield ) 是由 王南 李果 王林生 张鸿 曾健 鲁岱 于 2021-09-27 设计创作,主要内容包括:一种合成3-丁炔-2-醇的方法,以三聚乙醛作为原料乙醛来源,以氢氧化钾或异丁醇钾或叔丁醇钾作催化剂,有机溶剂作分散剂,先将乙炔与催化剂制备成活性乙炔悬浮浆料,再与乙醛溶液混合后通过管式反应器高温快速反应生成目标产物。反应终点物料水解脱除氢氧化钾后,用水相萃取分离目标产物3-丁炔-2-醇。本发明具有乙炔反应压力低、目标产物收率高等特点。(A method for synthesizing 3-butine-2-alcohol uses paraldehyde as raw material acetaldehyde source, potassium hydroxide or potassium isobutyl alcohol or potassium tert-butyl alcohol as catalyst and organic solvent as dispersing agent, and includes such steps as preparing active acetylene suspension slurry from acetylene and catalyst, mixing it with acetaldehyde solution, and high-temp. quick reaction in tubular reactor to obtain target product. After the potassium hydroxide is removed by hydrolyzing the materials at the end of the reaction, the target product 3-butyne-2-ol is extracted and separated by using a water phase. The method has the characteristics of low acetylene reaction pressure, high target product yield and the like.)

1. A method for synthesizing 3-butyn-2-ol, comprising the following steps:

(1) preparation of an acetaldehyde solution

Catalyzing and depolymerizing initial raw material paraldehyde by sulfuric acid, and then absorbing and dissolving by using an organic solvent to prepare an acetaldehyde solution;

(2) preparation of active acetylene suspension

Grinding an organic solvent and a catalyst into slurry, stirring and heating the slurry to dissolve the slurry into transparent or semitransparent slurry, cooling the slurry to prepare catalyst suspension slurry, and introducing acetylene to react to prepare active acetylene suspension, namely acetylene-catalyst complex or catalyst suspension;

(3) premixing and low-temperature pre-reaction of reactants

Continuously introducing acetylene, simultaneously uniformly and slowly adding a part of acetaldehyde solution into the active acetylene suspension, continuously introducing acetylene for temperature control reaction until the acetaldehyde in the material is basically reacted and converted and the residual catalyst is basically converted into an acetylene-catalyst complex, then cooling and not introducing acetylene any more, and completely adding and uniformly mixing the residual acetaldehyde solution;

(4) high-temperature rapid reaction for synthesizing target product

Pumping the mixed material into a tubular reactor for reaction to generate a catalyst complex of 3-butyne-2-ol, and immediately entering stirred clear water to terminate the reaction after the reaction material flows out of the reaction tube;

(5) hydrolysis separation dealkalization

Stirring the materials at the end of the reaction together with the water solution for hydrolysis reaction, standing the materials for layering, and separating oil phase and water phase;

(6) product of extraction separation

And separating the hydrolyzed oil phase liquid in a water extraction mode to obtain a target product 3-butyne-2-ol.

2. The method for synthesizing 3-butyn-2-ol according to claim 1, wherein the organic solvent used in step (1) and step (2) simultaneously satisfies the following three conditions:

boiling point of solvent is higher than 80 deg.c (preparing catalyst suspension liquid temperature);

secondly, the raw material acetaldehyde and the reaction product 3-butyne-2-ol have high solubility, the acetylene-catalyst complex has certain solubility, and the water intersolubility is low;

③ the strong base is stable;

further, the organic solvent in the step (1) and the step (2) is n-propyl ether, ethyl butyl ether, n-pentyl ether, isopentyl ether, n-hexyl ether or ethylene glycol dibutyl ether;

the concentration of the acetaldehyde solution in the step (1) is 20-40%.

3. The method for synthesizing 3-butyn-2-ol according to claim 1, wherein in the step (2), the catalyst used is potassium hydroxide, potassium iso-butoxide or potassium tert-butoxide with an industrial grade purity of 92-94%; the feeding proportion of the catalyst and the organic solvent is determined according to the type of the used catalyst, when potassium hydroxide is selected as the catalyst, the weight ratio of the pure potassium hydroxide to the organic solvent is 1: 10-1: 5, and when potassium isobutyl alkoxide or potassium tert-butyl alkoxide is selected as the catalyst, the weight ratio of the pure potassium alkoxide to the organic solvent is 1: 6-1: 3;

the temperature for preparing the catalyst suspension by heating is 60-80 ℃, the reaction temperature for preparing the active acetylene suspension by introducing acetylene is 10-15 ℃, the acetylene pressure is less than or equal to 0.15MPa, and the reaction time is 1-2 hours.

4. The method for synthesizing 3-butyn-2-ol according to claim 1, wherein in step (3), the total amount of acetaldehyde is fed in such a way that the molar ratio of acetaldehyde to catalyst is less than or equal to 1, wherein the initial pre-reaction is performed by adding 10-30% of the total amount of acetaldehyde.

5. The method for synthesizing 3-butyn-2-ol according to claim 1, wherein in the step (3), the reaction temperature of the pre-reaction is controlled in the range of 10 ℃ to 15 ℃; the acetylene pressure is kept to be less than or equal to 0.15MPa in the pre-reaction process, the total pre-reaction time is 1-2 hours, and the temperature of all acetaldehyde materials mixed after pre-reaction is 4-8 ℃.

6. The method for synthesizing 3-butyn-2-ol according to claim 1, wherein in the step (4), the mixed material is directly pressed into a reaction tube for reaction without introducing acetylene, the inner diameter of the reaction tube is 5 mm-20 mm, and the length of the reaction tube is 60 m-80 m; the temperature of a heat transfer medium outside the reaction tube is 40-50 ℃; the reaction materials stay in the reaction tube for 1-2 minutes; the feeding amount of the clean water for terminating the reaction is 1-2 times of the feeding amount of the initial catalyst.

7. The method for synthesizing 3-butyn-2-ol according to claim 1, wherein in the step (5), the hydrolysis temperature is 30-40 ℃; the hydrolysis reaction time is 30-60 minutes.

8. The method for synthesizing 3-butyn-2-ol according to claim 1, wherein in the step (6), the weight ratio of the water for extraction to the oil phase is 1: 1-1: 2; the extraction temperature is 30-40 ℃.

Technical Field

The invention relates to a synthetic method of a chemical 3-butyne-2-alcohol.

Background

The 3-butyn-2-ol is a chemical intermediate, and an industrial product thereof is a racemic mixture, can be used as a raw material for preparing R-3-butyn-2-ol optical active bodies and S-3-butyn-2-ol optical active bodies by resolution, and also can be used as an intermediate for preparing pesticides and the like.

Acetaldehyde and acetylene are generally used as raw materials to synthesize 3-butyn-2-ol industrially, two synthesis technical routes are provided, one synthesis technical route is to prepare acetylene into a Grignard reagent (ethynyl magnesium bromide) and then react with the acetaldehyde to generate the 3-butyn-2-ol, and the synthesis technical route has the advantages of specific generated product and high yield of a target product to the acetaldehyde, but the preparation operation process of the ethynyl magnesium bromide in the technical route is complicated, has the danger of combustion and explosion, and has higher separation and purification operation cost of the product. The other synthesis technical route is a Reppe process route, and generally, acetaldehyde aqueous solution and acetylene react under the action of a metal catalyst to generate 3-butyn-2-ol. The technical route has the advantages that acetylene and acetaldehyde can be directly subjected to condensation reaction, the operation process is simple, the implementation of the reaction needs high acetylene pressure, the acetylene explosion risk exists, the specificity of the reaction product is poor, 3-butyne-2-ol is easy to further condense with acetaldehyde into 3-hexyne-2, 5-diol, the reaction product can only obtain a mixture with less 3-butyne-2-ol and more 3-hexyne-2, 5-diol, and the yield of the target product 3-butyne-2-ol is low.

The production and synthesis method which adopts a simpler Reppe process route and takes the synthesis of 3-butine-2-alcohol as a main target product is not disclosed and reported at present.

Disclosure of Invention

The invention aims to provide a method for synthesizing 3-butyne-2-ol, which has low acetylene reaction pressure and high target product yield.

The purpose of the invention is realized as follows:

the method comprises the following steps of taking paraldehyde as an acetaldehyde raw material source, taking potassium hydroxide or potassium alcoholate as a catalyst, reacting with acetylene in an organic solvent, and carrying out production synthesis of 3-butyne-2-ol according to the following technical scheme.

1. Preparation of an acetaldehyde solution

Catalytic depolymerizing initial material paraldehyde with sulfuric acid, absorbing with organic solvent to dissolve into acetaldehyde solution, and sealing for use.

In this step, the acetaldehyde content of the prepared acetaldehyde solution is controlled to be 20-40%, and the acetaldehyde solution concentration is preferably 25-35%.

The organic solvent selected in this step should satisfy the following three conditions simultaneously:

(1) the boiling point of the solvent needs to be higher than 80 ℃ (temperature for preparing catalyst suspension slurry);

(2) the compound has higher solubility to raw material acetaldehyde and reaction product 3-butyne-2-ol, has certain solubility to acetylene-catalyst complex, and has small intersolubility with water;

(3) is stable to strong alkali.

Meanwhile, the organic solvent satisfying the above conditions includes ether solvents such as n-propyl ether, ethyl butyl ether, n-pentyl ether, isopentyl ether, n-hexyl ether, and ethylene glycol dibutyl ether.

2. Preparation of active acetylene suspension slurry

Grinding an organic solvent and a catalyst into slurry in grinding equipment, then transferring the slurry into reaction equipment, stirring and heating the slurry to 60-80 ℃, keeping the temperature for 0.5-1 hour, and continuing stirring and slowly cooling the slurry to 10-15 ℃ after the material is in a transparent or nearly transparent state, namely the catalyst is completely or mostly dissolved in the organic solvent. After the temperature is reduced, the organic solution is in a semitransparent state, and the catalyst is uniformly dispersed in the organic solution in the form of fine suspended particles in a partially dissolved part.

After the catalyst suspension slurry is prepared, the catalyst suspension slurry is continuously stirred, and acetylene is introduced for reaction to prepare active acetylene (acetylene-catalyst complex) suspension slurry.

The organic solvent used in this step is the same as that used previously to prepare the acetaldehyde solution.

In the operation, the catalyst is potassium hydroxide (industrial grade, purity is 92% -94%), potassium isobutyl alkoxide or potassium tert-butyl alkoxide, and any one of the above can be used.

The feeding proportion of the catalyst and the organic solvent is determined according to the type of the used catalyst, when potassium hydroxide is selected as the catalyst, the weight ratio of potassium hydroxide (pure substance) to the organic solvent =1: 10-1: 5, and the content of the product in the oil phase liquid of the final reaction material is 10-20%. When potassium isobutyl alkoxide or potassium tert-butyl alkoxide is selected as the catalyst, the content of potassium alkoxide (pure substance) and organic solvent =1: 6-1: 3 (weight ratio), which corresponds to the product content in the final reaction material oil phase liquid is 10% -20%. The reaction product concentration is controlled to be low here in order to ensure that the catalyst is largely or completely converted to active acetylene (acetylene-catalyst complex) in this and the subsequent pre-reaction dosing operation.

In the operation, the reaction temperature for preparing the active acetylene suspension slurry by introducing acetylene is 10-15 ℃; the acetylene pressure is less than or equal to 0.15MPa, preferably 0.08MPa to 0.15 MPa. (ii) a The reaction time is 1-2 hours.

3. Premixing and low-temperature pre-reaction of reaction materials

Continuously introducing acetylene, simultaneously uniformly and slowly adding 10-30 percent of acetaldehyde solution, preferably 15-25 percent of acetaldehyde solution into the active acetylene suspension slurry, controlling the adding within 30-60 minutes, then continuously controlling the temperature to be 10-15 ℃ and keeping introducing acetylene for reaction for 30-60 minutes. Until the acetaldehyde in the material is substantially reacted and converted and the remaining catalyst is also substantially converted to active acetylene (acetylene-catalyst complex).

And (3) adjusting the temperature of the materials in the reaction kettle to be reduced to 4-8 ℃, adding the residual acetaldehyde solution into the reaction kettle without introducing acetylene, and uniformly mixing the materials.

In the operation of the step, the total adding amount of the acetaldehyde solution is determined by the acetaldehyde concentration and the initial catalyst amount, namely, the acetaldehyde to catalyst ratio is controlled to be less than or equal to 1 (molar ratio), preferably, the acetaldehyde to catalyst ratio is =0.7: 1-0.9: 1 (molar ratio), namely, the active acetylene excess in the reaction material is always ensured.

Since the amount of acetaldehyde in the first stage is very small and the molar amount of active acetylene in the feed is kept above 3 times that of acetaldehyde, substantially all of the acetaldehyde is converted to active 3-butyn-2-ol (butynol-catalyst complex) in the pre-reaction. Part of the active acetylene is consumed through pre-reaction to ensure that the residual suspended catalyst can be completely converted into the active acetylene.

After the pre-reaction is completed, the residual acetaldehyde solution is added, and because the material temperature is low and the reaction speed is slow, the effect of mixing the materials is achieved, and basically no reaction occurs.

4. High-temperature rapid reaction for synthesizing target product

Pumping the mixed material into a tubular reactor for reaction to generate a catalyst complex of the 3-butyne-2-ol, and immediately entering stirred clear water to terminate the reaction after the reaction material flows out of the reaction tube.

This reaction operation is carried out in a tubular reactor. The inner diameter of the reaction tube is 5 mm-20 mm, and the length of the reaction tube is 60 m-80 m; the temperature of a heat transfer medium outside the reaction tube is 40-50 ℃; the reaction materials stay in the reaction tube for 1-2 minutes.

The adding amount of clear water for terminating the reaction is 1-2 times of the adding amount of the initial catalyst, the hydrolyzed aqueous phase solution is maintained to be a high-concentration potassium hydroxide solution, and the solubility of the 3-butyne-2-ol in the aqueous phase solution can be greatly reduced.

In the operation, the mixed material is heated rapidly to react when passing through the reaction tube, the acetaldehyde in the starting material can be completely consumed as the mixed material always keeps excessive active acetylene to the acetaldehyde, the reaction product is mainly the target product 3-butyne-2-ol, and the mixed material is stopped after staying in the reaction tube for 1-2 minutes, which is also beneficial to the reaction product staying in the catalyst complex stage of the 3-butyne-2-ol.

5. Hydrolysis separation dealkalization

Stirring the materials (together with water liquid) at the end of the reaction to carry out hydrolysis reaction, hydrolyzing the catalyst complex of the 3-butyn-2-ol in the materials to decompose the catalyst complex into the 3-butyn-2-ol and the potassium hydroxide, wherein the potassium hydroxide is dissolved into the water phase, and the 3-butyn-2-ol material is still remained in the oil phase liquid. After the hydrolyzed material is kept stand for layering, oil and water phases are separated.

In this step, the hydrolysis temperature is 30 ℃ to 40 ℃. The hydrolysis reaction time is 30-60 minutes.

6. Product of extraction separation

Separating the hydrolyzed oil phase liquid in a water extraction manner to obtain a target product 3-butyne-2-ol, wherein the weight ratio of extraction water to oil phase =1: 1-1: 2; the extraction temperature is 30-40 ℃.

The 3-butyne-2-alcohol aqueous solution obtained by extraction is subjected to activated carbon adsorption, decoloration and impurity removal, and then is adjusted to an aqueous solution with a proper concentration or purified by fractionation according to requirements.

The invention has the following beneficial effects:

1. the catalyst is ground into suspension slurry and then reacted to prepare active acetylene, the catalyst can be fully utilized, the active acetylene in the reaction material is always excessive, and the reaction is facilitated to mainly generate the target product 3-butyne-2-ol.

2. Partial acetaldehyde is converted into a target product in the pre-reaction, and then the high-temperature rapid reaction is adopted in the subsequent tubular reaction and is rapidly terminated, so that the complete reaction of the acetaldehyde is facilitated and stays at the stage of the target product 3-butyn-2-ol, and the further side reaction is inhibited. The yield of the target product corresponding to the raw material acetaldehyde can reach more than 95 percent.

3. The residual acetaldehyde in the reaction end product is little and less than 0.5 percent, and the recovery treatment of the residual acetaldehyde is not needed.

Detailed Description

Example 1:

(1) the paraldehyde is depolymerized and evaporated by sulfuric acid catalysis, and is absorbed by ethyl butyl ether solvent to prepare a solution with the acetaldehyde content of 28-32%, and the solution is sealed for standby.

(2) 1500g of solvent ethyl butyl ether and 200g of catalyst potassium hydroxide (industrial grade, purity 94%) are sequentially added into a grinder to be ground into slurry, the slurry is transferred into a reaction kettle, stirring is started, the mixture is heated to 70-80 ℃ for 1 hour, and then the temperature is reduced to 10-15 ℃ for control. And introducing acetylene gas, keeping the acetylene pressure within the range of 0.12MPa to 0.14MPa, and reacting for 1.5 hours.

(3) Uniformly and slowly adding a first batch of acetaldehyde solution (containing about 25g of acetaldehyde) into the reaction kettle from the head tank, controlling the adding to be finished within 50-60 minutes, and simultaneously keeping the acetylene pressure within the range of 0.12-0.14 MPa for reaction. After the acetaldehyde solution is added, the temperature is kept between 10 and 15 ℃ for reaction for about 1 hour, and the acetylene is stopped to be introduced.

(3) And (3) cooling to 4-8 ℃, adding a second batch of acetaldehyde solution (containing 93g of acetaldehyde) into the reaction kettle, uniformly mixing, pumping the mixed material into the tubular reactor, controlling the flow speed of the material in the reaction tube, and immediately feeding the material flowing out of the reaction tube into the stirred clear water to terminate the reaction.

In this example, the total amount of acetaldehyde added in two times cumulatively is potassium hydroxide (pure) =0.8:1 (molar ratio)

The inner diameter of the reaction tube is 12mm, and the length of the reaction tube is 70 m; the outer shell of the reaction tube uses water as a heat transfer medium, and flows reversely with the reaction material, and the entering temperature of the water medium is controlled to be 40-44 ℃; and controlling the residence time of the reaction materials in the reaction tube to be 1.5-2 minutes.

The total amount of clear water used for terminating the reaction was about 300 g.

(4) Stirring the reaction material (together with water solution) at 30-40 deg.C for 0.5 hr, standing for layering, and separating the lower layer (containing potassium hydroxide) of water phase solution.

(5) Stirring and extracting the oil phase liquid by 1100g of clear water at the extraction temperature of 30-40 ℃, standing and layering, and separating oil phase and water phase.

Adsorbing and decoloring the aqueous phase liquid containing the 3-butyne-2-ol by using activated carbon, and detecting the content.

1279.3g of aqueous phase (concentration of 3-butyn-2-ol 14.1%) were obtained and the yield of the product 3-butyn-2-ol (relative to the theoretical yield) was calculated to be 95.5%.

Example 2:

the procedure was followed as in example 1, wherein: the solvent in the operation steps (1) and (2) is n-butyl ether, the feeding amount in the operation (2) is 1800g of n-butyl ether, and the catalyst is 400g of potassium tert-butoxide (technical grade, purity 98%). The acetylene pressure is 0.08MPa to 0.1 MPa.

In the operation step (2), the acetaldehyde solution in the first batch contains about 25g of acetaldehyde, the acetaldehyde solution in the second batch contains about 115g of acetaldehyde, and the total amount of the acetaldehyde is potassium tert-butoxide (pure) =0.9:1 (molar ratio). The acetylene pressure is 0.08MPa to 0.1 MPa.

In the operation step (3), the temperature of the water medium entering the reaction tube is controlled to be 48-50 ℃; and controlling the residence time of the reaction materials in the reaction tube to be 1-1.5 minutes. The total amount of clear water used for terminating the reaction was about 350 g.

In the operation step (5), 1500g of clear water is used for extraction.

1712.5g of aqueous liquid (concentration of 3-butyn-2-ol 12.4%) were obtained and the yield of product (relative to theoretical) was calculated to be 95.9%.

Example 3:

the procedure was followed as in example 1, wherein: the solvent in the operation steps (1) and (2) is ethylene glycol dibutyl ether, the feeding amount in the operation step (2) is 1600g of ethylene glycol dibutyl ether, and the catalyst is 400g of potassium isobutyl alcohol (self-made, with the purity of 97.5%). The acetylene pressure is 0.1MPa to 0.12 MPa.

In the operation step (2), the acetaldehyde solution in the first batch contains about 20g of acetaldehyde, the acetaldehyde solution in the second batch contains about 88g of acetaldehyde, and the total amount of acetaldehyde is potassium isobutyl alkoxide (pure) =0.7:1 (molar ratio). The acetylene pressure is 0.1MPa to 0.12 MPa.

In the operation step (3), the temperature of the water medium entering the reaction tube is controlled to be 48-50 ℃; and controlling the residence time of the reaction materials in the reaction tube to be 1-1.5 minutes. The total amount of clear water used for terminating the reaction was about 350 g.

In the operation (5), 1100g of clear water is used for extraction.

1266.7g of aqueous liquid (concentration of 3-butyn-2-ol 13.2%) were obtained and the yield of product (relative to theoretical) was calculated to be 96.7%.

Herein, the concentration of the solution is the weight percentage concentration.

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