Preparation method of propargyl alcohol

Abstract

The invention relates to a preparation method of propargyl alcohol, and belongs to the technical field of organic chemistry. The reaction formula is as follows: # imgabs0 #; comprising the following steps: (1) taking Z-1, 3-dichloropropene as a raw material, adding dimethyl sulfoxide and solid alkali into an organic solvent, heating, carrying out heat preservation reaction until the content of the Z-1, 3-dichloropropene is less than or equal to 1%, and cooling to room temperature; (2) adding a phase transfer catalyst and water into the reaction liquid obtained in the step (1), heating, and carrying out a heat preservation reaction until an intermediate 3-chloropropyl-2-ene-1-ol is less than or equal to 0.5%; cooling to room temperature; (3) filtering, separating liquid, and adding an extracting agent into a water phase for extraction; and rectifying the extracted organic phase to obtain propargyl alcohol. By controlling the alkaline strength and reaction parameters in the reaction, the production of organic impurity ether compounds can be effectively controlled, the purity and yield of the product are improved, and meanwhile, the reaction time is shortened.

Description

Technical Field

[0001] The invention relates to the technical field of organic chemistry, and in particular to a method for preparing propynyl alcohol. Background Art

[0002] Propargyl alcohol, also known as 2-propynyl-1-ol, 3-hydroxymethylacetylene, and ethynylmethanol, is a colorless, transparent liquid with a pungent odor at room temperature. It is an important organic intermediate raw material. In the pharmaceutical industry, propargyl alcohol is an important intermediate for the synthesis of fosfomycin sodium, fosfomycin calcium, and sulfadiazine. It is also used in the production of pharmaceutical products such as acrylol, acrolein, and vitamin A. In the pesticide industry, it is used to synthesize the pesticide propargyl; in the electroplating industry, propargyl alcohol and its derivatives are used as an excellent nickel plating fastener in the nickel plating process because of their good leveling and brightness; in the steel industry, propargyl alcohol and its downstream compounds can inhibit the corrosion of acidic substances such as acetic acid, phosphoric acid, sulfuric acid, and hydrochloric acid on metals such as iron, copper, and nickel; in oil extraction, propargyl alcohol is used as a key effective component of an efficient acidizing corrosion inhibitor under high temperature, high pressure, and high-concentration hydrochloric acid in oil and gas wells.

[0003] At present, the most widely used methods for preparing propargyl alcohol at home and abroad are mainly the following three: the first method is the high-pressure acetylene aldehyde method. The conversion rate of formaldehyde in the synthesis reaction process is about 98%, of which the yield of propargyl alcohol is 31.3% and the yield of butynediol is 66.7%. In this method, the yield of propargyl alcohol is low and the safety is poor. The second method is that 1,4-butynediol is cracked under the action of a catalyst to produce propargyl alcohol and formaldehyde, and the reaction is carried out under a slightly positive pressure or normal pressure. The yield of propargyl alcohol is 33.3%. The main disadvantages of this method are the low yield of propargyl alcohol and the high cost of using metal catalysts. The third method is to use 1,3-dichloropropylene as a raw material, and hydrolyze it to generate a 3-chloroprop-2-ene-1-ol intermediate through a base catalytic reaction such as sodium carbonate. Then, under the action of a strong base such as sodium hydroxide, the intermediate is dehydrochlorinated to generate propargyl alcohol. For example, patent CN116283488A uses this method, which first uses sodium carbonate to hydrolyze 1,3-dichloropropylene; then adds DMSO solvent, and then adds sodium hydroxide, and reacts at 100~150°C to obtain propargyl alcohol, and the yield of propargyl alcohol can reach 73.8%. Although the third method uses 1,3-dichloropropylene as a raw material to obtain a relatively high yield of propargyl alcohol, this method still has the following disadvantages: 1. The use of polar solvent DMSO makes solvent recovery difficult; 2. The use of mixed alkali has a high cost of alkali; 3. The reflux insulation time is long and the reaction cycle is long; 4. Azeotropic distillation is used to recover propargyl alcohol, which has high energy consumption, and the final yield of propargyl alcohol is only about 73%; 5. A large number of ether impurities are generated, which affects the purity of the product. The structure of ether impurities is as follows: . Summary of the invention

[0004] In view of the problems of long reaction cycle, low yield, high ether impurity content, high material cost, etc. in the existing process for preparing propargyl alcohol, the present invention provides a method for preparing propargyl alcohol to solve the above problems. The present invention can effectively control the generation of organic impurity ether compounds by controlling the alkalinity strength and reaction parameters in the reaction, thereby improving the purity and yield of the product and shortening the reaction time.

[0005] The technical solution of the present invention is as follows: A method for preparing propargyl alcohol, the reaction formula is as follows: ; The steps include: (1) Using Z-1,3-dichloropropylene as raw material, add dimethyl sulfoxide and solid base in an organic solvent, raise the temperature, keep the temperature to react until the Z-1,3-dichloropropylene content is ≤1%, and then cool to room temperature; (2) adding a phase transfer catalyst and water to the reaction solution of step (1), raising the temperature, and keeping the temperature to react until the intermediate 3-chloroprop-2-en-1-ol is ≤ 0.5%; then cooling to room temperature; (3) Filtration, separation, adding an extractant to the aqueous phase for extraction; and distilling the organic phase after extraction to obtain propargyl alcohol; As an embodiment, the organic solvent in step (1) is one of petroleum ether, toluene or xylene. Preferably, the boiling range of petroleum ether is 90°C to 120°C.

[0006] As an embodiment, the phase transfer catalyst is dodecyl methyl ammonium chloride, trioctyl methyl ammonium chloride or trioctyl methyl ammonium bromide.

[0007] As a more preferred embodiment, the molar ratio of the phase transfer catalyst to Z-1,3-dichloropropylene is 0.01-0.05:1.

[0008] As a preferred embodiment, the molar ratio of the phase transfer catalyst to Z-1,3-dichloropropylene is 0.02-0.03:1.

[0009] As an embodiment, the solid base is sodium hydroxide or potassium hydroxide.

[0010] As a more preferred embodiment, the molar ratio of the solid base to Z-1,3-dichloropropylene is 2-2.2:1.

[0011] As an embodiment, the amount of dimethyl sulfoxide used is 0.05-0.10 g / g based on the weight of Z-1,3-dichloropropylene.

[0012] As an embodiment, the amount of the organic solvent used is 4-6 g / g based on the mass of Z-1,3-dichloropropylene.

[0013] As an embodiment, in step (1), the insulation reaction temperature is 95°C to 100°C.

[0014] As an embodiment, in the step (2), the heat preservation reaction temperature is 95°C to 100°C; and the amount of water used is 1-3 g / g based on the weight of Z-1,3-dichloropropene.

[0015] As an embodiment, the extractant in step (3) is n-hexanol.

[0016] The beneficial effects of the present invention are: The invention uses Z-1,3-dichloropropylene as a starting raw material, which has abundant raw material sources and low price, and avoids the use of acetylene gas, so the cost is relatively low and safe. During the reaction process, the concentration of the alkali gradually decreases, that is, the strong alkaline environment of the system gradually weakens, which reduces the polymerization of propargyl alcohol at high temperature, and further increases the yield of propargyl alcohol to 90% to 92%.

[0017] During the hydrolysis process, an organic solvent is used as a reaction solvent, and a single sodium hydroxide or potassium hydroxide is used as a base. The reaction is a two-phase reaction, and the raw materials and intermediates are dissolved in the solvent, thereby ensuring that the pH of the reaction system is low and stable, thereby controlling the production of organic impurity ether compounds (produced by the reaction of intermediates and raw materials), and obtaining a propynyl alcohol content of more than 98.5%, and a yield of more than 90%.

[0018] The same base is used in the hydrolysis process and the elimination reaction process, avoiding the inconvenience caused by using different bases in the two steps, and the molar ratio of the sodium hydroxide base is reduced (if sodium carbonate base is used in the first step of hydrolysis, the reaction produces sodium bicarbonate as a by-product. If the by-product is not removed and the base is directly added for the elimination reaction, 1 equivalent of the base will be consumed by sodium bicarbonate to generate sodium carbonate), reducing the use of caustic soda flakes, reducing part of the raw material cost, and shortening the reaction time.

[0019] In the elimination reaction process, an organic solvent is used to react with water in two phases. The intermediate is dissolved in the organic phase, while the solubility of the product in the organic phase is very small and it mainly exists in the water phase. If the reaction is qualified, the product can be directly filtered and desalted, and the liquid can be separated by standing. The aqueous solution of the product can be collected, and the process operation is simple. The separated organic phase can be continuously applied to the next batch of reactions, so that the raw material conversion rate is close to 100%, and the solvent consumption is reduced; since the amount of alkali used in this process is reduced, the amount of water is relatively reduced, and the amount of wastewater is reduced. In the aqueous phase, the content of propargyl alcohol is relatively high, which is conducive to the extraction of propargyl alcohol by extraction method. Multiple extractions are used, the organic phases are combined, and then the extract phases are distilled and separated, and the fractions at 113°C~115°C are collected to obtain propargyl alcohol, and the content of propargyl alcohol reaches more than 98.5%. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0021] The raw materials used in the examples are all commercially available products, specifically: 1,3-dichloropropylene, cis-1,3-dichloropropylene is selected, and the effective substance content is 97%; petroleum ether has a boiling range of 90°C to 120°C; n-hexanol, the effective substance content is 99%; dodecyl methyl ammonium chloride content is 97%.

[0022] Example 1 A method for preparing 3-chloropropenol, a propynol intermediate, is as follows: Weigh 11.4 g Z-1,3-dichloropropylene into a 250 ml four-necked flask, add 57 g organic solvent, weigh 0.8 g dimethyl sulfoxide and 10.2 g powdered sodium hydroxide into the flask, start stirring, slowly raise the temperature to reflux temperature, keep the temperature for 1.5 hours, cool to room temperature, and take samples to detect the intermediate 3-chloropropylene alcohol.

[0023] Comparing the reaction conditions of different organic reaction solvents, the results are shown in Table 1: Table 1 - Effect of step (1) reaction solvent on the quality of intermediate 3-chloropropenol

[0024] It can be seen that for two-phase reactions, using a non-polar solvent with a high boiling point will result in relatively less raw material remaining under the same reaction time, which is more conducive to the reaction. Both petroleum ether and toluene can be used as reaction solvents, but from a safety perspective, petroleum ether (boiling range 90°C~120°C) was ultimately selected as the reaction solvent.

[0025] Example 2 A method for preparing 3-chloropropenol, a propynol intermediate, is as follows: Weigh 11.4g of 1,3-dichloropropylene into a 250ml four-necked flask, add 57g of petroleum ether (boiling range 90℃~120℃), weigh 0.8g of dimethyl sulfoxide and 10.2g of powdered sodium hydroxide into the flask, start stirring, slowly increase the temperature, keep the reaction for 1.5h, cool to room temperature, and take samples for testing. Compare the reaction conditions at different reaction temperatures, the results are shown in Table 2 below: Table 2 - Effect of reaction temperature in step (1) on the quality of intermediate 3-chloropropenol

[0026] Under the same reaction time, the lower the insulation reaction temperature, the slower the reaction rate and the more residual raw materials; the higher the insulation reaction temperature, the faster the reaction rate. When the reaction temperature exceeds a certain temperature, even if the temperature continues to rise, the rate does not change much. The preferred reaction temperature is 95°C~100°C.

[0027] Example 3 A method for preparing 3-chloropropenol, a propynol intermediate, is as follows: Weigh 11.4g of 1,3-dichloropropylene into a 250ml four-necked flask, add 57g of petroleum ether (boiling range 90℃~120℃), weigh 0.8g of dimethyl sulfoxide and 10.2g of sodium hydroxide into the flask, start stirring, slowly heat to 95℃, keep warm for 2h, cool to room temperature, and take samples for testing. Compare the reaction conditions of sodium hydroxide with different particle sizes, the results are shown in Table 3 below: Table 3 - Effect of different particle sizes of sodium hydroxide on the quality of intermediate 3-chloropropenol in step (1)

[0028] In the same reaction time, it can be seen from the remaining raw materials that the reaction speed is faster when using crushed sodium hydroxide alkali. This is mainly because the smaller the alkali particles, the larger the specific surface area, and the greater the probability of contact between the raw materials and the alkali, which is conducive to increasing the reaction speed.

[0029] Example 4 A method for preparing propargyl alcohol, comprising the following steps: (1) Weigh 11.4g of 1,3-dichloropropylene into a 250ml four-necked flask, add 57g of petroleum ether (boiling range 90℃~120℃), weigh 0.8g of dimethyl sulfoxide and a certain amount of sodium hydroxide into the flask, start stirring, slowly raise the temperature to 95℃, keep the temperature for 2h, cool to room temperature, take samples for testing; track the gas phase until the raw material Z-1,3-dichloropropylene is ≤1%, the reaction is qualified, and the system is cooled to room temperature; (2) Under mechanical stirring, add 0.97 g of weighed dodecyl methyl ammonium chloride phase transfer catalyst, add 34.2 g of water, slowly raise the temperature to 95°C, keep the temperature for 2 hours, cool to room temperature, and take samples for testing. Compare the effects of different sodium hydroxide feed ratios on the product, the results are shown in Table 4: Table 4 - Effect of different feeding amounts of sodium hydroxide on product quality

[0030] In the same reaction time, the molar ratio of sodium hydroxide is increased, and the residual intermediates are gradually reduced. When the molar ratio of sodium hydroxide is further increased, the shortening of the hydrolysis and elimination insulation time is not very obvious, and the impurities will gradually become larger, so the final preferred raw material: sodium hydroxide molar ratio is 1:2.2.

[0031] Example 5 A method for preparing propargyl alcohol, comprising the following steps: (1) Weigh 11.4g of 1,3-dichloropropylene into a 250ml four-necked flask, add 45.6g of petroleum ether (boiling range 90℃~120℃), weigh 0.8g of dimethyl sulfoxide and 9.0g of powdered sodium hydroxide into the flask, start stirring, slowly raise the temperature to 95℃, keep the temperature for 2h, cool to room temperature, take samples for testing; track the gas phase until the raw material Z-1,3-dichloropropylene is ≤1%, the reaction is qualified, and the system is cooled to room temperature; (2) Under mechanical stirring, add 0.97g of weighed phase transfer catalyst and 34.2g of water, slowly raise the temperature to 95°C, keep the temperature for 2h, cool to room temperature, and take samples for testing. Compare the effects of different phase transfer catalysts on the product, the results are shown in Table 5: Table 5 - Effect of different phase transfer catalysts on product quality

[0032] By comparing the reaction effects of several phase transfer catalysts, it was found that the catalytic effects of some of them were not much different. In terms of material properties, price, etc., dodecyl methyl ammonium chloride was finally selected as the phase transfer catalyst.

[0033] Example 6 A method for preparing propargyl alcohol, comprising the following steps: (1) Weigh 11.4g of 1,3-dichloropropylene into a 250ml four-necked flask, add 68.4g of petroleum ether (boiling range 90℃~120℃), weigh 0.8g of dimethyl sulfoxide and 9.0g of powdered sodium hydroxide into the flask, start stirring, slowly raise the temperature to 95℃, keep the temperature for 2h, cool to room temperature, take samples for testing; track the gas phase until the raw material Z-1,3-dichloropropylene is ≤1%, the reaction is qualified, and the system is cooled to room temperature; (2) Under mechanical stirring, add weighed dodecyl methyl ammonium chloride, add 34.2g water, slowly raise the temperature to 95°C, keep the temperature for 2h, cool to room temperature, and take samples for testing. Compare the effects of different amounts of phase transfer catalyst on the product. The results are shown in Table 6 below: Table 6 - Effect of different amounts of phase transfer catalyst on product quality

[0034] It can be seen that as the molar ratio of the phase transfer catalyst increases, the reaction rate increases. However, as the molar ratio continues to increase, the reaction rate of the intermediate and the main peak of the product do not change significantly, and the impurities tend to become larger. The preferred molar ratio of the raw material to the phase transfer catalyst is 1:0.02.

[0035] Example 7 A method for preparing propargyl alcohol, comprising the following steps: (1) Weigh 11.4g of 1,3-dichloropropylene into a 250ml four-necked flask, add 57g of petroleum ether (boiling range 90℃~120℃), weigh 0.8g of dimethyl sulfoxide and 9.0g of powdered sodium hydroxide into the flask, start stirring, slowly raise the temperature to 95℃, keep the temperature for 2h, cool to room temperature, take samples for testing; track the gas phase until the raw material Z-1,3-dichloropropylene is ≤1%, the reaction is qualified, and the system is cooled to room temperature; (2) Under mechanical stirring, add 0.64 g of dodecyl methyl ammonium chloride and a certain amount of water, slowly raise the temperature to 100°C, keep the temperature for 2 hours, cool to room temperature, and take samples for testing. Compare the effects of different amounts of water on the product. The results are shown in Table 7 below: Table 7 - Effect of different amounts of water on product quality

[0036] It can be seen that in the second step of the elimination reaction, adding different amounts of water still has a certain impact on the reaction. If there is less water, the alkali concentration is high and the impurities in the process become larger.

[0037] Example 8 A method for preparing propargyl alcohol, comprising the following steps: (1) Weigh 11.4g of 1,3-dichloropropylene into a 250ml four-necked flask, add 57g of petroleum ether (boiling range 90℃~120℃), weigh 0.8g of dimethyl sulfoxide and 9.0g of powdered sodium hydroxide into the flask, start stirring, slowly raise the temperature to 95℃, keep the temperature for 2h, cool to room temperature, take samples for testing; track the gas phase until the raw material Z-1,3-dichloropropylene is ≤1%, the reaction is qualified, and the system is cooled to room temperature; (2) Under mechanical stirring, add 0.64 g of dodecyl methyl ammonium chloride and 22.8 g of water, slowly raise the temperature to 100°C, keep the temperature for 2 hours, cool to room temperature, and take samples for testing.

[0038] (3) After the liquid is cooled to room temperature, adjust the pH to 7.0, centrifuge to remove salt, let the filtrate stand for 0.5 h, separate the liquid, separate the aqueous phase, weigh it, and send it for product content measurement (separate the upper organic phase and weigh it to test the product content); add the same mass of extractant, stir at room temperature for 1 h, let it stand for 0.5 h, separate the extracted organic phase, weigh it, and test the content. Calculate the extraction efficiency and yield based on the weight and content of the liquid before and after extraction.

[0039] Extraction efficiency calculation method: Extraction efficiency = (weight of extracted organic phase × content of propargyl alcohol in the extracted organic phase) ÷ (weight of aqueous phase before extraction × content of propargyl alcohol in the aqueous phase before extraction) × 100%.

[0040] Yield calculation method: Yield = (weight of reaction organic phase × content of propargyl alcohol in reaction organic phase + weight of aqueous phase × content of propargyl alcohol in aqueous phase) ÷ theoretical weight of propargyl alcohol × 100%.

[0041] Comparing the extraction conditions of different extractants, the results are shown in Table 8: Table 8 - Effect of different extractants on product quality and yield

[0042] Comparing the extraction effects of several extractants, n-hexanol is preferred as the extractant. At the end of the reaction, a small amount of product propargyl alcohol will inevitably exist in the organic phase of the reaction. The yield of this part of the product is calculated to be about 1.0%. After the organic phase is applied to the next batch of reactions, the yield of this part of propargyl alcohol will not be lost; similarly, there is still propargyl alcohol remaining in the aqueous phase after extraction. This part of propargyl alcohol will be azeotropically evaporated with water during the post-treatment of the aqueous phase after extraction. The mixture of this part of water and propargyl alcohol can be applied to the next batch as reaction water, which will not affect the overall yield of propargyl alcohol. The total yield of propargyl alcohol in batch reactions is 91%~92%.

[0043] Example 9 A method for preparing propargyl alcohol, comprising the following steps: (1) Weigh 11.4g of 1,3-dichloropropylene into a 250ml four-necked flask, add 57g of petroleum ether (boiling range 90℃~120℃), weigh 0.8g of dimethyl sulfoxide and 9.0g of powdered sodium hydroxide into the flask, start stirring, slowly raise the temperature to 95℃, keep the temperature for 2h, cool to room temperature, take samples for testing; track the gas phase until the raw material Z-1,3-dichloropropylene is ≤1%, the reaction is qualified, and the system is cooled to room temperature; (2) Under mechanical stirring, add 0.64 g of dodecyl methyl ammonium chloride and 22.8 g of water, slowly raise the temperature to 100°C, keep the temperature for 2 hours, cool to room temperature, and take samples for testing.

[0044] (3) After the feed liquid is cooled to room temperature, the pH is adjusted to 7.0, the salt is centrifuged out, the filtrate is allowed to stand for 0.5 h, the liquid is separated, the aqueous phase is separated, weighed, and the product content is measured (the upper organic phase is separated and weighed, and the product content is tested); the same mass of extractant is added, the mixture is stirred at room temperature for 1 h, the mixture is allowed to stand for 0.5 h, the extracted organic phase is separated, weighed, and the content is tested; the same mass of extractant as the aqueous phase is added, the mixture is stirred at room temperature for 1 h, the mixture is allowed to stand for 0.5 h, the organic phase is separated, weighed, and the content is tested. The extraction efficiency and yield are calculated based on the weight and content of each phase.

[0045] (4) The extractant and propargyl alcohol are separated by extractive distillation. The fractions at 113°C to 115°C are collected, weighed, and sent for content measurement. The recovered extractant can be continuously applied.

[0046] Extraction efficiency calculation method: Extraction efficiency = (weight of organic phase × content of propargyl alcohol in organic phase) ÷ (weight of aqueous phase before extraction × content of propargyl alcohol in aqueous phase before extraction) × 100%.

[0047] Comparison of the effects of different water phase: extractant mass ratios on the product, the results are shown in Table 9: Table 9 - Effect of the ratio of extractant to water and the number of extractions on product quality and yield

[0048] From the above experimental data, it can be seen that increasing the mass ratio of the extractant does not significantly improve the extraction effect. Instead, multiple extractions are more conducive to the extraction and recovery of propargyl alcohol. The mass ratio of the aqueous phase to the extractant is preferably 1:2, and the extraction is performed in three times, and the mass ratio of the three extractants is 1:0.5:0.5.

[0049] After optimization of the small-scale process, the final reaction conditions were determined as follows: the molar ratio of raw material Z-1,3-dichloropropylene: sodium hydroxide = 1:2.2, the amount of dimethyl sulfoxide was 7% of the raw material mass, and the organic solvent was petroleum ether of 5 times the mass of the raw material. The first step of hydrolysis reaction temperature was 95-100°C, the insulation time was 2h, the tracking raw material was ≤1%, after the reaction was completed, the temperature was lowered, and the phase transfer catalyst dodecylmethylammonium chloride was added, the raw material: phase transfer catalyst = 1:0.02 molar ratio, the temperature was raised to 95-100°C, the reaction was 2h, the tracking intermediate was ≤0.5%, the reaction was qualified, the temperature was lowered and the salt was filtered out, and the extractant was added to extract the product, the aqueous phase liquid: extractant = 1:2 mass ratio, after three extractions, the extract phases were combined, and propargyl alcohol was separated by distillation. The content of propargyl alcohol was detected to be 98.5-99.0%, and the total yield of propargyl alcohol was calculated to be 91%~92%.

[0050] Comparative Example 1 The method introduced in the reference "Summary of the Experimental Synthesis of Propargyl Alcohol from OD Mixture" was used to prepare propargyl alcohol, using Z-1,3-dichloropropylene as the starting material and water as the reaction solvent. The first step of the hydrolysis reaction used a 10% sodium carbonate solution, with a raw material: alkali molar ratio of 1:1.2, and refluxed at 84°C~90°C for 2h. After sampling and tracking, it was cooled and the pH was adjusted to 6~7. The reaction solution was fractionated to collect the 97°C~100°C azeotrope, dehydrated with potassium carbonate, and distilled to collect the 147°C~149°C fraction. The collected fractions were put into a high-pressure reactor, and liquid caustic soda with a content of 50% was added, with a molar ratio of Z-1,3-dichloropropylene to liquid caustic soda of 1:1.2. After sealing, 120 ml of liquid ammonia was introduced, the temperature was raised to 75°C, and after stirring for 1 hour, the temperature was lowered, the pressure was released, and the residual liquid ammonia was removed under negative pressure. The pH was adjusted to 7, and the solution was azeotropically obtained by distillation at normal pressure. The content was measured, and the final yield of propargyl alcohol was 64.1%. After optimizing the reaction system through a small laboratory test, the final yield of propargyl alcohol was 68.9%.

[0051] Comparative Example 1 strictly follows the pure water system in the literature (the first step uses weak sodium carbonate, and the second step uses strong sodium hydroxide and liquid ammonia in a high-pressure reactor) for a small test reaction. The final yield of propanol is only 64.1%, which is low. The conditions in the literature involve high pressure, liquid ammonia and other conditions. The use of high-pressure reaction results in large equipment loss and reduced safety; the price of liquid ammonia is relatively expensive, resulting in high raw material costs; the yield is low, resulting in high raw material costs; after the first step of the hydrolysis reaction, water and intermediates are first evaporated, and then the intermediates are distilled out. Two distillations are designed, which consumes a lot of energy. The above has no advantages in terms of safety and cost.

[0052] Comparative Example 2 Refer to the method in patent CN116283488A, using water + DMSO as the reaction system: In a 250mL reaction flask, add 0.12mol of solid sodium carbonate, add weighed water 117g, stir to dissolve all the solid sodium carbonate, add 0.1mol of Z-1,3-dichloropropylene, slowly heat to 78℃~80℃, reflux and keep warm for 5~6h, track the gas phase until the raw material is ≤0.5%, after the reaction is qualified, cool to room temperature, add 0.11mol of DMSO solvent, add 0.19mol of sodium hydroxide three times, slowly heat to 50℃, keep warm for 10~17h, track sampling, cool to room temperature, salt precipitates, filter, adjust pH to 7 with concentrated hydrochloric acid, azeotropically distill a mixture of water and propargyl alcohol at normal pressure, weigh, measure the content, and calculate the yield.

[0053] In the reaction process, after adding caustic soda in the second step and keeping the temperature for 10 hours, the intermediate 3-chloroprop-2-en-1-ol still remained at 27.8%. After further sampling and tracking, the intermediate residue remained basically unchanged, which was suspected to be related to the small amount of caustic soda used. After adding 0.05 mol of caustic soda, the reaction was continued for 2 hours and the intermediate residue was 21.1%. After adding 0.1 mol of caustic soda, the reaction was continued for 5 hours and the intermediate residue was 1.8%. The propargyl alcohol aqueous solution obtained by azeotropic distillation had a detected content of 6.7% and a calculated yield of 60.8%. After material balance, the total yield was 62.4%.

[0054] It can be seen from Comparative Example 2 that: 1. The laboratory repeated the reaction conditions described in the patent for experimental verification, and the yield of the obtained product was not as high as described in the patent, and the repeatability was poor; 2. In Comparative Example 2, 1.2 equivalents of sodium carbonate were used in the first step. During the reaction, sodium carbonate became sodium bicarbonate. After the hydrolysis reaction was completed, 1.9 equivalents of caustic soda were added to the system without desalination. The byproduct sodium bicarbonate produced in the first step would react with 1 equivalent of caustic soda to generate sodium carbonate, resulting in insufficient caustic soda, and thus incomplete reaction of the intermediate 3. DMSO solvent was used in Comparative Example 2. The solvent is miscible with water and difficult to recycle. Even if there is a recycling process, the energy consumption of DMSO recovery is high and the cost is also high; 4. After the second step of elimination reaction in Comparative Example 2, atmospheric pressure azeotropic distillation was used to refine the propargyl alcohol aqueous solution, which has high energy consumption. 5. Comparative Example 2 has a low yield and high raw material cost.

[0055] Although the present invention also uses a solvent, the solvent does not need to be processed and can be continuously applied; at the end of the reaction, the present invention uses a solvent to extract the product in the water phase, and then distills it, and compared with the comparative example, one less distillation operation is required; the amount of caustic soda flakes used is reduced, and relatively less waste salt is generated; the first step of hydrolysis of the present invention uses a solid-liquid two-phase reaction, and the second step uses a liquid-liquid two-phase reaction, and the purpose of controlling impurities is achieved by controlling the concentration of raw materials and intermediates, so that the yield of propargyl alcohol is improved, thereby reducing the cost of raw materials.

[0056] Although the present invention has been described in detail by way of preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, a person of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and such modifications or substitutions shall be within the scope of the present invention. Any person of ordinary skill in the art may easily conceive of changes or substitutions within the technical scope disclosed by the present invention, and such changes or substitutions shall be within the scope of protection of the present invention.

Claims

1. A method for preparing propargyl alcohol, characterized in that: The reaction formula is as follows: ； The steps include: (1) Using Z-1,3-dichloropropylene as raw material, add dimethyl sulfoxide and solid base in an organic solvent, raise the temperature, keep the temperature to react until the Z-1,3-dichloropropylene content is ≤1%, and then cool to room temperature; (2) adding a phase transfer catalyst and water to the reaction solution of step (1), raising the temperature, and keeping the temperature to react until the intermediate 3-chloroprop-2-en-1-ol is ≤ 0.5%; then cooling to room temperature; (3) Filtration, separation, adding an extractant to the aqueous phase for extraction; and distilling the organic phase after extraction to obtain propargyl alcohol; In step (1), the organic solvent is one of petroleum ether, toluene or xylene.

2. The method for preparing propynyl alcohol according to claim 1, characterized in that: The phase transfer catalyst is dodecyl methyl ammonium chloride, trioctyl methyl ammonium chloride or trioctyl methyl ammonium bromide.

3. The method for preparing propynyl alcohol as claimed in claim 1 or 2, characterized in that: The molar ratio of the phase transfer catalyst to Z-1,3-dichloropropylene is 0.01-0.05:

1.

4. The method for preparing propargyl alcohol according to claim 1, characterized in that: In step (1), the solid base is sodium hydroxide or potassium hydroxide.

5. The method for preparing propargyl alcohol according to claim 1 or 4, characterized in that: In step (1), the molar ratio of the solid base to Z-1,3-dichloropropylene is 2-2.2:

1.

6. The method for preparing propynyl alcohol according to claim 1, characterized in that: The amount of dimethyl sulfoxide used is 0.05-0.10 g / g based on the weight of Z-1,3-dichloropropylene.

7. The method for preparing propargyl alcohol according to claim 1, characterized in that: The amount of the organic solvent used is 4-6 g / g based on the mass of Z-1,3-dichloropropylene.

8. The method for preparing propargyl alcohol according to claim 1, characterized in that: In the step (1), the reaction temperature is kept at 95°C to 100°C.

9. The method for preparing propynyl alcohol according to claim 1, characterized in that: In the step (2), the reaction temperature is kept at 95°C to 100°C; the amount of water used is 1 to 3 g / g based on the weight of Z-1,3-dichloropropylene.

10. The method for preparing propargyl alcohol according to claim 1, characterized in that: In step (3), the extractant is n-hexanol.

Images