Method for preparing 1, 2, 3-trichloropropene with high selectivity by dehydrochlorination of 1, 2, 2, 3-tetrachloropropane

Abstract

The invention discloses a method for preparing 1, 2, 3-trichloropropene with high selectivity by dehydrochlorination of 1, 2, 2, 3-tetrachloropropane, and belongs to the technical field of catalysis. The method comprises the following steps: stirring 1, 2, 2, 3-tetrachloropropane and a sodium hydroxide solution under the conditions of normal pressure and 40-100 DEG C for reflux reaction, after the reaction is finished, cooling the reaction liquid to room temperature, separating the liquid by using a separating funnel, rectifying the obtained oil phase to obtain 1, 2, 3-trichloropropene, adding an improver into the reaction system, and carrying out solid-liquid separation to obtain the 1, 2, 3-trichloropropene. The improver is a complex system composed of a metal salt and a bidentate phosphine ligand or a metal composite oxide. The method provided by the invention has the advantages of fewer reaction steps and simpler equipment, the yield of 1, 2, 3-trichloropropene is as high as 86%, the conversion rate of 1, 2, 2, 3-tetrachloropropane is as high as 92%, the selectivity of the target product is as high as 98%, and the conversion rate and the selectivity of the target product are remarkably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of catalysis, and particularly relates to a method for preparing 1,2,3-trichloropropene by dehydrochlorination of 1,2,2,3-tetrachloropropane with high selectivity. Background Art

[0002] 1,2,3-Trichloropropene can be used as a degreasing agent, paint remover and solvent for motor washing. In addition, it can also be used as a raw material for organic synthesis to prepare trichloropropene, dichloropropene and pesticides such as chlormequat and avena cava. However, the production process of 1,2,3-trichloropropene is still relatively complicated, and it is difficult to improve the purity and yield.

[0003] 1,2,3-Trichloropropene can be prepared from α-chloropropene. Invention patent CN 108658722A mentions a method for synthesizing 1,2,3-trichloropropene, which is to obtain 1,2,3-trichloropropene by gasifying 3-chloropropene and reacting it with chlorine. Although the utilization rate has been improved, chlorine is still required for the reaction, and the reaction process is relatively complicated, requiring gasification before reaction. In order to simplify the reaction process and avoid using a large amount of chlorine, the development of a new process for preparing 1,2,3-trichloropropene has become an important topic that needs to be studied urgently. Summary of the invention

[0004] In order to solve the problems existing in the background technology, the purpose of the present invention is to provide a method for preparing 1,2,3-trichloropropene with high selectivity by dehydrochlorination of 1,2,2,3-tetrachloropropane, wherein 1,2,2,3-tetrachloropropane and sodium hydroxide solution are reacted at normal pressure to prepare 1,2,3-trichloropropene, and the selectivity of the target product can be as high as 98%.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention provides a method for preparing 1,2,3-trichloropropene by dehydrochlorination of 1,2,2,3-tetrachloropropane with high selectivity, and the reaction route is as follows:

[0007]

[0008] Based on the above technical solution, further, the method comprises the following steps: stirring and refluxing 1,2,2,3-tetrachloropropane with sodium hydroxide solution at normal pressure and 40-100°C, and after the reaction is completed, cooling the reaction solution to room temperature, separating the solution with a separatory funnel, and obtaining 1,2,3-trichloropropene by distillation of the obtained oil phase.

[0009] Based on the above technical solution, further, the mass ratio of 1,2,2,3-tetrachloropropane to sodium hydroxide solution is 1:3 to 3:1, the reaction temperature is 60 to 80° C., and the reaction time is 4 to 24 hours.

[0010] Based on the above technical solution, further, the concentration of the sodium hydroxide solution is 10-25wt%.

[0011] Based on the above technical solution, further, an improver is added to the reaction system, and the function of the improver is to inhibit the further polymerization of 1,2,3-trichloropropene to produce by-products; the improver is a coordination system or a metal composite oxide composed of a metal salt and a bidentate phosphine ligand; the metal salt is one or a combination of two or more of nitrates, hydrochlorides, perchlorates, phosphates, acetates, and oxalates of cesium, potassium, lead, and niobium, preferably one or a combination of two or more of cesium chloride, potassium chloride, lead phosphate, and niobium phosphate; the metal composite oxide is a composite metal oxide synthesized by combining two or more metals among cesium, potassium, lead, and niobium.

[0012] Based on the above technical solution, further, the amount of the improver added to the reaction system is 1% to 10% of the amount of the substrate substance.

[0013] Based on the above technical solution, further, the bidentate phosphine ligand is one of the large sterically hindered rigid phosphine ligands A to E, and its structure is shown below:

[0014]

[0015] Based on the above technical scheme, further, the preparation method of the metal composite oxide is as follows: add two or more metal salts to an alcohol solution, add an acid solution dropwise under stirring conditions until a large amount of suspended matter precipitates, then stir at room temperature for 6 to 18 hours, centrifuge, and repeatedly wash with water until the pH value of the waste liquid is 6 to 7. Finally, dry and grind the obtained solid product, place it in an air atmosphere at 400 to 650°C and calcine it for 2 to 8 hours to obtain a metal composite oxide.

[0016] Based on the above technical scheme, further, the alcohol solution is a mixed alcohol solution of one or more monovalent normal carbon alcohols with a carbon atom number less than 12, preferably a mixed alcohol solution of one or more of methanol, ethanol, propanol, and butanol; the acid solution is one of nitric acid, hydrochloric acid, sulfuric acid, phosphoric acid, perchloric acid or carbonic acid, and the concentration is 0.5-3 mol / L; the metal salt is one or a combination of two or more of nitrate, hydrochloride, perchlorate, phosphate, acetate, and oxalate of cesium, potassium, lead, and niobium, preferably one or a combination of two or more of cesium chloride, potassium chloride, lead phosphate, and niobium phosphate.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The method for preparing 1,2,3-trichloropropene of the present invention has fewer reaction steps, and the equipment used is relatively simple. The yield of 1,2,3-trichloropropene is as high as 86%, the conversion rate of 1,2,2,3-tetrachloropropane is as high as 92%, and the selectivity of the target product is as high as 98%, which significantly improves the conversion rate and the selectivity of the target product. DETAILED DESCRIPTION

[0019] The present invention is described in detail below with reference to the embodiments, but the embodiments of the present invention are not limited thereto. Obviously, the embodiments described below are only partial embodiments of the present invention. For those skilled in the art, other similar embodiments obtained without creative labor all fall within the protection scope of the present invention.

[0020] 1,2,3-Trichloropropene yield = 1,2,2,3-tetrachloropropane conversion rate * 1,2,3-trichloropropene selectivity

[0021] 1,2,2,3-Tetrachloropropane conversion rate = (1-φ1,2,2,3-Tetrachloropropane)*100%

[0022] 1,2,3-Trichloropropene selectivity = φ1,2,3-Trichloropropene / (1-φ1,2,2,3-tetrachloropropane)*100%

[0023] φ1,2,2,3-Tetrachloropropane and φ1,2,3-Trichloropropene represent the molar concentration percentages of 1,2,2,3-tetrachloropropane and 1,2,3-trichloropropene, respectively.

[0024] The structures of ligands A to E used in the examples are shown below:

[0025]

[0026] All ligands were purchased from J&K Chemicals.

[0027] Comparative Example 1: Reaction without modifier

[0028] In a 150mL three-necked flask, 18.1g of 1,2,2,3-tetrachloropropane (purchased from Inokai) was added, and 40g of 25% sodium hydroxide solution was added dropwise. The temperature of the reaction system was maintained at 70°C, and reflux reaction was carried out under stirring for 12h. After the reaction, the reaction liquid was cooled to room temperature, and the oil phase was a mixed solution of the target product 1,2,3-trichloropropene. The oil phase was separated by a separating funnel and rectified by a distillation tower to obtain the final product 1,2,3-trichloropropene. The yield of 1,2,3-trichloropropene was 50.4%, the conversion rate of 1,2,2,3-tetrachloropropane was 70.0%, and the selectivity of 1,2,3-trichloropropene was 72.0%.

[0029] Example 1: Reaction of a cesium-based modifier with A as a ligand

[0030] In a 150mL three-necked flask, 18.1g of 1,2,2,3-tetrachloropropane (purchased from Inokai), 1.68g of cesium chloride and 1.97g of ligand A were added as improvers, and 40g of 25wt% sodium hydroxide solution was added dropwise. The temperature of the reaction system was maintained at 70°C, and reflux reaction was carried out under stirring for 12h. After the reaction, the reaction liquid was cooled to room temperature, and the oil phase was a mixed solution of the target product 1,2,3-trichloropropene. The oil phase was separated by a separatory funnel and rectified by a distillation tower to obtain the final product 1,2,3-trichloropropene. The yield of 1,2,3-trichloropropene was 62.0%, the conversion rate of 1,2,2,3-tetrachloropropane was 72.0%, and the selectivity of 1,2,3-trichloropropene was 86.1%.

[0031] Example 2: Reaction of a Cesium-Based Modifier Using B as a Ligand

[0032] In a 150mL three-necked flask, 18.1g of 1,2,2,3-tetrachloropropane (purchased from Inokai), 1.68g of cesium chloride and 2.18g of ligand B were added as improvers, and 40g of 25wt% sodium hydroxide solution was added dropwise. The temperature of the reaction system was maintained at 70°C, and reflux reaction was carried out under stirring for 12h. After the reaction, the reaction liquid was cooled to room temperature, and the oil phase was a mixed solution of the target product 1,2,3-trichloropropene. The mixture was separated by a separating funnel and rectified by a distillation tower to obtain the final product 1,2,3-trichloropropene. The yield of 1,2,3-trichloropropene was 79.2%, the conversion rate of 1,2,2,3-tetrachloropropane was 89.0%, and the selectivity of 1,2,3-trichloropropene was 89.0%.

[0033] Example 3: Reaction of Cesium-Based Modifier with C as Ligand

[0034] In a 150mL three-necked flask, 18.1g of 1,2,2,3-tetrachloropropane (purchased from Inokai), 1.68g of cesium chloride and 2.69g of ligand C were added as improvers, and 40g of 25wt% sodium hydroxide solution was added dropwise. The temperature of the reaction system was maintained at 70°C, and reflux reaction was carried out under stirring for 12h. After the reaction, the reaction liquid was cooled to room temperature, and the oil phase was a mixed solution of the target product 1,2,3-trichloropropene. After separation by a separating funnel, the final product 1,2,3-trichloropropene was obtained by distillation in a distillation tower. The yield of 1,2,3-trichloropropene was 82.8%, the conversion rate of 1,2,2,3-tetrachloropropane was 90.0%, and the selectivity of 1,2,3-trichloropropene was 92.0%.

[0035] Example 4: Reaction of a Cesium-Based Modifier Using D as a Ligand

[0036] In a 150mL three-necked flask, 18.1g of 1,2,2,3-tetrachloropropane (purchased from Inokai), 1.68g of cesium chloride and 2.29g of ligand D were added as improvers, and 40g of 25wt% sodium hydroxide solution was added dropwise. The temperature of the reaction system was maintained at 70°C, and reflux reaction was carried out under stirring for 12h. After the reaction, the reaction liquid was cooled to room temperature, and the oil phase was a mixed solution of the target product 1,2,3-trichloropropene. The oil phase was separated by a separatory funnel and rectified by a distillation tower to obtain the final product 1,2,3-trichloropropene. The yield of 1,2,3-trichloropropene was 74.8%, the conversion rate of 1,2,2,3-tetrachloropropane was 88.0%, and the selectivity of 1,2,3-trichloropropene was 85%.

[0037] Example 5: Reaction of cesium-based modifier with E as ligand

[0038] In a 150mL three-necked flask, 18.1g of 1,2,2,3-tetrachloropropane (purchased from Inokai), 1.68g of cesium chloride and 2.49g of ligand E were added as improvers, and 40g of 25wt% sodium hydroxide solution was added dropwise. The temperature of the reaction system was maintained at 70°C, and reflux reaction was carried out under stirring for 12h. After the reaction, the reaction liquid was cooled to room temperature, and the oil phase was a mixed solution of the target product 1,2,3-trichloropropene. The oil phase was separated by a separating funnel and rectified by a distillation tower to obtain the final product 1,2,3-trichloropropene. The yield of 1,2,3-trichloropropene was 77.4%, the conversion rate of 1,2,2,3-tetrachloropropane was 89.0%, and the selectivity of 1,2,3-trichloropropene was 87%.

[0039] Example 6: Reaction of potassium-based modifier with E as ligand

[0040] In a 150mL three-necked flask, 18.1g of 1,2,2,3-tetrachloropropane (purchased from Inokai), 1.48g of potassium chloride and 2.49g of ligand E were added as improvers, and 40g of 25wt% sodium hydroxide solution was added dropwise. The temperature of the reaction system was maintained at 70°C, and reflux reaction was carried out under stirring for 12h. After the reaction, the reaction liquid was cooled to room temperature, and the oil phase was a mixed solution of the target product 1,2,3-trichloropropene. The oil phase was separated by a separatory funnel and rectified by a distillation tower to obtain the final product 1,2,3-trichloropropene. The yield of 1,2,3-trichloropropene was 80.1%, the conversion rate of 1,2,2,3-tetrachloropropane was 92.0%, and the selectivity of 1,2,3-trichloropropene was 87.0%.

[0041] Example 7: Reaction of a lead-based modifier with E as a ligand

[0042] In a 150mL three-necked flask, 18.1g of 1,2,2,3-tetrachloropropane (purchased from Inokai), 8.1g of lead phosphate and 2.49g of ligand E were added as improvers, and 40g of 25wt% sodium hydroxide solution was added dropwise. The temperature of the reaction system was maintained at 70°C, and reflux reaction was carried out under stirring for 12h. After the reaction, the reaction liquid was cooled to room temperature, and the oil phase was a mixed solution of the target product 1,2,3-trichloropropene. The oil phase was separated by a separatory funnel and rectified by a distillation tower to obtain the final product 1,2,3-trichloropropene. The yield of 1,2,3-trichloropropene was 80.8%, the conversion rate of 1,2,2,3-tetrachloropropane was 85.0%, and the selectivity of 1,2,3-trichloropropene was 95.0%.

[0043] Example 8: Reaction of a niobium-based modifier with E as a ligand

[0044] In a 150mL three-necked flask, 18.1g of 1,2,2,3-tetrachloropropane (purchased from Inokai), 2.0g of niobium phosphate and 2.49g of ligand E were added as improvers, and 40g of 25wt% sodium hydroxide solution was added dropwise. The temperature of the reaction system was maintained at 70°C, and reflux reaction was carried out under stirring for 12h. After the reaction, the reaction liquid was cooled to room temperature, and the oil phase was a mixed solution of the target product 1,2,3-trichloropropene. The oil phase was separated by a separating funnel and rectified by a distillation tower to obtain the final product 1,2,3-trichloropropene. The yield of 1,2,3-trichloropropene was 87.2%, the conversion rate of 1,2,2,3-tetrachloropropane was 89.0%, and the selectivity of 1,2,3-trichloropropene was 98.0%.

[0045] Example 9

[0046] (1) Synthesis of lead-cesium composite oxide improver:

[0047] In a 100mL flask, add 4.97g 2-ethylhexanoate lead (II), then add 20mL 1-butanol, 20mL ethanol, and weigh 3.36g CsCl (easy to hydrolyze, a small amount of hydrochloric acid gas will be released during weighing), pour into the flask while stirring, the mixing process will generate heat, and a purple-black suspension is obtained after mixing. Add 20mL of 2mol / L HNO3 solution to the flask while stirring. There is no change in the initial stage of dropwise addition, and then a yellow-green product gradually appears. When a large amount of product precipitates, the reaction system becomes viscous. Increase the speed and stir, then continue to drop, the suspension gradually becomes yellow-green, and you can drop it a little faster. After dropping, stir at room temperature for 12h. The next day, use a centrifuge to separate at about 3500r / min, and wash it repeatedly with water. It needs to be washed until the waste liquid pH is 6-7. At this time, it is about 8000r / min. After 10-20min of centrifugation, solid-liquid separation can be achieved. The solid product was dried and ground, and calcined at 550° C. in an air atmosphere for 2 h to obtain a lead-cesium composite oxide.

[0048] (2) Preparation of 1,2,3-trichloropropene from 1,2,2,3-tetrachloropropane

[0049] In a 150 mL three-necked flask, 18.1 g of 1,2,2,3-tetrachloropropane (purchased from Inokai) and 0.4 g of the improver prepared in (1) were added, and 40 g of a 25 wt% sodium hydroxide solution was added dropwise. The temperature of the reaction system was maintained at 70° C. and a reflux reaction was carried out under stirring for 12 h. After the reaction was completed, the reaction liquid was cooled to room temperature. The oil phase was a mixed solution of the target product 1,2,3-trichloropropene. The mixture was separated by a separating funnel and rectified by a distillation tower to obtain the final product 1,2,3-trichloropropene. The yield of 1,2,3-trichloropropene was 75.6%, the conversion rate of 1,2,2,3-tetrachloropropane was 88.0%, and the selectivity of 1,2,3-trichloropropene was 86.0%.

[0050] Example 10

[0051] (1) Synthesis of lead-niobium composite oxide improver:

[0052] In a 100mL flask, add 4.97g of 2-ethylhexanoate lead (II), then add 20mL of 1-butanol and 20mL of ethanol, and then weigh 3.36g of niobium oxalate, and pour it into the flask while stirring. The mixing process will generate heat, and a purple-black suspension will be obtained after mixing. Add 20mL of 2mol / L HNO3 solution to the flask while stirring, and increase the speed of stirring until a large amount of precipitation occurs. Then continue to add, and stir at room temperature for 12h after the dripping. The next day, use a centrifuge to separate at about 3500r / min, and wash it repeatedly with water. It is necessary to wash until the waste liquid pH is 6-7, at this time, about 8000r / min, and centrifuge after 10-20min to achieve solid-liquid separation. The solid product is dried and ground, and calcined at 550℃ in air atmosphere for 2h to obtain a lead-niobium composite oxide.

[0053] (2) Preparation of 1,2,3-trichloropropene from 1,2,2,3-tetrachloropropane

[0054] In a 150 mL three-necked flask, 18.1 g of 1,2,2,3-tetrachloropropane (purchased from Inokai) and 0.4 g of the improver prepared in (1) were added, and 40 g of a 25 wt% sodium hydroxide solution was added dropwise. The temperature of the reaction system was maintained at 70° C. and a reflux reaction was carried out under stirring for 12 h. After the reaction was completed, the reaction liquid was cooled to room temperature. The oil phase was a mixed solution of the target product 1,2,3-trichloropropene. The mixture was separated by a separating funnel and rectified by a distillation tower to obtain the final product 1,2,3-trichloropropene. The yield of 1,2,3-trichloropropene was 86.3%, the conversion rate of 1,2,2,3-tetrachloropropane was 89.0%, and the selectivity of 1,2,3-trichloropropene was 97.0%.

[0055] Embodiment 11

[0056] (1) Synthesis of cesium niobium composite oxide improver:

[0057] In a 100mL flask, add 3.36g CsCl, then add 20mL 1-butanol and 20mL ethanol, and then weigh 3.36g niobium oxalate, and pour it into the flask while stirring. The mixing process will generate heat, and a purple-black suspension will be obtained after mixing. Add 20mL of 2mol / L HNO3 solution to the flask while stirring, and increase the speed to stir until a large amount of precipitation occurs. Then continue to add, and stir at room temperature for 12h after the dripping. The next day, use a centrifuge to separate at about 3500r / min, and wash it repeatedly with water. It is necessary to wash until the waste liquid pH is 6-7, at this time about 8000r / min, and centrifuge after 10-20min to achieve solid-liquid separation. The solid product is dried and ground, and calcined at 550℃ in air atmosphere for 2h to obtain cesium niobium composite oxide.

[0058] (2) Preparation of 1,2,3-trichloropropene from 1,2,2,3-tetrachloropropane

[0059] In a 150 mL three-necked flask, 18.1 g of 1,2,2,3-tetrachloropropane (purchased from Inokai) and 0.4 g of the improver prepared in (1) were added, and 40 g of a 25 wt% sodium hydroxide solution was added dropwise. The temperature of the reaction system was maintained at 70° C. and a reflux reaction was carried out under stirring for 12 h. After the reaction was completed, the reaction liquid was cooled to room temperature. The oil phase was a mixed solution of the target product 1,2,3-trichloropropene. The mixture was separated by a separating funnel and rectified by a distillation tower to obtain the final product 1,2,3-trichloropropene. The yield of 1,2,3-trichloropropene was 84.6%, the conversion rate of 1,2,2,3-tetrachloropropane was 89.0%, and the selectivity of 1,2,3-trichloropropene was 95.0%.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing 1,2,3-trichloropropene by dehydrochlorination of 1,2,2,3-tetrachloropropane with high selectivity, characterized in that: The reaction route is as follows:

2. The method according to claim 1, characterized in that The method comprises the following steps: stirring and refluxing 1,2,2,3-tetrachloropropane and sodium hydroxide solution at normal pressure and 40-100° C., cooling the reaction solution to room temperature after the reaction is completed, separating the solution with a separating funnel, and distilling the obtained oil phase to obtain 1,2,3-trichloropropene.

3. The method according to claim 2, characterized in that The mass ratio of 1,2,2,3-tetrachloropropane to sodium hydroxide solution is 1:3-3:1, the reaction temperature is 60-80°C, and the reaction time is 4-24h.

4. The method according to claim 2, characterized in that: The concentration of the sodium hydroxide solution is 10-25wt%.

5. The method according to claim 1, characterized in that An improver is added to the reaction system, wherein the improver is a coordination system composed of a metal salt and a bidentate phosphine ligand or a metal composite oxide; the metal salt is one or a combination of two or more of nitrates, hydrochlorides, perchlorates, phosphates, acetates and oxalates of cesium, potassium, lead and niobium, preferably one or a combination of two or more of cesium chloride, potassium chloride, lead phosphate and niobium phosphate; the metal composite oxide is a composite metal oxide synthesized by combining two or more metals among cesium, potassium, lead and niobium.

6. The method according to claim 5, characterized in that The amount of the improver added to the reaction system is 1% to 10% of the amount of the substrate.

7. The method according to claim 5, characterized in that The bidentate phosphine ligand is one of the large sterically hindered rigid phosphine ligands A to E, and its structure is shown below:

8. The method according to claim 5, characterized in that The preparation method of the metal composite oxide is as follows: adding two or more metal salts to an alcohol solution, adding an acid solution dropwise under stirring until a large amount of suspended matter is precipitated, then stirring at room temperature for 6 to 18 hours, centrifuging, and repeatedly washing with water until the pH value of the waste liquid is 6 to 7. Finally, drying and grinding the obtained solid product, placing it in an air atmosphere at 400 to 650° C. and calcining it for 2 to 8 hours to obtain the metal composite oxide.

9. The method according to claim 8, characterized in that The alcohol solution is one or a mixed alcohol solution of two or more monovalent normal carbon alcohols having a carbon atom number less than 12, preferably a mixed alcohol solution of one or more of methanol, ethanol, propanol, and butanol; the acid solution is one of nitric acid, hydrochloric acid, sulfuric acid, phosphoric acid, perchloric acid, or carbonic acid, with a concentration of 0.5 to 3 mol / L; the metal salt is one or a combination of two or more of nitrate, hydrochloride, perchlorate, phosphate, acetate, and oxalate of cesium, potassium, lead, and niobium, preferably one or a combination of two or more of cesium chloride, potassium chloride, lead phosphate, and niobium phosphate.

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