A kind of industrialized continuous production method of 4-chlorobenzaldehyde dimethyl acetal

Abstract

The invention discloses a method for industrialized continuous production of 4-chlorobenzaldehyde dimethyl acetal: p-chlorobenzaldehyde, trimethyl orthoformate and a catalyst are introduced into a synthesis reactor at a designed flow rate, and the synthesis reactor continuously produces qualified products. The continuous productivity of the entire process is maintained by designing factors such as the material molar ratio, the residence time of the material in the synthesis reactor, the temperature, the pH and the pressure. Compared with intermittent production, continuous production has obvious advantages: no solvent is required; the annual output of the product is large; the product quality is high; the raw material conversion rate is high; the degree of automation is high; the heat release is uniform, and the safety factor is high.

Description

Technical Field

[0001] The invention belongs to the technical field of fine chemicals, and in particular relates to an industrialized continuous production method for a fungicide intermediate, 4-chlorobenzaldehyde dimethyl acetal. Background Art

[0002] 4-Chlorobenzaldehyde dimethyl acetal is an important intermediate of 2-(4-chlorophenyl)-3-cyclopropyl-1-(1H-1,2,4-triazol-1-yl)butan-2-ol (also known as cyproconazole). Cyproconazole is widely used in cereal crops, coffee, sugar beets, fruit trees and grapes to prevent and control a variety of pathogens. It is widely studied by scientific researchers because of its high efficiency and low toxicity.

[0003] At present, the preparation of intermediate 4-chlorobenzaldehyde dimethyl acetal is basically obtained by intermittent production in solvent chloroform as raw materials with p-chlorobenzaldehyde and trimethyl orthoformate. However, in this preparation process, because it needs to use a large amount of chloroform, on the one hand, the raw material and solvent recovery costs are increased; on the other hand, because chloroform is volatile and has a low boiling point, there is a risk of explosion in the production process, that is, using chloroform as a solvent increases the risk factor of the production process; in addition, due to manual operation factors and necessary operation time, on the one hand, batch differences are caused in the product, and on the other hand, the output is limited to affect the production of cyproconazole later; and, with the price increase of trimethyl orthoformate, the trimethyl orthoformate that needs to be consumed in this process is more, which also brings cost increase; in addition, with the requirements of modern production technology, this intermittent production is difficult to realize automatic control. Therefore, it is necessary to reduce the amount of chloroform used, reduce manual operation, reduce the entire reaction time, and reduce the consumption of trimethyl orthoformate as much as possible, so as to realize comprehensive automatic control. Summary of the invention

[0004] Purpose of the invention: The purpose of the present invention is to provide an industrial continuous production method of 4-chlorobenzaldehyde dimethyl acetal, which has the advantages of increasing output, improving raw material conversion rate, improving product quality, being simple to operate, reducing cost, not requiring solvent, having a high degree of automation and a high safety factor, in view of the shortcomings of the prior art.

[0005] Technical solution: The industrialized continuous production method of 4-chlorobenzaldehyde dimethyl acetal described in the present invention has a reaction chemical equation as shown in formula (I), which specifically comprises the following steps:

[0006]

[0007] (1) Add the prepared mixed solution of p-chlorobenzaldehyde and trimethyl orthoformate into the first raw material kettle, heat and stir evenly; the mass percentage of p-chlorobenzaldehyde in the mixed solution to the raw materials in the first raw material kettle is 50-80wt.%;

[0008] (2) Add the prepared mixed solution of trimethyl orthoformate and catalyst into the second raw material kettle, heat and stir evenly; the mass percentage of catalyst in the mixed solution to the raw materials in the second raw material kettle is 5-15wt.%;

[0009] (3) Using a flow meter and a material transfer pump in combination, the mixed liquid in the first raw material kettle is continuously transferred into the first reaction kettle, and the materials are self-circulated and transferred in the first reaction kettle; using a flow meter and a material transfer pump in combination, the mixed liquid in the second raw material kettle is continuously transferred into the first reaction kettle, and the materials are self-circulated and transferred in the first reaction kettle;

[0010] (4) After the first reactor has been in heat preservation condition and the material has been transferred in a self-circulating manner for a set time, the discharge valve of the first reactor is opened, and the material in the first reactor is continuously transferred to the second reactor through the cooperation of the flow meter and the transfer pump. The discharge flow rate of the first reactor is equal to the total feed flow rate of the first reactor;

[0011] (5) After the second reactor is insulated and the material is transferred in a self-circulating manner for a set time, the discharge valve of the second reactor is opened, and the material in the second reactor is continuously and alternately transferred to the 1st to Nth finished product tanks through the use of a flow meter and a transfer pump. The discharge flow rate of the second reactor is equal to the total feed flow rate of the second reactor; wherein N ≥ 2; the continuous alternating material transfer process is as follows: after the first finished product tank is filled with material, its feed valve is closed, the discharge valve is opened, the product is sent to the storage bin, and the second finished product tank is opened for feeding at the same time. The feed valve is opened to connect the materials. After the second finished product tank is full of materials, its feed valve is closed, and the discharge valve is opened to send the product to the storage bin; until the feed valve of the N-1th finished product tank is opened and full of materials, its feed valve is closed, and the discharge valve is opened to send the product to the storage bin, and at the same time the Nth finished product tank is opened to connect the materials; after the Nth finished product tank is full of materials, its feed valve is closed, and the discharge valve is opened to send the product to the storage bin, and at the same time the feed valve of the 1st finished product tank is opened to connect the materials; so that the entire production system is in a continuous production state.

[0012] Furthermore, as a preferred embodiment, the mass percentage of p-chlorobenzaldehyde in the mixed liquid of step (1) to the raw materials in the first raw material kettle is 60-65wt.%; and the temperature is 50-70°C.

[0013] Furthermore, as a preferred embodiment, the mass percentage of the catalyst in the mixed liquid of step (2) to the raw materials in the second raw material kettle is 7-9wt.%, and the temperature is 20-30°C.

[0014] Furthermore, as a preferred embodiment, the catalyst used in step (2) is p-toluenesulfonic acid.

[0015] Furthermore, as a preferred embodiment, in step (3), when designing the flow rate, it is ensured that the molar ratio of p-chlorobenzaldehyde to trimethyl orthoformate simultaneously entering the first reaction kettle is 1:1.05-1.15.

[0016] Furthermore, as a preferred embodiment, the temperature of the first reactor in step (5) is 60-80°C; and the ratio of the total volume of the material in the first reactor to the total volume flow rate of the feed is 15-20min.

[0017] Furthermore, as a preferred embodiment, the temperature of the second reaction kettle in step (5) is 60-80°C.

[0018] Beneficial effects:

[0019] (1) The method provided by the present invention is applied to production, which can achieve "ready-to-use" or 24-hour uninterrupted production of products, thereby increasing annual output;

[0020] (2) The 4-chlorobenzaldehyde dimethyl acetal produced in the present invention has no batch difference and can always maintain a high quality of 98%. On the one hand, it avoids the economic loss caused by quality differences due to artificial factors in intermittent reactions. On the other hand, it also improves the conversion rate of raw materials and saves production costs;

[0021] (3) Compared with intermittent production, the continuous production in the present invention not only does not require solvents, but also releases heat evenly during the synthesis process, thus saving costs and increasing the safety factor;

[0022] (4) The number of equipment used in the present invention is much smaller than the number of equipment required for batch reaction, thus reducing various investment costs for equipment;

[0023] (5) The present invention adopts a continuous production method. Compared with intermittent production, it can achieve comprehensive automated control, avoid various dangerous operations in intermittent production, and increase the safety factor. DETAILED DESCRIPTION

[0024] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 are within the scope of protection of the present invention.

[0025] Example 1: 4-chlorobenzaldehyde dimethyl acetal was prepared by the intermittent production process in the prior art.

[0026] Use a 3000ml reactor, add 1400g chloroform, 158.5g trimethyl orthoformate, 175.0g p-chlorobenzaldehyde at 20-30℃, cool to 12-15℃, add 2.4g p-toluenesulfonic acid (add twice, add 1.2g for the first time, slowly raise the temperature to 25℃, and then add 1.2g.), continue stirring and reacting for 5 minutes after adding, measure PH=3-4, T=24-28℃, and react for another 2.5 hours, take samples for testing, p-chlorobenzaldehyde <2%, otherwise continue to keep warm until p-chlorobenzaldehyde <2%, measure PH every half hour during the insulation, and require PH<4, otherwise add p-toluenesulfonic acid, 0.1g each time, and add trimethyl orthoformate, 2g each time. Until PH<4, the qualitative test is qualified. In this process: the molar ratio of p-chlorobenzaldehyde to trimethyl orthoformate is 1:1.20, the conversion rate of p-chlorobenzaldehyde is 95.68%, and the purity of the product is 88.90%. The results are shown in the data in Table 1.

[0027] Embodiment 2: Production process 1 of the present invention

[0028] Prepare 422.66g of a mixed solution of p-chlorobenzaldehyde and trimethyl orthoformate (of which p-chlorobenzaldehyde accounts for 63.27% and trimethyl orthoformate accounts for 36.73%) in the first raw material kettle, heat it to 60°C, and stir it evenly; prepare 60.82g of a mixed solution of p-toluenesulfonic acid and trimethyl orthoformate (of which p-toluenesulfonic acid accounts for 7.14% and trimethyl orthoformate accounts for 92.86%) in the second raw material kettle, heat it to 25°C, and stir it evenly; use a peristaltic pump to continuously transfer the raw materials in the first raw material kettle to the first reactor at a rate of 26.09ml / min; use a peristaltic pump to continuously transfer the raw materials in the second raw material kettle to the first reactor at a rate of 4.18ml / min; heat and raise the temperature to keep the material temperature in the first reactor at 70°C. After 15 minutes of material transfer, open the discharge valve of the first reactor; use a peristaltic pump The material in the first reactor is continuously transferred to the second reactor at a speed of 30.27 ml / min, and the temperature of the material in the second reactor is maintained at 70°C; 15 minutes after the transfer, the discharge valve of the second reactor is opened, and the material in the second reactor is continuously transferred to the first product tank at a speed of 30.27 ml / min through a peristaltic pump; 60 minutes after the transfer, the discharge valve of the first product tank is opened, the feed valve of the first product tank is closed, the feed valve of the second product tank is opened, and the material in the second reactor is continuously transferred to the second product tank through a peristaltic pump; 60 minutes after the transfer, the first product tank is emptied, the feed valve of the first product tank is opened, the discharge valve of the first product tank is closed, the feed valve of the second product tank is closed, the discharge valve of the second product tank is opened, and the material in the second reactor is continuously transferred to the first product tank through a peristaltic pump. At this point, the first and second product tanks are alternately used, and the whole process is in a continuous production state, maintaining continuous input of raw materials and continuous output of products. In this process: the molar ratio of p-chlorobenzaldehyde to trimethyl orthoformate is 1:1.05, the conversion rate of p-chlorobenzaldehyde is 98.05%, and the purity of the product is 92.89%. The results are shown in the data in Table 1.

[0029] Embodiment 3: Production process 2 of the present invention

[0030] Prepare 422.66g of a mixed solution of p-chlorobenzaldehyde and trimethyl orthoformate (of which p-chlorobenzaldehyde accounts for 63.27% and trimethyl orthoformate accounts for 36.73%) in the first raw material kettle, heat it to 60°C, and stir it evenly; prepare 67.49g of a mixed solution of p-toluenesulfonic acid and trimethyl orthoformate (of which p-toluenesulfonic acid accounts for 7.14% and trimethyl orthoformate accounts for 92.86%) in the second raw material kettle, heat it to 25°C, and stir it evenly; transfer the raw materials in the first raw material kettle to the first reactor at a rate of 26.09ml / min through a peristaltic pump; transfer the raw materials in the second raw material kettle to the first reactor at a rate of 4.64ml / min through a peristaltic pump; heat and raise the temperature to keep the material temperature in the first reactor at 70°C. After 15 minutes of transfer, open the discharge valve of the first reactor; and transfer the raw materials to the first reactor through a peristaltic pump. The material in the first reactor is continuously transferred to the second reactor at a speed of 30.73 ml / min, and the temperature of the material in the second reactor is maintained at 70°C; 15 minutes after the transfer, the discharge valve of the second reactor is opened, and the material in the second reactor is continuously transferred to the first product tank at a speed of 30.73 ml / min through a peristaltic pump; 60 minutes after the transfer, the discharge valve of the first product tank is opened, the feed valve of the first product tank is closed, the feed valve of the second product tank is opened, and the material in the second reactor is continuously transferred to the second product tank through a peristaltic pump; 60 minutes after the transfer, the first product tank is emptied, the feed valve of the first product tank is opened, the discharge valve of the first product tank is closed, the feed valve of the second product tank is closed, the discharge valve of the second product tank is opened, and the discharge valve of the second product tank is opened, and the material in the second reactor is continuously transferred to the first product tank through a peristaltic pump. At this point, the first and second product tanks are alternately used, and the whole process is in a continuous production state, maintaining continuous input of raw materials and continuous output of products. In this process: the molar ratio of p-chlorobenzaldehyde to trimethyl orthoformate is 1:1.08, the conversion rate of p-chlorobenzaldehyde is 98.59%, and the purity of the product is 92.88%. The results are shown in the data in Table 1.

[0031] Embodiment 4: Production process three of the present invention

[0032] Prepare 422.66g of a mixed solution of p-chlorobenzaldehyde and trimethyl orthoformate (of which p-chlorobenzaldehyde accounts for 63.27% and trimethyl orthoformate accounts for 36.73%) in the first raw material kettle, heat it to 60°C, and stir it evenly; prepare 71.84g of a mixed solution of p-toluenesulfonic acid and trimethyl orthoformate (of which p-toluenesulfonic acid accounts for 7.14% and trimethyl orthoformate accounts for 92.86%) in the second raw material kettle, heat it to 25°C, and stir it evenly; transfer the raw materials in the first raw material kettle to the first reactor at a rate of 26.09ml / min through a peristaltic pump; transfer the raw materials in the second raw material kettle to the first reactor at a rate of 4.94ml / min through a peristaltic pump; heat and raise the temperature to keep the material temperature in the first reactor at 70°C. After 15 minutes of material transfer, open the discharge valve of the first reactor; and transfer the raw materials to the first reactor through a peristaltic pump. The material in the first reactor is continuously transferred to the second reactor at a speed of 31.03 ml / min, and the temperature of the material in the second reactor is maintained at 70°C; 15 minutes after the transfer, the discharge valve of the second reactor is opened, and the material in the second reactor is continuously transferred to the first product tank at a speed of 31.03 ml / min through a peristaltic pump; 60 minutes after the transfer, the discharge valve of the first product tank is opened, the feed valve of the first product tank is closed, the feed valve of the second product tank is opened, and the material in the second reactor is continuously transferred to the second product tank through a peristaltic pump; 60 minutes after the transfer, the first product tank is emptied, the feed valve of the first product tank is opened, the discharge valve of the first product tank is closed, the feed valve of the second product tank is closed, the discharge valve of the second product tank is opened, and the discharge valve of the second product tank is opened, and the material in the second reactor is continuously transferred to the first product tank through a peristaltic pump. At this point, the first and second product tanks are alternately used, and the whole process is in a continuous production state, maintaining continuous input of raw materials and continuous output of products. In this process: the molar ratio of p-chlorobenzaldehyde to trimethyl orthoformate is 1:1.11, the conversion rate of p-chlorobenzaldehyde is 98.89%, and the purity of the product is 93.12%. The results are shown in the data in Table 1.

[0033] Embodiment 5: Production process 4 of the present invention

[0034] Prepare 422.66g of a mixed solution of p-chlorobenzaldehyde and trimethyl orthoformate (of which p-chlorobenzaldehyde accounts for 63.27% and trimethyl orthoformate accounts for 36.73%) in the first raw material kettle, heat it to 60°C, and stir it evenly; prepare 82.79g of a mixed solution of p-toluenesulfonic acid and trimethyl orthoformate (of which p-toluenesulfonic acid accounts for 7.14% and trimethyl orthoformate accounts for 92.86%) in the second raw material kettle, heat it to 25°C, and stir it evenly; use a peristaltic pump to continuously transfer the raw materials in the first raw material kettle to the first reactor at a rate of 26.09ml / min; use a peristaltic pump to continuously transfer the raw materials in the second raw material kettle to the first reactor at a rate of 5.69ml / min; heat and raise the temperature to keep the material temperature in the first reactor at 70°C. After 15 minutes of material transfer, open the discharge valve of the first reactor; use a peristaltic pump The material in the first reactor is continuously transferred to the second reactor at a speed of 31.78 ml / min, and the temperature of the material in the second reactor is maintained at 70°C; 15 minutes after the transfer, the discharge valve of the second reactor is opened, and the material in the second reactor is continuously transferred to the first product tank at a speed of 31.78 ml / min through a peristaltic pump; 60 minutes after the transfer, the discharge valve of the first product tank is opened, the feed valve of the first product tank is closed, the feed valve of the second product tank is opened, and the material in the second reactor is continuously transferred to the second product tank through a peristaltic pump; 60 minutes after the transfer, the first product tank is emptied, the feed valve of the first product tank is opened, the discharge valve of the first product tank is closed, the feed valve of the second product tank is closed, the discharge valve of the second product tank is opened, and the discharge valve of the second product tank is opened, and the material in the second reactor is continuously transferred to the first product tank through a peristaltic pump. At this point, the first and second product tanks are alternately used, and the whole process is in a continuous production state, maintaining continuous input of raw materials and continuous output of products. In this process: the molar ratio of p-chlorobenzaldehyde to trimethyl orthoformate is 1:1.15, the conversion rate of p-chlorobenzaldehyde is 99.10%, and the purity of the product is 93.09%. The results are shown in the data in Table 1.

[0035] Embodiment 6: Production process 5 of the present invention

[0036] Prepare 422.66g of a mixed solution of p-chlorobenzaldehyde and trimethyl orthoformate (of which p-chlorobenzaldehyde accounts for 63.27% and trimethyl orthoformate accounts for 36.73%) in the first raw material kettle, heat it to 60°C, and stir it evenly; prepare 89.39g of a mixed solution of p-toluenesulfonic acid and trimethyl orthoformate (of which p-toluenesulfonic acid accounts for 7.14% and trimethyl orthoformate accounts for 92.86%) in the second raw material kettle, heat it to 25°C, and stir it evenly; transfer the raw materials in the first raw material kettle to the first reactor at a rate of 26.09ml / min through a peristaltic pump; transfer the raw materials in the second raw material kettle to the first reactor at a rate of 6.14ml / min through a peristaltic pump; heat and raise the temperature to keep the material temperature in the first reactor at 70°C. After 15 minutes of transfer, open the discharge valve of the first reactor; and transfer the raw materials to the first reactor through a peristaltic pump. The material in the first reactor is continuously transferred to the second reactor at a speed of 32.23 ml / min, and the temperature of the material in the second reactor is maintained at 70°C; 15 minutes after the transfer, the discharge valve of the second reactor is opened, and the material in the second reactor is continuously transferred to the first product tank at a speed of 32.23 ml / min through a peristaltic pump; 60 minutes after the transfer, the discharge valve of the first product tank is opened, the feed valve of the first product tank is closed, the feed valve of the second product tank is opened, and the material in the second reactor is continuously transferred to the second product tank through a peristaltic pump; 60 minutes after the transfer, the first product tank is emptied, the feed valve of the first product tank is opened, the discharge valve of the first product tank is closed, the feed valve of the second product tank is closed, the discharge valve of the second product tank is opened, and the discharge valve of the second product tank is opened, and the material in the second reactor is continuously transferred to the first product tank through a peristaltic pump. At this point, the first and second product tanks are alternately used, and the whole process is in a continuous production state, maintaining continuous raw material input and continuous product output. In this process: the molar ratio of p-chlorobenzaldehyde to trimethyl orthoformate is 1:1.18, the conversion rate of p-chlorobenzaldehyde is 99.10%, and the purity of the product is 93.12%. The results are shown in the data in Table 1.

[0037] Table 1 Test data of products in Examples 1 to 6

[0038] Examples Molar Ratio p-Chlorobenzaldehyde conversion rate Product Purity 1 1∶1.20 95.68% 88.90% 2 1∶1.05 98.05% 92.89% 3 1∶1.08 98.59% 92.88% 4 1∶1.11 98.89% 93.12% 5 1∶1.15 99.10% 93.09% 6 1∶1.18 99.10% 93.12%

[0039] As can be seen from the data comparison in Table 1, the products synthesized by the existing intermittent production process require a large amount of chloroform as a solvent, and the p-chlorobenzaldehyde conversion rate and product purity are both low, and the amount of trimethyl orthoformate consumed is high. However, the p-chlorobenzaldehyde conversion rate and product purity of the present invention are both high, and no solvent is required, and the consumption of trimethyl orthoformate is also low. This proves that the production process has obvious advantages over the existing production process.

[0040] As described above, although the present invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the present invention itself. Various changes in form and details may be made without departing from the spirit and scope of the present invention as defined in the appended claims.

Claims

1. A method for industrialized continuous production of 4-chlorobenzaldehyde dimethyl acetal, characterized in that: The reaction chemical equation is shown in formula (I), which specifically includes the following steps: ； (1) Add the prepared mixed solution of p-chlorobenzaldehyde and trimethyl orthoformate into the first raw material kettle, heat and stir evenly; the mass percentage of p-chlorobenzaldehyde in the mixed solution to the raw materials in the first raw material kettle is 50-80wt.%; (2) Add the prepared mixed solution of trimethyl orthoformate and catalyst into the second raw material kettle, heat and stir evenly; the mass percentage of catalyst in the mixed solution to the raw materials in the second raw material kettle is 5-15wt.%; (3) Using a flow meter and a material transfer pump together, the mixed liquid in the first raw material kettle is continuously transferred into the first reaction kettle, and the materials are self-circulated in the first reaction kettle; The mixed liquid in the second raw material kettle is continuously transferred into the first reaction kettle by using a flow meter and a transfer pump, and the materials are self-circulated in the first reaction kettle; (4) After the first reactor has been in heat preservation condition and the material has been transferred in a self-circulating manner for a set time, the discharge valve of the first reactor is opened, and the material in the first reactor is continuously transferred to the second reactor through the cooperation of the flow meter and the transfer pump. The discharge flow rate of the first reactor is equal to the total feed flow rate of the first reactor; (5) After the second reactor is insulated and the material is transferred in a self-circulating manner for a set time, the discharge valve of the second reactor is opened, and the material in the second reactor is continuously and alternately transferred to the 1st to Nth finished product tanks through the use of a flow meter and a transfer pump. The discharge flow rate of the second reactor is equal to the total feed flow rate of the second reactor; wherein N ≥ 2; the continuous alternating material transfer process is as follows: after the first finished product tank is filled with material, its feed valve is closed, the discharge valve is opened, the product is sent to the storage bin, and the second finished product tank is opened for feeding at the same time. The feed valve is opened to connect the materials. After the second finished product tank is full of materials, its feed valve is closed, and the discharge valve is opened to send the product to the storage bin; until the feed valve of the N-1th finished product tank is opened and full of materials, its feed valve is closed, and the discharge valve is opened to send the product to the storage bin, and at the same time the Nth finished product tank is opened to connect the materials; after the Nth finished product tank is full of materials, its feed valve is closed, and the discharge valve is opened to send the product to the storage bin, and at the same time the feed valve of the 1st finished product tank is opened to connect the materials; so that the entire production system is in a continuous production state.

2. The industrialized continuous production method of 4-chlorobenzaldehyde dimethyl acetal according to claim 1, characterized in that: The mass percentage of p-chlorobenzaldehyde in the mixed liquid of step (1) to the raw materials in the first raw material kettle is 60-65wt.%; and the temperature is 50-70°C.

3. The industrialized continuous production method of 4-chlorobenzaldehyde dimethyl acetal according to claim 2, characterized in that: The mass percentage of the catalyst in the mixed liquid of step (2) to the raw materials in the second raw material kettle is 7-9wt.%, and the temperature is 20-30°C.

4. The industrialized continuous production method of 4-chlorobenzaldehyde dimethyl acetal according to claim 3, characterized in that: The catalyst used in step (2) is p-toluenesulfonic acid.

5. The industrialized continuous production method of 4-chlorobenzaldehyde dimethyl acetal according to any one of claims 1 to 4, characterized in that: In step (3), when designing the flow rate, it is ensured that the molar ratio of p-chlorobenzaldehyde to trimethyl orthoformate entering the first reaction kettle simultaneously is 1:1.05-1.

15.

6. The industrialized continuous production method of 4-chlorobenzaldehyde dimethyl acetal according to claim 5, characterized in that: The temperature of the first reactor in step (4) is 60-80°C.

7. The industrialized continuous production method of 4-chlorobenzaldehyde dimethyl acetal according to claim 6, characterized in that: The temperature of the second reactor in step (5) is 60-80°C.

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