Method for recovering 4-BMA in mother liquor by adopting membrane treatment technology

Abstract

The invention belongs to the technical field of 4-BMA mother liquor recycling, and relates to a method for recycling 4-BMA in mother liquor by adopting a membrane treatment technology, which comprises the following steps: dropwise adding isopropylamine into 4-BMA refining wastewater, adjusting the pH value to 8-9, selecting a proper filter membrane, and filtering by using membrane filtering equipment at a certain temperature to obtain concentrated liquor and permeate liquid; the maximum separation effect is achieved by controlling the volume ratio of the permeate to the concentrated solution, and the 4-BMA isopropylamine salt concentrated solution is obtained; ethyl acetate is added into the 4-BMA isopropylamine salt concentrated solution for extraction, then 13.5 wt% hydrochloric acid is dropwise added for crystallization, and a 4-BMA product is obtained. According to different solubility of 4-BMA, isomer and isopropylamine after salification in water, the isomer salt is dissolved in water to be removed, 4-BMA salt with high purity is obtained, qualified 4-BMA with the purity larger than or equal to 98.00% is obtained through acid adjustment, and the purity of 4-BMA is larger than or equal to 98.00%. The method is low in energy consumption, simple in process, simpler to operate and easier to convert.

Description

Technical Field

[0001] The invention belongs to the technical field of 4-BMA mother liquor recovery and utilization, and particularly relates to a method for recovering 4-BMA in mother liquor by adopting membrane treatment technology. Background Art

[0002] Membrane separation technology is the selective separation of mixtures of molecules of varying sizes at the molecular level as they pass through a semipermeable membrane. Due to its unique advantages, including separation, environmental friendliness, molecular-level filtration, and process simplicity and ease of control, membrane separation technology is currently widely used in the food, pharmaceutical, biological, environmental, chemical, metallurgical, energy, petroleum, water treatment, electronics, and biomimetics industries, generating significant economic and social benefits.

[0003] Carbapenem antibiotics (i.e., penems) are a new type of β-lactam antibiotics known for their broad antibacterial spectrum and strong antibacterial effects. The key intermediate used in the synthesis of the main ring of penems is β-methylazetidin-2-one (abbreviated as 4-BMA, CAS number: 90776-58-2, molecular formula: C 14 H 27 NO4Si). The introduction of a methyl group at the C-1β position of 4-BMA significantly improves the stability of the final penem-like drug against renal dehydrogenase (DHP-I), eliminating the need for co-administration with a DHP-I inhibitor while maintaining its antibacterial activity. The most effective and feasible method for synthesizing penem-like drugs is to synthesize the intermediate 4-acetoxyazetidinone (4AA) into 4-BMA and then introduce the C-1β methyl group via the intermediate.

[0004] The 4-BMA mother liquor is mainly composed of water, sodium chloride, a small amount of hydrochloric acid, 1‰-3‰ of 4-BMA, and a small amount of 4-BMA isomers. Due to its high value, 4-BMA is worth recovering. However, the mother liquor is currently treated with MVR distillation after alkali adjustment. 4-BMA is treated as hazardous waste along with the waste salt. There is no suitable recovery plan, let alone a plan to use membrane treatment technology to recover 4-BMA from the mother liquor. Summary of the Invention

[0005] The object of the present invention is to provide a method for recovering 4-BMA from a mother liquor by using a membrane treatment technology, and to obtain 4-BMA with higher purity by utilizing the different solubilities of 4-BMA and its isomers in water after being salted with isopropylamine.

[0006] The technical solution adopted by the present invention to solve the technical problem is: a method for recovering 4-BMA from mother liquor using membrane treatment technology, comprising the following steps:

[0007] a. Add isopropylamine dropwise to the 4-BMA refined wastewater, adjust the pH to 8-9, select a suitable filter membrane, and filter with a membrane filtration device at a certain temperature to obtain a concentrate and a permeate. The maximum separation effect is achieved by controlling the volume ratio of the permeate to the concentrate to obtain a 4-BMA isopropylamine salt concentrate;

[0008] b. Ethyl acetate was added to the 4-BMA isopropylamine salt concentrate obtained in step a for extraction, and then 13.5 wt % hydrochloric acid was added dropwise for crystallization to obtain a 4-BMA product.

[0009] Furthermore, in step a, a membrane filtration device is used to enrich the 4-BMA isopropylamine salt wastewater, the molecular weight cut-off of the filter membrane is 300 Da, the treatment temperature is 20-35° C., and the volume percentage of the concentrate to the total volume of the permeate and the concentrate is 9-12%.

[0010] Furthermore, the amount of isopropylamine added in step a is based on the pH value of 8-9.

[0011] Furthermore, after adding ethyl acetate for extraction in step b, the temperature was controlled at 15-20° C., 13.5 wt % hydrochloric acid was added dropwise, the pH was adjusted to 1.5, the mixture was kept warm for 1 hour, cooled to 0-5° C., filtered, and vacuum dried to obtain the 4-BMA product.

[0012] The present invention has the following beneficial effects:

[0013] 1. The present invention directly recovers qualified 4-BMA from 4-BMA refining wastewater. 4-BMA and its isomers have different solubilities in water after being salted with isopropylamine. The isomer salt is dissolved in water and removed to obtain a 4-BMA salt with higher purity. Other 4-BMA ammonium salts or sodium salts do not have this effect. Qualified 4-BMA with a purity of ≥98.00% is then obtained by acid adjustment.

[0014] 2. By adding isopropylamine, 4-BMA is converted into ammonium salt. The molecular weight difference between it and sodium chloride is larger, which can be used to select the filter membrane. At the same time, by screening the appropriate concentration ratio, a concentrated 4-BMA salt solution is obtained.

[0015] 3. The method of the present invention has low energy consumption, simple process, simpler operation and easier conversion. DETAILED DESCRIPTION

[0016] The following are specific embodiments of the present invention to further describe the technical solution of the present invention, but the scope of protection of the present invention is not limited to these embodiments. Any changes or equivalent substitutions that do not deviate from the concept of the present invention are included in the scope of protection of the present invention.

[0017] Example 1

[0018] To 100 L of 4-BMA refined wastewater solution, isopropylamine was added dropwise to a pH of 8. The solution was then filtered using a membrane filtration system at 35°C, with a 300 Da molecular weight cutoff, to produce a concentrate and a permeate. The concentrate volume was controlled at 10 L. 400 g of ethyl acetate was added to the concentrate for extraction. The temperature was controlled at 15-20°C, and 13.5 wt% hydrochloric acid was added dropwise to adjust the pH to 1.5. The solution was incubated for 1 hour, cooled to 0-5°C, and filtered. Vacuum drying yielded 164.3 g of 4-BMA with a purity of 98.42%.

[0019] Example 2

[0020] To 100 L of 4-BMA refined wastewater solution, isopropylamine was added dropwise to a pH of 9. The solution was then filtered using a membrane filtration system at 25°C, with a membrane molecular weight cutoff of 300 Da, to produce a concentrate and a permeate. The volume of the concentrate was controlled to 9 L. 340 g of ethyl acetate was added to the concentrate for extraction. The temperature was controlled at 15-20°C, and 13.5 wt% hydrochloric acid was added dropwise to adjust the pH to 1.5. The solution was incubated for 1 hour, cooled to 0-5°C, and filtered. Vacuum drying yielded 165.2 g of 4-BMA with a purity of 98.22%.

[0021] Example 3

[0022] To 100 L of 4-BMA refined wastewater solution, isopropylamine was added dropwise to a pH of 8.5. The solution was then filtered using a membrane filtration system at 20°C, with a molecular weight cutoff of 300 Da, to obtain a concentrate and a permeate. The volume of the concentrate was controlled at 12 L by adding 490 g of ethyl acetate for dissolution and extraction. The temperature was controlled at 15-20°C, and 13.5 wt% hydrochloric acid was added dropwise to adjust the pH to 1.5. The solution was incubated for 1 hour, cooled to 0-5°C, and filtered. Vacuum drying yielded 164.9 g of 4-BMA with a purity of 98.37%.

[0023] The present invention is not limited to the above-mentioned embodiments. Anyone should be aware that any structural changes made under the guidance of the present invention, and any technical solutions that are the same or similar to those of the present invention, fall within the scope of protection of the present invention.

[0024] The technology, shape, and structure not described in detail in the present invention are all well-known technologies.

Claims

1. A method for recovering 4-BMA from mother liquor using membrane treatment technology, characterized in that: The following steps are involved: a. Add isopropylamine dropwise to the 4-BMA refined wastewater, adjust the pH to 8-9, select a suitable filter membrane, and filter with a membrane filtration device at a certain temperature to obtain a concentrate and a permeate. The maximum separation effect is achieved by controlling the volume ratio of the permeate to the concentrate to obtain a 4-BMA isopropylamine salt concentrate; b. Ethyl acetate was added to the 4-BMA isopropylamine salt concentrate obtained in step a for extraction, and then 13.5 wt % hydrochloric acid was added dropwise for crystallization to obtain a 4-BMA product.

2. The method for recovering 4-BMA from mother liquor using membrane treatment technology according to claim 1, characterized in that: In step a, 4-BMA isopropylamine salt wastewater is enriched using a membrane filtration device, the molecular weight cut-off of the filter membrane is 300 Da, the processing temperature is 20-35° C., and the volume percentage of the concentrated liquid is 9-12%.

3. The method for recovering 4-BMA from mother liquor using membrane treatment technology according to claim 1, characterized in that: The amount of isopropylamine added in step a is based on pH 8-9.

4. The method for recovering 4-BMA from mother liquor using membrane treatment technology according to claim 1, wherein: After adding ethyl acetate for extraction in step b, the temperature was controlled at 15-20° C., 13.5 wt % hydrochloric acid was added dropwise, the pH was adjusted to 1.5, the temperature was kept for 1 hour, the temperature was lowered to 0-5° C., the mixture was filtered, and vacuum dried to obtain the 4-BMA product.