Production method for co-production of isopropanolamine and DL-2-aminopropanol

Abstract

The invention belongs to the technical field of raw material preparation, and particularly relates to a production method for co-production of isopropanolamine and DL-2-aminopropanol. The production method for co-production of isopropanolamine and DL-2-aminopropanol comprises the following steps: adding ammonium carbonate, ammonium carbamate, epoxypropane and water into a high-pressure reaction kettle, uniformly stirring, heating to 88-90 DEG C, preserving heat for 30-35 minutes under 0.8 MPa, then heating to 100-103 DEG C, reacting for 40-45 minutes under 1.0 MPa, cooling to room temperature, filtering, washing, and drying to obtain the DL-2-aminopropanol. And after the reaction is finished, carrying out post-treatment to obtain a mixture of isopropanolamine and DL-2-aminopropanol. According to the production method for co-production of isopropanolamine and DL-2-aminopropanol, the process is simple, parameters are easy to control, reaction conditions are relatively mild, it is guaranteed that a large amount of monoisopropanolamine and DL-2-aminopropanol are generated, and meanwhile generation of by-products diisopropanolamine and triisopropanolamine is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of raw material preparation, and particularly relates to a production method for co-producing isopropanolamine and DL-2-aminopropanol. Background Art

[0002] DL-2-aminopropanol is a colorless viscous liquid at room temperature, with a molecular formula of C3H9NO, a molecular weight of 75, and a CAS number of 6168-72-5. It is an important intermediate for the synthesis of levofloxacin. Currently, the method for synthesizing DL-2-aminopropanol mainly uses DL-2-aminopropionic acid as the starting material and is prepared through two steps of condensation and reduction. The difference lies in the use of different reducing reagents. The main reducing agents used are LiBH4, NaBH4, BFR resin, etc. These reducing agents all have different disadvantages. For example, the post-treatment of using LiBH4 is difficult, and the price is expensive, with certain risks and an unsatisfactory yield. The usage amount of NaBH4 is large, increasing the production cost. BFR resin needs to be pretreated first, increasing the process steps.

[0003] Isopropanolamine includes three homolog products: mono-isopropanolamine (1-amino-2-propanol, abbreviated as MIPA), di-isopropanolamine (2'-dihydroxydipropylamine, abbreviated as DIPA), and tri-isopropanolamine (1,1',1''-nitrilotri-2-propanol, abbreviated as TIPA). Among them, mono-isopropanolamine is the common name of 1-amino-2-propanol, also known as monoisopropanolamine. Mono-isopropanolamine is widely used in the electronic chemicals and detergent industries and is one of the important pharmaceutical synthesis intermediates.

[0004] Generally, isopropanolamine is produced using ammonia and propylene oxide as raw materials, with water as the catalyst. Propylene oxide is ammonolyzed to obtain mono-isopropanolamine, and at the same time, di-isopropanolamine and tri-isopropanolamine are by-produced. This production process is very mature, with a small reaction pressure, a low temperature, and high process safety. Since the solubility of ammonia is low at a higher temperature, in order to avoid excessive formation of di-isopropanolamine, it is necessary to increase the ratio of ammonia to propylene oxide. The amount of circulating water and ammonia in the system is large, and the dehydration energy consumption is high.

[0005] Both mono-isopropanolamine and DL-2-aminopropanol are very important chemical raw materials, and the existing production methods for both have drawbacks. However, the two can be converted through chemical reactions. Therefore, how to produce mono-isopropanolamine and DL-2-aminopropanol co-production has become an urgent technical problem to be solved. Summary of the Invention

[0006] The object of the present invention is to provide a production method for co-producing isopropanolamine and DL-2-aminopropanol. This method has mild reaction conditions and a simple process, ensuring a large amount of production of mono-isopropanolamine and DL-2-aminopropanol while reducing the formation of by-products di-isopropanolamine and tri-isopropanolamine.

[0007] The production method of isopropanolamine co-producing DL-2-aminopropanol according to the present invention comprises the following steps: Add ammonium carbonate, ammonium carbamate, propylene oxide and water into a high-pressure reactor, stir evenly, heat up to 88 - 90 °C, keep warm at 0.8 MPa for 30 - 35 min, then heat up to 100 - 103 °C, and react at 1.0 MPa for 40 - 45 min. After the reaction is completed, a mixture of isopropanolamine and DL-2-aminopropanol is prepared through post-treatment.

[0008] Among them: The molar ratio of propylene oxide, ammonium carbonate and ammonium carbamate is 1 : 3.5 - 3.8 : 1.0 - 1.2.

[0009] The mass of water accounts for 20 - 22% of the total mass of ammonium carbonate, ammonium carbamate, propylene oxide and water.

[0010] The stirring speed is 700 - 800 r / min.

[0011] During the reaction process, first heat up to 88 - 90 °C at a heating rate of 2.5 °C / min and keep warm for 30 - 35 min, then heat up to 100 - 103 °C at a heating rate of 1.5 °C / min and react for 40 - 45 min.

[0012] The post-treatment is to control the pressure at 0.01 MPa, the temperature at 50 - 55 °C, and the reaction time at 1 - 1.2 h to remove unreacted NH3, CO2 and H2O, then control the pressure at 0.01 MPa, the temperature at 90 - 93 °C, collect the gas, and condense it with 10 °C circulating water to prepare a mixture of DL-2-aminopropanol and isopropanolamine.

[0013] The production method of isopropanolamine co-producing DL-2-aminopropanol according to the present invention uses propylene oxide, ammonium carbonate, and ammonium carbamate as reaction raw materials and water as a catalyst. The compound use of ammonium carbonate and ammonium carbamate replaces the existing ammonia water system, greatly reducing the amount of circulating water and ammonia water in the system, thereby reducing the dehydration energy consumption. First, the temperature is raised to 88-90°C and kept warm for 30-35 minutes. Ammonium carbonate undergoes partial thermal decomposition to generate ammonia, carbon dioxide, and water, while ammonium carbamate undergoes complete thermal decomposition to generate nitrogen and carbon dioxide. The CO2 and NH3 generated by the decomposition dynamically participate in the subsequent reaction to form an ammonium carbamate intermediate, adjusting the alkaline environment of the system. Propylene oxide undergoes ring opening under alkaline conditions, and ammonia, as a nucleophilic reagent, preferentially attacks the β-carbon of propylene oxide, that is, the end with smaller steric hindrance, to generate DL-2-aminopropanol. At this temperature, a small amount of ammonia attacks the α-carbon to generate a large amount of mono-isopropanolamine. A sufficient ammonia concentration can inhibit the addition of propylene oxide and water to form propylene glycol. At the high-temperature stage, that is, 1.0 MPa, 100-103°C, the reaction rate increases. At this time, the attack site of ammonia shifts towards the α-carbon, resulting in an increase in the production ratio of mono-isopropanolamine. In addition, the solubility of CO2 decreases, weakening the regeneration of ammonium carbamate and further affecting the product distribution. Strictly control the molar ratio of propylene oxide to ammonium salt. The excess ammonium salt ensures the continuous supply of ammonia, inhibits the deep reaction of propylene oxide, that is, inhibits the formation of di-isopropanolamine and tri-isopropanolamine. At the same time, a high concentration of ammonia is beneficial to the stereoselectivity of β-carbon attack, thereby increasing the proportion of DL-2-aminopropanol. During the reaction process, control the rotation speed at 700-800 r / min to ensure the rapid mixing of ammonia and propylene oxide and avoid side reactions of isomerization caused by too high local concentration.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The production method of isopropanolamine co-producing DL-2-aminopropanol according to the present invention has a simple process, easy-to-control parameters, relatively mild reaction conditions, ensures the large-scale production of mono-isopropanolamine and DL-2-aminopropanol while reducing the generation of by-products di-isopropanolamine and tri-isopropanolamine, and is easy to realize industrial production. Specific embodiments

[0015] The present invention will be further described below in conjunction with embodiments.

[0016] Example 1 The production method of isopropanolamine co-producing DL-2-aminopropanol described in this Example 1 consists of the following steps: Add ammonium carbonate, ammonium carbamate, propylene oxide, and water to a high-pressure reactor and stir evenly. Raise the temperature to 89°C, keep warm at 0.8 MPa for 33 minutes, then raise the temperature to 101°C, and react at 1.0 MPa for 43 minutes. After the reaction is completed, a mixture of isopropanolamine and DL-2-aminopropanol is prepared through post-treatment.

[0017] Among them: The molar ratio of propylene oxide, ammonium carbonate, and ammonium carbamate is 1:3.7:1.1.

[0018] The mass of water accounts for 21% of the total mass of ammonium carbonate, ammonium carbamate, propylene oxide, and water.

[0019] The stirring speed is 750 r / min.

[0020] During the reaction process, the temperature is first raised to 89°C at a heating rate of 2.5°C / min and held for 33 min, and then raised to 101°C at a heating rate of 1.5°C / min and reacted for 43 min.

[0021] The post-treatment is to control the pressure at 0.01 MPa, the temperature at 53°C, and the reaction time at 1.1 h to remove unreacted NH3, CO2, and H2O, and then control the pressure at 0.01 MPa and the temperature at 92°C to collect the gas and condense it with 10°C circulating water to prepare a mixture of DL-2-aminopropanol and isopropanolamine.

[0022] After detection, the product contains 53.28% of mono-isopropanolamine, 42.34% of DL-2-aminopropanol, 2.60% of di-isopropanolamine, and 1.78% of tri-isopropanolamine.

[0023] Example 2 The production method of co-producing isopropanolamine and DL-2-aminopropanol described in this Example 2 consists of the following steps: Add ammonium carbonate, ammonium carbamate, propylene oxide, and water to a high-pressure reactor, stir evenly, heat up to 88°C, hold at 0.8 MPa for 35 min, then heat up to 100°C, and react at 1.0 MPa for 45 min. After the reaction is completed, a mixture of isopropanolamine and DL-2-aminopropanol is prepared through post-treatment.

[0024] Among them: The molar ratio of propylene oxide, ammonium carbonate, and ammonium carbamate is 1:3.5:1.2.

[0025] The mass of water accounts for 20% of the total mass of ammonium carbonate, ammonium carbamate, propylene oxide, and water.

[0026] The stirring speed is 700 r / min.

[0027] During the reaction process, the temperature is first raised to 88°C at a heating rate of 2.5°C / min and held for 35 min, and then raised to 100°C at a heating rate of 1.5°C / min and reacted for 45 min.

[0028] The post-treatment is to control the pressure at 0.01 MPa, the temperature at 50 °C, and the reaction time at 1.2 h to remove unreacted NH3, CO2, and H2O, and then control the pressure at 0.01 MPa and the temperature at 90 °C to collect the gas and condense it with 10 °C circulating water to prepare a mixture of DL-2-aminopropanol and isopropanolamine.

[0029] After detection, mono-isopropanolamine accounts for 52.69% in the product, DL-2-aminopropanol accounts for 41.45%, di-isopropanolamine accounts for 3.84%, and tri-isopropanolamine accounts for 2.02%.

[0030] Example 3 The production method of co-producing DL-2-aminopropanol with isopropanolamine described in this Example 3 comprises the following steps: Add ammonium carbonate, ammonium carbamate, propylene oxide, and water to a high-pressure reactor, stir evenly, heat up to 90 °C, keep the temperature at 0.8 MPa for 30 min, then heat up to 103 °C, and react at 1.0 MPa for 40 min. After the reaction is completed, a mixture of isopropanolamine and DL-2-aminopropanol is prepared through post-treatment.

[0031] Among them: The molar ratio of propylene oxide, ammonium carbonate, and ammonium carbamate is 1:3.8:1.0.

[0032] The mass of water accounts for 22% of the total mass of ammonium carbonate, ammonium carbamate, propylene oxide, and water.

[0033] The stirring speed is 800 r / min.

[0034] During the reaction process, first heat up to 90 °C at a heating rate of 2.5 °C / min and keep the temperature for 30 min, then heat up to 103 °C at a heating rate of 1.5 °C / min and react for 40 min.

[0035] The post-treatment is to control the pressure at 0.01 MPa, the temperature at 55 °C, and the reaction time at 1 h to remove unreacted NH3, CO2, and H2O, and then control the pressure at 0.01 MPa and the temperature at 93 °C to collect the gas and condense it with 10 °C circulating water to prepare a mixture of DL-2-aminopropanol and isopropanolamine.

[0036] After detection, mono-isopropanolamine accounts for 53.15% in the product, DL-2-aminopropanol accounts for 42.07%, di-isopropanolamine accounts for 2.87%, and tri-isopropanolamine accounts for 1.91%.

[0037] Comparative Example 1 The production method of isopropanolamine co-producing DL-2-aminopropanol described in Comparative Example 1 consists of the following steps: Add ammonium carbonate, propylene oxide and water into a high-pressure reactor, stir evenly, heat up to 89 °C, keep warm at 0.8 MPa for 33 min, then heat up to 101 °C and react at 1.0 MPa for 43 min. After the reaction is completed, a mixture of isopropanolamine and DL-2-aminopropanol is prepared through post-treatment.

[0038] Among them: The molar ratio of propylene oxide to ammonium carbonate is 1:3.7.

[0039] The mass of water accounts for 21% of the total mass of ammonium carbonate, propylene oxide and water.

[0040] The stirring speed is 750 r / min.

[0041] During the reaction process, first heat up to 89 °C at a heating rate of 2.5 °C / min and keep warm for 33 min, then heat up to 101 °C at a heating rate of 1.5 °C / min and react for 43 min.

[0042] The post-treatment is to control the pressure at 0.01 MPa, the temperature at 53 °C, and the reaction time at 1.1 h to remove unreacted NH3, CO2 and H2O, and then control the pressure at 0.01 MPa and the temperature at 92 °C to collect the gas and condense it with 10 °C circulating water to prepare a mixture of DL-2-aminopropanol and isopropanolamine.

[0043] After detection, mono-isopropanolamine in the product accounts for 71.79%, DL-2-aminopropanol accounts for 1.24%, di-isopropanolamine accounts for 15.07%, tri-isopropanolamine accounts for 7.23%, and propylene glycol accounts for 4.67%.

[0044] Comparative Example 2 The production method of isopropanolamine co-producing L-2-aminopropanol described in Comparative Example 2 consists of the following steps: Add ammonium carbamate, propylene oxide and water into a high-pressure reactor, stir evenly, heat up to 89 °C, keep warm at 0.8 MPa for 33 min, then heat up to 101 °C and react at 1.0 MPa for 43 min. After the reaction is completed, a mixture of mono-isopropanolamine and L-2-aminopropanol is prepared through post-treatment.

[0045] Among them: The molar ratio of propylene oxide to ammonium carbamate is 1:1.1.

[0046] The mass of water accounts for 21% of the total mass of ammonium carbamate, propylene oxide and water.

[0047] The stirring speed is 750 r / min.

[0048] During the reaction process, the temperature is first raised to 89 °C at a heating rate of 2.5 °C / min and held for 33 min, and then raised to 101 °C at a heating rate of 1.5 °C / min and reacted for 43 min.

[0049] The post-treatment is to control the pressure at 0.01 MPa, the temperature at 53 °C, and the reaction time at 1.1 h to remove unreacted NH3, CO2, and H2O, and then control the pressure at 0.01 MPa and the temperature at 92 °C to collect the gas and condense it with 10 °C circulating water to prepare a mixture of DL-2-aminopropanol and isopropanolamine.

[0050] After testing, the product contains 60.48% of monoisopropanolamine, 6.35% of DL-2-aminopropanol, 17.24% of diisopropanolamine, 10.15% of triisopropanolamine, and 5.78% of propylene glycol.

Claims

1. A production method of co-producing isopropanolamine and DL-2-aminopropanol, characterized in that: The method comprises the following steps: adding ammonium carbonate, ammonium carbamate, propylene oxide and water into a high-pressure reactor and stirring uniformly, heating to 88-90° C., keeping the temperature at 0.8 MPa for 30-35 minutes, then heating to 100-103° C., reacting at 1.0 MPa for 40-45 minutes, and after completion of the reaction, performing post-treatment to prepare a mixture of isopropanolamine and DL-2-aminopropanol.

2. The production method of isopropanolamine co-producing DL-2-aminopropanol according to claim 1, characterized in that: The molar ratio of propylene oxide, ammonium carbonate and ammonium carbamate is 1:3.5-3.8:1.0-1.

2.

3. The production method of isopropanolamine co-producing DL-2-aminopropanol according to claim 1, characterized in that: The mass of water accounts for 20-22% of the total mass of ammonium carbonate, ammonium carbamate, propylene oxide and water.

4. The production method of isopropanolamine co-producing DL-2-aminopropanol according to claim 1, characterized in that: The stirring speed is 700-800r / min.

5. The production method of isopropanolamine co-production of DL-2-aminopropanol according to claim 1, wherein: During the reaction, the temperature was first raised to 88-90°C at a heating rate of 2.5°C / min and kept for 30-35 minutes, and then raised to 100-103°C at a heating rate of 1.5°C / min and reacted for 40-45 minutes.

6. The production method of isopropanolamine co-producing DL-2-aminopropanol according to claim 1, characterized in that: The post-treatment is to control the pressure to 0.01 MPa, the temperature to 50-55°C, the reaction time to 1-1.2 hours, remove unreacted NH3, CO2 and H2O, then control the pressure to 0.01 MPa, the temperature to 90-93°C to collect the gas and condense it with 10°C circulating water to prepare a mixture of DL-2-aminopropanol and isopropanolamine.