Process for the production of dl-2-amino propanol with isopropanolamine

Abstract

The application belongs to the technical field of raw material preparation, and particularly relates to a production method of co-producing isopropanolamine and DL-2-aminopropanol. The production method of co-producing isopropanolamine and DL-2-aminopropanol comprises the following steps: adding ammonium carbonate, ammonium carbamate, propylene oxide and water into a high-pressure reaction kettle, stirring until uniform, heating to 88-90 DEG C, keeping at 0.8 MPa for 30-35 min, then heating to 100-103 DEG C, reacting at 1.0 MPa for 40-45 min, and after the reaction is completed, post-treatment is performed to obtain a mixture of isopropanolamine and DL-2-aminopropanol. The production method of co-producing isopropanolamine and DL-2-aminopropanol is simple in process, easy to control in parameters, and relatively mild in reaction conditions, so that a large amount of isopropanolamine and DL-2-aminopropanol is generated while the generation of by-products diisopropanolamine and triisopropanolamine is reduced.

Description

TECHNICAL FIELD

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

[0002] DL-2-aminopropanol is a colorless viscous liquid at room temperature, and has a molecular formula of C3H9NO, a molecular weight of 75, and a CAS number of 6168-72-5. DL-2-aminopropanol is an important intermediate for synthesis of levofloxacin. At present, the method for synthesizing DL-2-aminopropanol mainly uses DL-2-aminopropanoic acid as a starting material, and then DL-2-aminopropanol is prepared through two steps of condensation and reduction. The difference lies in the use of different reducing agents. The reducing agents used mainly include LiBH4, NaBH4 and BFR resin. These reducing agents have different shortcomings, such as difficult post-treatment after using LiBH4, high price, certain danger and unsatisfactory yield, large use amount of NaBH4, increased production cost and BFR resin needing pretreatment, thus increasing the process.

[0003] Isopropanolamine includes three homologous products of 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 mono-isopropanolamine. Mono-isopropanolamine is widely used in electronic chemicals and detergent industry, and is one of important pharmaceutical synthesis intermediates.

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

[0005] Mono-isopropanolamine and DL-2-aminopropanol are both very important chemical raw materials. The existing production methods of both have drawbacks, but they can be converted through chemical reaction. Therefore, how to prepare mono-isopropanolamine co-production of DL-2-aminopropanol becomes a technical problem to be solved. SUMMARY

[0006] The purpose of the present application is to provide a production method of isopropanolamine co-production of DL-2-aminopropanol. The method has mild reaction conditions and simple process, and can ensure the generation of a large amount of mono-isopropanolamine and DL-2-aminopropanol while reducing the generation of by-products di-isopropanolamine and tri-isopropanolamine.

[0007] The production method of isopropanolamine and DL-2-aminopropanol produced by the application comprises the following steps: adding ammonium carbonate, ammonium carbamate, propylene oxide and water into a high-pressure reaction kettle, stirring them uniformly, heating to 88-90 DEG C, keeping the temperature for 30-35 min under 0.8 MPa, then heating to 100-103 DEG C, reacting for 40-45 min under 1.0 MPa, and after the reaction is completed, preparing a mixture of isopropanolamine and DL-2-aminopropanol through post-treatment.

[0008] wherein:

[0009] The molar ratio of propylene oxide, ammonium carbonate and ammonium carbamate is 1:3.5-3.8:1.0-1.2.

[0010] The mass of water accounts for 20-22% of the total mass of ammonium carbonate, ammonium carbamate, propylene oxide and water.

[0011] The stirring speed is 700-800 r / min.

[0012] In the reaction process, first, the temperature is raised to 88-90 DEG C at a rate of 2.5 DEG C / min, keeping the temperature for 30-35 min, then the temperature is raised to 100-103 DEG C at a rate of 1.5 DEG C / min, and reacting for 40-45 min.

[0013] The post-treatment is to control the pressure to be 0.01 MPa, the temperature to be 50-55 DEG C, and the reaction time to be 1-1.2 h, remove the unreacted NH3, CO2 and H2O, then control the pressure to be 0.01 MPa, the temperature to be 90-93 DEG C, collect the gas, and prepare the mixture of DL-2-aminopropanol and isopropanolamine through condensation by 10 DEG C circulating water.

[0014] The production method of isopropyl alcohol amine and DL-2-aminopropanol produced by the application uses propylene oxide, ammonium carbonate and ammonium carbamate as reaction raw materials, and water as a catalyst, and ammonium carbonate and ammonium carbamate are used in combination to replace the existing ammonia system, thereby greatly reducing the use amount of system circulating water and ammonia water, and reducing the dehydration energy consumption. First, the temperature is raised to 88-90 DEG C and kept for 30-35 min, the ammonium carbonate is partially thermally decomposed to generate ammonia, carbon dioxide and water, and the ammonium carbamate is completely thermally decomposed to generate nitrogen and carbon dioxide, and the CO2 and NH3 generated by the decomposition dynamically participate in the subsequent reaction to form an ammonium carbamate intermediate, and the alkaline environment of the system is adjusted. The propylene oxide is opened under alkaline conditions, and the ammonia gas preferentially attacks the beta-carbon of the propylene oxide, i.e. the end with smaller steric hindrance, to generate DL-2-aminopropanol, and at this temperature, a small amount of ammonia gas attacks the alpha-carbon to generate a large amount of mono-isopropyl alcohol amine, and sufficient ammonia gas concentration can inhibit the addition of propylene oxide and water to generate propylene glycol, and in the high temperature stage, i.e. 1.0 MPa, 100-103 DEG C, the reaction rate is accelerated, at this time, the attack site of ammonia gas shifts to the alpha-carbon, resulting in the increase of the generation proportion of mono-isopropyl alcohol amine. In addition, the solubility of CO2 is reduced, which weakens the regeneration of ammonium carbamate, and further affects the product distribution. The molar ratio of propylene oxide to ammonium salt is strictly controlled, the excess of ammonium salt ensures the continuous supply of ammonia gas, and the deep reaction of propylene oxide is inhibited, i.e. the generation of diisopropyl alcohol amine and triisopropyl alcohol amine is inhibited, and at the same time, the high concentration of ammonia gas is beneficial to the stereoselectivity of beta-carbon attack, thereby improving the proportion of DL-2-aminopropanol. The rotation speed is controlled to 700-800 r / min during the reaction process to ensure the rapid mixing of ammonia gas and propylene oxide, and avoid the isomerization side reaction caused by local high concentration.

[0015] Compared with the prior art, the application has the following beneficial effects:

[0016] The production method of isopropyl alcohol amine and DL-2-aminopropanol produced by the application has the advantages of simple process, easy control of parameters, relatively mild reaction conditions, ensuring the generation of a large amount of mono-isopropyl alcohol amine and DL-2-aminopropanol while reducing the generation of by-products diisopropyl alcohol amine and triisopropyl alcohol amine, and easy industrial production. DETAILED DESCRIPTION

[0017] The application will be further described below in combination with examples.

[0018] Example 1

[0019] The production method of isopropanolamine and DL-2-aminopropanol in the embodiment 1 comprises the following steps: adding ammonium carbonate, ammonium carbamate, propylene oxide and water into a high-pressure reaction kettle, stirring uniformly, heating to 89 DEG C, keeping for 33 min under 0.8 MPa, then heating to 101 DEG C, reacting for 43 min under 1.0 MPa, and preparing the mixture of isopropanolamine and DL-2-aminopropanol through post-treatment after the reaction is completed.

[0020] Wherein:

[0021] The molar ratio of propylene oxide, ammonium carbonate and ammonium carbamate is 1:3.7:1.1.

[0022] The mass of water accounts for 21% of the total mass of ammonium carbonate, ammonium carbamate, propylene oxide and water.

[0023] The stirring speed is 750 r / min.

[0024] During the reaction, the temperature is first increased to 89 DEG C at a rate of 2.5 DEG C / min, kept for 33 min, then increased to 101 DEG C at a rate of 1.5 DEG C / min, and reacted for 43 min.

[0025] The post-treatment is to remove unreacted NH3, CO2 and H2O by controlling the pressure to be 0.01 MPa, the temperature to be 53 DEG C and the reaction time to be 1.1 h, then collecting the gas by controlling the pressure to be 0.01 MPa and the temperature to be 92 DEG C, and condensing the collected gas by 10 DEG C circulating water to prepare the mixture of DL-2-aminopropanol and isopropanolamine.

[0026] Through detection, the content of mono-isopropanolamine in the product is 53.28%, the content of DL-2-aminopropanol is 42.34%, the content of di-isopropanolamine is 2.60%, and the content of tri-isopropanolamine is 1.78%.

[0027] Embodiment 2

[0028] The production method of isopropanolamine and DL-2-aminopropanol in the embodiment 2 comprises the following steps: adding ammonium carbonate, ammonium carbamate, propylene oxide and water into a high-pressure reaction kettle, stirring uniformly, heating to 88 DEG C, keeping for 35 min under 0.8 MPa, then heating to 100 DEG C, reacting for 45 min under 1.0 MPa, and preparing the mixture of isopropanolamine and DL-2-aminopropanol through post-treatment after the reaction is completed.

[0029] Wherein:

[0030] The molar ratio of propylene oxide, ammonium carbonate and ammonium carbamate is 1:3.5:1.2.

[0031] The mass of water accounts for 20% of the total mass of ammonium carbonate, ammonium carbamate, propylene oxide and water.

[0032] The stirring speed is 700 r / min.

[0033] During the reaction, first, the temperature is raised to 88℃ at a rate of 2.5℃ / min and kept for 35 min, then the temperature is raised to 100℃ at a rate of 1.5℃ / min and kept for 45 min.

[0034] The post-treatment is to remove the unreacted NH3, CO2 and H2O by controlling the pressure to be 0.01 MPa and the temperature to be 50℃ for 1.2 h, and then to collect the gas by controlling the pressure to be 0.01 MPa and the temperature to be 90℃ to prepare the mixture of DL-2-aminopropanol and isopropanolamine.

[0035] It is detected that the isopropanolamine accounts for 52.69%, the DL-2-aminopropanol accounts for 41.45%, the diisopropanolamine accounts for 3.84%, and the triisopropanolamine accounts for 2.02% in the product.

[0036] Example 3

[0037] The production method of isopropanolamine and DL-2-aminopropanol in the example 3 comprises the following steps: adding the ammonium carbonate, the ammonium carbamate, the propylene oxide and the water into a high-pressure reactor and stirring them uniformly, raising the temperature to 90℃, keeping the temperature for 30 min under 0.8 MPa, then raising the temperature to 103℃, reacting for 40 min under 1.0 MPa, and preparing the mixture of isopropanolamine and DL-2-aminopropanol by post-treatment after the reaction is completed.

[0038] In the formula, n is 1.0-1.2.

[0039] The molar ratio of the propylene oxide, the ammonium carbonate and the ammonium carbamate is 1:3.8:1.0.

[0040] The mass of the water accounts for 22% of the total mass of the ammonium carbonate, the ammonium carbamate, the propylene oxide and the water.

[0041] The stirring speed is 800 r / min.

[0042] During the reaction, first, the temperature is raised to 90℃ at a rate of 2.5℃ / min and kept for 30 min, then the temperature is raised to 103℃ at a rate of 1.5℃ / min and kept for 40 min.

[0043] The post-treatment is to remove the unreacted NH3, CO2 and H2O by controlling the pressure to be 0.01 MPa and the temperature to be 55℃ for 1 h, and then to collect the gas by controlling the pressure to be 0.01 MPa and the temperature to be 93℃ to prepare the mixture of DL-2-aminopropanol and isopropanolamine.

[0044] The product was detected, mono-isopropanolamine accounted for 53.15%, DL-2-aminopropanol accounted for 42.07%, di-isopropanolamine accounted for 2.87%, and tri-isopropanolamine accounted for 1.91%.

[0045] Comparative Example 1

[0046] The production method of isopropanolamine and DL-2-aminopropanol in the comparative example 1 consists of the following steps: adding ammonium carbonate, propylene oxide and water into a high-pressure reaction kettle, stirring uniformly, heating to 89℃, keeping at 0.8MPa for 33min, then heating to 101℃, reacting at 1.0MPa for 43min, and then preparing the mixture of isopropanolamine and DL-2-aminopropanol after post-treatment.

[0047] Among them:

[0048] The molar ratio of propylene oxide to ammonium carbonate is 1:3.7.

[0049] The mass of water accounts for 21% of the total mass of ammonium carbonate, propylene oxide and water.

[0050] The stirring speed is 750r / min.

[0051] During the reaction, first heat to 89℃ at a rate of 2.5℃ / min for 33min, then heat to 101℃ at a rate of 1.5℃ / min for 43min.

[0052] The post-treatment is to control the pressure at 0.01MPa, the temperature at 53℃, and the reaction time at 1.1h to remove unreacted NH3, CO2 and H2O, and then control the pressure at 0.01MPa, the temperature at 92℃ to collect the gas to prepare the mixture of DL-2-aminopropanol and isopropanolamine condensed by 10℃ circulating water.

[0053] The product was detected, mono-isopropanolamine accounted for 71.79%, DL-2-aminopropanol accounted for 1.24%, di-isopropanolamine accounted for 15.07%, tri-isopropanolamine accounted for 7.23%, and propylene glycol accounted for 4.67%.

[0054] Comparative Example 2

[0055] The production method of isopropanolamine and DL-2-aminopropanol in the comparative example 2 consists of the following steps: adding ammonium carbamate, propylene oxide and water into a high-pressure reaction kettle, stirring uniformly, heating to 89℃, keeping at 0.8MPa for 33min, then heating to 101℃, reacting at 1.0MPa for 43min, and then preparing the mixture of mono-isopropanolamine and L-2-aminopropanol after post-treatment.

[0056] Among them:

[0057] The molar ratio of propylene oxide to ammonium carbamate is 1:1.1.

[0058] The mass of water accounts for 21% of the total mass of ammonium carbamate, propylene oxide and water.

[0059] The stirring speed is 750 r / min.

[0060] During the reaction, first, the temperature is raised to 89℃ at a rate of 2.5℃ / min and kept for 33 min, then the temperature is raised to 101℃ at a rate of 1.5℃ / min and kept for 43 min.

[0061] The post-treatment is to remove unreacted NH3, CO2 and H2O by controlling the pressure at 0.01 MPa and the temperature at 53℃ for 1.1 h, then to collect the gas by controlling the pressure at 0.01 MPa and the temperature at 92℃ to prepare a mixture of DL-2-aminopropanol and isopropanolamine by condensation with 10℃ circulating water.

[0062] It is detected that in the product, mono-isopropanolamine accounts for 60.48%, DL-2-aminopropanol accounts for 6.35%, di-isopropanolamine accounts for 17.24%, tri-isopropanolamine accounts for 10.15%, and propylene glycol accounts for 5.78%.

Claims

1. A process for the production of isopropanolamine co-producing DL-2-aminopropanol, characterized by: The preparation method comprises the following steps: adding ammonium carbonate, ammonium carbamate, propylene oxide and water into a high-pressure reaction kettle, stirring uniformly, heating to 88-90 DEG C, keeping the temperature for 30-35 min under 0.8 MPa, then heating to 100-103 DEG C, reacting for 40-45 min under 1.0 MPa, and preparing a mixture of isopropanolamine and DL-2-aminopropanol through post-treatment after the reaction is completed; The molar ratio of propylene oxide, ammonium carbonate and ammonium carbamate is 1:3.5-3.8:1.0-1.

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

2. The process for the production of isopropanolamine co-producing DL-2-aminopropanol according to claim 1, characterized by: The stirring speed is 700-800 r / min.

3. The process for the production of isopropanolamine co-producing DL-2-aminopropanol according to claim 1, characterized by: In the reaction process, the temperature is first increased to 88-90 DEG C at a rate of 2.5 DEG C / min, kept for 30-35 min, then increased to 100-103 DEG C at a rate of 1.5 DEG C / min, and reacted for 40-45 min.

4. The process for the production of isopropanolamine co-producing DL-2-aminopropanol according to claim 1, characterized by: The post-treatment is controlling the pressure to be 0.01 MPa, the temperature to be 50-55 DEG C, and the reaction time to be 1-1.2 h, removing unreacted NH3, CO2 and H2O, then controlling the pressure to be 0.01 MPa, the temperature to be 90-93 DEG C, collecting gas, and condensing to prepare the mixture of DL-2-aminopropanol and isopropanolamine through 10 DEG C circulating water.