KR100730460B1 - Method for preparing 2-amino-2-methyl-1,3-propanediol continuously using heterogeneous catalysts - Google Patents

Abstract

The present invention is hydrogenated by 2-nitro-2-methyl-1,3-propanediol in a fixed bed reactor packed with a heterogeneous catalyst. The present invention relates to a method for continuously preparing 2-methyl-2-propanediol (2-amino-2-methyl-1,3-propanediol), more specifically 2-nitro-2-methyl-1,3- At least one selected from the group consisting of ruthenium (Ru), palladium (Pd), platinum (Pt), nickel (Ni), rhodium (Rh), iridium (Ir) and osmium (Os) after dissolving propanediol in a solvent Using a fixed bed reactor packed with the above metals or catalysts supported by the inorganic oxide carrier at 1 to 20% by weight of these metals, a reaction temperature of 0 to 150 ° C., a reaction pressure of 15 to 2,500 psig and a 0.1 to 10 h ⁻¹ The present invention relates to a method for continuously producing 2-amino-2-methyl-1,3-propanediol by hydrogenation at a weight hourly space velocity. According to the method of the present invention, 2-amino-2-methyl-1,3-propanediol, which is a pharmaceutical intermediate, can be obtained in high purity and high yield in comparison with a conventional batch production method, which also does not use harmful substances. It is an economical process that can be industrially mass-produced by increasing the production efficiency per hour because it is environmentally friendly and relatively simple.

Heterogeneous catalyst, fixed bed reactor, 2-nitro-2-methyl-1,3-propanediol, hydrogenated, 2-amino-2-methyl-1,3-propanediol

Description

Method for preparing 2-amino-2-methyl-1,3-propanediol continuously using heterogeneous catalysts

The present invention relates to a continuous production method of 2-amino-2-methyl-1,3-propanediol using a heterogeneous catalyst, more specifically 2-nitro-2-methyl-1 as shown in Scheme 1 below. The present invention relates to a method of continuously producing high yield and high purity of 2-amino-2-methyl-1,3-propanediol through hydrogenation of, 3-propanediol using a heterogeneous catalyst.

Pure 2-amino-2-methyl-1,3-propanediol is widely used as an intermediate material for pharmaceutical preparations, cosmetic preparations, agriculture, chemicals, and the like.                         

A method of using a nickel (Ni) catalyst in the presence of methanol solvents of US Pat. Nos. 1,264,518 and 3,546,298, and a method of using ruthenium (Ru / C) and Raney Ni catalysts (Zh. Org. Khim, 8) (3), 527-8, 1972) describe a batch production process, but they require a large reactor size, increased reaction selectivity due to increased reaction time, and reduced reaction selectivity. And the manufacturing process, such as the need to remove the catalyst with a filter has a complex disadvantage.

U.S. Patent No. 3,564,057 discloses the use of a Lenny nickel catalyst in the presence of a water solvent, in order to reduce the production of side reactants such as secondary and tertiary amine compounds produced during the reduction of nitro compounds. Although it was possible to obtain a reaction selectivity at a level of 90% or more using the above, the patent is also an environmentally friendly manufacturing process because a large amount of waste is generated by using an excessive amount of an amine compound which is a batch production method and a hazardous substance.

In addition, U.S. Patent No. 4,830,717 (European Publication No. 287419) applies an electrochemical reduction method to a reduction reaction of converting a nitro compound to an amino compound, thereby applying copper (Cu) or zinc (Zn) -cadmium (Cd). Metals such as binary catalyst and platinum are coated on a cathode electrode plate and reacted with a power source of 5 to 6 volts under a solvent system in which water and methanol are mixed. The patents have a low production yield of about 63%. In addition, the production cost of the reactor is high and economical is low.

Therefore, most of the processes used in the above-described prior art adopt a batch process that is highly likely to generate side reactions, resulting in low productivity, a large amount of waste using harmful reaction reagents, and complicated processes, resulting in low overall yield. It is difficult to apply industrially because it is impossible to produce. Therefore, the process is simple, mass production is possible, and there is a demand for an environment-friendly process due to the low amount of waste generated.

Accordingly, in the present invention, in order to solve the problems as described above, the development of heterogeneous catalyst that can easily commercial production of 2-amino-2-methyl-1,3-propanediol and increase the production efficiency and high yield and As a result of extensive research for the development of a reaction system for obtaining high purity, 2-nitro-2-methyl-1,3-propanediol was prepared in the presence of a heterogeneous catalyst and an organic solvent in which a noble metal was supported on an inorganic oxide carrier, and fixed-bed continuous High purity and high yield of 2-amino-2-methyl-1,3-propanediol was continuously obtained in the course of hydrogenation to the reactor, and based on this, the present invention was completed.

It is therefore an object of the present invention to provide a process for the continuous production of high purity and high yield of 2-amino-2-methyl-1,3-propanediol using a fixed bed reactor under heterogeneous catalysts.

In order to achieve the above object, the method for preparing 2-amino-2-methyl-1,3-propanediol of the present invention is dissolved 2-nitro-2-methyl-1,3-propanediol in a solvent, 1 to 20 or at least one metal selected from the group consisting of ruthenium (Ru), palladium (Pd), platinum (Pt), nickel (Ni), rhodium (Rh), iridium (Ir) and osmium (Os) Hydrogenated at a reaction temperature of 0 to 150 ° C., a reaction pressure of 15 to 2,500 psig, and an hourly weight space velocity of 0.1 to 10 h ⁻¹ using a fixed bed reactor packed with a catalyst supported on an inorganic oxide carrier by weight% Is done.

Hereinafter, the present invention will be described in more detail.

The present invention is hydrogenated by reaction of 2-nitro-2-methyl-1,3-propanediol represented by the following Chemical Formula 1 using a fixed bed reactor in the presence of a heterogeneous catalyst system in which a metal or a metal is supported on a carrier. The present invention relates to a method for continuously producing 2-amino-2-methyl-1,3-propanediol in high yield and high purity, and 2-amino-2 having little by-product according to heterogeneous catalyst and reaction conditions according to the present invention. -Methyl-1,3-propanediol could be obtained.

According to the present invention, the hydrogenation reaction first dissolved 2-nitro-2-methyl-1,3-propanediol represented by the formula (1) in a solvent. The solvent can dissolve 2-nitro 2-methyl-1,3-propanediol well, and can be smoothly supplied to the reactor, and easily remove the heat of reaction generated by the hydrogenation reaction exothermic reaction, Non-reacting with 2-nitro-2-methyl-1,3-propanediol and hydrogen, methyl alcohol, ethyl alcohol, normal propyl alcohol, isopropyl alcohol, normal butyl alcohol, secondary-butyl alcohol, and tert- It is selected from the group consisting of butyl alcohol, Preferably it is methyl alcohol. In addition, the 2-nitro-2-methyl-1,3-propanediol is dissolved in the solvent at a concentration of 1 to 50% by weight, preferably 2 to 40% by weight, and the concentration is less than 1% by weight. There is a problem that the production of side reactants increases, the conversion rate is reduced if it exceeds 50% by weight.

The catalyst used in the present invention is at least one metal selected from the group consisting of ruthenium (Ru), palladium (Pd), platinum (Pt), nickel (Ni), rhodium (Rh), iridium (Ir) and osmium (Os) Alternatively, these metals are filled with a catalyst supported on the inorganic oxide carrier at 1 to 20% by weight, and the metal is preferably ruthelium or palladium, and the supported amount is 5 to 15% by weight. When the amount of the catalyst supported on the inorganic oxide carrier is less than 1% by weight, the hydrogenation activity and the selectivity of 2-methyl-2-amino-1,3-propanediol are reduced. There is a problem that the economics of the process is lowered due to the price.

Meanwhile, the inorganic oxide carrier on which the metal is supported may be alumina, silica, silica-alumina, zirconia, titania, zeolite, and molecular sieve. ), Preferably alumina. In addition, the shape of the carrier particles may be circular, cylindrical, granular, or any type of pellets, but in order to have suitable mechanical properties, pellets of circular or cylindrical shape may be used. It is preferably molded into the form of)

As a method of supporting the noble metal on the carrier, any method such as incipient wetness impregnation, excess water impregnation, spraying or physical mixing can be used.

The catalyst on which the metal is supported must be calcined for 2 hours or more in an air atmosphere or an inert gas atmosphere, wherein the temperature is maintained at 300 to 700 ° C, more preferably 300 to 550 ° C. If the firing temperature is less than 300 ℃ firing is incomplete and the precursor decomposition of the metal used during the metal support is insufficient, if the firing temperature exceeds 700 ℃ dispersibility of the metal is lowered, the catalyst can not exhibit the proper performance. After filling the fixed catalyst in a fixed bed reactor, the catalyst must be reduced with hydrogen prior to the addition of the reactants, and the reducing conditions are maintained at 50 to 400 ° C. for at least 2 hours depending on the type of the supported metal. shall.

In the present invention, a higher yield compared to the reaction space time can be obtained, the catalyst can be repeatedly reused without further processing, and a fixed bed reaction system is used as a method for greatly simplifying the process. In the fixed bed reaction system, there is no restriction on the shape of the reactor or the direction of the input and flow of the reactants, but in order to facilitate the contact between the reactants, the reactants hydrocarbon and hydrogen flow together from the top to the bottom of the reactor, and the reactants are evenly distributed throughout the reactor. Preference is given to using reactors in the form of trickle-beds with equipment which can be used.

Hydrogenation of 2-nitro-2-methyl-1,3-propanediol using the fixed bed reactor to produce 2-amino-2-methyl-1,3-propanediol in high yield and high purity is 0 to 150 ° C. reaction temperature, 15 to be performed in a reaction pressure of 0.1 to 10h ^-1 and a weight hourly space velocity of the 2,500psig, preferably from 20 to reaction temperature of 100 ℃, of from 100 to 1,500psig reaction pressure, and from 0.1 to 6h ^{- It} is carried out at a weight space velocity per hour of ¹ . If the reaction temperature is less than 0 ℃, the reaction does not occur, if it exceeds 150 ℃ can not obtain the desired reactants due to the thermal decomposition of the raw material, if the reaction pressure is less than 15 psig conversion rate is lowered, if the pressure exceeds 2,500 psig This makes the reactor operation difficult. In addition, when the weight hourly space velocity per hour is less than 0.1h ^-1 there is a problem that the generation of side reactants is increased, the conversion rate is lowered if it exceeds 10h ^-1 .

Therefore, when the reaction conditions are out of the range as described above, the hydrogenation reaction selectivity of 2-amino-2-methyl-1,3-propanediol is lowered, the production yield is lowered, and the deactivation rate of the catalyst is increased, It is impossible to obtain the advantages of the continuous manufacturing process proposed in the present invention.

The hydrogen added in the hydrogenation reaction according to the invention is 2-nitro- to completely convert 2-nitro-2-methyl-1,3-propanediol to 2-amino-2-methyl-1,3-propanediol. The molar ratio of hydrogen to 2-methyl-1,3-propanediol is preferably 4.0 or more, but is maintained at 1 to 10 in consideration of the economics of the process. Meanwhile, hydrogen which is not used for the reaction and passes through the reactor is recompressed and circulated to the reactor.

The reaction product exiting the reactor is sent to a device for recovering the solvent, where at least some of the solvent is separated from the rest of the reaction product. Such a recovery device may use any type of device such as a distillation column or a flash vaporizer. The product or concentrate exiting the bottom of the solvent recovery unit is sent to a vacuum distillation unit.

As described above, hydrogenation of 2-nitro-2-methyl-1,3-propanediol in a fixed bed reactor in the presence of a heterogeneous catalyst system yields 2-amino-2-methyl-1,3-propanediol with little byproducts. A high yield could be obtained and the process could be simplified.

Hereinafter, the present invention will be described in detail with reference to Examples, but the scope of the present invention is not limited to the following Examples.

Preparation Example 1

Preparation of Ruthenium Catalyst

200 cc of distilled water was added to a 500 cc flask, and 18 g of ruthenium chloride (RuCl ₃ ) was added thereto to prepare an aqueous ruthenium chloride solution. After putting 100 g (1/8 inch) of spherical alumina in a metal carrying container equipped with a motor capable of adjusting the rotation speed, the ruthenium solution was evenly dispersed in the alumina while rotating the motor at 200 rpm.

After the addition of the ruthenium solution was completed, the motor was further rotated at the same speed for about 60 minutes, and then the ruthenium-supported catalyst was transferred to a muffle furnace and calcined at 500 ° C. for 3 hours in an air atmosphere. After firing, the content of ruthenium in the catalyst was 7.0% by weight as measured by x-ray fluorescence.

Preparation Example 2

Preparation of Palladium Catalyst

50 cc of secondary distilled water was added to a 100 cc flask, and 6.35 g of palladium nitro compound (Aldrich, Pd (NO ₃ ) ₂ ) was added thereto to prepare an aqueous solution of palladium nitro. 100 g of spherical alumina was placed in a metal carrying container equipped with a motor capable of adjusting the rotation speed, and the palladium chloride solution was evenly dispersed in the alumina while rotating the motor at a speed of 50 rpm.

After the addition of the palladium nitro compound solution was completed, the motor was further rotated at the same speed for about 30 minutes, and then, the catalyst carrying the palladium nitro compound was transferred to a muffle furnace and calcined at 400 ° C. for 3 hours in an air atmosphere. After calcination, the content of palladium in the catalyst was measured by X-ray fluorescence and found to be 10% by weight.

Example 1-4

Continuous Production Reaction of 2-amino-2-methyl-1,3-propanediol

10 g of the catalyst obtained according to Preparation Example 1 was charged in a continuous high pressure reactor made of 316 stainless steel, and the catalyst in the reactor was raised to 350 ° C. at a temperature rising rate of 2 ° C. per minute in a hydrogen atmosphere, followed by reduction for 6 hours. The reactor was then cooled and blown inside with nitrogen. 100 sccm of hydrogen was flowed while raising the temperature inside the reactor at a temperature rising rate of 1 ° C. per minute from room temperature to the reaction temperature. The injected amount of hydrogen was increased twice as much as required for the reaction, and 2-nitro-2-methyl-1,3-propanediol was dissolved in an organic solvent to be 10% by weight, and injected into a continuous reactor. At this time, the reaction results according to the injection amount of the reactants and the change of conditions in the reactor are shown in Table 1 below. The reaction product was taken every 4 hours and analyzed by FID of gas chromatograph (50 m × 0.2 mm × 0.5 m, beta-DEX column).

Temperature, ℃ Pressure, psig WHSV, h-1 Conversion rate,% Selectivity,% ¹⁾ Example 1 80 900 1.0 100 95 Example 2 50 900 1.0 85 90 Example 3 120 900 1.0 100 75 Example 4 80 500 1.0 82 94

1) Reaction selectivity of 2-amino-2-methyl-1,3-propanediol

As shown in Table 1, it showed generally excellent conversion and selectivity, and in particular, at a temperature of 80 ° C., a pressure of 900 psig, and a weight hourly space velocity (WHSV) of 1.0 h ⁻¹ to a conversion rate of 100% and a selectivity of 95%. The best results were found.

Example 5-8

Hydrogenation of 2-nitro-2-methyl-1,3-propanediol using methanol as a solvent was carried out in the same manner as in Example 1, the temperature 80 ℃, hydrogen pressure 900psig, and the hourly weight space velocity (WHSV) 1.0h ^-1 The reaction was carried out under the conditions of, and the reaction results according to various kinds of catalysts used were shown in Table 2 below. The catalysts used are commercially available catalysts and catalysts prepared by the present invention.

catalyst Conversion rate,% Selectivity,% ²⁾ Example 5 7% Ru / Al ₂ O ₃ 100 95.0 Example 6 ¹⁾ 5% Pd / C 98.0 88.2 Example 7 10% Pd / Al ₂ O ₃ 99.0 91.0 Example 8 5% Pd / Al ₂ O ₃ 97.5 91.5

1) Aldrich Reagent Class

2) Reaction Selectivity of 2-amino-2-methyl-1,3-propanediol

As shown in Table 2, the excellent conversion and selectivity were generally shown, but in particular, when the catalyst of 7% Ru / Al ₂ O ₃ was used, the conversion was 100% and the selectivity was 95.0%.

Example 9

Continuous reaction and recovery of 2-amino-2-methyl-1,3-propanediol

50 g of the catalyst obtained according to Preparation Example 1 was used, and the reaction was carried out in the same reactor as the reactor illustrated in Examples 1-4. During the reaction, the pressure was maintained at 900 psig, and after the reaction was conducted for 100 hours under the same conditions, 5 L of a solution containing 95% by weight of 2-amino-2-methyl-1,3-propanediol was obtained. . In order to recover 2-amino-2-methyl-1,3-propanediol crystals from the solution, the solution was injected into a 10 L glass reactor equipped with a reduced pressure distillation apparatus. The temperature of the glass reactor was distilled under reduced pressure at 55 ° C. and 100 mbar at a heating rate of 5 ° C. per minute to evaporate about 90% of methanol in the solution, and then filtered to remove sodium chloride (NaCl). 4 L of isopropyl alcohol was introduced into the glass reactor, and the temperature of the glass reactor was distilled under reduced pressure at 70 ° C. and 100 mbar at a temperature increase rate of 5 ° C. per minute to obtain 90 weights of 2-amino-2-methyl-1,3-propanediol. After removing isopropyl alcohol until it is more than%, separated under reduced pressure using a thin film distillation apparatus at 125 to 130 ℃, 0.5 to 1mbr conditions and crystallized with a butanol solvent to yield 2-amino-2-methyl with a total yield of 80%, purity 99.2% -1,3-propanediol crystals were obtained

As described above, the method for preparing pure 2-amino-2-methyl-1,3-propanediol from 2-nitro-2-methyl-1,3-propanediol according to the present invention is compared to the conventional batch production method. High yield, high productivity, eco-friendly process without harmful reactants, economical by regeneration and continuous use of catalyst, and complex post-treatment process such as removing catalyst by filter, It is possible to continuously prepare 2-amino-2-methyl-1,3-propanediol in high yield and high purity with a simple manufacturing process.

Claims (7)

After 2-nitro-2-methyl-1,3-propanediol is dissolved in a solvent, ruthenium (Ru), palladium (Pd), platinum (Pt), nickel (Ni), rhodium (Rh), and iridium (Ir) And at least one metal selected from the group consisting of osmium (Os) or a fixed bed reactor packed with a catalyst supported by the inorganic oxide carrier at 1 to 20% by weight of these metals, at a reaction temperature of 0 to 150 ° C, and 15 to 150 ° C. A process for the continuous production of 2-amino-2-methyl-1,3-propanediol, characterized in that the hydrogenation reaction at a reaction pressure of 2,500 psig and a weight hourly space velocity of 0.1 to 10 h ⁻¹ . The method of claim 1, wherein the solvent is selected from the group consisting of methyl alcohol, ethyl alcohol, normal propyl alcohol, isopropyl alcohol, normal butyl alcohol, secondary-butyl alcohol, and tert-butyl alcohol. . The method of claim 1 or 2, wherein the 2-nitro-2-methyl-1,3-propanediol is dissolved in the solvent at a concentration of 1 to 50% by weight. The method of claim 1, wherein the inorganic oxide carrier is selected from the group consisting of alumina, silica, silica-alumina, zirconia, titania, zeolite and molecular sieve. The method of claim 1, wherein the catalyst is characterized in that 5 to 15% by weight of ruthenium or palladium supported. The method of claim 1, wherein the molar ratio of 2-nitro-2-methyl-1,3-propanediol / hydrogen used in the hydrogenation reaction is 1 to 10. The method of claim 1, wherein the hydrogenation reaction is performed at a reaction temperature of 20 to 100 ° C., a reaction pressure of 100 to 1,500 psig, and a weight hourly space velocity of 0.1 to 6 h ⁻¹ .