A continuous flow process for the preparation of cobalamin sulfite or a salt thereof and uses thereof

Abstract

This invention provides a continuous flow preparation method for cobalt sulfite or its salts, and its applications. The preparation method includes: S1 loading a compound of formula III onto an adsorbent as a stationary phase; S2 using an aqueous solution of sulfite as a mobile phase, conveying the mobile phase liquid through the stationary phase, and obtaining cobalt sulfite on the adsorbent through a continuous flow ion exchange reaction. This invention, by loading cyanocobalamin onto the adsorbent as a stationary phase and using a sulfite solution as the mobile phase, allows the flowing solution to carry away cyano ions, disrupting the original ion exchange equilibrium and causing the reaction to irreversibly proceed towards cobalt sulfite. This allows cyanocobalamin to be almost completely converted to cobalt sulfite, greatly reducing the residual cyanocobalamin. The preparation method of this invention can provide high-purity cobalt sulfite, providing high-quality raw materials for the preparation of drugs such as hydroxycobalamin, and reducing the risk of excessive impurities.

Description

Technical Field

[0001] This invention relates to the field of pharmaceuticals and chemicals. Specifically, this invention provides a continuous flow preparation method for cobalt sulfite or its salts and its applications. Background Technology

[0002] Vitamin B 12 Cobalamin and its derivatives, collectively known as cobalamin, are essential water-soluble vitamins for the human body. Cobalamin is a polycyclic compound consisting of a corrin ring containing trivalent cobalt at its center, a benzimidazole nucleotide, and an R-coordinating group. Figure 1 As shown. Common cobalamins are classified according to the different R groups, including cyanocobalamin (vitamin B12). 12 Cobalamin contains cyanocobalamin and hydroxycobalamin, among which cyanocobalamin and hydroxycobalamin are the main molecular forms of cobalamin transported in the human body, but the active forms that constitute coenzymes (related to cell replication and division) are methylcobalamin and 5-adenosylcobalamin.

[0003] Hydroxocobalamin, due to its long residence time in the body and high bioavailability, is also known as long-acting vitamin B. 12 (B 12b Hydroxycobalamin plays a stabilizing role in human metabolism and is clinically used to treat neuropathy, pernicious anemia, and growth retardation. In addition, hydroxycobalamin can also be used clinically as an antidote for cyanide poisoning, with rapid onset and safety.

[0004] In related technologies, the preparation methods of hydroxycobalamin mostly use cyanocobalamin as a raw material, and are obtained through fermentation or synthesis. However, the fermentation method requires the extraction, separation, and purification of hydroxycobalamin from the fermentation broth, a very difficult process; therefore, the main preparation method for hydroxycobalamin is synthesis. Figure 2 As shown, patents US3167539, CN1323746A, WO2014142640A1, etc. use cyanocobalamin (Formula III) as raw material and react with an acetic acid aqueous solution of metabisulfite under high temperature in an oxygen-filled (air or oxygen) state to convert it into cobalt sulfite (Formula II), and then obtain hydroxycobalamin (Formula I) through nitrosation and diazotization reactions.

[0005] like Figure 2 As shown, the reaction from cyanocobalamin to cobalt sulfite requires an ion exchange process, namely, the reaction of metabisulfite with the cyano ions (CN) in cyanocobalamin. -The reaction involves the exchange of cyano groups to form cobalt pyrosulfite, which is then oxidized and decomposed into cobalt sulfite. This reaction requires high temperature and oxygen (or air) to remove the cyano groups; otherwise, due to the strong affinity of cyano groups for cobalt, they will exchange with the sulfite groups of cobalt sulfite, converting it back to cyanocobalamin. This makes the reaction difficult to complete, resulting in a significant amount of cyanocobalamin residue in the cobalt sulfite. When cobalt sulfite is subsequently used to prepare hydroxycobalamin, the reaction conditions are also insufficient to convert cyanocobalamin to hydroxycobalamin. Consequently, the residual cyanocobalamin from the cobalt sulfite preparation reaction is transferred to the finished hydroxycobalamin, causing the hydroxycobalamin to fail to meet pharmaceutical requirements. Summary of the Invention

[0006] The present invention aims to provide a continuous flow preparation method for cobalt sulfite or its salts and its application. The method can solve the problems of insufficient raw material conversion, difficult product purification, and high impurity content in the reaction of preparing cobalt sulfite from cyanocobalamin.

[0007] In a first aspect, the present invention provides a continuous flow preparation method for cobalt sulfite or its salts, wherein the structure of the cobalt sulfite or its salts is shown in Formula II.

[0008]

[0009] Wherein, R1 is an -OA group; and A is H, Na, K, etc.

[0010] When R1 is -OA and A is H, the compound of formula II is cobalt sulfite, which can be converted into sodium or potassium salts under suitable conditions.

[0011] The preparation method of the present invention includes the following steps:

[0012] S1 loads cyanocobalamin (Formula III) onto an adsorbent as a stationary phase;

[0013]

[0014] S2 uses an aqueous solution of sulfite as the mobile phase, transports the mobile phase liquid through the stationary phase, and obtains cobalt sulfite or its salt on the adsorbent through a continuous flow ion exchange reaction.

[0015] According to embodiments of the present invention, one of the technical solutions has at least one of the following advantages or beneficial effects:

[0016] The preparation of cobaltamine sulfite is an ion exchange process, which is reversible. This invention addresses this by loading cyanocobalamin onto an adsorbent as the stationary phase and using a sulfite solution as the mobile phase. The flowing solution carries away the cyano ions, disrupting the original ion exchange equilibrium and causing the reaction to irreversibly proceed towards cobaltamine sulfite. By overcoming the reversibility issue, and with a suitable reaction time, cyanocobalamin can be almost completely converted to cobaltamine sulfite, significantly reducing the residual cyanocobalamin.

[0017] Furthermore, since the ion exchange process of the present invention is a continuous flow reaction, it is carried out at room temperature. The reaction conditions are mild, avoiding the high temperature, oxygen-filled, and strong acid conditions required for the synthesis of cobalt sulfite in the prior art, thereby minimizing the generation of degradation impurities.

[0018] In summary, the method for preparing cobalt sulfite of the present invention can produce cobalt sulfite with high yield and high purity.

[0019] In some embodiments of the present invention, the continuous flow preparation method further includes the following steps: after obtaining cobalt sulfite amine on the adsorbent, the product is separated and purified.

[0020] In some embodiments of the present invention, the separation and purification includes the following steps: S3 desorption to obtain a solution containing cobalt sulfite; S4 adding a precipitant to the solution containing cobalt sulfite, or concentrating the solution containing cobalt sulfite.

[0021] Figure 3 This is an exemplary reaction process of the present invention.

[0022] In some embodiments of the present invention, when preparing a compound of formula II in which A is Na or K, the step of converting cobalt sulfite into its sodium or potassium salt is further included.

[0023] In some embodiments of the present invention, in step S1, the loading is to dissolve the compound of formula III in water or an aqueous solution of sulfite, and then pass the resulting solution through a fixed bed formed by the adsorbent.

[0024] In some embodiments of the present invention, in step S1, the mass / volume ratio (g / mL) of the compound of formula III to water or an aqueous solution of sulfite is 1:10 to 1:1000, preferably 1:30 to 1:200 or 1:40 to 1:100.

[0025] In some embodiments of the present invention, the mass concentration of the aqueous solution of sulfite is 0.01% to 35%, preferably 0.1% to 20%, and more preferably 0.5% to 10%.

[0026] In some embodiments of the present invention, the mass concentration of the aqueous solution of sulfite is 0.1% to 10%.

[0027] In some embodiments of the present invention, the adsorbent includes one or more of macroporous resin, alumina, octadecyl bonded silica gel, and octyl bonded silica gel; preferably, the adsorbent is a macroporous resin.

[0028] In some embodiments of the present invention, the macroporous resin includes one or more non-polar to polar resins, such as non-polar, moderately polar, polar macroporous adsorption resins, and macroporous cation exchange resins.

[0029] In some embodiments of the present invention, the macroporous adsorption resin includes A21, AB-8, ADS-7, ADS-17, CAD-40, D101, D201, D290, D301, D301G, D3520, D4006, D4020, DA201, DM130, DM301, FL-6, GDX-502, H103, H1020, HLD16, HP-10, HP20, HPD100~5000, HPD-T01, H One or more of the following models: PD-BJHQ, HZ-801, HZ-816, HZ-818, HZ-830, LSA-21, LX-16, LX-17, LX-28, LX-38, NKA-2, NKA-9, S-8, SA-3, SP, SQD-205CS, X-5, XAD-2, XAD16, XAD18, XAD761, XAD1180, XAD1600N, YPR-II, or similar models.

[0030] In some embodiments of the present invention, the adsorbent includes one or more macroporous adsorption resins of types such as HP20, H103, AB-8, and D201.

[0031] In some embodiments of the present invention, the adsorbent is subjected to conventional activation treatment before use, for example: soaking the adsorbent in ethanol for more than 24 hours, then washing it with ethanol until the washing solution is clear, washing it several times with water, and storing it in water for later use.

[0032] In some embodiments of the present invention, the treatment of the adsorbent further includes: transferring the activated adsorbent to a chromatography column and washing it sequentially with ethanol and water to form a fixed bed.

[0033] In this invention, treatment of the adsorbent (including activation treatment) is not necessary, and the specific steps of treatment are not limited to the methods described in this invention.

[0034] In some embodiments of the present invention, the mass / volume ratio of the compound of formula III to the adsorbent is approximately 1:10 to 1:1000 (g / mL).

[0035] In some embodiments of the present invention, in step S1, the mass / volume ratio (g / mL) of the compound of formula III to the adsorbent is 1:20 to 1:1000; preferably, the mass / volume ratio (g / mL) of the compound of formula III to the adsorbent is 1:20 to 1:500, 1:30:1 to 1:300, 1:40 to 1:200, or 1:50 to 1:100.

[0036] In some embodiments of the present invention, the sulfite includes at least one of metabisulfite, sulfite, and bisulfite.

[0037] In some embodiments of the present invention, the sulfite includes one or more of sodium metabisulfite, potassium metabisulfite, sodium sulfite, potassium sulfite, sodium bisulfite, and potassium bisulfite.

[0038] When sulfite is used in step S1, its type, concentration, pH value, etc., may be the same as or different from those of the sulfite in step S2.

[0039] In some embodiments of the present invention, the aqueous solution of sulfite described in step S2 is a solution prepared using water or substantially water as a solvent.

[0040] In some embodiments of the present invention, the mass concentration of the aqueous solution of sulfite in step S2 is 0.01% to 35%, preferably 0.1% to 20% or 0.5% to 10%.

[0041] In some embodiments of the present invention, the mobile phase in step S2 is selected from an aqueous solution of sodium bisulfite with a mass concentration of 0.1% to 10%, an aqueous solution of sodium metabisulfite with a mass concentration of 0.1% to 20%, or an aqueous solution of sodium sulfite with a mass concentration of 0.1% to 10%.

[0042] In some embodiments of the present invention, the pH of the sodium sulfite aqueous solution is adjusted to 4.0-5.5 with acid.

[0043] In some embodiments of the present invention, the acid used to adjust the pH value of sodium sulfite can be one or more of acetic acid, sulfuric acid, and hydrochloric acid.

[0044] The present invention does not have any special requirements on the amount of mobile phase used in step S2, as long as the amount of sulfite contained therein is sufficient to convert cyanocobalamin to cobalt sulfite.

[0045] In some embodiments of the present invention, the molar ratio of cyanocobalamin to sulfite in step S2 is 1:1 to 1:1000.

[0046] In some embodiments of the present invention, the molar ratio of cyanocobalamin to sulfite in step S2 is 1:2 to 1:500, 1:5 to 1:200, or 1:10 to 1:50.

[0047] In some embodiments of the present invention, the desorption includes the following steps: using an organic solvent as a desorbent to perform desorption, thereby obtaining a solution containing cobalt sulfite.

[0048] In some embodiments of the present invention, the desorbent includes one or more organic solvents selected from methanol, ethanol, isopropanol, acetone, and acetonitrile, and optionally may also contain water in any proportion.

[0049] In some embodiments of the present invention, the desorbent is methanol.

[0050] In some embodiments of the present invention, the volume ratio of organic solvent to water in the desorbent can be 1-0.2:0-0.8, 0.9-0.6:0.1-0.4, or 0.9-0.8:0.1-0.2.

[0051] In some embodiments of the present invention, the desorbent is 60-90% (v / v) acetone / water solution.

[0052] In some embodiments of the present invention, the desorbent is 60-90% (v / v) ethanol / water solution.

[0053] In some embodiments of the present invention, the desorbent is 90% (v / v) ethanol / water solution or 80% (v / v) acetone / water solution.

[0054] The present invention does not have a particular limitation on the amount of desorbent used, as long as it can fully desorb cobalt sulfite ammonium.

[0055] In some embodiments of the present invention, the volumetric amount of the desorbent can be 30 to 1000 times (mL / g), 60 to 500 times (mL / g), or 100 to 400 times (mL / g) of the weight of the raw material cyanocobalamin.

[0056] In some embodiments of the present invention, before desorption, residual sulfite on the adsorbent is rinsed off with water.

[0057] In some embodiments of the present invention, the precipitant includes one or a mixture of acetone and acetonitrile in any proportion.

[0058] In some embodiments of the present invention, the concentration refers to the removal of solvent by rotary evaporation, atmospheric pressure or vacuum distillation.

[0059] Figure 4This is an exemplary process flow diagram of the present invention.

[0060] The compound of formula II prepared by the continuous flow method provided by this invention can be further used to prepare high-purity hydroxycobalamin (formula I) and its pharmaceutically acceptable salt. The preparation of formula I can be found in previously disclosed methods, such as patents US3167539, CN1323746, and WO2014142640, etc., and the specific implementation process is as follows: Figure 2 As shown.

[0061] Therefore, another aspect of the present invention provides the application of the preparation method described in the first aspect of the present invention in the preparation of vitamin drugs.

[0062] In some embodiments of the present invention, the vitamin drug includes vitamin B. 12 Drugs and their salts.

[0063] In some embodiments of the present invention, the vitamin drug includes hydroxycobalamin or a pharmaceutically acceptable salt thereof.

[0064] In this invention, unless otherwise stated, scientific and technical terms used herein have the meanings commonly understood by those skilled in the art.

[0065] The term "pharmaceutically acceptable salt" refers to the pharmaceutically acceptable salt formed by the compound of Formula I of the present invention with an acid, including inorganic acid salts such as phosphates, hydrochlorides, sulfates, hydroiodides, and hydrobromic acids, and organic acid salts such as formates, acetates, malates, fumarates, or citrates.

[0066] The term "macroporous adsorption resin" refers to a polymeric material with a porous framework structure, mainly composed of styrene and acrylate monomers, vinylbenzene as a crosslinking agent, and toluene and xylene as porogens, formed through polymerization. Based on polarity and monomer molecular structure, it is divided into four categories: The first category is non-polar macroporous resins, including styrene and divinylbenzene polymers, also known as aromatic adsorbents, such as HPD-100 and D-101; the second category is moderately polar macroporous resins, made from polyacrylate polymers, using multifunctional methacrylates as crosslinking agents, known as aliphatic adsorbents; the third category is polar macroporous resins containing sulfur, oxy, and amide groups, such as acrylamide; and the fourth category is strongly polar macroporous resins containing nitric oxide groups, such as nitric oxides.

[0067] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0068] (1) This invention utilizes a solid-phase supported continuous-flow ion exchange reaction. Simultaneously, while sulfite in the mobile phase exchanges ions with cyano ions of cobalt sulfite in the stationary phase, the flowing solution carries away the cyano ions, preventing them from undergoing a reverse reaction with cobalt sulfite. This causes the reaction to irreversibly proceed towards cobalt sulfite. By overcoming the reversible reaction problem, and with a suitable reaction time, cobalt sulfite can be almost completely converted to cobalt sulfite, greatly reducing the residual cobalt sulfite.

[0069] (2) The continuous flow reaction of the present invention is carried out at room temperature, the reaction conditions are mild and the operation is safe, avoiding the use of high temperature, oxygen and strong acid conditions, and minimizing the generation of degradation impurities.

[0070] (3) The continuous flow reaction of the present invention can realize the simultaneous reaction and separation, and can also realize the continuous feeding and discharging, thus improving production efficiency.

[0071] (4) In the preparation method of the present invention, the ion exchange reaction and desorption are independent processes. Therefore, the mobile phase and desorption liquid after the reaction can be treated separately. The mobile phase can be reused after removing cyanide ions using known methods. The portion of the desorption liquid that is concentrated and evaporated can also be reused, which is beneficial to environmental protection and saves production costs.

[0072] (5) The cobalt sulfite ammonium prepared by the continuous flow method of the present invention has higher purity, which can meet the requirements for raw material quality for the preparation of high-purity hydroxycobalamin and its pharmaceutically acceptable salts, and reduce the risk of excessive impurities in hydroxycobalamin. Attached Figure Description

[0073] Figure 1 This is the structure of a common cobalamin compound.

[0074] Figure 2 This is a typical route for the chemical synthesis of hydroxycobalamin.

[0075] Figure 3 This is a reaction flow diagram of the present invention.

[0076] Figure 4 This is a process flow diagram of the present invention.

[0077] Figure 5 This is the HPLC spectrum of Example 1 of the present invention.

[0078] Figure 6 This is the HPLC chromatogram of Comparative Example 1 of the present invention. Detailed Implementation

[0079] The present invention will be further described in detail below through specific embodiments. Unless otherwise specified, the raw materials, reagents, or apparatus used in the embodiments and comparative examples are all available from conventional commercial sources or can be obtained by existing technical methods. Unless otherwise specified, the test or measurement methods are conventional methods in the art. In the following embodiments, unless otherwise specified, the reagents used are generally of analytical grade; the concentrations of cyanocobalamin solution and sulfite solution are mass concentrations; when different liquids are mixed, the ratio generally refers to the volume ratio, and the volume percentage refers to the percentage of one liquid in the total volume of all liquids constituting the mixed solution. The macroporous adsorption resins in the embodiments and comparative examples have all been activated. See the embodiments for reference. Figure 4 The process flow diagram operation.

[0080] Example 1

[0081] Step S1: Transfer the solution of cyanocobalamin (10.00 g, 7.4 mmol) and water (800 mL) to a 2 L storage bottle A for later use. Add 1000 mL of activated HP20 macroporous adsorption resin to a 2 L glass chromatography column, and wash successively with ethanol and water to ensure uniform resin particle distribution and the absence of bubbles, forming a fixed bed. Transfer the cyanocobalamin solution from storage bottle A to the chromatography column using a pump, controlling the flow rate at approximately 20 mL / min through the resin fixed bed to load the cyanocobalamin onto the macroporous adsorption resin. Collect the waste liquid in receiving bottle 1.

[0082] Step S2: In another storage bottle B, add a pre-prepared sodium bisulfite aqueous solution of approximately 10%. Use a pump to continuously flow the sodium bisulfite aqueous solution through the macroporous adsorption resin at a mobile phase flow rate of approximately 20 mL / min. The cyanocobalamin supported on the stationary phase undergoes an ion exchange reaction with the mobile phase to form cobalt sulfite product. The amount of mobile phase used is approximately 10 L. The color of the stationary phase gradually changes from bright red to yellowish-brown. The waste liquid is collected in receiving bottle 1.

[0083] Step S3: First, rinse the resin with water to remove the residual sodium bisulfite, and collect the waste liquid in receiving bottle 1; then use 4L of 80% acetone / hydrolysis to desorb the adsorbate, and collect the desorbed liquid in receiving bottle 2.

[0084] Step S4: Concentrate the desorption solution under reduced pressure, add 100 mL of acetone to the residue to crystallize, filter, and vacuum dry to obtain 10.20 g of dark red solid, namely cobalt sulfite, with a yield of 98.02% and an HPLC purity of 98.79%. There was virtually no residual cobalt cyanide. The HPLC chromatogram is shown below. Figure 5 . Figure 5 As can be seen from the data, the retention time of cobalt sulfite is 31.075 min and the peak area accounts for 98.79%, indicating that the cobalt sulfite prepared by the method of the present invention has high purity and meets production requirements.

[0085] The mass spectrometry data of cobalt sulfite amine prepared in Example 1 are as follows:

[0086] ESI-MS(m / z):705.8546[1 / 2(M+H)] + 1410.6872[M+H] + .

[0087] Example 2

[0088] Step S1: Transfer cyanocobalamin (10.00 g, 7.4 mmol) and 0.5% sodium sulfite aqueous solution (500 mL, pH adjusted to 4.0–5.0 with sulfuric acid) to a 2 L storage bottle A for later use. Add 1000 mL of activated H103 macroporous adsorption resin to a 2 L glass chromatography column, and wash successively with ethanol and water to ensure uniform resin particle distribution and the absence of bubbles, forming a fixed bed. Transfer the cyanocobalamin solution from storage bottle A to the chromatography column using a pump, controlling the flow rate at approximately 20 mL / min through the resin fixed bed to load the cyanocobalamin onto the macroporous resin. Collect the waste liquid in receiving bottle 1.

[0089] Step S2: In another storage bottle B, add a pre-prepared sodium sulfite aqueous solution of approximately 0.5% (adjust the pH to 4.0–5.0 with acetic acid). Flow the sodium sulfite aqueous solution continuously through the macroporous adsorption resin using a pump, with a mobile phase flow rate of approximately 20 mL / min. The cyanocobalamin supported on the stationary phase undergoes an ion exchange reaction with the mobile phase to form cobalt sulfite amine product. The amount of mobile phase used is approximately 15 L. The color of the stationary phase gradually changes from bright red to yellowish-brown. The waste liquid is collected in receiving bottle 1.

[0090] Step S3: First, rinse the resin with water to remove the residual sodium sulfite, and collect the waste liquid in receiving bottle 1; desorb the resin with 3L of methanol, and collect the desorbed liquid in receiving bottle 2.

[0091] Step S4: Concentrate the desorption solution under reduced pressure and evaporate to dryness to obtain 10.04 g of dark red solid, namely cobalt sulfite, with a yield of 96.50%, HPLC purity of 98.76%, and virtually no cyanocobalamin residue.

[0092] Example 3

[0093] Step S1: Transfer the solution of cyanocobalamin (1.00 g, 0.74 mmol) and water (80 mL) to a 500 mL storage bottle A for later use. Add 100 mL of activated D201 macroporous adsorption resin to a 200 mL glass chromatography column, and wash sequentially with ethanol and water to ensure uniform resin particle distribution and the absence of air bubbles, forming a fixed bed. Transfer the cyanocobalamin solution from storage bottle A to the chromatography column using a pump, controlling the flow rate at approximately 5 mL / min through the resin fixed bed to load the cyanocobalamin onto the macroporous adsorption resin. Collect the waste liquid in receiving bottle 1.

[0094] Step S2: In another storage bottle B, add a pre-prepared 5% sodium bisulfite aqueous solution. Use a pump to continuously flow the sodium bisulfite aqueous solution through the macroporous adsorption resin at a mobile phase flow rate of approximately 8 mL / min. The cyanocobalamin supported on the stationary phase undergoes an ion exchange reaction with the mobile phase to form cobalt sulfite product. The amount of mobile phase used is approximately 1 L. The color of the stationary phase gradually changes from bright red to yellowish-brown. The waste liquid is collected in receiving bottle 1.

[0095] Step S3: First, rinse the resin with water to remove the residual sodium bisulfite, and collect the waste liquid in receiving bottle 1; desorb the resin with 200 mL of methanol, and collect the desorbed liquid in receiving bottle 2.

[0096] Step S4: Concentrate the desorption solution under reduced pressure, add 20 mL of acetone to the residue to crystallize, filter, and vacuum dry to obtain 1.01 g of dark red solid, namely cobalt sulfite, with a yield of 97.20%, HPLC purity of 98.25%, and virtually no cyanocobalamin residue.

[0097] Example 4

[0098] Step S1: Transfer the solution of cyanocobalamin (1.00 g, 0.74 mmol) and water (80 mL) to a 200 mL storage bottle A for later use. Add 100 mL of activated HP20 macroporous adsorption resin to a 200 mL glass chromatography column, and wash successively with ethanol and water to ensure uniform resin particle distribution and the absence of bubbles, forming a fixed bed. Transfer the cyanocobalamin solution from storage bottle A to the chromatography column using a pump, controlling the flow rate at approximately 5 mL / min through the resin fixed bed to load the cyanocobalamin onto the macroporous adsorption resin. Collect the waste liquid in receiving bottle 1.

[0099] Step S2: In another storage bottle B, add a pre-prepared 5% sodium metabisulfite aqueous solution. Flow the sodium metabisulfite aqueous solution continuously through the macroporous adsorption resin using a pump, with a mobile phase flow rate of approximately 5 mL / min. The cyanocobalamin supported on the stationary phase undergoes an ion exchange reaction with the mobile phase to form cobalt sulfite amine product. The amount of mobile phase used is approximately 2 L. The color of the stationary phase gradually changes from bright red to yellowish-brown. The waste liquid is collected in receiving bottle 1.

[0100] Step S3: First, rinse the resin with water to remove the residual sodium metabisulfite, and collect the waste liquid in receiving bottle 1; desorb the resin with 200 mL of methanol, and collect the desorbed liquid in receiving bottle 2.

[0101] Step S4: Concentrate the desorption solution under reduced pressure, add 20 mL of acetone to the residue to crystallize, filter, and vacuum dry to obtain 1.02 g of dark red solid, namely cobalt sulfite, with a yield of 98.50%, HPLC purity of 98.15%, and virtually no cyanocobalamin residue.

[0102] Example 5

[0103] Step S1: Transfer the solution of cyanocobalamin (1.00 g, 0.74 mmol) and water (80 mL) to a 500 mL storage bottle A for later use. Add 100 mL of activated AB-8 macroporous adsorption resin to a 200 mL glass chromatography column, and wash sequentially with ethanol and water to ensure uniform resin particle distribution and the absence of air bubbles, forming a fixed bed. Transfer the cyanocobalamin solution from storage bottle A to the chromatography column using a pump, controlling the flow rate at approximately 5 mL / min through the resin fixed bed to load the cyanocobalamin onto the macroporous adsorption resin. Collect the waste liquid in receiving bottle 1.

[0104] Step S2: In another storage bottle B, add a pre-prepared 1% sodium bisulfite aqueous solution. Use a pump to continuously flow the sodium bisulfite aqueous solution through the macroporous adsorption resin at a flow rate of approximately 8 mL / min. The cyanocobalamin supported on the stationary phase undergoes an ion exchange reaction with the mobile phase to form cobalt sulfite product. The amount of mobile phase used is approximately 2 L. The color of the stationary phase gradually changes from bright red to yellowish-brown. The waste liquid is collected in receiving bottle 1.

[0105] Step S3: First, rinse the resin with water to remove the residual sodium bisulfite, and collect the waste liquid in receiving bottle 1; desorb the resin with 200 mL of methanol, and collect the desorbed liquid in receiving bottle 2.

[0106] Step S4: Concentrate the desorption solution under reduced pressure, add 20 mL of acetone to the residue to crystallize, filter, and vacuum dry to obtain 1.01 g of dark red solid, namely cobalt sulfite, with a yield of 98.06%, HPLC purity of 98.46%, and virtually no cyanocobalamin residue.

[0107] Example 6

[0108] Step S1: Transfer the solution of cyanocobalamin (1.00 g, 0.74 mmol) and water (80 mL) to a 500 mL storage bottle A for later use. Add 100 mL of activated HP20 macroporous adsorption resin to a 200 mL glass chromatography column, and wash successively with ethanol and water to ensure uniform resin particle distribution and the absence of bubbles, forming a fixed bed. Transfer the cyanocobalamin solution from storage bottle A to the chromatography column using a pump, controlling the flow rate at approximately 5 mL / min through the resin fixed bed to load the cyanocobalamin onto the macroporous adsorption resin. Collect the waste liquid in receiving bottle 1.

[0109] Step S2: In another storage bottle B, add a pre-prepared 1% sodium bisulfite aqueous solution. Use a pump to continuously flow the sodium bisulfite aqueous solution through the macroporous adsorption resin at a mobile phase flow rate of approximately 10 mL / min. The cyanocobalamin supported on the stationary phase undergoes an ion exchange reaction with the mobile phase to form cobalt sulfite product. The amount of mobile phase used is approximately 1.5 L. The color of the stationary phase gradually changes from bright red to yellowish-brown. The waste liquid is collected in receiving bottle 1.

[0110] Step S3: First, rinse the resin with water to remove the residual sodium bisulfite, and collect the waste liquid in receiving bottle 1; then desorb the resin with 250 mL of 90% ethanol / water, and collect the desorbed liquid in receiving bottle 2.

[0111] Step S4: Concentrate the desorption solution under reduced pressure, add 20 mL of acetone to the residue to crystallize, filter, and vacuum dry to obtain 1.02 g of dark red solid, namely cobalt sulfite, with a yield of 98.40%, HPLC purity of 98.26%, and virtually no cyanocobalamin residue.

[0112] Comparative Example 1

[0113] In a 1L three-necked flask equipped with a reflux condenser, sodium metabisulfite (18.06g, 95mmol) and purified water (600mL) were added and stirred to dissolve. Acetic acid was added to adjust the pH to 4.0–5.0. Cyanocobalamin (10.00g, 7.4mmol) was added and stirred to dissolve at 50°C. The mixture was then reacted with air at 50°C for 2 hours.

[0114] TLC analysis (developing solvent: methanol / water volume ratio = 1:1) revealed the presence of cyanocobalamin residue.

[0115] The temperature was lowered to room temperature, and the reaction solution was desalted using HP20 macroporous adsorption resin. Adsorption was performed using 80% acetone / hydrolysis. The desorbed solution was concentrated under reduced pressure, and the residue was crystallized with 100 mL of acetone. The crystals were filtered and vacuum dried to obtain a dark red solid, namely cobalt sulfite, with a mass of 9.66 g, a yield of 92.91%, and an HPLC purity of 87.69%. The content of cyanocobalamin was approximately 1.9%, and there was another impurity, with a content of approximately 7.9%, which was different from cyanocobalamin. The HPLC chromatogram is shown below. Figure 6 . Figure 6 The peak area of ​​cobalt sulfite in the study was approximately 1.9%, indicating that the method in Comparative Example 1 was not applicable.

[0116] Comparative Example 2

[0117] In a 1L three-necked flask equipped with a reflux condenser, sodium metabisulfite (18.06g, 95mmol) and purified water (600mL) were added and stirred to dissolve. Acetic acid was added to adjust the pH to 4.0–5.0. Cyanocobalamin (10.00g, 7.4mmol) was added and stirred to dissolve at 50°C. The mixture was then reacted with air at 50°C for 5 hours.

[0118] TLC analysis (developing solvent: methanol / water volume ratio = 1:1) showed that the cyanocobalamin reaction was complete.

[0119] The temperature was lowered to room temperature, and the reaction solution was desalted with HP20 macroporous adsorption resin. It was then adsorbed with 80% acetone / hydrolysis. The desorbed solution was concentrated under reduced pressure, and the residue was crystallized with 100 mL of acetone. After filtration and vacuum drying, 9.78 g of dark red solid, namely cobalt sulfite, was obtained. The yield was 94.05%, the HPLC purity was 95.50%, and there was basically no cyanocobalamin residue, but there was an impurity with a content of about 3% that was different from cyanocobalamin.

[0120] Comparative Example 3

[0121] In a 250 mL three-necked flask, sodium metabisulfite (1.81 g, 9.5 mmol) and purified water (80 mL) were added and stirred to dissolve. Then, cyanocobalamin (1.00 g, 0.74 mmol) was added, and the mixture was stirred at room temperature for 5 hours.

[0122] TLC analysis (developing solvent: methanol / water volume ratio = 1:1) revealed a large amount of cyanocobalamin residue.

[0123] The reaction solution was desalted using HP20 macroporous adsorption resin, desorbed with methanol, concentrated under reduced pressure, and the residue was crystallized with 20 mL of acetone. After filtration and vacuum drying, 0.84 g of a dark red solid, namely cobalt sulfite, was obtained, with a yield of 80.77% and an HPLC purity of 76.24%.

[0124] Comparative Example 4

[0125] In a 250 mL three-necked flask, sodium bisulfite (5.00 g, 48 mmol) and purified water (100 mL) were added and stirred to dissolve. Then, cyanocobalamin (1.00 g, 0.74 mmol) was added, and the mixture was stirred at room temperature for 5 hours.

[0126] TLC analysis (developing solvent: methanol / water volume ratio = 1:1) revealed a large amount of cyanocobalamin residue.

[0127] The reaction solution was desalted using HP20 macroporous adsorption resin, desorbed with methanol, concentrated under reduced pressure, and the residue was crystallized with 20 mL of acetone. After filtration and vacuum drying, 0.83 g of a dark red solid, namely cobalt sulfite, was obtained, with a yield of 80.70% and an HPLC purity of 80.40%.

[0128] In summary, in all embodiments of the present invention, cyanocobalamin was completely converted, and the purity of the cobalt sulfite product reached over 98%, with a reaction yield of over 96%. In Comparative Example 1, however, the cyanocobalamin reaction was incomplete, with approximately 1.9% residue in the product, and another impurity of approximately 7.9% was also generated. Comparative Example 2 extended the reaction time, resulting in virtually no cyanocobalamin residue in the product, but also generating more other impurities, with a product purity of approximately 95.5%, significantly lower than the embodiments of the present invention. Neither the methods of Comparative Example 1 nor Comparative Example 2 can obtain high-purity cobalt sulfite, increasing the difficulty of its application in actual production.

[0129] Surprisingly, the preparation method of this invention can be carried out efficiently at room temperature without the need for additional air or oxygen. Furthermore, the reaction proceeds smoothly and completely when the sulfite is sodium bisulfite (Examples 1, 3, 5, 6), sodium sulfite (Example 2), and sodium metabisulfite (Example 4). In contrast, in Comparative Examples 3 and 4, when cyanocobalamin reacted with sodium bisulfite or sodium metabisulfite in a reaction flask with stirring at room temperature, a large amount of cyanocobalamin remained unconverted, and the purity of the product could only reach a maximum of about 80%. This made it unsuitable for direct or simple purification as a raw material for the production of other cobalamin-based pharmaceuticals such as hydroxycobalamin and its pharmaceutically acceptable salts.

[0130] In the preparation method of the present invention, during the ion exchange between sulfite and cyanocobalamin, the displaced cyano ions are carried away by the mobile phase, so that the reaction proceeds irreversibly towards cyanocobalamin at room temperature, thereby greatly reducing the residue of cyanocobalamin.

[0131] The reaction conditions of this invention are mild, the range of sulfites that can be selected is wide, and the conditions of high temperature, oxygenation, and strong acid are avoided. This minimizes the generation of degradation impurities, improves the yield and purity of cobalt sulfite, and can provide high-quality raw materials for the preparation of subsequent products such as hydroxycobaltamine, while reducing the risk of excessive impurities.

[0132] Although specific embodiments of the invention have been described in detail, those skilled in the art will understand that various modifications and substitutions can be made to those details based on all the teachings disclosed, and all such changes are within the scope of protection of the invention. The full scope of the invention is given by the appended claims and any equivalents thereof.

Claims

1. A continuous flow preparation method for cobalt sulfite ammonium or its salt, characterized in that, The cobalt sulfite or its salt has the structure shown in Formula II. Wherein, R1 is an -OA group; and A is selected from H, Na, or K; The preparation method includes the following steps: S1 loads the compound of formula III onto the adsorbent as a stationary phase; S2 uses an aqueous solution of sulfite as the mobile phase, transports the mobile phase liquid through the stationary phase, and obtains cobalt sulfite or its salt on the adsorbent through a continuous flow ion exchange reaction.

2. The continuous flow preparation method according to claim 1, characterized in that, In step S1, the mass / volume ratio (g / mL) of the compound of formula III to the adsorbent is 1:20 to 1:1000; preferably, the mass / volume ratio (g / mL) of the compound of formula III to the adsorbent is 1:20 to 1:500, 1:30:1 to 1:300, 1:40 to 1:200, or 1:50 to 1:

100.

3. The continuous flow preparation method according to claim 1, characterized in that, In step S1, the loading is achieved by dissolving the compound of formula III in an aqueous solution of water or sulfite, and then passing the resulting solution through a fixed bed formed by the adsorbent.

4. The continuous flow preparation method according to claim 3, characterized in that, In step S1, the mass / volume ratio (g / mL) of the compound of formula III to water or an aqueous solution of sulfite is 1:10 to 1:1000, preferably 1:30 to 1:200 or 1:40 to 1:

100.

5. The continuous flow preparation method according to any one of claims 1-4, characterized in that, The adsorbent includes one or more of macroporous resin, alumina, octadecyl bonded silica gel, and octyl bonded silica gel; preferably, the adsorbent is a macroporous resin; preferably, the macroporous resin is a non-polar to polar macroporous adsorption resin or a macroporous cation exchange resin.

6. The continuous flow preparation method according to any one of claims 1-4, characterized in that: The sulfite includes at least one of metabisulfite, sulfite, and bisulfite; preferably, the sulfite is at least one of sodium metabisulfite, potassium metabisulfite, sodium sulfite, potassium sulfite, sodium bisulfite, and potassium bisulfite; and when the sulfite is used in step S1, it may be the same as or different from the sulfite in step S2.

7. The continuous flow preparation method according to any one of claims 1-4, characterized in that, The aqueous solution of the sulfite has a mass concentration of 0.01% to 35%, preferably 0.1% to 20%, and more preferably 0.5% to 10%.

8. The continuous flow preparation method according to claim 1, characterized in that, The continuous flow preparation method further includes the following steps: after obtaining cobalt sulfite amine on the adsorbent, the product is separated and purified.

9. The continuous flow preparation method according to claim 8, characterized in that, The separation and purification process includes the following steps: S3 desorption to obtain a solution containing cobalt sulfite; S4 adding a precipitant to the solution containing cobalt sulfite, or concentrating the solution containing cobalt sulfite.

10. Use of the process according to any one of claims 1 to 4 for the preparation of a vitamin medicament, preferably the vitamin medicament comprises vitamin B 12 ; more preferably the vitamin medicament comprises hydroxycobalamin or a pharmaceutically acceptable salt thereof.

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