Synthetic method of cocarboxylase tetrahydrate

Abstract

The invention discloses a synthetic method of cocarboxylase tetrahydrate, which comprises the following steps: reacting thiamine phosphate with a condensing agent in an organic solvent to obtain an intermediate I; and reacting the intermediate I with phosphate to obtain cocarboxylase, and refining the cocarboxylase to obtain cocarboxylase tetrahydrate. According to the method disclosed by the invention, the byproduct thiamine monophosphate recovered in a traditional preparation process is used as a starting material to prepare the cocarboxylase tetrahydrate, so that the reaction selectivity is high, and the material utilization rate is increased; according to the method, the high-temperature reaction condition of the traditional process is avoided, the emission of hydrogen chloride gas is avoided, the use of organic solvents and highly toxic reagents is reduced, the pressure on environmental protection is relieved, and the reaction safety is improved.

Description

Technical Field

[0001] This field belongs to the field of drug synthesis technology, and specifically relates to a method for synthesizing a tetrahydrated cocarboxylase. Background Technology

[0002] Cocarboxylase tetrahydrate, also known as thiamine tetrahydrate pyrophosphate, is one of the raw materials for injectable multivitamins (12). It is a form of vitamin B1 that participates in the oxidative decarboxylation of pyruvate and α-ketoglutarate in the body's sugar metabolism. When deficient, oxidation is hindered, leading to the formation of pyruvate and lactic acid accumulation, which affects the body's energy supply. Its symptoms are mainly manifested in the nervous system, cardiovascular system, and digestive system.

[0003] There are many reported methods for preparing tetrahydrated cocarboxylases. In 1937, Stern and Hofer prepared thiamine pyrophosphate by reacting vitamin B1 with phosphorus oxychloride [Science, Vol. 85, p. 483 (1937)]. J. Weijlard and H. Tauber prepared thiamine pyrophosphate by using a mixture of vitamin B1 and sodium pyrophosphate with phosphoric acid, and obtained thiamine pyrophosphate by treating it with a large amount of organic solvent using phosphotungstic acid solution, with a yield of about 10% [Joura1 of the American Chemical Society, Vol. 60, p. 2263 (1938)]. In 1940, a literature report described the reaction of the vitamin B1 analog 5-ethylenethiazole bromide with silver phosphate to prepare vitamin B1 chloride pyrophosphate, which precipitates as a silver salt. The silver ions are removed with hydrogen sulfide and then treated with hydrogen chloride to obtain thiamine chloride pyrophosphate [Biochemica1 Journa1 , Vol.34 , p.980(1940)]. The above method requires the use of toxic reagents or large amounts of organic solvents, or high temperatures, which is not conducive to environmental protection.

[0004] US5047223, US2991284, CN1887891A, and CN101787048B disclose a method for producing vitamin B1 as a raw material, reacting it with phosphorylation reagents (phosphorus pentoxide with phosphoric acid, or phosphorus pentoxide with pyrophosphate). The treated reaction solution is first purified using a weakly basic anion exchange resin column, then a weakly acidic cation exchange resin column. The qualified components are concentrated at 35°C, and the product is obtained by crystallization with ethanol. This method is currently a common method for producing tetrahydrated cocarboxylase. However, this method requires high-temperature conditions, releases hydrogen chloride gas during the reaction, and uses a large amount of organic solvent, which is detrimental to environmental protection. Furthermore, the reaction yield is very low, with a maximum yield of around 40% (CN101787048B), and the reaction selectivity is very poor. The byproduct thiamine monophosphate accounts for 60%~70% of the production (US5047223), and direct disposal as waste would result in material waste and increase production costs. Therefore, there is an urgent need for a method to convert thiamine monophosphate into tetrahydrated cocarboxylase. Summary of the Invention

[0005] In view of the above-mentioned shortcomings in the existing technology, in order to improve the material conversion rate and reduce the cost, this invention uses thiamine monophosphate, a by-product recovered in the traditional preparation process, as the starting material. The first step involves reacting it with a condensing agent to obtain intermediate I. The second step involves reacting intermediate I with phosphate and a catalyst to obtain a cocarboxylase. Finally, the cocarboxylase is purified to obtain tetrahydrated cocarboxylase. The synthetic route is as follows:

[0006]

[0007] Its features include the following steps:

[0008] Step 1: In solvent A, at a temperature of 15~30℃, thiamine monophosphate reacts with a condensing agent under the action of an alkali to obtain intermediate I.

[0009]

[0010] Step 2: In solvent B, at a temperature of -5~30℃, intermediate I reacts with phosphate under the action of a catalyst to obtain cocarboxylase;

[0011]

[0012] Step 3: The cocarboxylase is purified to obtain tetrahydrate cocarboxylase.

[0013]

[0014] The above-mentioned method for synthesizing tetrahydrate cocarboxylase is characterized in that the condensing agent in step one is one of dicyclohexylcarbodiimide-morpholine and N,N′-carbonyldiimidazole;

[0015] The above-mentioned method for synthesizing tetrahydrate cocarboxylase is characterized in that the molar ratio of condensing agent to thiamine monophosphate in step one is (3~4):1;

[0016] The above-mentioned method for synthesizing tetrahydrate cocarboxylase is characterized in that the reaction temperature in step one is 15~30℃;

[0017] The above-mentioned method for synthesizing tetrahydrate cocarboxylase is characterized in that, in step one, solvent A is one of acetonitrile, N,N-dimethylformamide, and N,N-dimethylacetamide; and the mass ratio of solvent A to thiamine monophosphate in step one is (8~10):1.

[0018] The above-mentioned method for synthesizing tetrahydrate cocarboxylase is characterized in that the phosphate substance used in the reactions of step one and step two is one of triethylamine phosphate, tributylamine phosphate, and tetrabutylammonium phosphate.

[0019] The above-mentioned method for synthesizing tetrahydrate cocarboxylase is characterized in that the molar ratio of phosphate to intermediate I in step two is (3~5):1;

[0020] The above-mentioned method for synthesizing tetrahydrate cocarboxylase is characterized in that, in step two, solvent B is one of acetonitrile, acetone, and tetrahydrofuran; and the bulk ratio of solvent B to intermediate I in step two is (10~15):1.

[0021] The above-mentioned method for synthesizing tetrahydrate cocarboxylase is characterized in that the reaction temperature in step two is -5~30℃;

[0022] The above-mentioned method for synthesizing tetrahydrate cocarboxylase is characterized in that the catalyst in step two is one of magnesium sulfate, manganese chloride, and zinc chloride, and the mass ratio of the catalyst to intermediate I is (0.04~0.06):1;

[0023] The above-mentioned method for synthesizing tetrahydrate cocarboxylase is characterized in that the purification process in step three is as follows: the wet cocarboxylase obtained in step two is added to purified water, heated to dissolve, activated carbon is added, stirred, filtered while hot, the filtrate is cooled, ethanol is added dropwise until a white solid gradually precipitates out, stirred, filtered, and dried to obtain tetrahydrate cocarboxylase.

[0024] In step three, the preferred ratio of purified water to cocarboxylase is 9:1; the preferred ratio of ethanol to cocarboxylase is 15:1.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] 1. The method of the present invention uses thiamine monophosphate, a byproduct recovered in the traditional preparation process, as the starting material to prepare tetrahydrated cocarboxylase, thereby improving the material utilization rate.

[0027] 2. The preparation process of this invention avoids the high-temperature reaction conditions of traditional processes, eliminates the emission of hydrogen chloride gas, reduces the use of organic solvents and highly toxic reagents, alleviates the pressure on environmental protection, and improves the safety of the reaction.

[0028] 3. A new tetrahydrated cocarboxylase preparation route was developed, which has high reaction selectivity and significantly improved the product yield to 70.6%; the liquid phase detection results of the product showed that the purity was greater than 99.5%.

[0029] 4. The raw materials used in the route of this invention are readily available, the process is simple, the preparation steps are short, the reaction process is easy to control, and it is suitable for industrial production. Attached Figure Description

[0030] Figure 1 Synthetic route for preparing tetrahydrated cocarboxylase using thiamine monophosphate as the starting material.

[0031] Figure 2 The liquid phase diagram shows the tetrahydrated cocarboxylase prepared according to patent US5047223.

[0032] Figure 3 This is a liquid phase diagram of the tetrahydrated cocarboxylase obtained in Example 1 of the present invention. Detailed Implementation

[0033] The present invention will be further described below with reference to specific embodiments. The following description is only for explaining the present invention. The scope of protection of the present invention is not limited to these embodiments. Those skilled in the art should understand that equivalent substitutions or corresponding improvements made to the content of the present invention still fall within the scope of protection of the present invention.

[0034] (1) Sample source:

[0035] Thiamine monophosphate was prepared in-house, synthesized and separated according to the method described in patent US5047223;

[0036] Triethylamine phosphate, tributylamine phosphate, tetrabutylammonium phosphate, and other reagents are all commercially available.

[0037] (2) The purity of tetrahydrate cocarboxylase was determined by high performance liquid chromatography:

[0038] The chromatographic column was Yuexu Ultimate@AQ-C18, 5μm, 4.6×250mm;

[0039] The mobile phase was 0.2 mol / L KH2PO4 buffer solution-methanol (99.7:0.3).

[0040] The wavelength is 235nm.

[0041] The invention is described in detail below with specific examples, but this does not limit the scope of this patent.

[0042] Example 1

[0043] 1. Preparation of intermediate I:

[0044] Thiamine monophosphate (34.4 g, 1.0 eq), dicyclohexylcarbodiimide (61.8 g, 3 eq), and morpholine (26.14 g, 3 eq) were placed in a reaction flask, and 300 ml of N,N-dimethylacetamide was added. The mixture was stirred and triethylamine (35.5 g, 3.5 eq) was added dropwise while maintaining the temperature at 30 °C. After the addition was complete, the reaction was continued at 30 °C. After the reaction was completed as detected by liquid chromatography, purified water and ethyl acetate were added to the reaction solution, and the mixture was stirred and separated. The organic phase was concentrated to obtain 37.2 g of intermediate I.

[0045] 2. Preparation of tetrahydrated cocarboxylase:

[0046] The intermediate I (37.2 g, 1.0 eq) and zinc chloride (2.23 g, 0.06 eq) obtained in the previous step were placed in a reaction flask, 500 ml of acetone was added, stirring was started, and the temperature was controlled at 30 °C. Tributylamine phosphate (76.5 g, 3.0 eq) was slowly added, and the reaction was continued at 30 °C. After the reaction was completed by liquid chromatography, the mixture was filtered, and the filter cake was washed with acetone to obtain 27.7 g of cocarboxylase, which was directly used in the next step of the reaction.

[0047] The above wet sample was placed back into the reaction flask, purified water (9V / W) was added, and the temperature was raised to 60°C. After the solid was completely dissolved, activated carbon was added, and the mixture was stirred for 1 hour. The mixture was then filtered while hot. The filtrate was cooled to 40°C, and ethanol (15V / W) was added dropwise. A white solid gradually precipitated in the filtrate. The mixture was stirred for another hour, filtered under vacuum, and the filter cake was washed with ethanol. The filtrate was dried at 40°C to obtain 32.4 g of tetrahydrated cocarboxylase (15.5% moisture), with a total yield of 65.0% (based on the amount of thiamine monophosphate fed) and a purity of 99.84%. The table below shows the liquid chromatography results of the tetrahydrated cocarboxylase prepared according to patent US5047223 and the tetrahydrated cocarboxylase prepared according to Example 1. See the attached liquid chromatogram for details. Figure 1 and attached Figure 2 .

[0048] name Retention time Peak area percentage Tetrahydrated cocarboxylase prepared according to patent US5047223 8.496 99.83 Tetrahydrated cocarboxylase prepared in Example 1 8.367 99.84 .

[0049] Example 2

[0050] 1. Preparation of intermediate I:

[0051] Thiamine monophosphate (34.4 g, 1.0 eq) and N,N′-carbonyldiimidazole (65.0 g, 4 eq) were placed in a reaction flask, and 344 ml of acetonitrile was added. The mixture was stirred and triethylamine (35.5 g, 3.5 eq) was added dropwise at 20 °C. After the addition was complete, the reaction was continued at 30 °C. After the reaction was completed by liquid chromatography, the mixture was filtered, the filter cake was washed with acetonitrile, and dried under reduced pressure at 30 °C to obtain 31.5 g of intermediate I.

[0052] 2. Preparation of tetrahydrated cocarboxylase:

[0053] The intermediate I (31.5 g, 1.0 eq) and magnesium sulfate (1.58 g, 0.05 eq) obtained in the previous step were placed in a reaction flask, 315 ml of acetonitrile was added, stirring was started, and tetrabutylammonium phosphate (81.3 g, 3.0 eq) was slowly added while maintaining the temperature at -5 °C. The reaction was continued at -5 °C. After the reaction was completed by liquid phase detection, the mixture was filtered, and the filter cake was washed with acetonitrile to obtain 31.1 g of cocarboxylase, which was directly used in the next step of the reaction.

[0054] The above wet product was placed back into the reaction flask, purified water (9V / W) was added, and the temperature was raised to 60°C. After the solid was completely dissolved, activated carbon was added, and the mixture was stirred for 1 hour. The mixture was filtered while hot, and the filtrate was cooled to 40°C. Ethanol (15V / W) was added dropwise, and a white solid gradually precipitated in the filtrate. The mixture was stirred for another hour, filtered, and the filter cake was washed with ethanol and dried at 40°C to obtain 33.8 g of tetrahydrate cocarboxylase (15.3% moisture), with a total yield of 68.0% (calculated based on the amount of thiamine monophosphate added).

[0055] Example 3

[0056] 1. Preparation of intermediate I:

[0057] Thiamine monophosphate (34.4 g, 1.0 eq), dicyclohexylcarbodiimide (82.4 g, 4 eq), and morpholine (34.9 g, 4 eq) were placed in a reaction flask, and 276 ml of N,N-dimethylformamide was added. The mixture was stirred and triethylamine (35.5 g, 3.5 eq) was added dropwise while maintaining the temperature at 15 °C. After the addition was complete, the reaction was continued at 15 °C. After the reaction was completed, purified water and ethyl acetate were added to the reaction solution, and the mixture was stirred and separated. The organic phase was examined and concentrated to obtain 38.8 g of intermediate I.

[0058] 2. Preparation of tetrahydrated cocarboxylase:

[0059] The intermediate I (38.8 g, 1.0 eq) and manganese chloride (1.55 g, 0.04 eq) obtained in the previous step were placed in a reaction flask, 582 ml of tetrahydrofuran was added, stirring was started, and triethylamine phosphate (79.8 g, 5.0 eq) was slowly added while maintaining the temperature at 30 °C. The reaction was continued at 30 °C. After the reaction was completed by liquid chromatography, the mixture was filtered, and the filter cake was washed with tetrahydrofuran to obtain 32.2 g of cocarboxylase, which was directly used in the next step of the reaction.

[0060] The above wet product was placed back into the reaction flask, purified water (9V / W) was added, and the temperature was raised to 60°C. After the solid was completely dissolved, activated carbon was added, and the mixture was stirred for 1 hour. The mixture was filtered while hot, and the filtrate was cooled to 40°C. Ethanol (15V / W) was added dropwise, and a white solid gradually precipitated in the filtrate. The mixture was stirred for another hour, filtered, and the filter cake was washed with ethanol and dried at 40°C to obtain 35.0 g of tetrahydrate cocarboxylase (15.1% moisture), with a total yield of 70.6% (calculated based on the amount of thiamine monophosphate added).

[0061] The above description is merely some embodiments of the present invention. The scope of protection of the present invention is not limited to these embodiments. Those skilled in the art should understand that equivalent substitutions or corresponding improvements made to the content of the present invention still fall within the scope of protection of the present invention.

Claims

1. A method for synthesizing a tetrahydrated cocarboxylase, characterized in that, The method uses thiamine monophosphate as the starting material, reacts with a condensing agent to obtain intermediate I, intermediate I reacts with phosphate and catalyst to obtain cocarboxylase, and the cocarboxylase is purified to obtain tetrahydrate cocarboxylase. The condensing agent is one of dicyclohexylcarbodiimide-morpholine and N,N′-carbonyldiimidazole; The structural formula of intermediate I is: or ; The phosphate is one of triethylamine phosphate, tributylamine phosphate, and tetrabutylammonium phosphate; The catalyst is one of magnesium sulfate, manganese chloride, and zinc chloride.

2. A method for synthesizing a tetrahydrated cocarboxylase, characterized in that, Includes the following steps: Step 1: In solvent A, at a temperature of 15~30℃, thiamine monophosphate reacts with a condensing agent under the action of alkali to obtain intermediate I; ； Solvent A is one of acetonitrile, N,N-dimethylformamide, and N,N-dimethylacetamide; The condensing agent is one of dicyclohexylcarbodiimide-morpholine and N,N′-carbonyldiimidazole; Step 2: In solvent B, at a temperature of -5~30℃, intermediate I reacts with phosphate under the action of a catalyst to obtain cocarboxylase; ； Solvent B is one of acetonitrile, acetone, and tetrahydrofuran; The catalyst is one of magnesium sulfate, manganese chloride, and zinc chloride; The phosphate is one of triethylamine phosphate, tributylamine phosphate, and tetrabutylammonium phosphate; Step 3: The cocarboxylase is purified to obtain tetrahydrate cocarboxylase; 。 3. The method according to claim 2, characterized in that, In step one, the molar ratio of the condensing agent to thiamine phosphate is (3~4):

1.

4. The method according to claim 2, characterized in that, In step one, the mass ratio of solvent A to thiamine phosphate is (8~10):

1.

5. The method according to claim 2, characterized in that, In step two, the molar ratio of phosphate to intermediate I is (3~5):

1.

6. The method according to claim 2, characterized in that, In step two, the mass ratio of catalyst to intermediate I is (0.04~0.06):

1.

7. The method according to claim 2, characterized in that, In step two, the volume ratio of solvent B to intermediate I is (10~15):

1.

8. The method according to claim 2, characterized in that, The purification process in step three is as follows: the cocarboxylase obtained in step two is added to purified water, heated to dissolve, activated carbon is added, stirred, filtered while hot, the filtrate is cooled, ethanol is added dropwise to the filtrate to gradually precipitate a white solid, stirred, filtered, and dried to obtain cocarboxylase tetrahydrate.

9. The method according to claim 8, characterized in that, The mass ratio of purified water to cocarboxylase is 9:1; the mass ratio of ethanol to cocarboxylase is 15:

1.

10. The method according to any one of claims 1 to 9, characterized in that, The application of intermediate I in the preparation of tetrahydrated cocarboxylase.

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