JP3901321B2 - Method for producing riboflavin-5'-phosphate or a sodium salt thereof - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a novel industrially superior method for producing riboflavin (III) phosphate, which is useful as a medicine, food additive, feed, industrial intermediate and the like.
[0002]
[Prior art]
The present invention relates to a method for producing riboflavin-5′-phosphate (hereinafter referred to as 5′-FMN) or a monosodium salt thereof, which is valuable as a pharmaceutical product. 5'-FMN has an important role as a coenzyme in different enzyme reactions in vivo, and is a compound used as a drug, food and feed additive in the form of its salt, especially sodium-5'FMN. Conventionally, riboflavin-5'-phosphate is produced by adding riboflavin to a mixture of polar solvent, tertiary amine, phosphorous oxychloride and water and reacting, and then adding a large amount of water to the system to add excess oxychlorination. Decompose phosphorus, hydrolyze it with hydrochloric acid (water) as a by-product, adjust the pH and concentrate (JP-A-48-54099), add riboflavin to the mixture of lactones and phosphorus oxychloride and react Then, a large amount of water is added to the system to decompose excess phosphorus oxychloride, hydrolyzed with hydrochloric acid (water) by-produced there, and filtered after pH adjustment (Japanese Patent Laid-Open No. 3-109394) Since these methods decompose using a large amount of water, they require a large number of reaction cans. In addition, a large amount of phosphoric acid waste liquid is produced. According to the present invention, excess phosphorylating agent (such as POCl ₃ ) can be easily recovered and reused without being decomposed by a concentration operation, so that a large reactor is not required, and phosphoric acid waste liquid can be reduced and used in the reaction. Solvents are easily recovered without worrying about thermal abuse of the target product. In addition, the amount of free phosphoric acid in the target product, which is a problem in quality due to separation from excess phosphorus oxychloride, is extremely small. In addition, as described above, in the conventional method, the hydrolysis in the next step is performed with hydrochloric acid (water) by-produced by the decomposition of the excess phosphorylating reagent, so it is not easy to change the conditions to ensure high quality. In this method, since riboflavin cyclic 4 ′, 5′-phosphoridate (II) or a salt thereof, which is an intermediate, is isolated, any concentration and acid species can be selected and there is no excess acid. For this reason, the amount of aqueous sodium hydroxide solution required for pH adjustment is reduced, and the amount of salt produced as a by-product is reduced.
[0003]
The present invention relates to a method for producing riboflavin-5′-phosphate (hereinafter referred to as 5′-FMN) or a monosodium salt thereof, which is valuable as a pharmaceutical product. 5'-FMN has an important role as a coenzyme in different enzyme reactions in vivo, and is a compound used as a drug, food and feed additive in the form of its salt, especially sodium-5'FMN. Conventionally, riboflavin-5'-phosphate is produced by adding riboflavin to a mixture of polar solvent, tertiary amine, phosphorus oxychloride and water and reacting, and then adding water to the system to remove excess phosphorus oxychloride. Decomposition, hydrolysis with by-product hydrochloric acid (water), pH adjustment and concentration (JP-A-48-54099), riboflavin is added to the mixture of lactones and phosphorus oxychloride, and then reacted. There are methods such as adding water to the system to decompose excess phosphorus oxychloride, hydrolyzing with hydrochloric acid (water) as a by-product, adjusting the pH and filtering (JP-A-3-109394). Although the purity of 5′-FMN obtained in 1) satisfies the JP standards, it contains a large amount of 3′-FMN, 4′-FMN, which are inactive isomers in vivo, and unreacted riboflavin. For example, 3'-FMN 5-7%, 4'-FMN 11-13%, unreacted riboflavin 1-2% (5'-FMN 75-80%) according to the follow-up examination of the former patent, description of the latter patent 3′-FMN 5-7%, 4′-FMN 9-11%, unreacted riboflavin 4-5.8% (5′-FMN 76-80%). In order to obtain a higher-purity target product, it is necessary to perform a technically expensive purification method (for example, column chromatography).
FMN is known to have equilibrium in 3 ', 4', 5 'isomers in its acid solution. (Eur. J. biochem., 66, 567-577, 1976.) The ratio is about 3 ': 4': 5 '= 5: 15: 80, and the above patent results also suggest these values. In the study of shifting the equilibrium to the 5'-FMN side, we found a method of shifting the equilibrium by selectively removing 5'-FMN from the system as a crystal by changing the acid concentration.
According to the present invention, high-purity 5′-FMN can be obtained without an expensive purification method.
The present invention is characterized in that riboflavin cyclic 4 ′, 5′-phosphoridate (II), which is an intermediate deposited by a predetermined reaction, or a salt thereof is collected by filtration and isomerized with an appropriate concentration and amount of acid. To do. Specifically, 1 to 35.5 (w / v)% concentration, preferably 5 to 18%, more preferably 12% acid, for example, mineral acid such as hydrochloric acid, nitric acid, sulfuric acid (preferably hydrochloric acid), riboflavin as the starting material 1-10 times volume (preferably 2 times volume) is added to the mixture, and the reaction is stirred at 10-100 ° C (preferably 20-40 ° C). The progress of isomerization is carried out by HPLC, and the time when the 5′-FMN purity exceeds 90% is set as a temporary end point, and the post-treatment is started. In the post-treatment, acid or alkaline water is added to the obtained suspension reaction solution and dissolved, and then the pH is adjusted to 5.5 with an alkali or acid opposite to the previously used liquid property. The liquid is cooled, filtered, washed with alcohol and dried. The target product obtained by the method according to the present invention is 3'-FMN 3-5%, 4'-FMN 4-6%, 5'-FMN 88-90%, unreacted riboflavin -1%, pharmacopoeia grade There is no need to continue the costly purification process.
[Problems to be solved by the present invention]
As described above, an industrially excellent method for producing riboflavin (III) phosphate or a sodium salt thereof has not yet been established, and a new and superior method has been demanded.
[0004]
[Means for Solving the Problems]
The inventors of the present invention have been diligently researching to improve the above problems. As a result, the inventors have found that the problem can be solved by the method described in detail below, and have completed the present invention.
[0005]
More specifically, the present invention is one of the following methods.
(1) In the reaction of producing riboflavin phosphate (III) by reacting riboflavin (I) with phosphorus oxychloride, the reaction intermediate riboflavin cyclic 4 ', 5'-phosphoridate (II) or a salt thereof is added. Take it out of the system and disassemble it.
(2) Riboflavin cyclic 4 ', 5'-phosphoridate (II) is decomposed under acidic conditions.
(3) The acidic condition is adjusted by using 1 to 35.5 (w / v)% acid at 1 to 10 times the volume of riboflavin as the starting material.
[0006]
Subsequently, in order to specifically describe the present invention, examples and comparative examples are listed below, but it goes without saying that the present invention is not limited thereto.
【Example】
[0007]
Example 1 Production of Riboflavin Phosphate 300 ml of acetonitrile, 150 ml of phosphorus oxychloride and 127 ml of pyridine are stirred in a 1 L four-necked flask equipped with a stirrer, calcium chloride tube, thermometer and baffle. Add 16.7 ml of water under ice cooling, add 100 g of riboflavin, and stir overnight at room temperature.
On the next day, the intermediate precipitated in Nutsche was collected by suction filtration and washed with 250 ml of acetonitrile. The obtained intermediate is transferred to a 1 L eggplant flask, 80 ml of concentrated hydrochloric acid and 80 ml of water are added, and the mixture is stirred at 50 ° C. for 3 hours. The solution is cooled to 20 ° C. or lower, and 250 ml of 25% NaOH water is added dropwise to adjust the pH to 5.5. After cooling this solution to 10 ° C. or lower, the crude FMN precipitated in Nutsche was collected by suction filtration and washed with 200 ml of methanol. The obtained crude FMN was transferred to a 1 L eggplant flask, recrystallized with water and methanol, filtered and dried under reduced pressure to obtain 88.8 g of fine FMN. (Equivalent to 70% of theoretical amount)
By HPLC analysis, the product contained:
Riboflavin-3-phosphate 2.5%
Riboflavin-4-phosphate 8.5%
Riboflavin-5-phosphate 86.8%
Riboflavin 1.4%
The optical rotation was + 38.5 °.
[0008]
Example 2 Production of Riboflavin Phosphate 600 ml of acetonitrile, 150 ml of phosphorus oxychloride and 220 ml of triethylamine are placed in a 1 L four-necked flask equipped with a stirrer, calcium chloride tube, thermometer and baffle and stirred. Add 16.7 ml of water under ice cooling, add 100 g of riboflavin, and stir overnight at room temperature. On the next day, the intermediate precipitated in Nutsche was collected by suction filtration and washed with 250 ml of acetonitrile. The obtained intermediate is transferred to a 1 L eggplant flask, 80 ml of concentrated hydrochloric acid and 80 ml of water are added, and the mixture is stirred at 50 ° C. for 2 hours. The solution is cooled to 20 ° C. or lower, and 250 ml of 25% NaOH water is added dropwise to adjust the pH to 5.5. After cooling this solution to 10 ° C. or lower, the crude FMN precipitated in Nutsche was collected by suction filtration and washed with 200 ml of methanol. The obtained crude FMN was transferred to a 1 L eggplant flask, recrystallized with water and methanol, filtered and dried under reduced pressure to obtain 81.3 g of fine FMN. (Equivalent to 64% of theoretical amount)
By HPLC analysis, the product contained:
Riboflavin-3-phosphate 2.5%
Riboflavin-4-phosphate 8.4%
Riboflavin-5-phosphate 86.2%
Riboflavin 1.9%
The optical rotation was + 38.5 °.
[0009]
Example 3 Production of riboflavin phosphate The reaction was carried out in the same manner as in Example 1 except that 300 ml of tetrahydrofuran was used from acetonitrile. After filtration, it was dried under reduced pressure to obtain 88.9 g of fine FMN. (Corresponding to 70.0% of theory) This product contained the following by HPLC analysis:
Riboflavin-3-phosphate 2.4%
Riboflavin-4-phosphate 8.4%
Riboflavin-5-phosphate 87.1%
Riboflavin 1.0%
The optical rotation was + 38.7 °.
[0010]
Example 4 Production of Riboflavin Phosphate 650 ml of the intermediate filtrate in the 100 g scale reaction of riboflavin was transferred to a 1000 ml eggplant flask, subjected to atmospheric distillation, and 495 ml was recovered at a distillation temperature of 78-82C. This was a mixture of acetonitrile, phosphorus oxychloride and HCl, and 5% phosphorus oxychloride by titration analysis. This results in 85% recovery of used acetonitrile and 60% recovery of unreacted phosphorus oxychloride.
[0011]
Example 5 Production of riboflavin phosphate The reaction was carried out in the same manner as in Example 1 except that 315 ml of recovered acetonitrile (containing 5% phosphorus oxychloride, corresponding to 15 ml as phosphorus oxychloride) and 135 ml phosphorus oxychloride were used. It was. After filtration, it was dried under reduced pressure to obtain 88.7 g of fine FMN. (Equivalent to 69.9% of theoretical amount)
By HPLC analysis, the product contained:
Riboflavin-3-phosphate 2.1%
Riboflavin-4-phosphate 7.7%
Riboflavin-5-phosphate 88.1%
Riboflavin 1.4%
The optical rotation was + 38.7 °.
[0012]
Example 6 Production of Riboflavin Phosphate 300 ml of acetonitrile, 150 ml of phosphorus oxychloride and 127 ml of pyridine are stirred in a 1 L four-necked flask equipped with a stirrer, calcium chloride tube, thermometer and baffle. Add 16.7 ml of water under ice cooling, add 100 g of riboflavin, and stir overnight at room temperature.
On the next day, the intermediate precipitated in Nutsche was collected by suction filtration and washed with 300 ml of acetonitrile. The obtained intermediate is transferred to a 1 L four-necked flask, 67 ml of concentrated hydrochloric acid and 133 ml of water are added, and the mixture is stirred at 40 ° C. for 21 hours. At this time, the solution changed from a clear brown solution to a yellow suspension solution, and showed an HPLC value of 91.2%. When 25% NaOH aqueous solution is gradually added to this reaction solution and 280 ml is added, pH is 9.3 and a clear brown solution is obtained. When 34 ml of concentrated hydrochloric acid is gradually added and pH is 5.5, a suspension reaction solution is obtained. After cooling, the mixture was filtered with suction, washed with alcohol, and dried under reduced pressure to obtain 104.2 g of the desired product. (Equivalent to 82% of theoretical amount)
By HPLC analysis, the product contained:
Riboflavin-3-phosphate 2.8%
Riboflavin-4-phosphate 5.4%
Riboflavin-5-phosphate 88.9%
Riboflavin 0.8%
The optical rotation was + 38.4 °.
[0013]
Example 7 Production of riboflavin phosphate Into a 1 L four-necked flask equipped with a stirrer, calcium chloride tube, thermometer and baffle, 300 ml of acetonitrile, 150 ml of phosphorus oxychloride and 127 ml of pyridine are added and stirred. Add 16.7 ml of water under ice cooling, add 100 g of riboflavin, and stir overnight at room temperature.
On the next day, the intermediate precipitated in Nutsche was collected by suction filtration and washed with 300 ml of acetonitrile. The obtained intermediate is transferred to a 1 L four-necked flask, 67 ml of concentrated hydrochloric acid and 133 ml of water are added, and the mixture is stirred at 40 ° C. for 21 hours. At this time, the solution changed from a clear brown solution to a yellow suspension solution, and showed an HPLC value of 90.2%. Concentrated hydrochloric acid is gradually added to the reaction solution, and when 110 ml is added, a clear brown solution is obtained. Furthermore, when 392 ml of 25% alkaline water is gradually added, pH = 5.5 is exhibited and a suspension reaction solution is obtained. After cooling, the mixture was filtered with suction, washed with alcohol, and dried under reduced pressure to obtain 108.8 g of the desired product. (Equivalent to 85.7% of theoretical amount)
By HPLC analysis, the product contained:
Riboflavin-3-phosphate 3.3%
Riboflavin-4-phosphate 6.1%
Riboflavin-5-phosphate 88.6%
Riboflavin 0.8%
The optical rotation was + 38.7 °.
[0014]
Example 8 Production of riboflavin phosphate The intermediate obtained in the same manner as in Example 6 was transferred to a 1 L four-necked flask, added with 53 ml of concentrated nitric acid and 167 ml of water, and stirred at 50 ° C for 16 hours. After cooling to room temperature, 220 ml of 25% NaOH water was added to adjust pH to 5.5. Further, 200 ml of methanol was added, and after cooling, suction filtered, washed with alcohol and dried under reduced pressure to obtain 111.3 g of the desired product. (Equivalent to 87.6% of theoretical amount)
From HPLC analysis, the product contained:
Riboflavin-3-phosphate 4.5%
Riboflavin-4-phosphate 6.1%
Riboflavin-5-phosphate 88.1%
Riboflavin 0.6%
The optical rotation was + 38.7 °.
[0015]
Example 9 Production of Riboflavin Phosphate
A 1000 mL 4-neck flask was charged with 250 mL of acetonitrile, 127 mL of pyridine, and 150 mL of phosphorus oxychloride, and cooled with ice water. A mixture of 16.6 mL of ion exchange water / 100 mL of acetonitrile was added over 1 hour, 100 g of riboflavin was added, and the mixture was stirred overnight. The next morning, the precipitate was filtered and washed with 150 mL of acetonitrile.
In a separate flask, 187.5 mL of ion exchange water and 62.5 mL of concentrated hydrochloric acid were taken in advance to prepare 9% aqueous HCl. The entire amount of the precipitate collected by filtration was added, and the mixture was stirred overnight in a 50 ° C. warm water bath. The solution was dissolved by adding 267 mL of 25% NaOH aqueous solution while cooling the next morning, and at a temperature of 31 ° C., 28.5 mL of concentrated hydrochloric acid was added to adjust to pH = 5.5, and the mixture was further stirred overnight under cooling.
The crystals precipitated the next morning were separated and washed with 200 mL of 10% water / methanol. The wet crystals were transferred into a 1000 mL eggplant flask, dried in a 20 ° C. water bath under reduced pressure of 60 mmHg overnight, and further dried in a 40 ° C. water bath at a vacuum of 10 mmHg or less to give 102 g of the title compound. (Yield; 77.4%, 5'-FMN purity; 90.3%, moisture; 3.6%, methanol; not detected)
[0016]
Example 10 Production of riboflavin phosphate Riboflavin and phosphorus oxychloride were reacted in the same manner as in Example 9.
In a separate flask, 187.5 mL of ion exchange water and 62.5 mL of concentrated hydrochloric acid were taken in advance to prepare 9% aqueous HCl. The whole amount of the precipitate collected by filtration was added, and the reaction was carried out in the same manner as in Example 9 in a 40 ° C. hot water tank.
After cooling in the morning, 292 mL of 25% NaOH water was added and dissolved, and then 40 mL of concentrated hydrochloric acid was added at an internal temperature of 34 ° C. to pH = 5.5. After cooling, the crystals were separated and washed with 15% water / 300 mL of methanol. Thereafter, drying was conducted in the same manner as in Example 9 to obtain 101 g of the title compound. (Yield; 77.1%, 5'-FMN purity; 88.4%, moisture; 3.1%, methanol; not detected)
[0017]
Example 11 Production of riboflavin phosphate Riboflavin and phosphorus oxychloride were reacted in the same manner as in Example 9.
In a separate flask, 187.5 mL of ion exchange water and 62.5 mL of concentrated hydrochloric acid were taken in advance to prepare 9% aqueous HCl. The whole amount of the precipitate collected by filtration was added, and the reaction was conducted in the same manner as in Example 9 in a 60 ° C. hot water tank.
After cooling in the morning, 288 mL of 25% NaOH water was added and dissolved, and then 40 mL of concentrated hydrochloric acid was added at an internal temperature of 34 ° C. to pH = 5.5. After cooling, the crystals were separated and washed with 15% water / 300 mL of methanol.
The wet crystals were transferred into a 1000 mL eggplant flask and dried overnight at 40 mmHg in a 20 ° C. water bath and further in a 40 ° C. water bath at a vacuum of 10 mmHg or less to give 100.7 g of the title compound. (Yield; 76.4%, 5'-FMN purity; 87.5%, moisture; 3.7% ;, methanol; not detected)
[0018]
Example 12 Production of riboflavin phosphate Riboflavin and phosphorus oxychloride were reacted in the same manner as in Example 9.
In a separate flask, 195 mL of ion exchange water and 55 mL of concentrated hydrochloric acid were taken in advance to prepare 8% HCl water. The whole amount of the precipitate collected by filtration was added, and the reaction was carried out in the same manner as in Example 9 in a 40 ° C. hot water tank.
After cooling the next morning, 276 mL of 25% NaOH water was added and dissolved, and 36.8 mL of concentrated hydrochloric acid was added at an internal temperature of 29 ° C. to pH = 5.5. After cooling, the crystals were separated and washed with 300 mL of 10% water / methanol. The wet crystals were transferred to a dryer, dried by ventilation overnight, and further dried at a vacuum of 40 ° C./10 mmHg or less to obtain 99 g of the title compound. (Yield: 75.5%, 5'-FMN purity: 90.7%, moisture 3.1%, methanol; not detected)
[0019]
Example 13 Production of riboflavin phosphate Riboflavin and phosphorus oxychloride were reacted in the same manner as in Example 9.
In a separate flask, 180.4 mL of ion exchange water and 69.6 mL of concentrated hydrochloric acid were taken in advance to prepare 10% aqueous HCl. The whole amount of the precipitate collected by filtration was added, and the reaction was conducted in warm water at 40 ° C. in the same manner as in Example 9.
After cooling the next morning with 308 mL of 25% NaOH water, the solution was dissolved at an internal temperature of 27 ° C. to add 38.4 mL of concentrated hydrochloric acid to pH = 5.5. After cooling, the crystals were separated and washed with 300 mL of 10% water / methanol. Thereafter, drying was conducted in the same manner as in Example 12 to obtain 101 g of the title compound. (Yield; 77.1%, 5'-FMN purity; 88.6%, moisture; 3.1%, methanol; not detected)
[0020]
Example 14 Production of riboflavin phosphate Riboflavin and phosphorus oxychloride were reacted in the same manner as in Example 9.
In a separate flask, 133 mL of ion-exchanged water and 67 mL of concentrated hydrochloric acid were taken in advance to prepare 12% HCl aqueous solution. The whole amount of the precipitate collected by filtration was added, and the reaction was carried out in the same manner as in Example 9 in a 40 ° C. hot water tank.
The solution was dissolved by adding 280 mL of 25% NaOH water the next day while cooling, and then adjusted to pH = 5.5 by adding concentrated hydrochloric acid 34 mL at an internal temperature of 25 ° C. After cooling, the crystals were separated and washed with 200 mL of 5% water / methanol. Thereafter, drying was conducted in the same manner as in Example 12 to obtain 106.2 g of the title compound. (Yield; 80.4%, 5'-FMN purity; 88.9%, moisture; 3.9%, methanol; not detected)
[0021]
Example 15 Production of riboflavin phosphate Riboflavin and phosphorus oxychloride were reacted in the same manner as in Example 9.
In a separate flask, 133 mL of ion-exchanged water and 67 mL of concentrated hydrochloric acid were taken in advance to prepare 12% HCl aqueous solution. The whole amount of the precipitate collected by filtration was added, and the reaction was carried out in the same manner as in Example 9 in a 40 ° C. hot water tank.
Concentrated hydrochloric acid (110 mL) was added and dissolved by stirring the following day while cooling, and then 392 mL of 25% NaOH water was added to adjust the pH to 5.5. After cooling, the crystals were separated and washed with 5% water / 200 mL methanol. Thereafter, drying was conducted in the same manner as in Example 12 to obtain 111 g of the title compound. (Yield; 83.9%, 5'-FMN purity; 88.6%, moisture; 4.0%, methanol; not detected)
[0022]
Example 16 Production of riboflavin phosphate Riboflavin and phosphorus oxychloride were reacted in the same manner as in Example 9.
In a separate flask, 182.5 mL of ion-exchanged water and 61.5 mL of concentrated nitric acid were taken in advance to prepare 15% aqueous nitric acid. The whole amount of the precipitate collected by filtration was added and reacted in the same manner as in Example 9 in a 50 ° C. hot water tank.
Add 280 mL of 25% aqueous NaOH while cooling the next day, dissolve, add 24.8 mL of concentrated nitric acid at an internal temperature of 28 ° C to pH = 5.5, add methanol 100 mL, cool, separate crystals, and wash with 200 mL of methanol did. Thereafter, drying was conducted in the same manner as in Example 12 to obtain 98.8 g of the title compound. (Yield; 74.7%, 5'-FMN purity; 89.1%, moisture; 3.0%, methanol; not detected)
[0023]
Example 17 Production of riboflavin phosphate Riboflavin and phosphorus oxychloride were reacted in the same manner as in Example 9.
In a separate flask, 187 mL of ion-exchanged water and 53 mL of concentrated nitric acid were taken in advance to prepare 13% nitric acid solution. The whole amount of the precipitate collected by filtration was added and reacted in the same manner as in Example 9 in a 50 ° C. hot water tank.
While cooling the next day, 220 mL of 25% NaOH water was added to adjust the pH to 5.5, 200 mL of methanol was added and the mixture was cooled, and then the crystals were separated and washed with 500 mL of methanol. Thereafter, drying was conducted in the same manner as in Example 9 to obtain 111.3 g of the title compound. (Yield; 85.8%, 5'-FMN purity; 86.5%, moisture; 2.1%, methanol; not detected)
[0024]
Comparative Example 1 Production of Riboflavin Phosphate (Additional Examination of JP-A-48-54099)
In a 1 L four-necked flask equipped with a stirrer, calcium chloride tube, thermometer and baffle, 80 ml of acetonitrile, 22.5 ml of phosphorus oxychloride and 19 ml of pyridine are added and stirred. Under ice cooling, 2.5 ml of water was added dropwise, 10 g of riboflavin was added, and the mixture was stirred at room temperature for 5 hours. After adding 500 ml of water, the solvent was distilled off under reduced pressure. The aqueous solution in which the crystals were precipitated was dissolved by heating and then cooled, and the pH was adjusted to 5.5 with 25% NaOH water. The solution was concentrated to dryness, water was added to the residue to make 300 ml, and the mixture was heated and dissolved again. After cooling, the precipitated crystals were collected by filtration, washed with water, alcohol and ether and dried under reduced pressure to obtain 11.0 g of the desired product. (Equivalent to 86.6% of theoretical amount)
By HPLC analysis, the product contained:
Riboflavin-3-phosphate 5.7%
Riboflavin-4-phosphate 12.6%
Riboflavin-5-phosphate 78.2%
Riboflavin 0.4%
The optical rotation was + 39.5 °.
[0025]
Comparative Example 2 Production of Riboflavin Phosphate (Additional Examination of JP-A-48-54099)
The same procedure as in Comparative Example 1 was carried out except that pyridine was changed to 33 ml of triethylamine to obtain 10.3 g of the desired product. (Equivalent to 81.1% of theoretical amount)
By HPLC analysis, the product contained:
Riboflavin-3-phosphate 6.0%
Riboflavin-4-phosphate 12.0%
Riboflavin-5-phosphate 73.8%
Riboflavin 2.1%
The optical rotation was + 39.4 °.
[0026]
Comparative Example 3 Production of Riboflavin Phosphate (Additional Examination of JP-A-3-109394)
42 ml of γ-butyrolactone was put in a 500 ml brown eggplant flask, and 10.8 g of riboflavin and 6.4 ml of phosphorus oxychloride were sequentially added with stirring. The solution in the flask was slowly heated to 35 ° C. and stirred at this temperature for 1 hour. The reaction solution was rapidly charged with 18 ml of water and then heated to 90 ° C., and further 25 ml of water was added and kept at 90 ° C. internal temperature for 10 minutes. Further, 43 ml of water was added and cooled to room temperature. The solution was cooled to pH = 5.5 with 25% NaOH aqueous solution, filtered, washed and dried under reduced pressure to obtain 10.4 g of the desired product. (Equivalent to 81.9% of theoretical amount)
By HPLC analysis, the product contained:
Riboflavin-3-phosphate 5.5%
Riboflavin-4-phosphate 12.0%
Riboflavin-5-phosphate 73.1%
Riboflavin 3.8%
The optical rotation was + 38.9 °.
From the above Examples and Comparative Examples, the excellent effects of the present invention are clear.

Claims (4)

A production method for producing riboflavin-5′-phosphate represented by the following formula (III) from riboflavin represented by the following formula (I),

Reacting the riboflavin with phosphorus oxychloride in the presence of pyridine or triethylamine to obtain a riboflavin cyclic 4 ′, 5′-phosphoridate represented by the formula (II);
Extracting the riboflavin cyclic 4 ′, 5′-phosphoridate out of the system;
Hydrolyzing under acidic conditions so as to decompose and isomerize the riboflavin cyclic 4 ′, 5′-phosphoridate taken out of the system,
Hydrolysis under the acidic condition is a production method in which an acid having a concentration of 1 to 35.5 (w / v)% is used at a volume of 1 to 10 times that of the riboflavin.   The manufacturing method according to claim 1, wherein the acid is hydrochloric acid, nitric acid, or sulfuric acid. A production method for producing riboflavin-5′-phosphate sodium salt from riboflavin represented by the following formula (I):

Reacting the riboflavin with phosphorus oxychloride in the presence of pyridine or triethylamine to obtain a riboflavin cyclic 4 ′, 5′-phosphoridate represented by the formula (II);
Extracting the riboflavin cyclic 4 ′, 5′-phosphoridate out of the system;
Hydrolyzing under acidic conditions so as to decompose and isomerize the riboflavin cyclic 4 ′, 5′-phosphoridate taken out of the system;
Treating the compound represented by the formula (III) with sodium hydroxide,
Hydrolysis under the acidic condition is a production method in which an acid having a concentration of 1 to 35.5 (w / v)% is used at a volume of 1 to 10 times that of the riboflavin.   The manufacturing method according to claim 3, wherein the acid is hydrochloric acid, nitric acid, or sulfuric acid.