CN113430546A - Preparation method of homocysteine thiolactone hydrochloride - Google Patents
Preparation method of homocysteine thiolactone hydrochloride Download PDFInfo
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- CN113430546A CN113430546A CN202110640974.6A CN202110640974A CN113430546A CN 113430546 A CN113430546 A CN 113430546A CN 202110640974 A CN202110640974 A CN 202110640974A CN 113430546 A CN113430546 A CN 113430546A
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- homocystine
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- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B3/00—Electrolytic production of organic compounds
- C25B3/20—Processes
- C25B3/25—Reduction
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- C25B3/00—Electrolytic production of organic compounds
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- C25B3/05—Heterocyclic compounds
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- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B3/00—Electrolytic production of organic compounds
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- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B3/00—Electrolytic production of organic compounds
- C25B3/01—Products
- C25B3/09—Nitrogen containing compounds
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- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B3/00—Electrolytic production of organic compounds
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Abstract
The invention discloses a preparation method of homocysteine thiolactone hydrochloride, which is characterized in that homocysteine is subjected to electrolytic reduction to obtain homocysteine thiolactone hydrochloride; wherein the electrolytic reduction is carried out in an ion diaphragm electrolytic cell; the catholyte is a hydrochloric acid solution of homocystine, and the anolyte is a dilute sulfuric acid solution; the cathode adopts a titanium wire, and a carbon felt net is fixed at the bottom of the titanium wire; the anode adopts lead wire; the metal ion content in the product is low; in the synthesis process, the operation is safe, no waste water and no waste gas are generated, and the method is green and environment-friendly. In addition, the method has high product yield.
Description
Technical Field
The invention relates to a preparation method of homocysteine thiolactone hydrochloride.
Background
Homocysteine thiolactone hydrochloride is an important biochemical reagent and a drug intermediate, and can be used for preparing medicines such as cetivone, erdosteine and the like. The cetivone can be mainly used for treating acute craniocerebral trauma and conscious disturbance after brain operation; erdosteine is used for treating airway obstruction caused by acute and chronic bronchitis and thick sputum.
At present, homocysteine thiolactone hydrochloride is synthesized by reducing homocysteine by using metal zinc or tin and hydrochloric acid.
However, the homocysteine thiolactone hydrochloride synthesized by the method has high metal ion content in the homocysteine thiolactone hydrochloride product; secondly, the method needs to use a large amount of zinc or tin and hydrochloric acid to generate a large amount of hydrogen, has high operation danger, also generates a large amount of waste water of zinc salt or tin salt, and is very environment-friendly; thirdly, the yield of the method is not high, and the yield is about 50 to 60 percent when the homocystine is used as a raw material.
Disclosure of Invention
In view of the above disadvantages, there is a need for a new method for preparing homocysteine thiolactone hydrochloride.
A method for preparing homocysteine thiolactone hydrochloride comprises the steps of carrying out electrolytic reduction on homocysteine to obtain homocysteine thiolactone hydrochloride;
wherein the electrolytic reduction is carried out in an ion diaphragm electrolytic cell; the catholyte is a hydrochloric acid solution of homocystine, and the anolyte is a dilute sulfuric acid solution; the cathode adopts a titanium wire, and a carbon felt net is fixed at the bottom of the titanium wire; the anode adopts lead wire.
According to the preparation method, the content of metal ions in the product is low; in the synthesis process, the operation is safe, no waste water and no waste gas are generated, and the method is green and environment-friendly. In addition, the method has high product yield.
Preferably, the electrolytic reduction adopts a constant current power supply, and the electrolytic time is 8-10 h.
Preferably, the current of the constant current source is 3A.
Preferably, the ionic membrane in the ionic membrane electrolysis cell is a cationic membrane.
Preferably, before the electrolytic reduction, inert gas is introduced into the cathode chamber for 3 min to 5 min.
Preferably, after the electrolytic reduction, the method further comprises the following steps:
concentrating and filtering the catholyte, washing a filtered product with absolute ethyl alcohol, drying in vacuum, and collecting to obtain a first product; concentrating the absolute ethyl alcohol washing solution in vacuum, drying the concentrate in vacuum, and collecting to obtain a second product; and combining and collecting the first product and the second product.
Preferably, the temperature of the electrolytic reduction is 30-70 ℃.
Preferably, the concentration of the dilute sulfuric acid solution is 1-3 mol/L; the hydrochloric acid solution of homocystine is formed by dissolving homocystine crystals in 1-3 mol/L hydrochloric acid.
Preferably, homocystine in the catholyte is obtained by:
methionine and concentrated sulfuric acid are mixed according to a molar ratio of 1: 2-5, reacting at 70-110 ℃, adjusting the pH to 5-6 after the reaction is finished, and filtering the precipitated solid to obtain homocystine.
Preferably, homocystine in the catholyte is obtained by:
reacting methionine with 10% -60% hydrobromic acid and concentrated sulfuric acid, heating under inert atmosphere to react, adjusting pH to 5-6 after the reaction is finished, and filtering separated solid to obtain homocystine.
Drawings
FIG. 1 is a NMR chart of the product of example 2.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to specific embodiments. It should be understood that the detailed description and specific examples, while indicating the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
A method for preparing homocysteine thiolactone hydrochloride comprises the steps of carrying out electrolytic reduction on homocysteine to obtain homocysteine thiolactone hydrochloride;
wherein the electrolytic reduction is carried out in an ion diaphragm electrolytic cell; the catholyte is a hydrochloric acid solution of homocystine, and the anolyte is a dilute sulfuric acid solution; the cathode adopts a titanium wire, and a carbon felt net is fixed at the bottom of the titanium wire; the anode adopts lead wire.
The cathode adopts a titanium wire, and a carbon felt net is fixed at the bottom of the titanium wire; therefore, the overpotential of the cathode can be effectively reduced, the area of the cathode is increased, more hydrogen is generated by electrolysis in unit time, and the electrolytic reduction reaction is facilitated. The anode and the cathode are made of different materials, and the anode is made of lead wires; is beneficial to reducing the resistance of the whole electrolysis. If the same material as the cathode is used as the anode, the anolyte is a dilute sulfuric acid solution, so that the whole electrolytic resistance is extremely high, and the current is almost zero.
The whole electrolytic electrode is simple, easy and durable, has high mechanical strength and is suitable for mass production.
The homocysteine can be D-homocysteine, L-homocysteine or DL-homocysteine; the homocystine is D-homocystine, L-homocystine, DL-homocystine.
Preferably, the electrolytic reduction adopts a constant current power supply, and the electrolytic time is 8-10 h. The power supply equipment for electrolytic reduction is constant-current constant-voltage power supply equipment, can control constant current or constant voltage, and provides direct current.
Preferably, the current of the constant current source is 3A.
Preferably, the ionic membrane in the ionic membrane electrolytic cell is a cationic membrane, so that H can be generated+Ion passage to increase H in catholyte+The concentration of the ions. When the cation diaphragm is selected, the cation diaphragm preferably has certain acid resistance and high temperature resistanceAnd (4) sex.
Preferably, before the electrolytic reduction, inert gas is introduced into the cathode chamber for 3 min to 5 min. And inert gas is introduced for 3-5 min, so that air is exhausted, and interference is avoided.
Preferably, after the electrolytic reduction, the method further comprises the following steps:
concentrating and filtering the catholyte, washing a filtered product with absolute ethyl alcohol, drying in vacuum, and collecting to obtain a first product; concentrating the absolute ethyl alcohol washing solution in vacuum, drying the concentrate in vacuum, and collecting to obtain a second product; and combining and collecting the first product and the second product.
Preferably, the temperature of the electrolytic reduction is 30-70 ℃.
Preferably, the concentration of the dilute sulfuric acid solution is 1-3 mol/L; the hydrochloric acid solution of homocystine is formed by dissolving homocystine crystals in 1-3 mol/L hydrochloric acid.
Preferably, homocystine in the catholyte is obtained by:
methionine and concentrated sulfuric acid are mixed according to a molar ratio of 1: 2-5, reacting at 70-110 ℃, adjusting the pH to 5-6 after the reaction is finished, and filtering the precipitated solid to obtain homocystine.
Preferably, homocystine in the catholyte is obtained by:
reacting methionine with 10% -60% hydrobromic acid and concentrated sulfuric acid, heating under inert atmosphere to react, adjusting pH to 5-6 after the reaction is finished, and filtering separated solid to obtain homocystine.
The corresponding methionine is D-methionine, L-methionine, DL-methionine according to DL property of the final product.
The invention is further illustrated with reference to the following specific examples.
Example 1
Adding 1kg of homocystine into 8L of hydrochloric acid solution with the concentration of 2mol/L, and uniformly mixing to form a solution serving as catholyte; 1mol/L sulfuric acid solution is used as anode liquid.
The cathode adopts a titanium wire, a carbon felt net with a proper size is fixed at the bottom of the titanium wire, and the anode adopts a lead wire. The cathode chamber and the anode chamber of the electrolytic cell are separated by a cation diaphragm.
Electrolyzing for 8h under the condition that constant current is kept at 3.0A and the electrolysis temperature is 45 ℃; the cathode was detected to be free of DL-homocystine. Then concentrating the crystallized catholyte, filtering, washing with anhydrous ethanol, vacuum drying, vacuum concentrating the anhydrous ethanol filtrate, vacuum drying the concentrate, and mixing to obtain 1.01kg of solid with yield of 95% (calculated by taking homocystine as a base number) and purity of 99.03%.
Example 2
Adding 2kg of methionine and 4kg of concentrated sulfuric acid (mass fraction is 98%) into a reaction kettle in sequence, and reacting for 8 hours at the internal temperature of 100 ℃ to obtain hydrolysate. Neutralizing the hydrolysate with sodium hydroxide solution to pH 5-6, separating out solid, cooling, vacuum filtering, and washing to obtain homocystine 1.084kg with yield of 54.2% (calculated by methionine as base number).
1.084kg of homocystine was dissolved in 2mol/L of 8.7L hydrochloric acid solution as catholyte and 1mol/L of sulfuric acid solution as anolyte. The cathode of the electrolytic cell adopts titanium wires, a carbon felt net with proper size is fixed at the bottom of the electrolytic cell, and the anode adopts lead wires. The cathode chamber and the anode chamber of the electrolytic cell are separated by a cation diaphragm, and the cathode and the anode are applied to the cation diaphragm electrolytic cell. And (3) electrolyzing for 9 hours under the condition that the constant current is kept at 3.0A and the electrolysis temperature is 45 ℃, and detecting whether homocystine exists at the cathode. Then concentrating the crystallized catholyte, filtering, washing with absolute ethanol, vacuum drying, vacuum concentrating the absolute ethanol filtrate, vacuum drying the concentrate, and mixing to obtain 1.187kg of solid.
The product is analyzed by high performance liquid chromatography, the yield is 95.5 percent (calculated by taking homocystine as a base number), the yield is 53.9 percent (calculated by taking methionine as a base number), and the purity is 99.4 percent.
The product was subjected to nuclear magnetic resonance and the resulting product was homocysteine thiolactone, the results of which are shown in FIG. 1.
Example 3
Adding 2kg of methionine and 6.94kg of 40% hydrobromic acid into a reaction kettle in sequence, dropwise adding 2.68kg of concentrated sulfuric acid (the mass fraction is 98%) at low temperature, heating the system after dropwise adding, and reacting for 6 hours at the internal temperature of 120 ℃ to obtain hydrolysate. Neutralizing the hydrolysate with sodium hydroxide solution to pH 5-6, separating out solid, cooling, vacuum filtering, and washing to obtain homocystine 1.69kg with yield of 94% (calculated with methionine as base number).
1.69kg of homocystine is dissolved in 2mol/L, 13.5L hydrochloric acid solution as catholyte, and 1mol/L sulfuric acid solution as anolyte. The cathode of the electrolytic cell adopts titanium wires, a carbon felt net with proper size is fixed at the bottom of the electrolytic cell, and the anode adopts lead wires. The cathode chamber and the anode chamber of the electrolytic cell are separated by a cation diaphragm, and the cathode and the anode are applied to the cation diaphragm electrolytic cell. And (3) electrolyzing for 10 hours under the condition that the constant current is kept at 3.0A and the electrolysis temperature is 45 ℃, and detecting whether homocystine exists at the cathode. Then concentrating the crystallized catholyte, filtering, washing with absolute ethanol, vacuum drying, vacuum concentrating the absolute ethanol filtrate, vacuum drying the concentrate, and mixing to obtain 1.86kg of solid with yield of 96.1% (calculated based on homocystine), yield of 90.3% (calculated based on methionine) and purity of 99.6%.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (10)
1. A preparation method of homocysteine thiolactone hydrochloride is characterized in that homocysteine is electrolytically reduced to obtain homocysteine thiolactone hydrochloride;
wherein the electrolytic reduction is carried out in an ion diaphragm electrolytic cell; the catholyte is a hydrochloric acid solution of homocystine, and the anolyte is a dilute sulfuric acid solution; the cathode adopts a titanium wire, and a carbon felt net is fixed at the bottom of the titanium wire; the anode adopts lead wire.
2. The preparation method of homocysteine thiolactone hydrochloride according to claim 1 characterized in that the electrolytic reduction uses a constant current power supply, the electrolysis time is 8-10 h.
3. The method of claim 2, wherein the current of the constant current source is 3A.
4. The method of claim 1, wherein the ionic membrane of the ionic membrane electrolyzer is a cationic membrane.
5. The method for preparing homocysteine thiolactone hydrochloride according to claim 1 wherein inert gas is first introduced into the cathode chamber for 3-5 min before the electrolytic reduction.
6. The method of claim 1, further comprising the step of, after the electrolytic reduction:
concentrating and filtering the catholyte, washing a filtered product with absolute ethyl alcohol, drying in vacuum, and collecting to obtain a first product; concentrating the absolute ethyl alcohol washing solution in vacuum, drying the concentrate in vacuum, and collecting to obtain a second product; and combining and collecting the first product and the second product.
7. The method for producing homocysteine thiolactone hydrochloride according to claim 1 wherein the temperature of the electrolytic reduction is 30-70 ℃.
8. The method for preparing homocysteine thiolactone hydrochloride according to claim 1 wherein the concentration of the dilute sulphuric acid solution is 1-3 mol/L; the hydrochloric acid solution of homocystine is formed by dissolving homocystine crystals in 1-3 mol/L hydrochloric acid.
9. The method of claim 1, wherein the homocystine in the catholyte is obtained by:
methionine and concentrated sulfuric acid are mixed according to a molar ratio of 1: 2-5, reacting at 70-110 ℃, adjusting the pH to 5-6 after the reaction is finished, and filtering the precipitated solid to obtain homocystine.
10. The method of claim 1, wherein the homocystine in the catholyte is obtained by:
reacting methionine with 10% -60% hydrobromic acid and concentrated sulfuric acid, heating under inert atmosphere to react, adjusting pH to 5-6 after the reaction is finished, and filtering separated solid to obtain homocystine.
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Citations (6)
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| CN111004209A (en) * | 2019-12-24 | 2020-04-14 | 浙江工业大学 | Continuous production method of DL-homocysteine thiolactone hydrochloride |
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2021
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| CN1232091A (en) * | 1998-04-13 | 1999-10-20 | 华中师范大学 | Electrolytic bath for pollution-free electrolytic synthesis of L-cysteine hydrochloride and glyoxalic acid |
| CN101144169A (en) * | 2007-08-24 | 2008-03-19 | 湖北新生源生物工程股份有限公司 | Method for producing DL-homocysteine lactone hydrochlorate |
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