CN112251769A - Method for synthesizing sulfenyl diacetic acid - Google Patents
Method for synthesizing sulfenyl diacetic acid Download PDFInfo
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- CN112251769A CN112251769A CN202011079563.6A CN202011079563A CN112251769A CN 112251769 A CN112251769 A CN 112251769A CN 202011079563 A CN202011079563 A CN 202011079563A CN 112251769 A CN112251769 A CN 112251769A
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C319/00—Preparation of thiols, sulfides, hydropolysulfides or polysulfides
- C07C319/02—Preparation of thiols, sulfides, hydropolysulfides or polysulfides of thiols
- C07C319/12—Preparation of thiols, sulfides, hydropolysulfides or polysulfides of thiols by reactions not involving the formation of mercapto groups
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C319/00—Preparation of thiols, sulfides, hydropolysulfides or polysulfides
- C07C319/14—Preparation of thiols, sulfides, hydropolysulfides or polysulfides of sulfides
Abstract
The invention discloses a method for synthesizing sulfurous diacetic acid, which mainly comprises the following steps: dissolving homocystine in hydrochloric acid as catholyte, and performing electro-reduction reaction in an electrolytic bath to obtain homocysteine hydrochloride; dissolving homocysteine hydrochloride and chloroacetic acid in water, adding methanol, dropwise adding a catalyst and a dehydrating agent, stirring for reacting for 2-5 h, cooling, filtering to separate out homoserine lactone hydrochloride, and distilling the filtrate under reduced pressure to obtain methyl thioglycolate; dissolving the methyl thioglycolate and the methyl haloacetate in methanol, controlling the temperature to be 25-50 ℃ to react for 6-12 h, carrying out reduced pressure distillation, adding dilute sulfuric acid, heating to 50-80 ℃, and separating and purifying to obtain the thiodiacetic acid. The synthetic method of thiodiglycolic acid can effectively improve the yield.
Description
Technical Field
The invention relates to the technical field of chemical synthesis. More particularly, the present invention relates to a process for the synthesis of thiodiglycolic acid.
Background
Sulfylidenediacetic acid is a carboxylic acid organic substance and can be used as a drug synthesis intermediate. In the prior art, sodium chloroacetate and sodium sulfide are frequently used for reacting to generate sodium thiodiglycolate during the synthesis of thiodiglycolate, and then the sodium thiodiglycolate is acidified to finally prepare the thiodiglycolate. The synthesis by the method can generate obvious side reaction, so that the yield is reduced, and the side reaction can generate toxic gas of hydrogen sulfide, so that the operation is dangerous and the environment is polluted.
Disclosure of Invention
An object of the present invention is to solve at least the above problems and to provide at least the advantages described later.
It is still another object of the present invention to provide a process for the synthesis of thiodiglycolic acid to increase the synthesis yield.
To achieve these objects and other advantages in accordance with the purpose of the invention, there is provided a method for synthesizing thiodiglycolic acid, mainly comprising the steps of:
dissolving homocystine in hydrochloric acid to serve as catholyte, dilute sulfuric acid to serve as anolyte, separating the two poles by using a bipolar membrane, and carrying out an electroreduction reaction in an electrolytic tank to prepare homocysteine hydrochloride;
dissolving homocysteine hydrochloride and chloroacetic acid in water, heating to 30-80 ℃, reacting for 5-8 h, reducing the temperature, reducing the pressure, recovering solvent water, adding methanol, controlling the temperature to 30-60 ℃, dropwise adding a catalyst and a dehydrating agent, stirring, reacting for 2-5 h, reducing the temperature, filtering and separating out homoserine lactone hydrochloride, and carrying out reduced pressure distillation on filtrate to obtain methyl thioglycolate, wherein the molar ratio of homocysteine hydrochloride to chloroacetic acid to methanol is 1 (1-5) to 1-1.2;
and step three, mixing and dissolving the methyl thioglycolate and the methyl haloacetate in the molar ratio of 1 (1-1.2) in methanol, controlling the temperature to be 25-50 ℃ to react for 6-12 h, carrying out reduced pressure distillation, adding dilute sulfuric acid, heating to 50-80 ℃, and separating and purifying to obtain the thiodiacetic acid.
Preferably, in the first step, the bipolar membrane is formed by compounding a cation exchange membrane, an intermediate interface catalyst layer and an anion exchange membrane.
Preferably, the cation exchange membrane and the anion exchange membrane have finger-shaped pore structures, and both are prepared by adopting a membrane preparation process by a solution phase inversion method.
Preferably, the cation exchange membrane is made of a sulfonic acid type cation exchange resin, and the anion exchange membrane is made of a quaternary ammonium salt type anion exchange resin.
Preferably, the intermediate interface catalyst layer is a polystyrene layer mixed with a metal complex, the mixed solution of polystyrene and the metal complex is spun on the surface of the cation exchange membrane by an electrostatic spinning method, and the anion exchange membrane is fixed on the surface of the cation exchange membrane spun with the intermediate interface catalyst layer by a hot pressing or bonding method, so that the bipolar membrane is obtained.
Preferably, the anode material of the electrolytic cell in the first step is lead-antimony-tin alloy, and the cathode material is lead.
Preferably, the electrolysis temperature in the first step is 30-50 ℃, and the current density is 0.08-0.09A/cm2The electrolysis time is 8-10 h.
Preferably, the catalyst in the second step is SO4 -2/TiO2。
Preferably, the dehydrating agent in the second step is thionyl chloride, thionyl bromide, benzene, toluene or xylene.
The invention at least comprises the following beneficial effects: according to the invention, the homocystine is subjected to electrolytic reduction reaction, on the basis of the prior art, the bipolar membrane with the middle interface layer is selected for electrostatic spinning, the cation exchange membrane and the anion exchange membrane of the bipolar membrane are both in porous structures, the middle interface layer can reduce the water dissociation voltage, and the porous structures can accelerate the conduction rate of ions, so that the conversion rate of homocystine is improved; in addition, the homocysteine is used as a raw material to prepare the thiodiglycolic acid, the products are easy to separate and purify, the yield of the thiodiglycolic acid is improved, the three wastes are less generated, and compared with the traditional reduction method, the method reduces the consumption of the raw material and reduces the pollution to the environment.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.
Detailed Description
The present invention is further described in detail below with reference to examples to enable those skilled in the art to practice the invention with reference to the description.
It will be understood that terms such as "having," "including," and "comprising," as used herein, do not preclude the presence or addition of one or more other elements or groups thereof.
It is to be noted that the experimental methods described in the following embodiments are all conventional methods unless otherwise specified, and the reagents and materials are commercially available unless otherwise specified.
The synthesis circuit of the invention is as follows:
< example 1>
Dissolving homocystine in hydrochloric acid to serve as catholyte, dilute sulfuric acid to serve as anolyte, lead-antimony-tin alloy serving as an anode material of an electrolytic tank, lead serving as a cathode material, separating the two electrodes by using a commercial BPM bipolar membrane, and performing electrolysis at the temperature of 40 ℃ and at the current density of 0.08A/cm2Carrying out electro-reduction reaction for 10h to prepare homocysteine hydrochloride;
dissolving homocysteine hydrochloride and chloroacetic acid in water, heating to 40 ℃, reacting for 8 hours, reducing the temperature and the pressure to recover solvent water, adding methanol to control the temperature to be 40 ℃, and dropwise adding SO4 -2/TiO2Reacting with thionyl chloride for 5 hours under stirring, cooling, filtering to separate out homoserine lactone hydrochloride, and distilling the filtrate under reduced pressure to prepare methyl thioglycolate, wherein the molar ratio of homocysteine hydrochloride to chloroacetic acid to methanol is 1:1.5: 1.2;
step three, mixing and dissolving the methyl thioglycolate and the methyl haloacetate in the molar ratio of 1:1.2 in methanol, controlling the temperature to react for 10 hours at 30 ℃, carrying out reduced pressure distillation, adding dilute sulfuric acid, heating to 60 ℃, and carrying out separation and purification to obtain the thiodiacetic acid.
< example 2>
Step one, taking a polystyrene film mixed with a metal complex as an intermediate interface catalyst layer, and bonding a commercially available sulfonic acid type cation exchange membrane, the intermediate interface catalyst layer and a commercially available quaternary ammonium salt type anion exchange membrane to form a self-made bipolar membrane;
dissolving homocystine in hydrochloric acid to serve as catholyte, dilute sulfuric acid to serve as anolyte, lead-antimony-tin alloy serving as an anode material of the electrolytic tank, lead serving as a cathode material, separating the two electrodes by the self-made bipolar membrane, and controlling the current density to be 0.09A/cm at the electrolysis temperature of 30 DEG C2Carrying out electro-reduction reaction for 8h to prepare homocysteine hydrochloride;
dissolving homocysteine hydrochloride and chloroacetic acid in water, heating to 50 ℃, reacting for 6h, reducing the temperature and the pressure to recover solvent water, adding methanol to control the temperature to be 45 ℃, and dropwise adding SO4 -2/TiO2Reacting with thionyl chloride for 4 hours under stirring, cooling, filtering and separating out homoserine lactone hydrochloride, and distilling the filtrate under reduced pressure to prepare methyl thioglycolate, wherein the molar ratio of homocysteine hydrochloride to chloroacetic acid to methanol is 1:1: 1;
step four, mixing and dissolving the methyl thioglycolate and the methyl haloacetate in the molar ratio of 1:1 in methanol, controlling the temperature to be 40 ℃ for reacting for 8 hours, carrying out reduced pressure distillation, adding dilute sulfuric acid, heating to 70 ℃, and carrying out separation and purification to obtain the thiodiacetic acid.
< example 3>
Preparing a sulfonic acid type cation exchange membrane and a quaternary ammonium salt type anion exchange membrane with finger-shaped pore structures by using a solution phase inversion method, dissolving polystyrene particles in an organic solvent, adding a metal complex for mixing, spinning the mixed solution on the surface of the cation exchange membrane by using an electrostatic spinning method, and bonding and fixing the anion exchange membrane on the surface of the cation exchange membrane spun with the polystyrene-metal complex to prepare the self-made bipolar membrane.
Dissolving homocystine in hydrochloric acid to serve as catholyte, dilute sulfuric acid to serve as anolyte, lead-antimony-tin alloy serving as an anode material of the electrolytic tank, lead serving as a cathode material, separating the two electrodes by the self-made bipolar membrane, and controlling the current density to be 0.09A/cm at the electrolysis temperature of 30 DEG C2And carrying out electro-reduction reaction for 8h to obtain homocysteine hydrochloride；
Dissolving homocysteine hydrochloride and chloroacetic acid in water, heating to 50 ℃, reacting for 6h, reducing the temperature and the pressure to recover solvent water, adding methanol to control the temperature to be 45 ℃, and dropwise adding SO4 -2/TiO2Reacting with thionyl chloride for 4 hours under stirring, cooling, filtering and separating out homoserine lactone hydrochloride, and distilling the filtrate under reduced pressure to prepare methyl thioglycolate, wherein the molar ratio of homocysteine hydrochloride to chloroacetic acid to methanol is 1:1.2: 1.2;
step four, mixing and dissolving the methyl thioglycolate and the methyl haloacetate in the molar ratio of 1:1.2 in methanol, controlling the temperature to be 40 ℃ for reacting for 8 hours, carrying out reduced pressure distillation, adding dilute sulfuric acid, heating to 70 ℃, and separating and purifying to obtain the thiodiacetic acid.
< comparative example 1>
Dissolving homocystine in hydrochloric acid to serve as catholyte, dilute sulfuric acid to serve as anolyte, lead-antimony-tin alloy serving as an anode material of an electrolytic cell, lead serving as a cathode material, separating the two electrodes by a commercial Nafion427 cation exchange membrane at the electrolysis temperature of 50 ℃, wherein the current density is 0.08A/cm2Carrying out electro-reduction reaction for 10h to prepare homocysteine hydrochloride;
dissolving homocysteine hydrochloride and chloroacetic acid in water, heating to 40 ℃, reacting for 8 hours, reducing the temperature and the pressure to recover solvent water, adding methanol to control the temperature to be 40 ℃, and dropwise adding SO4 -2/TiO2Reacting with thionyl chloride for 5 hours under stirring, cooling, filtering to separate out homoserine lactone hydrochloride, and distilling the filtrate under reduced pressure to prepare methyl thioglycolate, wherein the molar ratio of homocysteine hydrochloride to chloroacetic acid to methanol is 1:1.5: 1.2;
step three, mixing and dissolving the methyl thioglycolate and the methyl haloacetate in the molar ratio of 1:1.2 in methanol, controlling the temperature to react for 10 hours at 30 ℃, carrying out reduced pressure distillation, adding dilute sulfuric acid, heating to 60 ℃, and carrying out separation and purification to obtain the thiodiacetic acid.
< comparative example 2>
Dissolving chloroacetic acid in water, adding sodium bicarbonate with equal amount of substances to prepare sodium chloroacetate, then dropwise adding sodium sulfide into the sodium chloroacetate, wherein the molar ratio of the sodium chloroacetate to the sodium sulfide is 1:2.2, generating sodium thioidene diacetate, neutralizing to be acidic by utilizing sulfuric acid, and separating and purifying to prepare the thioidene diacetic acid.
The reaction principle is as follows:
side reactions that may occur during the reaction:
comparative example 2 the thiodiglycolic acid is prepared by the traditional method, and the toxic gas of hydrogen sulfide is generated by the side reaction generated in the reaction process, so that the operation of experimenters is dangerous, and the environment is polluted. Compared with the comparative example 2, products in the reaction processes of the examples 1-3 are easy to separate, side reactions are few, the yield of three wastes is low, and the operation is safe.
< measurement of yield and purity >
The yields and purities of the thiodiglycolic acids of examples 1 to 3 and comparative examples 1 to 2 were compared, wherein the yield is the ratio of the molar amount of the produced thiodiglycolic acid to the molar amount of the sulfur element in the raw material used, and the purity is the percentage content of the thiodiglycolic acid in the final product measured by a high performance liquid chromatography analyzer. The results are shown in table 1:
TABLE 1 comparison of yields
| Example 1 | Example 2 | Example 3 | Comparative example 1 | Comparative example 2 | |
| Yield (%) | 71.8 | 76.5 | 80.8 | 69.4 | 63.8 |
| Purity (%) | 98.32 | 98.55 | 99.12 | 97.88 | 99.01 |
The test results show that the yield and purity are the lowest, since comparative example 2 may produce more side reactions. Comparative example 1 electrolytic reaction Using cation exchange Membrane, H+Gradually decreases, the reaction rate becomes slow, and the electrolytic conversion rate also decreases, resulting in a decrease in the yield of the final product. Examples 1-3 use bipolar membranes for electrolysis, and compared to conventional electrolysis, bipolar membrane dissociation processes do not generate gas, low energy consumption, no electrochemical reaction, and no generation of undesired products or destruction of redox reactions of desired products, resulting in high electrolysis conversion rate, and the conversion rate of final products is also higher than that of comparative examples1-2 high. Example 2 an improvement was made on the basis of a bipolar membrane, in which an intermediate interface catalyst layer, which is a polystyrene membrane mixed with a metal complex, was bonded between a cation exchange membrane and an anion exchange membrane, thereby reducing the resistance drop and cell voltage of the conventional bipolar membrane, further increasing the electrolytic conversion rate, and improving the product yield. Example 3 an electrostatic spinning process is used to spray a polystyrene casting solution mixed with a metal complex onto the surface of a cation exchange membrane, the diameter of the fiber sprayed by electrostatic spinning is nano-scale, the fiber has high specific surface area and porosity, and can be well combined with the cation exchange membrane, so that the compatibility of the two membrane layers is increased, the specific surface area of the inner side of the bipolar membrane is increased, the cation exchange membrane and the anion exchange membrane of the bipolar membrane are both porous structures, the intermediate interface layer can reduce the water dissociation voltage, and the porous structures can accelerate the conduction rate of ions, thereby improving the electrolytic conversion rate and the product difference rate.
< measurement of Bipolar Membrane conductivity >
The bipolar membranes used in examples 1 to 3 and comparative example 1 were subjected to conductivity measurement, and the measurement results are shown in table 2:
TABLE 2 comparison of conductivity at 30 deg.C
Test results show that the bipolar membranes used in examples 1-3 have higher conductivity than the cation exchange membranes used in comparative example 1, and have better ionization efficiency. In example 1, a commercially available bipolar membrane was used, and example 2 was an improvement of the bipolar membrane in which an intermediate interface catalyst layer, which is a polystyrene membrane mixed with a metal complex, was bonded between a cation exchange membrane and an anion exchange membrane, so that the resistance drop and cell voltage of the conventional bipolar membrane were reduced, and the conductivity was increased. Example 3 an electrostatic spinning process is used to spray a polystyrene casting solution mixed with a metal complex onto the surface of a cation exchange membrane, the diameter of the fiber sprayed by electrostatic spinning is nano-scale, the fiber has high specific surface area and porosity, and can be well combined with the cation exchange membrane, so that the compatibility of the two membrane layers is increased, the specific surface area of the inner side of the bipolar membrane is increased, the cation exchange membrane and the anion exchange membrane of the bipolar membrane are both porous structures, the intermediate interface layer can reduce the water dissociation voltage, and the porous structure can accelerate the conduction rate of ions, thereby further improving the conductivity and the electrolytic conversion rate.
< measurement of stability of intermediate interface catalyst layer of bipolar membrane >
The stability test was performed on the intermediate interface catalyst layer of the bipolar membranes prepared in examples 2 and 3, the intermediate interface catalyst layer prepared in example 2 and the cation exchange membrane were labeled as a membrane a by adhesion, the cation exchange membrane with the surface spun with the polystyrene-metal complex compound prepared in example 3 was labeled as a membrane B by adhesion, the membrane a and the membrane B were immersed in pure water for 12 hours, the pure water was changed every other hour, and after being taken out, the membrane was dried in an oven at 40 ℃, and then the surface metal element analysis was performed, and the results are shown in table 3:
TABLE 3 analysis of metallic elements on the surface of the film
The determination result shows that the content of the metal elements on the surface of the membrane A is reduced to some extent through 12-hour soaking compared with non-soaking, and the content of the metal elements on the surface of the membrane B is reduced to a small extent, which indicates that the intermediate interface layer prepared by the electrostatic spinning method can combine metal ions with a cation exchange membrane more effectively, thereby ensuring the high efficiency and stability of the performance of the bipolar membrane.
The number of apparatuses and the scale of the process described herein are intended to simplify the description of the present invention. Applications, modifications and variations of the present invention will be apparent to those skilled in the art.
While embodiments of the invention have been described above, it is not limited to the applications set forth in the description and the embodiments, which are fully applicable to various fields of endeavor for which the invention may be embodied with additional modifications as would be readily apparent to those skilled in the art, and the invention is therefore not limited to the details given herein and to the examples shown and described without departing from the generic concept as defined by the claims and their equivalents.
Claims (9)
1. The method for synthesizing sulfenyl diacetic acid is characterized by mainly comprising the following steps:
dissolving homocystine in hydrochloric acid to serve as catholyte, dilute sulfuric acid to serve as anolyte, separating the two poles by using a bipolar membrane, and carrying out an electroreduction reaction in an electrolytic tank to prepare homocysteine hydrochloride;
dissolving homocysteine hydrochloride and chloroacetic acid in water, heating to 30-80 ℃, reacting for 5-8 h, reducing the temperature, reducing the pressure, recovering solvent water, adding methanol, controlling the temperature to 30-60 ℃, dropwise adding a catalyst and a dehydrating agent, stirring, reacting for 2-5 h, reducing the temperature, filtering and separating out homoserine lactone hydrochloride, and carrying out reduced pressure distillation on filtrate to obtain methyl thioglycolate, wherein the molar ratio of homocysteine hydrochloride to chloroacetic acid to methanol is 1 (1-5) to 1-1.2;
and step three, mixing and dissolving the methyl thioglycolate and the methyl haloacetate in the molar ratio of 1 (1-1.2) in methanol, controlling the temperature to be 25-50 ℃ to react for 6-12 h, carrying out reduced pressure distillation, adding dilute sulfuric acid, heating to 50-80 ℃, and separating and purifying to obtain the thiodiacetic acid.
2. The method for synthesizing thiodiglycolic acid according to claim 1, wherein in the first step, the bipolar membrane is formed by compounding a cation exchange membrane, an intermediate interface catalytic layer and an anion exchange membrane.
3. The method for synthesizing sulfurous diacetic acid according to claim 2, wherein the cation exchange membrane and the anion exchange membrane have a finger-shaped pore structure, and both are prepared by a membrane preparation process using a solution phase inversion method.
4. A process for the synthesis of thiodiglycolic acid according to claim 3, wherein said cation exchange membrane is made of a sulfonic acid type cation exchange resin and said anion exchange membrane is made of a quaternary ammonium salt type anion exchange resin.
5. The method for synthesizing thiodiglycolic acid according to claim 2, wherein the intermediate interface catalytic layer is a polystyrene layer mixed with a metal complex, the mixed solution of polystyrene and the metal complex is spun on the surface of the cation exchange membrane by an electrostatic spinning method, and the anion exchange membrane is fixed on the surface of the cation exchange membrane spun with the intermediate interface catalytic layer by a hot pressing or bonding method, so that the bipolar membrane is obtained.
6. The method for synthesizing sulfurous diacetic acid according to claim 1, wherein the anode material of the electrolytic cell in the first step is lead-antimony-tin alloy, and the cathode material is lead.
7. The method for synthesizing thiodiglycolic acid according to claim 1, wherein the electrolysis temperature in the first step is 30 to 50 ℃ and the current density is 0.08 to 0.09A/cm2The electrolysis time is 8-10 h.
8. The method of synthesizing thiodiglycolic acid according to claim 1, wherein the catalyst in the second step is SO4 -2/TiO2。
9. The method for synthesizing thiodiglycolic acid according to claim 1, wherein the dehydrating agent in the second step is thionyl chloride, thionyl bromide, benzene, toluene or xylene.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1089000A (en) * | 1992-12-31 | 1994-07-06 | 福建师范大学 | The electrode special that is used for preparing L-semicystine by electrolytic reduction |
| CN101074480A (en) * | 2007-03-30 | 2007-11-21 | 汕头市紫光古汉氨基酸有限公司 | Method for crystallizing L-cysteine muriate high-purity crystal |
| CN105401166A (en) * | 2015-11-19 | 2016-03-16 | 宁波市远发生物工程有限公司 | Method for preparing L-cysteine hydrochloride anhydrous substances |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1089000A (en) * | 1992-12-31 | 1994-07-06 | 福建师范大学 | The electrode special that is used for preparing L-semicystine by electrolytic reduction |
| CN101074480A (en) * | 2007-03-30 | 2007-11-21 | 汕头市紫光古汉氨基酸有限公司 | Method for crystallizing L-cysteine muriate high-purity crystal |
| CN105401166A (en) * | 2015-11-19 | 2016-03-16 | 宁波市远发生物工程有限公司 | Method for preparing L-cysteine hydrochloride anhydrous substances |
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