Preparation method for dithiothreitol

Abstract

The present invention discloses a method for preparing dithiothreitol (the compound of formula 1). The method is as shown in the following reaction scheme. In the method of the present invention, the compound of formula 2 below is oxidized with potassium permanganate to form the compound of formula 3; the compound of formula 3 is then reacted with sodium disulfide to form the compound of formula 4; and the compound of formula 4 is finally subjected to a reduction reaction with zinc powder to form the compound of formula 1. The preparation method of the present invention is simple, has mild reaction conditions and a high reaction yield, and facilitates industrial production.

Description

Preparation method of dithiothreitol Technical Field

[0001] The present invention relates to the field of chemical synthesis, and in particular to a method for synthesizing dithiothreitol. Background Art

[0002] One use of dithiothreitol is as a reducing agent and deprotecting agent for thiolated DNA. The terminal sulfur atoms of thiolated DNA tend to form dimers in solution, particularly in the presence of oxygen. This dimerization significantly reduces the efficiency of some coupling reactions, such as DNA immobilization in biosensors. Adding dithiothreitol to a DNA solution and removing it after a period of reaction can reduce DNA dimerization.

[0003] Currently, the following literature reports on the synthesis of dithiothreitol:

[0004] 1. Heterocycles (2003), 60(1), 47-56 reported: The compound of formula 4 reacts with trialkylphosphine and then hydrolyzes to obtain the compound of formula 1 (dithiothreitol) and trialkylphosphine oxide in a yield of 65%-70%.

[0005] The dithiothreitol yield of this method is not high (65%-70%), and the use of phosphorus-containing compounds in the reaction process will pollute the environment.

[0006] 2. Chinese patent document CN101503384A (2009-08-12) reports a method for synthesizing dithiothreitol (Formula 1). The specific synthetic route is as follows:

[0007] In this method, 1,4-butenediol is reacted with liquid bromine, hydrolyzed under alkaline conditions to produce dioxirane, which is then reacted with thioacetic acid to produce dithiothreitol diacetate. Finally, dithiothreitol (Formula 1) is hydrolyzed under alkaline conditions, with an overall yield of 35.4% to 36.4%. The first addition reaction utilizes liquid bromine, which is highly toxic and difficult to operate, and the third step utilizes thioacetic acid, which is foul-smelling and poses a significant risk to the production environment.

[0008] 3. Patent document CN103073462A (2013-05-01) reports a method for synthesizing the compound of formula 1. The specific synthesis route is as follows:

[0009] This method uses dimethyl tartrate as a raw material, which reacts with 2,2-dimethoxypropane to produce 2,3-O-isopropyl dimethyl tartrate, which is then reduced with sodium borohydride to produce 2,3-O-isopropylidene threonol. This compound reacts with sulfonyl chloride in the presence of sodium hydrogen to produce 2,3-O-isopropylidene threonol sulfonate. The resulting sulfonate reacts with thioacetate to produce 2,3-O-isopropylidene dithiothreitol diacetate, which is then hydrolyzed with alkali to produce the compound of Formula 1. This method has a lengthy reaction process, with dangerous and flammable sodium hydrogen used in the third step of the synthesis and foul-smelling thioacetic acid used in the fourth step. This creates a high risk and environmental impact in the production process.

[0010] 4. Patent document CN112028799A (2020-12-04) reports a synthesis method for the compound of formula 1. The specific synthesis route is as follows:

[0011] 1,4-disulfonic acid-2-butene is oxidized with peroxybenzoic acid or tungstic acid / hydrogen peroxide to produce an epoxide, which is then reduced with lithium aluminum hydride and sodium borohydride to produce the compound of Formula 1 in a yield of 78% to 79%. This method uses dangerous and flammable lithium aluminum hydride, making production highly risky.

[0012] Patent document CN115093352A (2022-09-23) reports the reaction method shown in the following flow chart:

[0013] 1,4-Dibromobutene reacts with pyridine to form a quaternary ammonium salt, which is then oxidized with potassium permanganate to a diol. The diol is then protected with acetic anhydride to form an ester, which reacts with potassium thioacetate to produce 1,4-diacetylmercapto-2,3-diacetoxybutane. Dithiothreitol is then produced in methanol with sulfuric acid under reflux, yielding a 55% overall yield. This method requires the use of the malodorous reagent pyridine, resulting in poor production environment and difficult disposal of the solvent DMF wastewater.

[0014] Therefore, there is an urgent need in the art for a dithiothreitol synthesis method that is simple to operate, safe, environmentally friendly, has a high yield, and is conducive to industrial production.

[0015] Summary of the Invention

[0016] The present invention aims to provide a novel method for synthesizing dithiothreitol, which has the advantages of being simple to operate, safe, environmentally friendly, high in yield, and conducive to industrial production.

[0017] The present invention provides a method for preparing dithiothreitol represented by Formula 1, as shown in the following reaction flow:

[0018] The method comprises the following steps:

[0019] 1) oxidizing the compound of formula 2 to produce the compound of formula 3;

[0020] 2) reacting the compound of formula 3 with sodium disulfide to produce the compound of formula 4;

[0021] 3) The compound of formula 4 is reduced to obtain the compound of formula 1. In a specific embodiment, in step 3), the compound of formula 4 is reduced with zinc to obtain the compound of formula 1.

[0022] In a specific embodiment, in step 3), zinc powder is used to reduce the compound of formula 4 to obtain the compound of formula 1. In a specific embodiment, in step 1), potassium permanganate is used to oxidize the compound of formula 2 to produce the compound of formula 3.

[0023] In a specific embodiment, potassium permanganate is used to oxidize the compound of formula 2 at a temperature of -20°C to 40°C, preferably 5°C to 10°C to produce the compound of formula 3.

[0024] In a specific embodiment, in step 2), the molar ratio of the compound of formula 3 to sodium disulfide is 1:1-1:3; preferably 1:1.5.

[0025] In a specific embodiment, in step 2), the reaction of the compound of formula 3 with sodium disulfide to produce the compound of formula 4 is carried out in a solvent selected from N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, THF or a mixed solvent thereof; preferably N,N-dimethylformamide.

[0026] In a specific embodiment, in step 2), the reaction of the compound of formula 3 with sodium disulfide to produce the compound of formula 4 is carried out in the presence of a catalyst, and the catalyst is selected from potassium iodide, sodium iodide, potassium bromide or a mixture thereof; preferably potassium iodide.

[0027] In a specific embodiment, in step 3), the reduction reaction of the compound of formula 4 to obtain the compound of formula 1 is carried out at a temperature of 20°C to 120°C, preferably 60°C to 65°C.

[0028] In a specific embodiment, the yield of the compound of formula 1 is above 90%, preferably above 95%, and more preferably above 96%.

[0029] It should be understood that within the scope of the present invention, the above-mentioned technical features of the present invention and the technical features described in detail below (such as in the embodiments) can be combined with each other to form new or preferred technical solutions. Due to space limitations, they will not be listed here one by one. DETAILED DESCRIPTION

[0030] After extensive and in-depth research, the inventors unexpectedly discovered a safe and industrially feasible synthesis method for the production of dithiothreitol (compound of Formula 1) using the compound of Formula 2 as a starting material, and completed the present invention on this basis.

[0031] Method of the present invention

[0032] The synthetic route reaction formula of the method of the present invention is as follows:

[0033] In the method of the present invention, the compound of Formula 2 first reacts with potassium permanganate to produce the compound of Formula 3, which is then reacted with sodium disulfide to produce the compound of Formula 4. The compound of Formula 4 is then reacted with reducing zinc powder to produce the compound of Formula 1. This method has a short synthetic route and utilizes inexpensive and readily available sodium disulfide as a thioreagent to construct the disulfide compound of Formula 4. Finally, zinc powder is used to reduce the compound of Formula 1.

[0034] In a specific embodiment, the preparation method of dithiothreitol of the present invention comprises the following steps:

[0035] 1) oxidizing the compound of formula 2 to produce the compound of formula 3;

[0036] 2) reacting the compound of formula 3 with sodium disulfide to produce the compound of formula 4;

[0037] 3) The compound of formula 4 is subjected to reduction reaction to obtain the compound of formula 1.

[0038] Based on the teachings of the present invention, those skilled in the art will know how to oxidize the compound of Formula 2 to produce the compound of Formula 3. For example, potassium permanganate can be used to oxidize the compound of Formula 2 to produce the compound of Formula 3. The oxidation of the compound of Formula 2 to produce the compound of Formula 3 with potassium permanganate can be carried out at a suitable temperature, for example, at a temperature between -20°C and 40°C, preferably between 5°C and 10°C.

[0039] In a specific embodiment, the reaction of the compound of formula 3 with sodium disulfide to produce the compound of formula 4 can be carried out at a suitable molar ratio of the compound of formula 3 to sodium disulfide. For example, the molar ratio of the compound of formula 3 to sodium disulfide can be 1:1-1:3, preferably 1:1.5.

[0040] In a specific embodiment, the reaction of the compound of formula 3 with sodium disulfide to produce the compound of formula 4 can be carried out in a suitable solvent. The solvent can be N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, THF, or a mixture thereof; preferably N,N-dimethylformamide.

[0041] In a specific embodiment, the reaction of the compound of formula 3 with sodium disulfide to produce the compound of formula 4 is carried out in the presence of a catalyst. The catalyst can be potassium iodide, sodium iodide, potassium bromide or a mixture thereof, but potassium iodide is preferred.

[0042] Based on the teachings of the present invention, those skilled in the art will know how to reduce the compound of formula 4 to obtain the compound of formula 1. For example, the compound of formula 4 can be reduced using zinc to obtain the compound of formula 1; preferably, the compound of formula 4 can be reduced using zinc powder to obtain the compound of formula 1.

[0043] In a specific embodiment, the reduction reaction of the compound of formula 4 to obtain the compound of formula 1 is carried out at a suitable temperature, for example, at a temperature of 20°C to 120°C, preferably at a temperature of 60°C to 65°C.

[0044] The method for preparing dithiothreitol of the present invention is not only simple to operate, safe, and suitable for large-scale industrial production, but also has a very high yield of dithiothreitol. In a specific embodiment, the yield of dithiothreitol prepared by the method of the present invention can reach more than 90%, preferably more than 95%, and more preferably more than 96%.

[0045] Advantages of the present invention:

[0046] 1. The method of the present invention uses sodium disulfide to construct thiol groups, avoiding the use of malodorous sulfiding reagents and improving the production environment;

[0047] 2. The method of the present invention uses zinc powder to replace the disulfide bond in trialkylphosphorus reduction formula 4, avoiding the use of phosphorus-containing compounds to pollute the environment;

[0048] 3. The reaction process conditions of the method of the present invention are optimized and the reaction yield is high;

[0049] 4. The reaction conditions of the method of the present invention are mild, easy to operate, and conducive to industrial production.

[0050] The technical solutions of the present invention are further described below with reference to specific implementation examples. However, the following examples do not constitute a limitation of the present invention. All various application methods adopted in accordance with the principles and technical means of the present invention are within the scope of the present invention. Experimental methods in the following examples, where specific conditions are not specified, generally follow conventional conditions or the conditions recommended by the manufacturer. Unless otherwise stated, percentages and parts are calculated by weight.

[0051] Example 1: Synthesis of Compound 3 (Study at Different Reaction Temperatures)

[0052] Add 16.25 g (0.13 mol) of 1,4-dichloro-2-butene (Formula 2) and 300 g of isopropyl alcohol to three reaction flasks, stirring to dissolve. Add 411 g of 5% neutral potassium permanganate dropwise to reaction flask #1 at a temperature of -15°C to -10°C. Adjust the pH to 3-4 with dilute sulfuric acid and continue to react at this temperature for 2 hours. Add 411 g of 5% neutral potassium permanganate dropwise to reaction flask #2 at a temperature of 5°C to 10°C. Adjust the pH to 3-4 with dilute sulfuric acid and continue to react at this temperature for 2 hours. Add 411 g of 5% neutral potassium permanganate dropwise to reaction flask #3 at a temperature of 15°C to 20°C. Adjust the pH to 3-4 with dilute sulfuric acid and continue to react at this temperature for 2 hours. TLC confirms complete reaction of all three starting materials. Filter, wash the filter cake with isopropyl alcohol, and concentrate the filtrate under reduced pressure to 110 g, precipitate, and filter and dry to obtain compound 3. The yields and purities of the three compounds of reaction formula 3 are calculated as shown in the following table.

[0053] Table 1

[0054] Example 2: Synthesis of Compound 3

[0055] Add 65 g (0.52 mol) of 1,4-dichloro-2-butene (Formula 2) and 1200 g of isopropyl alcohol to the reaction flask and stir to dissolve. Then, control the temperature of the reaction flask at 5°C to 10°C and dropwise add 1650 g of a 5% neutral potassium permanganate solution. After completion of the addition, adjust the pH to 3-4 with dilute sulfuric acid. Continue to control the temperature for 2 hours (TLC confirms the reaction is complete). Filter, wash the filter cake with isopropyl alcohol, and concentrate the filtrate under reduced pressure to 450 g to separate crystals. Filter and dry to obtain 76.5 g of the compound of Formula 3, with a yield of 92.5% and an HPLC yield of 99.2%.

[0056] Example 3: Synthesis of the compound of formula 4 (study of different feed ratios)

[0057] (1) Preparation of sodium disulfide solution: Na2S+S→Na2S2

[0058] Add 240.2g of sodium sulfide nonahydrate and 250ml of pure water to a 1000ml single-necked bottle, stir mechanically and slowly heat to 60°C until the raw material solid is completely dissolved, then add 32g of sulfur powder, continue to heat to 80°C until the sulfur powder solid is completely dissolved, keep warm for 60 minutes after dissolution, cool to room temperature and set aside.

[0059] (II) Synthesis of compound of formula 4:

[0060] Take three reaction bottles, add 31.8 grams (0.2 moles) of formula 3 and 150 grams of tetrahydrofuran, 1.6 grams of sodium iodide, respectively, stir and dissolve after addition, add 104.4 grams (0.2 moles) of prepared sodium disulfide solution to reaction bottle No. 1; add 156.6 grams (0.3 moles) of prepared sodium disulfide solution to reaction bottle No. 2; add 261.0 grams (0.5 moles) of prepared sodium disulfide solution to reaction bottle No. 3; after addition, the three reaction bottles are reacted at 55-60 ° C for 3 hours (TLC detection of the three reaction raw materials is complete). Add ethyl acetate, wash with water and separate the layers, extract the aqueous layer with ethyl acetate once, combine the organic layers, dry, filter, and concentrate the filtrate to obtain a residual liquid. The residual liquid is slurried with petroleum ether to obtain a compound of formula 4. The yields of the three reactions are calculated as shown in the following table.

[0061] Table 2

[0062] Example 4: Synthesis of Compound 4 (Comparative Study of Different Catalysts)

[0063] Take three reaction bottles, add 31.8 grams (0.2 moles) of formula 3 and 150 grams of tetrahydrofuran, 156.625 grams (0.3 moles) of prepared sodium disulfide solution, and add 1.6 grams of sodium iodide to reaction bottle No. 1; add 1.6 grams of potassium iodide to reaction bottle No. 2; add 1.6 grams of potassium bromide to reaction bottle No. 3; after the addition, the three reaction bottles are reacted at 55-60 ° C for 3 hours (TLC detection shows that the three reaction raw materials have reacted). Ethyl acetate is added, the layers are washed with water, the aqueous layer is extracted with ethyl acetate once, the organic layers are combined and dried, filtered, and the filtrate is concentrated to obtain a residual liquid. The residual liquid is slurried with petroleum ether to obtain a compound of formula 4. The yields of the three reactions are calculated as shown in the following table.

[0064] Table 3

[0065] Example 5: Synthesis of Compound 4 (Comparative Study of Different Reaction Solvents)

[0066] Take three reaction bottles and add 31.8 grams (0.2 moles) of formula 3, 156.6 grams (0.3 moles) of prepared sodium disulfide solution, and 1.6 grams of potassium iodide respectively. After the addition, add 150 grams of tetrahydrofuran to reaction bottle No. 1; add 150 grams of N, N-dimethylformamide to reaction bottle No. 2; add 150 grams of dimethyl sulfoxide to reaction bottle No. 3; after the addition, the three reaction bottles are reacted at 55-60°C for 3 hours (TLC detection shows that the three reaction raw materials have reacted). Add ethyl acetate, wash with water and separate the layers, extract the aqueous layer with ethyl acetate once, combine the organic layers, dry them, filter, and concentrate the filtrate to obtain a residual liquid. The residual liquid is slurried with petroleum ether to obtain a compound of formula 4. The yields of the three reactions are calculated as shown in the following table.

[0067] Table 4

[0068] Example 6: Synthesis of Compound 4

[0069] (1) Preparation of sodium disulfide solution:

[0070] Add 240.2g of sodium sulfide nonahydrate and 250ml of pure water to a 1000ml single-necked bottle, stir mechanically and slowly heat to 60°C until the raw material solid is completely dissolved, then add 32g of sulfur powder, continue to heat to 80°C until the sulfur powder solid is completely dissolved, keep warm for 60 minutes after dissolution, cool to room temperature and set aside.

[0071] (II) Synthesis of compound of formula 4:

[0072] To a reaction flask, add 159.0 g (1 mol) of the compound of formula 3, 750 g of N,N-dimethylformamide, and 8 g of potassium iodide. After complete addition, add the prepared sodium disulfide solution and react at 55-60°C for 3 hours (TLC confirms complete reaction). Add ethyl acetate, wash with water, and extract the layers once with ethyl acetate. Combine the organic layers and dry. Filter and concentrate the filtrate to obtain a residual solution. Slurry the residual solution with petroleum ether to obtain 143.9 g of the compound of formula 4, with a yield of 94.5%.

[0073] Example 7: Synthesis of the compound of formula 1 (comparative study of different reaction temperatures)

[0074] To three reaction flasks, 76.0 g (0.5 mol) of the compound of formula 4, 250 g of glacial acetic acid, and 98 g (1.5 mol) of zinc powder were added to each of them. The reaction was then carried out at 40-45°C for 4 hours in reaction flask #1; 60-65°C for 4 hours in reaction flask #2; and 80-85°C for 4 hours in reaction flask #3. TLC confirmed the complete reaction of the three reaction materials. The filtrate was filtered, and the glacial acetic acid was recovered by distillation. The residual liquid was subjected to high vacuum distillation at a vacuum of 400 Pa. The fraction at 90-95°C was collected and cooled naturally to obtain the compound of formula 1 as a white solid. The yields of the three reactions were calculated as shown in the following table.

[0075] Table 5

[0076] Example 8: Synthesis of Compound of Formula 1

[0077] To a reaction flask, add 152.2 g (1 mol) of the compound of Formula 4, 500 g of glacial acetic acid, and 196.1 g (3 mol) of zinc powder. After complete addition, react at 60-65°C for 4 hours (TLC confirms complete reaction). Filter, distill the filtrate to recover the glacial acetic acid, and subject the residual liquid to high vacuum distillation at 400 Pa. Collect the 90-95°C fraction, and cool naturally to yield 148.5 g of the compound of Formula 1 as a white solid, in a yield of 96.3%.

[0078] All documents mentioned in this application are incorporated herein by reference, just as if each document were incorporated herein by reference individually. It should also be understood that after reading the above teachings of the present invention, those skilled in the art may make various changes or modifications to the present invention, and that such equivalents also fall within the scope of the claims appended hereto.

Claims

1. The preparation method of dithiothreitol shown in Formula 1, and the method is as shown in the following reaction process: The method comprises the following steps: 1) Oxidize the compound of formula 2 to generate the compound of formula 3; 2) React the compound of formula 3 with sodium disulfide to generate the compound of formula 4; 3) The compound of formula 4 is obtained by a reduction reaction to get the compound of formula 1.

2. The method according to claim 1, characterized in that, In step 3), the compound of formula 4 is reduced with zinc to obtain the compound of formula 1.

3. The method according to claim 2, characterized in that In step 3), the compound of formula 4 is reduced with zinc powder to obtain the compound of formula 1.

4. The method according to any one of claims 1 to 3, characterized in that In step 1), the compound of formula 2 is oxidized with potassium permanganate to generate the compound of formula 3.

5. The method according to claim 4, characterized in that, Using potassium permanganate, oxidize the compound of formula 2 at a temperature of -20°C to 40°C, preferably 5°C to 10°C to generate the compound of formula 3.

6. The method according to any one of claims 1-3, characterized in that, In step 2), the molar ratio of the compound of formula 3 to sodium disulfide is 1:1 - 1:3; preferably 1:1.

5.

7. The method according to any one of claims 1 to 3, characterized in that, In step 2), the reaction of the compound of formula 3 with sodium disulfide to generate the compound of formula 4 is carried out in a solvent selected from N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, THF or a mixed solvent thereof; preferably N,N-dimethylformamide.

8. The method according to any one of claims 1 to 3, characterized in that, In step 2), the reaction of the compound of formula 3 with sodium disulfide to generate the compound of formula 4 is carried out in the presence of a catalyst selected from potassium iodide, sodium iodide, potassium bromide or a mixture thereof; preferably potassium iodide.

9. The method according to any one of claims 1 to 3, characterized in that In step 3), the reduction reaction of the compound of formula 4 to obtain the compound of formula 1 is carried out at a temperature of 20°C to 120°C, preferably 60°C to 65°C.

10. The method according to any one of claims 1-3, characterized in that, The yield of the compound of formula 1 is above 90%, preferably above 95%, more preferably above 96%.

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