2,3-Dimercaptopropanesulfonic acid sodium salt synthesis

Yield:4076-02-2 78.8 g

Reaction Conditions:

Stage #1:sodium 2,3-dibromopropane-1-sulfonate with sodium ethanolate in ethanol at 23 - 25; under 2250.23 - 3750.38 Torr; for 1.5 h;
Stage #2:lead acetate in water at 50 - 55; for 1 h;Further stages;Reagent/catalyst;Temperature;

Steps:

1.2 Example 1 (Embodiment of the present invention)
1. Preparation of sodium hydrosulfide: put 3250ml of anhydrous ethanol into the 5L high pressure reactor, under stirring 110 g (1.60mol) of sodium ethoxide is added in one portion. After the addition, close and tighten the feeding port, control the internal temperature at below 25 °C passing through the jacket cooling water, under agitation passing high pressure hydrogen sulfide gas into the kettle through a hydrogen sulfide gas cylinder, the reaction pressure is stirred in the range of 0.3-0.5MPa for about 30 minutes, the pH of the solution is brought to a range of 6.5-7.5.2. Thiolation reaction: after the above reaction has been completed, the pressure in the kettle is released; open the kettle lid, one injection of 230.3 g (0.75mol) of sodium 2, 3-dibromo propanesulfonate. after the addition, tighten thekettle lid and control the internal temperature at 23 ° C ~ 25 ° C, under stirring the high pressure hydrogen sulfide gas is introduced into the kettle, carry on stirring reaction for 90 min when the pressure reaches 0.3~0.5Mpa. After decompressing, the hydrogen sulfide gas is vacuum-driven (the exhaust gas is absorbed in series by the caustic solution and the activated carbon), and the reaction liquid is pumped into another reaction bottle, and at room temperature slowly drop 36% glacial acetic acid to adjust the pH at 4.6~4.7 and continue stirring for 30min, until the pH value is retested. Then let stand for 4h below 10°C. Filtering off sodium acetate after that obtained clear thiolation reaction solution.3. Lead salt reaction: dissolve 284.5 g of lead acetate (trihydrate) into 625 ml of preheated at 50 ° C ~ 55 ° C distilled water. In addition, the above thiolation reaction solution is transferred into a 5L reaction flask, and the temperature is raised at 50 ° C, under stirring adding an aqueous solution of lead acetate into the reaction solution. After the addition, continue stirring for 1 h, and then aging for 2h, then filter to the mother liquor. The crude lead salt cake is washed 3 times with hot water at 50 °C (800ml+600ml+400ml), after draining, use 1000ml with the same temperature hot water to stir and wash 30min. Finally, it is stirred once with 400 ml of cold anhydrous ethanol and dried under vacuum at 50 ° C until get dry, and then obtained 264.7 g of 2, 3-dimercaptopropanesulfonic acid lead salt complex.Lead salt yield (same as sodium 2, 3-dibromopropane sulfonate, the following examples are the same): 70.8%.4. Lead removal, salt formation: 250g of 2, 3-dimercaptopropanesulfonic acid lead salt complex is put into a 3L reaction bottle, add 2000ml of anhydrous ethanol, and slowly pass hydrogen sulfide gas at room temperature with stirring, until the yellow 2,3-dimercaptopropanesulfonic acid lead salt all particles disappear completely and fully converted into black lead sulfide precipitate. After standing for 1 hour, the temperature is raised at 35 ° C to stir off the hydrogen sulfide gas. After that heat up at 60 ° C, adding activated carbon, stirring and de-coloring for 15 minutes, filtering, de-carbonization. Again under stirring the milled sodium bicarbonate powder is uniformly added into the filtrate, carefully neutralize at pΗ4.3. After the neutralization, continue stirring for 15 minutes, until the retest is unchanged, and then filter. The filtrate is placed in a freezer at 1 °C or below to cool and crystallize overnight. The crystals are filtered, washed once with cold anhydrous ethanol, dried and dried in vacuum to get dryness, and then obtained 97.8g of crude sodium 2, 3-dimercaptopropane sulfonate, the content is 95.6%. Based on lead salts, the yield is 81.04%.5. Refining: 95.0 g of crude sodium 2,3-dimercaptopropane sulfonate was put into the reaction flask.After adding 1300ml of 90% ethanol, the temperature is raised to 65 ° C ~ 70 ° C,After the total dissolution, the powdered activated carbon was added, and the mixture was decolorized by stirring for 15 minutes, and then filtered.The clarified filtrate was placed in a refrigerator at 10 ° C to cool and crystallize overnight, filtered, washed and dried according to law.78.8 g of white sodium 2,3-dimercaptopropanesulfonate finished crystals were obtained. Product purity and yield results are listed in the table below:

References:

Hefei Cube Pharmaceutical Co., Ltd.;Ji Junqiu;Gao Meihua;Li Xiaochang;Chen Jun CN102531981, 2016, B Location in patent:Paragraph 0034; 0036; 0092; 0095; 0097; 0102; 0104

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