Sodium dimercaptopropansulfonate preparation method

Abstract

The invention relates to the field of chemical pharmacy, and specifically provides a sodium dimercaptopropansulfonate preparation method. The sodium dimercaptopropansulfonate preparation method comprises that 1) sodium allyl sulfonate and bromine are subjected to a reaction under the effect of an auxiliary agent to obtain sodium dibromo propansulfonate, wherein the auxiliary agent is selected from sodium bromide, sodium iodide, or a combination thereof; 2) the sodium dibromo propanesulfonate obtained in step 1), sodium hydrosulfide and zinc acetate are subjected to a reaction to obtain a sodium dimercaptopropansulfonate-zinc complex; and 3) the sodium dimercaptopropansulfonate-zinc complex obtained in the step 2) reacts with hydrogen sulfide to obtain the sodium dimercaptopropansulfonate. According to the present invention, the preparation method has characteristics of low toxicity of the used reagent, low environmental pollution, low cost of zinc acetate, low consumption, low cost, simple process, no requirement of high pressure equipment and safe operation, and is suitable for industrial production, and the obtained sodium dimercaptopropansulfonate has the high purity and meets the quality requirements of the bulk drug.

Description

technical field [0001] The invention belongs to the field of chemical pharmacy, and in particular relates to a preparation method of sodium dimercaptopropanesulfonate. Background technique [0002] Sodium dimercaptopropanesulfonate (also known as "sodium dimercaptopropanesulfonate, DMPS or Na-DMPS for short), chemical name: 2,3-sodium dimercaptopropanesulfonate, is a metal ion complexing agent containing mercapto groups , as an excellent detoxification drug, it has been widely used in the treatment of acute and chronic poisoning of heavy metals such as mercury, arsenic, copper, lead and cadmium. Its structure is as follows: [0003] [0004] The current method for preparing sodium dimercaptopropanesulfonate is to take allylsulfonic acid as raw material, step i): sodium allylsulfonate is dissolved in water, and bromine is added dropwise at room temperature to obtain sodium dibromopropanesulfonate Aqueous solution; step ii): After adjusting the pH of the aqueous solution o...

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Problems solved by technology

[0006] But this method has the disadvantages of the following disadvantages: when carrying out the reaction of step i), it is easy to generate a large amount of 2-hydroxyl-3-bromo-propanesulfonate or 2-bromo-3-hydroxyl-propanesulfonate by-product, the reaction Sodium dibromopropanesulfonate content is about 70% in the liquid, and the hydrobromic acid that generates makes reaction solution be strongly acidic, and pH value is less than 0.5; The lead acetate molecular weight that adopts in the step ii) is big, and atom utilization rate is low, and this method needs To use a large amount of lead acetate, its consumption is about three times of sodium allyl sulfonate, even up to seven times, so a large amount of lead-containing waste water is produced, which seriously pollutes the environment; Deposited in the still low, difficult to stir, unfavorable for fully absorbing hydrogen sulfide gas, insufficient reaction; in step iii) because the lead dimercapto salt is a yellow solid, after deleading, lead sulfide is generated as a black solid, but the reaction is about 30% Afterwards, the whole system is now black, and it is impossible to judge the end point of the reaction; when adjusting the pH to 4.5 with sodium bicarbonate in step iv), because it is carried out in methanol or ethanol solution, its pH value is difficult to detect, and sodium bicarbonate is in methanol or ethanol solution simultaneously. The solubility in ethanol is small, the reaction is slow, and it is easy to cause excessive sodium bicarbonate, resulting in an increase in the content of inorganic salts in sodium dimercaptopropanesulfonate

[0010] The method still has the following deficiencies: in step a), due to the excessive amount of zinc sulfate (about 1.8 equivalents, only 1.0 equivalents are required in theory), the purity of the sodium dimercaptopropanesulfonate zinc complex is poor, and the inorganic salt content High, even generate zinc dimercaptopropanesulfonate, the reaction equation is as follows:

[0012] And after the complexation of zinc ions and sodium dimercaptopropanesulfonate, a large amount of sulfuric acid is generated, which makes the reaction system strongly acidic, and sodium bicarbonate must be added to adjust; the reaction system is strongly alkaline when adding ammoniacal liquor dezincification in step b), And sodium dimercaptopropanesulfonate is easily degraded under alkaline conditions, which also affects the purity of the product; in addition, after dezincification, a large amount of acetic acid needs to be added to adjust the pH to 4.5, and a large amount of inorganic salt ammonium acetate is generated, but ammonium acetate is not easy Removed, further caused product content to reduce, actual result shows that the titration content of the product obtained by this method is only 83.2%

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