阅读说明：本技术 一种硝普钠的制备方法 (Preparation method of sodium nitroprusside ) 是由 刘开湘 李晓沪 张博 于 2021-10-28 设计创作，主要内容包括：本发明提供了一种硝普钠的制备方法,以亚硝基铁氰化钾或其水合物和碘化钠为原料,反应得到碘化钾和硝普钠,过滤除去沉淀Ⅰ并收集滤液,将滤液降温后收集沉淀Ⅱ,干燥即得。本发明所述的硝普钠的制备方法操作简单,对设备要求低,设备数量少,条件温和,生产周期短,未引入其他重金属离子,成本低,适合于工业化生产。(The invention provides a preparation method of sodium nitroprusside, which comprises the steps of taking potassium nitroferricyanide or a hydrate thereof and sodium iodide as raw materials, reacting to obtain potassium iodide and sodium nitroprusside, filtering to remove a precipitate I, collecting filtrate, cooling the filtrate, collecting a precipitate II, and drying to obtain the sodium nitroprusside. The preparation method of sodium nitroprusside has the advantages of simple operation, low requirement on equipment, small quantity of equipment, mild condition, short production period, no introduction of other heavy metal ions, low cost and suitability for industrial production.)

1. A preparation method of sodium nitroprusside is characterized in that potassium nitroferricyanide or a hydrate thereof and sodium iodide are used as raw materials to react to obtain potassium iodide and sodium nitroprusside, the potassium iodide and the sodium nitroprusside are filtered to remove a precipitate I, a filtrate is collected, the filtrate is cooled, a precipitate II is collected, and the sodium nitroprusside is obtained after drying.

2. The method for preparing sodium nitroprusside as claimed in claim 1, comprising: s1, heating the organic solvent to 30-60 ℃, adding potassium nitrosoferricyanide or a hydrate thereof, stirring until the potassium nitrosoferricyanide or the hydrate thereof is dissolved, cooling to 30-35 ℃, adding sodium iodide, and stirring for reaction for 5-30 min; s2, filtering to remove the precipitate I, collecting filtrate, cooling the filtrate to-5-10 ℃, and standing for 12-24 hours; s3, separating the precipitate, leaching and drying.

3. The method for preparing sodium nitroprusside as claimed in claim 1, wherein said step S3 comprises: s31, centrifuging, filtering and collecting a filter cake, and washing with 0.2-2 times (v/m) of organic solvent at 0-4 ℃; s32, putting the filter cake into an organic solvent with the temperature of 30-60 ℃, pulping and stirring for 10-30 min; s33, collecting the filter cake again after filtering and leaching; s34, and drying the filter cake in vacuum to obtain the filter cake.

4. The method for preparing sodium nitroprusside of claim 3, wherein the steps S32 and S33 can be repeated 1-3 times.

5. The method for preparing sodium nitroprusside as claimed in claim 2, wherein the molar equivalent ratio of potassium nitrosoferricyanide or its hydrate to sodium iodide in step S1 is 1-1.1: 1, the volume mass ratio of the organic solvent to the potassium nitrosoferricyanide or the hydrate thereof is (30-45): (2-4.5) mL/g.

6. The method for preparing sodium nitroprusside as claimed in claim 5, wherein the molar equivalent ratio of potassium nitrosoferricyanide or its hydrate to sodium iodide in step S1 is 1.05: 1, the volume mass ratio of the organic solvent to the potassium nitrosoferricyanide or the hydrate thereof is 10: 1 mL/g.

7. A process for preparing sodium nitroprusside as claimed in any of claims 2 to 6, wherein said potassium nitrosoferricyanide hydrate is potassium nitrosoferricyanide dihydrate.

8. The method for preparing sodium nitroprusside of claim 2, wherein the organic solvent in step S1 is a water-miscible organic solvent selected from methanol, ethanol, isopropanol, propylene glycol, glycerol, ethylene glycol, acetone, tetrahydrofuran, and acetonitrile, preferably methanol, ethanol, and acetone.

9. The method for preparing sodium nitroprusside as claimed in claim 3, wherein the centrifugation rotation speed in steps S31 and S33 is 1500-5000rpm, and the drying condition in step S34 is: the temperature is 30-70 ℃, the vacuum degree is not less than 0.08MPa, and the time is 2-15 h.

Technical Field

The invention relates to the technical field of medicinal chemistry, in particular to a preparation method of sodium nitroprusside.

Background

Sodium nitroprusside, chemical name is sodium nitrosoferricyanide dihydrate, molecular formula is Na₂[Fe(CN)₅NO].2H₂O, a specific vasodilator acting directly on the arteriovenous vascular bed. The effect is strong and rapid, and the effect can be achieved after intravenous drip for 1-2 min; the maintenance time is short, the blood pressure can rise to the level before the medicine within 1-10 min after the medicine is stopped, and the medicine is a common medicine for treating hypertension emergency and acute left heart failure. Clinically, the dropping speed of the sodium nitroprusside is adjusted to stabilize the blood pressure at an ideal level, and the sodium nitroprusside is used for controlling the blood pressure reduction during hypertension emergency and surgical anesthesia, acute heart failure and the like.

In order to ensure the safety of clinical medication,the Chinese pharmacopoeia (2015 edition) limits the content of sodium nitroprusside: defined as Na content in dry product₂Fe(CN)₅NO is not less than 99.0%, and the prior art discloses the following 3 methods:

1) chinese patent publication No. CN103159233A discloses a process for synthesizing sodium nitroprusside (sodium nitrosoferricyanide), which comprises reacting potassium nitrosoferricyanide and copper sulfate pentahydrate as reaction raw materials under appropriate conditions to generate copper nitrosoferricyanide, and reacting the copper nitrosoferricyanide with sodium bicarbonate to generate sodium nitroprusside, wherein the reaction formula is as follows:

K₂[Fe(CN)₅(NO)]+CuSO₄→Cu[Fe(CN)₅(NO)]+K₂SO₄Cu[Fe(CN)₅(NO)]+2NaHCO₃

→Na₂[Fe(CN)₅(NO)]+CuCO₃+CO₂+H₂O

but the content of sodium nitroprusside prepared by the method is less than or equal to 96 percent, and further refining treatment is needed; meanwhile, heavy metal ions such as copper and the like are introduced in the reaction, and if the heavy metal ions directly enter the body through intravenous injection, the risk of medication safety exists.

2) For example, in the method for preparing sodium nitroprusside disclosed in Z.Anorg.Allg.chem., 2001,627,1663-1668, potassium nitroferricyanide and nitric acid are used as raw materials to perform nitrosation reaction, and then sodium carbonate is used to adjust alkalinity to obtain sodium nitroprusside, which has the following reaction formula:

K₄[Fe(CN)₆]+6HNO₃→H₂[Fe(CN)₅(NO)]+CO₂+NH₄NO₃+4KNO₃

H₂[Fe(CN)₅(NO)]+Na₂CO₃→Na₂[Fe(CN)₅(NO)]+CO₂+H₂O

however, the method generates a large amount of inorganic salt impurities, such as potassium nitrate, sodium nitrate and the like, so that the purity of the sodium nitroprusside can not reach the pharmacopoeia standard.

3) For example, CN110342541A discloses a method for preparing sodium nitroprusside, which comprises a) reacting potassium nitroferricyanide and nitric acid in water to obtain nitroprusside; b) reacting nitroprusside with copper sulfate in water to generate nitroprusside precipitate; c) the nitroprusside reacts with sodium bicarbonate to obtain sodium nitroprusside, and the reaction formula is as follows:

K₄[Fe(CN)₆]+6HNO₃→H₂[Fe(CN)₅(NO)]+CO₂+NH₄NO₃+4KNO₃

H₂[Fe(CN)₅(NO)]+CuSO₄→Cu[Fe(CN)₅(NO)]+H₂SO₄

Cu[Fe(CN)₅(NO)]+2NaHCO₃→Na₂[Fe(CN)₅(NO)]+CuCO₃+CO₂+H₂O

however, the method has a plurality of reaction steps, so that the total yield (80-81.5%) is low and the production cost is high.

Therefore, the development of a preparation process of sodium nitroprusside which is efficient, high in yield, suitable for industrial production, high in product content and less in impurities is urgently needed.

Disclosure of Invention

In view of the above, the invention aims to provide a preparation method of sodium nitroprusside, so as to solve the defects that the existing production method is easy to introduce heavy metal ions, low in yield, multiple in reaction steps and the like.

In order to achieve the purpose, the technical scheme of the invention is realized as follows: a process for preparing sodium nitroprusside includes such steps as reaction between potassium nitroferricyanide or its hydrate and sodium iodide to obtain potassium iodide and sodium nitroprusside, filtering to remove I-potassium iodide, collecting filtrate, cooling, collecting II-sodium nitroprusside, and drying.

The reaction formula is as follows: k₂[Fe(CN)₅(NO)]+2NaI→Na₂[Fe(CN)₅(NO)]+2KI

The invention takes sodium iodide as a sodium source and reacts with potassium nitroferricyanide in an organic solvent, because the solubility of potassium iodide in ethanol is far less than that of sodium iodide and the crystallization settling speed of potassium iodide is far faster than that of sodium nitroferricyanide, potassium iodide precipitate is firstly filtered out through time difference, then filtrate is fully cooled and stood to obtain sodium nitroferricyanide and a small amount of other salt mixture, and residual sodium iodide, potassium iodide and potassium nitroferricyanide with higher solubility than the product are washed away by warm ethanol by utilizing different solubility and different dissolving speed, so that the high-purity sodium nitroferricyanide is obtained to meet the requirements of pharmacopoeia.

Preferably, the preparation method of sodium nitroprusside comprises the following steps: s1, heating the organic solvent to 30-60 ℃, adding potassium nitrosoferricyanide or a hydrate thereof, stirring until the potassium nitrosoferricyanide or the hydrate thereof is dissolved, cooling to 30-35 ℃, adding sodium iodide, and stirring for reaction for 5-30 min; s2, filtering to remove the precipitate I, collecting filtrate, cooling the filtrate to-5-10 ℃, and standing for 12-24 hours; s3, separating the precipitate, leaching and drying. For example, heating an organic solvent to 60 ℃, adding potassium nitrosoferricyanide or a hydrate thereof, stirring until the potassium nitrosoferricyanide or the hydrate thereof is dissolved, cooling to 30 ℃, adding sodium iodide, and stirring to react for 20 min;

preferably, the step S3 includes: s31, centrifuging, filtering and collecting a filter cake, and washing with 0.2-2 times (v/m) of organic solvent at 0-4 ℃; s32, putting the filter cake into an organic solvent with the temperature of 30-60 ℃ and stirring for 10-30 min; s33, cooling to-5-10 ℃, filtering by throwing, and collecting filter cakes again; s34, and drying the filter cake in vacuum to obtain the filter cake.

Preferably, the steps S32 and S33 can be repeated for 1-3 times.

Preferably, the molar equivalent ratio of the potassium nitrosoferricyanide or the hydrate thereof to the sodium iodide in step S1 is 1 to 1.1: 1, the volume mass ratio of the organic solvent to the potassium nitrosoferricyanide or the hydrate thereof is (30-45): (2-4.5) mL/g.

Preferably, the molar equivalent ratio of the potassium nitrosoferricyanide or the hydrate thereof to the sodium iodide in step S1 is 1.05: 1, the volume mass ratio of the organic solvent to the potassium nitrosoferricyanide or the hydrate thereof is 10: 1 mL/g.

Preferably, the potassium nitrosoferricyanide hydrate is potassium nitrosoferricyanide dihydrate.

Preferably, the organic solvent in step S1 is water-miscible organic solvent selected from methanol, ethanol, isopropanol, propylene glycol, glycerol, ethylene glycol, acetone, tetrahydrofuran, and acetonitrile, preferably methanol, ethanol, and acetone.

Preferably, the centrifugal rotation speed in steps S31 and S33 is 1500-: the temperature is 30-70 ℃, the vacuum degree is not less than 0.08MPa, and the time is 2-15 h.

Compared with the prior art, the preparation method of sodium nitroprusside has the following advantages: 1) the preparation method of sodium nitroprusside is simple to operate and low in equipment requirement; no special process and reagent are needed, no heavy metal ions are introduced, and the safety is high; 2) the temperature of the whole process is moderate between room temperature and 90 ℃, the condition is mild, and the method is suitable for industrial production; 3) the product yield is good, and the purity accords with the pharmacopoeia standard.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

The active component of sodium nitroprusside is sodium nitrosoferricyanide dihydrate which is a strong dilator directly acting on artery and vein blood vessels. The composition has direct dilating effect on resistance and volume blood vessel, and has effect on afterload greater than nitroglycerin, so as to reduce left ventricular filling pressure and increase cardiac output. Sodium nitroprusside is more rapidly and strongly efficacious than furosemide in acute blood loss compensation of chronic left ventricular failure patients. The sodium nitroprusside is convenient to use, takes effect quickly after intravenous drip, has quick disappearance of action, generally does not need traumatic hemodynamic monitoring, is a preferred medicament for various hypertensive emergencies, and has obvious curative effect on acute left heart failure and refractory heart failure (patients with increased blood pressure or normal blood pressure) and 'impact treatment' of the sodium nitroprusside matched with dobutamine intravenous drip.

In view of the defects in the prior art, sodium iodide is selected as a sodium source and reacts with potassium nitroferricyanide in a common organic solvent to produce sodium nitroprusside, and the obtained product meets the requirements of pharmacopoeia. Because the solubility of potassium iodide in ethanol is far less than that of sodium iodide, the double decomposition reaction is carried out between the ethanol solution of potassium nitroferricyanide and sodium iodide to generate potassium iodide and sodium nitroferricyanide with lower solubility, wherein the crystallization settling speed of potassium iodide is far faster than that of sodium nitroferricyanide, precipitated potassium iodide is firstly filtered out by utilizing the time difference, then the filtrate is fully placed and cooled to obtain the mixture of sodium nitroferricyanide and a small amount of other salts, and the residual sodium iodide, potassium iodide and potassium nitroferricyanide with higher solubility than the product are washed away by warm ethanol by utilizing the difference of solubility and the difference of dissolution speed to obtain the high-purity sodium nitroferricyanide; the method has the advantages of simple operation, low requirement on equipment, small equipment quantity, mild condition, short production period, suitability for industrial production and the like.

Example 1

A preparation method of sodium nitroprusside comprises the following steps: s1, adding 4.5kg of potassium nitroferricyanide dihydrate and 45L of absolute ethyl alcohol into a 100L glass lining reaction kettle, heating to 60 ℃ to promote dissolution, stopping heating, and cooling to 30 ℃;

s2, adding 2.15kg of anhydrous sodium iodide while stirring, wherein the molar ratio of the anhydrous sodium iodide to the potassium nitrosoferricyanide is 1.05: 1, stirring for 20min, quickly performing spin filtration at a centrifugal speed of 1500rpm, collecting filtrate, and separating potassium iodide solid 1.31 kg; the identification method of potassium iodide comprises the following steps: taking a small amount of solid, adding 3% hydrogen peroxide for reacting for five minutes, taking a starch test solution as an indicator, and determining the content of iodine by a sodium thiosulfate solution titration method; detecting and determining the positive ions as potassium ions by a flame photometer.

S3, cooling the filtrate to 5 ℃, standing for 16h, centrifuging at 2500rpm, and washing the filter cake twice with 2L of cold ethanol respectively; grinding, sieving with 80 mesh sieve, and vacuum drying to obtain red powder 4.10 kg.

S4, adding the dried red powder into 20L of 45 ℃ hot ethanol, pulping for 10 minutes, filtering while the red powder is hot, leaching with 1L of warm ethanol, drying the filter cake in vacuum to obtain 3.53 kg, wherein the yield is 87%, the product meets the standard of Chinese pharmacopoeia, and a flame photometer is used for detecting potassium ions independently, and the content is lower than 0.1%, so that the product meets the requirements. The vacuum drying is prior art and will not be described herein.

Example 2

A preparation method of sodium nitroprusside comprises the following steps: s1, adding 4.5kg of potassium nitroferricyanide dihydrate and 45 liters of absolute ethyl alcohol into a 100L glass lining reaction kettle, heating to 50 ℃ to promote dissolution, stopping heating, and cooling to 30 ℃;

s2, stirring and adding 2.25kg of anhydrous sodium iodide, wherein the molar ratio of the anhydrous sodium iodide to the potassium nitrosoferricyanide is 1.1: 1 stirring for 20 minutes, precipitating, centrifuging, filtering by spinning, and obtaining 1.35 kg of potassium iodide solid at a centrifugal speed of 3500 rpm. The identification method of potassium iodide comprises the following steps: taking a little solid, adding 3% hydrogen peroxide for reaction for five minutes, taking starch test solution as an indicator, and determining the content of iodine by a titration method of sodium thiosulfate solution; the positive ions are detected by a flame photometer and are qualified as potassium ions, so that the potassium iodide solid is determined.

S3, cooling the filtrate to about 5 ℃, standing for 16h, centrifuging, and performing spin filtration at a centrifugation speed of 4500 rp; the filter cake was washed twice with 2L of cold ethanol, ground, sieved through 80 mesh sieve, and vacuum dried to obtain 4.23kg of red powdery substance.

S4, adding the dried red powder into 20L of 45 ℃ hot ethanol, pulping for 10min, filtering while the red powder is hot, leaching with 1L of warm ethanol, and drying the filter cake in vacuum to obtain 3.59 kg. The yield is 88.3 percent, and the product meets the standard of Chinese pharmacopoeia. The content of potassium ions is lower than 0.1 percent and meets the requirement by using a flame photometer to separately detect the potassium ions.

Example 3

A preparation method of sodium nitroprusside comprises the following steps: s1, adding 30L of a mixed solvent (V: V ═ 2: 1) of potassium nitroferricyanide dihydrate 4.5kg and absolute ethanol and methanol to a 100L glass-lined reactor, and heating to 30 ℃ to promote dissolution;

s2, adding 2.15kg of anhydrous sodium iodide while stirring, wherein the molar ratio of the anhydrous sodium iodide to the potassium nitrosoferricyanide is 1.05: 1, stirring for 20 minutes until a precipitate is separated out, and carrying out centrifugal filtration at the centrifugal speed of 2500rpm to obtain 1.28 kg of potassium iodide solid. The identification method of potassium iodide comprises the following steps: taking a little solid, adding 3% hydrogen peroxide for reaction for five minutes, taking starch test solution as an indicator, and determining the content of iodine by a titration method of sodium thiosulfate solution; the positive ions are detected by a flame photometer and are qualified as potassium ions, so that the potassium iodide solid is determined.

S3, cooling the filtrate to about 5 ℃, standing for 16h, centrifuging at a speed of 3500rpm, washing the filter cake twice with 2L of cold ethanol, grinding, sieving with an 80-mesh sieve, and vacuum drying to obtain 4.10kg of red powdery substance.

S4, adding the dried red powder into 20L of 45 ℃ hot ethanol, pulping for 10min, filtering while the red powder is hot, leaching with 1L of warm ethanol, and drying the filter cake in vacuum to obtain 3.37 kg. The yield is 83 percent, and the product meets the standard of Chinese pharmacopoeia. The content of potassium ions is lower than 0.1 percent and meets the requirement by using a flame photometer to separately detect the potassium ions.

Example 4

A preparation method of sodium nitroprusside comprises the following steps: s1, adding 4.5kg of potassium nitroferricyanide dihydrate and 45L of absolute ethyl alcohol into a 100L glass lining reaction kettle, heating to 58 ℃ to promote dissolution, stopping heating, and cooling to 30 ℃;

s2, adding 2.35kg of anhydrous sodium iodide while stirring, wherein the molar ratio of the anhydrous sodium iodide to the potassium nitrosoferricyanide is 1.15: 1) stirring for 30min to precipitate, centrifuging at 3000rpm, and filtering to obtain solid potassium iodide 1.36 kg. The identification method of potassium iodide comprises the following steps: taking a little solid, adding 3% hydrogen peroxide for reaction for five minutes, taking starch test solution as an indicator, and determining the content of iodine by a titration method of sodium thiosulfate solution; the positive ions are detected by a flame photometer and are qualified as potassium ions, so that the potassium iodide solid is determined.

S3, cooling the filtrate to about 5 ℃, standing for 16 hours, centrifuging at the speed of 3000rpm, continuously washing the filter cake twice with 2L of cold ethanol respectively, grinding, sieving with a 80-mesh sieve, and vacuum drying to obtain 3.90kg of red powdery substance.

S4, adding the dried red powder into 20L of 45 ℃ hot ethanol, pulping for 10min, filtering while the red powder is hot, leaching with 1L of warm ethanol, and drying the filter cake in vacuum to obtain 3.41 kg. The yield is 84 percent, and the product meets the standard of Chinese pharmacopoeia.

It will be understood that the above embodiments are merely exemplary embodiments taken to illustrate the principles of the present invention, which is not limited thereto. It will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention, and these changes and modifications are also considered to be included in the scope of the invention.