JP2021025068A - Sodium dispersion removable method - Google Patents

Abstract

To provide a sodium dispersion removal method in which metallic sodium contained in sodium dispersion can easily and efficiently be removed.SOLUTION: A sodium dispersion removal method comprises a dissolution step in which a dispersion in which metallic sodium is dispersed in a dispersion solvent and an amide-based solvent or a polyether-based solvent are mixed to produce a solution in which metallic sodium is dissolved in an amide-based solvent or a polyether-based solvent.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for removing a sodium dispersion.

Conventionally, a starting compound and a dispersion in which metallic sodium is dispersed in a dispersion solvent composed of normal paraffin oil (hereinafter, may be referred to as “SD”, which is an abbreviation for Sodium Dispersion) are reacted and intermediate. A synthetic method for synthesizing a product and synthesizing a compound using this intermediate product is known (see, for example, Patent Document 1).

The synthetic method described in Patent Document 1 is a reaction between 2,2,6,6-tetramethylpiperidines and a dispersion in which sodium is dispersed in a dispersion solvent or a dispersion in which sodium is dispersed in a dispersion solvent. The obtained organic sodium compound having an aromatic ring is reacted in a reaction solvent to obtain an intermediate product of sodium 2,2,6,6-tetramethylpiperidides (hereinafter referred to as Na-TMP). It is synthesizing. This Na-TMP can be used for Wittig reaction, isomerization reaction through deprotonation of allylic hydrogen, deprotonation and functionalization reaction of heteroarene, functionalization reaction of heterocyclic compound, etc. It is possible. When a proton is extracted from a substrate of an aromatic ring or a heteroaromatic ring, the proton having the highest acidity is extracted. For example, the proton at the 2-position is extracted from meta-bromochlorobenzene. However, if an excess amount of metallic sodium is added during Na-TMP synthesis and the sodium is reacted with an organic halogen compound without being removed, not only the proton to be extracted but also the excess metallic sodium reacts with the halogen of the substrate. there is a possibility. That is, when preparing a base such as Na-TMP, it is necessary to remove excess metallic sodium added at the time of preparation. In the process of this synthesis method, filtration may be performed using a filter material such as a filter cloth in order to remove excess SD that was not used in the reaction in the synthesis of the intermediate product. The SD attached to this filter cloth needs to be removed (inactivated) so that the metallic sodium does not come into contact with air.

As a method for deactivating this metallic sodium, a technique is known in which water is added to a mixed solution of metallic sodium and an inert oil to convert it into caustic soda (see, for example, Patent Document 2). Patent Document 2 discloses a technique for adding a surfactant in order to increase the affinity between water and an inert oil.

JP-A-2018-123116 International Publication No. 2015/186637

When the deactivation method described in Patent Document 2 is used for deactivating SD adhering to the filter cloth, water and metallic sodium react with each other to generate heat, which may deteriorate the filter cloth. As a result, the filter cloth cannot be used repeatedly, and the efficiency of the synthetic process is reduced.

Therefore, there is a demand for a method for removing a sodium dispersion that can easily and efficiently remove metallic sodium contained in the sodium dispersion.

The feature of the method for removing a sodium dispersion according to the present invention is that a dispersion in which metallic sodium is dispersed in a dispersion solvent is mixed with an amide solvent or a polyether solvent, and the amide solvent or the polyether solvent is used as described above. The point is that it is provided with a dissolution step of producing a solution in which metallic sodium is dissolved.

By dissolving the metallic sodium contained in the dispersion in an amide solvent or a polyether solvent as in this method, it is possible to prevent the metallic sodium from coming into contact with air or water and generate heat, and the metallic sodium can be safely removed. can do.

Further, this method is convenient because it is possible to remove metallic sodium by adding an amide solvent or a polyether solvent to the dispersion. Moreover, since it dissolves under mild conditions in which heat generation is suppressed, the adhered object to which the dispersion adheres does not deteriorate. As a result, the excess dispersion can be efficiently removed in the synthesis process using the sodium dispersion.

Another characteristic method is that the dispersion is attached to a filter medium or a pipe.

As an example of the filter material, when the dispersion adhering to the filter cloth is deactivated with water or alcohol, it is easily deteriorated by heat generation. On the other hand, when the dispersion is dissolved in an amide solvent or a polyether solvent and removed as in this method, an exothermic reaction does not occur on the filter cloth, so that deterioration of the filter cloth can be prevented.

Another characteristic method is to deactivate the metallic sodium by adding an acidic salt and an alcohol to the solution and replacing the metallic sodium with a hydrogen atom in the acidic salt to form a positive salt. The point is that it has more processes.

By adding an acid salt and an alcohol to the solution as in this method, the metallic sodium is oxidized to an alkoxide, and this alkoxide is reduced by the acid salt to become an alcohol and a positive salt. As a result, alcohol can be used repeatedly while deactivating metallic sodium. Moreover, it is highly convenient because the heat generation at the time of deactivation can be controlled by the amount of alcohol added.

Another characteristic method is that the amide solvent is 1,3-dimethyl-2-imidazolidilinone and the acid salt is baking soda.

If 1,3-dimethyl-2-imidazolidilinone is used as the amide solvent and baking soda is used as the acid salt as in this method, metallic sodium can be efficiently dissolved and inactivated.

Another characteristic method is that after the deactivation step, a cleaning step of adding alcohol to the filter material or the pipe for cleaning is further provided.

If the filter cloth is washed with alcohol as an example of the filter material as in this method, the filter cloth can be reused, so that the cost of synthesizing the compound using the dispersion can be saved.

It is a removal flow chart of a sodium dispersion. It is a figure which shows the reaction heat in a melting process. It is a figure which shows the result of GC / MS analysis in this Example 1. It is a figure which shows the result of GC / MS analysis in this Example 2. It is a figure which shows the result of the GC / MS analysis in the comparative example 1. It is a figure which shows the result of the GC / MS analysis in the comparative example 2. It is a figure which shows the result of the GC / MS analysis in the comparative example 3.

Hereinafter, embodiments of the method for removing the sodium dispersion according to the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments, and various modifications can be made without departing from the gist thereof.

The method for removing the sodium dispersion according to the present embodiment is to remove (inactivate) metallic sodium from the excess sodium dispersion in the process of the synthesis method using the sodium dispersion.

In the method for removing the sodium dispersion in the present embodiment, the dispersion in which metallic sodium is dispersed in a dispersion solvent is mixed with an amide solvent or a polyether solvent, and the metallic sodium is dissolved in the amide solvent or the polyether solvent. Deactivation of metallic sodium by adding an acid salt and alcohol to the dissolution solution to generate the dissolved solution, and by substituting the metal sodium with the hydrogen atom in the acid salt to form a positive salt. It has an active process. When the dispersion is attached to the filter material or the pipe, it is preferable to further include a cleaning step of adding alcohol to the filter material or the pipe to clean the filter material or the pipe after the deactivation step. FIG. 1 shows 1,3-dimethyl-2-imidazolidilinone (DMI) as an amide-based solvent in which the dispersion adhered on the filter cloth 5 was stored in the storage tank 4 in the synthesis process using the dispersion. An example is shown in which sodium bicarbonate and alcohol as acid salts are added to the solution to inactivate the metallic sodium in the inactivation tank 2, and the details will be described later.

Examples of the filter material include a filter cloth such as a non-woven fabric, and a porous material such as a wire mesh or a filter paper, which are used when separating a surplus dispersion in a synthesis process using the dispersion. The pipe is a cast iron pipe, a steel pipe, a stainless steel pipe, or the like used for transporting a liquid containing a dispersion between reaction tanks in a synthesis process. Further, the method for removing the sodium dispersion in the present embodiment can also be suitably used when removing SD adhering to the wall surface of the reaction vessel.

A dispersion in which metallic sodium is dispersed in a dispersion solvent (hereinafter, may be abbreviated as "SD", which is an abbreviation for Sodium Dispersion) is one in which sodium is dispersed as fine particles in an insoluble solvent, or sodium is a liquid. It is dispersed in an insoluble solvent in the state of. Examples of sodium include metallic sodium and alloys containing metallic sodium. The average particle size of the fine particles is preferably less than 100 μm, particularly preferably less than 50 μm, further preferably less than 30 μm, and even more preferably less than 10 μm. The average particle size was represented by the diameter of a sphere having a projected area equivalent to the projected area obtained by image analysis of a micrograph.

As the dispersion solvent, a solvent known in the art can be used as long as sodium can be dispersed as fine particles or sodium can be dispersed in an insoluble solvent in a liquid state and the reaction between the starting compound and SD is not inhibited. .. Examples thereof include aromatic solvents such as xylene and toluene, normal paraffin solvents such as normal decane, heterocyclic solvent such as tetrahydrothiophene, and mixed solvents thereof.

It is preferable to use SD having an activity of 99.0% or more of phenylsodium with respect to the added chlorobenzene when reacted with chlorobenzene at 2.1 molar equivalents or more in a reaction solvent described later. .. By using such highly active SD, the synthetic process can proceed more efficiently. Here, in order to maintain high SD activity, it is preferable to store it in a container having a high gas barrier property such as a glass vial. However, it does not exclude storage in a container having a low gas barrier property, and in that case, it is used immediately after the production of SD, for example, within several weeks, preferably within 3 weeks.

The amide-based solvent or the polyether-based solvent is preferably a solvent that does not react with metallic sodium and dissolves metallic sodium. Examples of the amide solvent include 1,3-dimethyl-2-imidazolidilinone (DMI), N-methylpyrrolidone (NMP), N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMAc) and the like. Can be mentioned. Examples of the polyether solvent include diglyme and 15-crown-5. The amide solvent or the polyether solvent may be used as it is, or may be diluted with an organic solvent such as THF. Dilution with THF or the like reduces the cost of raw materials, but reduces the saturation concentration of metallic sodium. Dissolve or transfer metallic sodium to an amide solvent or a polyether solvent (dissolution step). In this case, since the dispersion solvent is not dissolved in the amide solvent or the polyether solvent, the metallic sodium contained in SD can be reliably removed. Then, a sodium solvent (an example of a solution) containing metallic sodium and an amide solvent or a polyether solvent is extracted. In this way, if the metallic sodium contained in SD is dissolved in an amide solvent or a polyether solvent, it becomes possible to prevent the metallic sodium from coming into contact with air or water and generating heat, so that the metallic sodium can be safely used. Can be removed. Further, it is convenient because metallic sodium can be removed by adding an amide solvent or a polyether solvent to SD.

Figure 2 shows the heat of reaction when metallic sodium was removed (dissolved) from SD using 1,3-dimethyl-2-imidazolidilinone (DMI) as the amide solvent, and SD using methanol as the alcohol. The relationship with the heat of reaction when metallic sodium is removed (inactivated) from the solvent is shown. In the figure, this example in which 30 ml of DMI is added to 0.1 g of SD and a comparative example in which 30 ml of methanol is added to 0.1 g of SD are shown. In this example, metallic sodium was removed (dissolved) from SD at room temperature, whereas in Comparative Example, metallic sodium was removed (inactivated) from SD with heat generation of about 70 ° C. The solution of this example was filtered with a filter cloth, but nothing remained on the filter cloth. Therefore, it was confirmed that all the metallic sodium was dissolved in DMI. As described above, in the dissolution step in the present embodiment, since the dissolution is performed under mild conditions in which heat generation is suppressed, the filter cloth to which SD is attached is not deteriorated. As a result, excess SD can be efficiently removed in the synthesis process using SD.

In the present embodiment, a solution containing metallic sodium dissolved in an amide solvent or a polyether solvent is inactivated with an alcohol and an acid salt (inactivation step). The acid salt means a salt in which a hydrogen atom that can be ionized in the molecule remains partially without being replaced with a metal or a positive group. As the acid salt, a hydrogen carbonate is preferably used. As the hydrogen carbonate, a salt of an alkali metal or an alkaline earth metal is preferably used, and sodium hydrogen carbonate (baking soda) is preferable. In addition, hydrogen sulfate, dihydrogen phosphate, hydrogen phosphate and the like may be used, and examples thereof include sodium hydrogen sulfate, sodium dihydrogen phosphate, disodium hydrogen phosphate and the like, but the present invention is limited thereto. It's not a thing.

The alcohol used in the deactivation step is preferably a lower alcohol such as isopropyl alcohol, methanol or ethanol, but a higher alcohol is also acceptable and is not particularly limited. Alcohols having a boiling point different from that of the reaction solvent by 20 ° C. or more are preferably used. Further, an alcohol that does not azeotrope with the reaction solvent is preferably used. Thereby, the reaction solvent mixed in the solution and the alcohol can be separated by utilizing the boiling point difference. The deactivating step needs to be performed in an inert gas atmosphere in which the inside of the deactivating tank is filled with an inert gas such as argon gas or nitrogen gas.

In the deactivation step, the solution containing metallic sodium is moved to the deactivation tank. The method for deactivating metallic sodium according to the present embodiment is to introduce an acid salt and an alcohol into a solution containing metallic sodium, and the metallic sodium is replaced with a hydrogen atom in the acidic salt to form a positive salt. Inactivates metallic sodium. For example, alcohol and sodium hydrogen carbonate (an example of an acidic salt) are introduced into an inactivation tank, and metallic sodium is converted to sodium carbonate (an example of a positive salt) by the following reaction formulas (1) and (2) and lost. Make it alive. By repeating this reaction, alcohol can be reused while inactivating metallic sodium. Therefore, the alcohol used in the deactivation step is preferably 1.0 molar equivalent or less, preferably 0.8 molar equivalent or less, relative to SD contained in the solution. Here, the amount of substance of SD means the amount of substance in alkali metal equivalent contained in SD.
(1) Na + R-OH ⇒ R-ONa + 1 / 2H ₂
(2) R-ONa + NaHCO ₃ ⇒ R-OH + Na ₂ CO ₃

Hereinafter, as an example of a synthetic process using a sodium dispersion using FIG. 1, sodium 2,2,6,6-tetramethylpiperidide (hereinafter, abbreviated as “Na-TMP”) is used as an intermediate product. A method for synthesizing Na-TMPs to be synthesized and a method for synthesizing using this Na-TMP will be described. This Na-TMP can be used for Wittig reaction, isomerization reaction through deprotonation of allylic hydrogen, deprotonation and functionalization reaction of heteroarene, functionalization reaction of heterocyclic compound, etc. it can. At this time, the reaction solvent in which Na-TMP is dissolved may contain solid impurities such as unreacted metallic sodium and phenyl sodium. Since it is not desirable to mix impurities, it is necessary to use a synthetic method that can obtain Na-TMP without impurities.

In the method for synthesizing Na-TMPs that do not contain solid impurities such as unreacted metallic sodium and phenyl sodium, an organic halogen compound as a starting compound and SD are mixed in a reaction solvent in the first reaction tank 1. The first step of reacting to obtain an organic sodium compound having solubility in an organic solvent, the reaction solvent containing the obtained organic sodium compound having solubility in an organic solvent is filtered to remove unreacted metallic sodium. In the second step, the second reaction vessel 3, a reaction solvent containing an organic sodium compound having solubility in an organic solvent containing no metallic sodium obtained by filtration was mixed with TMPs to obtain Na- as an intermediate product. It has a third step of obtaining TMPs. Examples of the soluble organic sodium compound include neopentyl sodium and 2-ethylhexyl sodium.

The TMPs which are the starting substances in the method for synthesizing Na-TMPs according to the present embodiment are 2,2,6,6-tetramethylpiperidine which may or may not have a substituent. , Appropriately set according to the desired Na-TMPs. Therefore, when it has a substituent, it may be introduced into a part or all of the carbon atoms at positions 3, 4, and 5 of the piperidine ring, depending on the desired Na-TMPs, and a plurality of substituents may be used. If they have, some or all of them may be the same, or all of them may be different. Examples of the substituent include, but are not limited to, an alkyl group such as a methyl group, an ethyl group, and a propyl group.

As the reaction solvent, a solvent known in the art can be used as long as the reaction between TMPs and SD is not inhibited. For example, an ether solvent, a normal paraffin solvent, a cycloparaffin solvent, an aromatic solvent, an amine solvent, and a heterocyclic compound solvent can be used. As the ether solvent, a cyclic ether solvent is preferable, and tetrahydrofuran (THF) is particularly preferable. As the normal paraffin solvent and the cycloparaffin solvent, hexane, normal decane, cyclohexane and the like are particularly preferable. As the aromatic solvent, xylene, toluene, benzene and the like are preferable. As the amine solvent, ethylenediamine and the like are preferable. Further, as the heterocyclic compound solvent, tetrahydrothiophene or the like can be preferably used. Only one type of these may be used, or two or more types may be used in combination as a mixed solvent. Here, the same type of dispersion solvent and reaction solvent may be used, or different types may be used.

Reagents such as TMPs, SD, and reaction solvent required for the method for synthesizing Na-TMPs need to be handled in an atmosphere of an inert gas such as nitrogen or argon. However, since each reagent is highly reactive and generates heat, it is desirable to carry out the reagent in an inert gas atmosphere in which the inside of the first reaction vessel 1 is filled with argon gas, nitrogen gas or the like. Further, the method for synthesizing Na-TMPs may be carried out while stirring the first reaction vessel 1, or may be carried out in a stationary state.

The amount of SD used can be appropriately set according to the types and amounts of TMPs and reaction solvents. Preferably, the reaction of TMPs with SD is such that 1 mmol of the substance of TMPs is reacted with 2.1 to 2.5 molar equivalents of SD in 1.0 to 2.0 molar equivalents of the reaction solvent. Is preferable. In addition, as a method for synthesizing Na-TMPs, the reaction between SD and an organic halogen compound in the first step takes into consideration the reactivity of the organic sodium compound from which impurities have been removed in the second step and the TMPs in the third step. Then, it is preferable to react 2.1 to 2.5 mol equivalents of SD with the organic halogen compound in 1.0 to 2.0 mol equivalents of the reaction solvent with respect to 1 mmol of the substance of TMPs in the third step. As a result, surplus SD that was not used in the reaction will be generated. Therefore, in the case of synthesizing using this Na-TMP or in the second step for producing Na-TMP, the SD is filtered out 5 ( It is necessary to filter with an example of a filter medium).

As shown in FIG. 1, the first on-off valve Va and the second on-off valve Vb are opened, and the organic sodium compound, TMPs, and the reaction solvent as the filtrate that have passed through the filter cloth 5 are used by the driving force of a pump or the like. , Supply to the second reaction tank 3. Then, in the second reaction vessel 3, the Na-TMP (intermediate product) produced by the reaction between the organic sodium compound and the TMPs is subjected to the Wittig reaction, the deprotonation of the allyl hydrogen, and the isomerization reaction. It is used for deprotonation and functionalization reactions of heteroarene, functionalization reactions of heterocyclic compounds, etc. (an example of a synthesis method using Na-TMP). The Wittig reaction is a reaction in which a Wittig reagent (linylide) reacts with an aldehyde (or ketone) to form an alkene, and the Wittig reagent treats a phosphonium salt produced by reacting triphenylphosphine with an alkyl halide with a base. It can be synthesized by doing. Further, the synthesis method using Na-TMP may be carried out while stirring the second reaction tank 3, or may be carried out in a stationary state.

When the organic sodium compound is supplied from the first reaction tank 1 to the second reaction tank 3, excess SD that has not been used in the reaction is separated and adhered to the surface of the filter cloth 5. In the present embodiment, the third on-off valve Vc and the fourth on-off valve Vd are opened, and 1,3-dimethyl-2-imidazolidilinone (DMI, amino) stored in the storage tank 4 by the driving force of a pump or the like is used. An example of a system solvent) is supplied onto the filter cloth 5, and the metallic sodium contained in SD is dissolved and removed as a solution. Then, the removed solution is supplied to the deactivation tank 2 in which alcohol is stored, and baking soda (an example of an acid salt) is added to inactivate metallic sodium. Since the baking soda precipitates in the deactivating tank 2, the deactivating step is executed while stirring. In the deactivation step, it is preferable to store 0.8 mol equivalent or less of alcohol with respect to the metallic sodium contained in the solution, and add 2.0 mol equivalent or more of baking soda, and add 3.0 mol equivalent or more of baking soda. Is particularly preferable. The deactivation time in the deactivation step is related to the amount of baking soda to be added, but is preferably 8 hours or more for baking soda of 2.0 molar equivalent or more, and 8 hours or more for baking soda of 3.0 molar equivalent or more. Especially preferable. Further, the reaction temperature in the deactivation step is 0 to 100 ° C, preferably 20 ° C to 80 ° C, and particularly preferably 30 ° C to 50 ° C.

As a result, if the SD attached to the filter cloth 5 is deactivated with water or alcohol, it is likely to deteriorate due to heat generation. However, if the SD is dissolved in DMI and removed as in the present embodiment, an exothermic reaction occurs on the filter cloth 5. Since it is not damaged, deterioration of the filter cloth 5 can be prevented. Further, in the deactivation tank 2, by adding baking soda and alcohol to the solution, metallic sodium is oxidized to alkoxide, and this alkoxide is reduced by baking soda to become alcohol and calcium carbonate. As a result, alcohol can be used repeatedly while deactivating metallic sodium. Moreover, it is highly convenient because the heat generation at the time of deactivation can be controlled by the amount of alcohol added.

After the deactivation step, it is preferable to carry out a washing step of adding alcohol to the filter cloth 5 for washing. If sodium is converted to sodium hydroxide by a small amount of water contained in the reaction solution, it will not dissolve in DMI, but will dissolve in alcohol. Therefore, in the cleaning step, cleaning may be performed a plurality of times (for example, twice) with DMI and alcohol, and the surface of the filter cloth 5 can always be kept clean. By this washing step, the filter cloth can be reused, so that the cost of synthesizing the compound using the dispersion can be saved. Further, when sodium hydroxide produced by reacting metallic sodium with water is attached to the filter cloth 5, the sodium hydroxide can be dissolved by alcohol, so that the filter cloth 5 can be used repeatedly. ..

[Example]
(Verification of dissolution process)
A filter cloth with a side of 10 cm was placed on the funnel, and 0.1 g of SD was dropped onto the filter cloth. Next, 5 ml of THF was added dropwise, and then SD on the filter cloth was dissolved with DMI. SD became a turquoise solution and was removed from the filter cloth. At this time, 30 ml of DMI was used, and the amount of DMI used was suppressed by repeatedly using the DMI contained in the solution. After removing the SD, the filter cloth was washed with 200 ml of isopropyl alcohol. When 25 ml of water was added dropwise to the filter cloth washed with isopropyl alcohol and the pH was measured with pH test paper, the neutrality was the same as that of the filter cloth without SD. As a result, it was verified that SD was dissolved in DMI and the filter cloth could be used repeatedly.

(Verification of deactivation process)
Add dibutylhydroxytoluene (hereinafter sometimes abbreviated as "BHT") and baking soda to a solution prepared by dissolving SD (0.09 g, 1 mmol, 1 mol equivalent) in DMI (10 ml), and add 0.5, 5 at 30 ° C. , Each reaction was carried out for 8 hours to inactivate metallic sodium. After the reaction, chlorotrimethylsilane (hereinafter, sometimes abbreviated as "TMSCl") (0.35 ml, about 2.4 mmol, about 2.4 mol equivalent) was added, and the mixture was stirred for 1 hour and reacted. In the presence of SD, the hydrogen of the hydroxy group of BHT is replaced with sodium derived from SD to form a sodium alkoxide. When TMSCl is reacted with the produced sodium alkoxide, BHT is converted to TMS. GC / MS analysis (Agilent 5977B: Agilent Technologies, Inc.) was performed on the product, and qualitative analysis data was acquired by MassHunter GC-MS Acquisition B.07.04.2260 (Agilent Technologies, Ltd.) and BHT. Confirmed TMS conversion.

The qualitative analysis data obtained is summarized in Table 1. In addition, FIGS. 3 to 7 show chromatograms showing the results of GC / MS analysis of the product. In Examples 1 and 2 shown in FIGS. 3 to 4, only the BHT peak (7.740 minutes) was confirmed, and the TMS-ized BHT peak could not be confirmed. This means that there is no uninactivated metallic sodium. In Comparative Examples 1 to 3 shown in FIGS. 5 to 7, a TMS-ized BHT peak (9.863 minutes) was confirmed together with a BHT peak (7.740 minutes). It can be understood that the alkoxide formation of BHT by sodium derived from SD and the subsequent TMS conversion, that is, the reaction between the sodium alkoxide and TMSCl is in progress. This means that uninactivated metallic sodium remains. Further, from Table 1, if 0.8 mol equivalent or less of alcohol is used with respect to the metallic sodium contained in the solution, 3 mol equivalent or more of baking soda is added, and the mixture is stirred for 8 hours or more, the sodium is surely inactivated. I was able to verify that.

[Other Embodiments]
(1) In the above-described embodiment, the Na-TMP synthesis process has been described, but the process is not particularly limited as long as it is a synthesis process in which excess SD is filtered through a filter medium. For example, it can be used for the synthesis of sodium-diisopropylamide and diphenylmethylsilyl sodium.
(2) The dissolution step and the deactivation step in the above-described embodiment can be used independently. For example, the wall surface cleaning may be carried out by dissolving the SD adhering to the wall surface of the reaction tank with an amide solvent or a polyether solvent and disposing of the solution without inactivating it. Further, the cleaning step described above may be omitted.

The present invention can be used for removing metallic sodium in a method for removing a sodium dispersion, particularly in a synthetic process using a sodium dispersion.

1: First reaction tank 2: Inactivation tank 3: Second reaction tank 4: Storage tank 5: Filter cloth (filter material)
Va: 1st on-off valve Vb: 2nd on-off valve Vc: 3rd on-off valve Vd: 4th on-off valve

Claims (5)

A dissolution step of mixing a dispersion in which metallic sodium is dispersed in a dispersion solvent with an amide solvent or a polyether solvent to generate a solution in which the metallic sodium is dissolved in the amide solvent or the polyether solvent. A method for removing the prepared sodium dispersion. The method for removing a sodium dispersion according to claim 1, wherein the dispersion is attached to a filter medium or a pipe. A claim further comprising an inactivation step of deactivating the metallic sodium by adding an acidic salt and an alcohol to the solution and substituting the metallic sodium with a hydrogen atom in the acidic salt to form a positive salt. Item 2. The method for removing a sodium dispersion according to Item 2. The method for removing a sodium dispersion according to claim 3, wherein the amide solvent is 1,3-dimethyl-2-imidazolidilinone, and the acid salt is baking soda. The method for removing a sodium dispersion according to claim 3 or 4, further comprising a cleaning step of adding alcohol to the filter medium or the pipe after the deactivation step.

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