KR102247859B1 - Method for preparing hydroxy oxime - Google Patents

Abstract

The present invention relates to a method for preparing hydroxy oxime, and more particularly, to a method for preparing hydroxy oxime, capable of improving a yield of each process step and reducing generation of ketoxime by-products that reduce metal extracting ability of the hydroxy oxime as an extractant. The method for preparing the hydroxy oxime comprises the following steps of: (a) reacting a first precursor represented by a chemical formula 1 in the presence of a metal catalyst to obtain a second precursor represented by a chemical formula 2; and (b) reacting the second precursor with a hydroxyl amine salt to obtain the hydroxy oxime represented by a chemical formula 3.

Description

Manufacturing method of hydroxy oxime {METHOD FOR PREPARING HYDROXY OXIME}

The present invention relates to a method of manufacturing a hydroxy oxime, and more specifically, a hydroxy oxime capable of improving the yield of each process step and reducing the occurrence of ketoxime by-products that lower the metal extraction ability of the hydroxy oxime as an extracting agent. It relates to a method of manufacturing.

Cobalt is a chemical element with the symbol Co and an atomic number of 27. It is a hard, ferromagnetic silver-white metallic element and is used in the manufacture of magnets and high-strength alloys. The compound has a dark blue color and is used as a pigment to add to inks, paints and varnishes, and as an additive used to make blue glass. The radioactive isotope cobalt-60 is used as a radioactive tracer. It is found only in the form of compounds in the crust and is contained in small amounts in the form of alloys in iron meteorites.

Recently, cobalt is not only used as a raw material for batteries, superalloys, hard materials and pigments of secondary batteries, but also used in superalloys such as aircraft jet engines because of its excellent heat resistance. In particular, electric vehicles are beginning to attract attention as a means of transportation in the future, and the demand for cobalt for lithium secondary batteries is increasing. According to statistics from the Rare Metals Industry Technology Center in 2019, the total amount of cobalt imports decreased slightly in 2009 from about 8,260 tons in 2008, and then continued to increase until 2014, and 24,546 tons in 2018 were imported. Cobalt is mainly imported in the form of compounds, and in 2018, it was reported that cobalt oxide (for lithium secondary battery manufacturing) 12,058 tons and cobalt sulfate for secondary battery manufacturing 7,336 tons, respectively, accounting for 49.0% and 29.9% of the total imports.

Cobalt ores often coexist with copper/nickel ores, and copper/nickel resources and regions are inevitably overlapped, so industrially, copper/nickel is collected as the main product and cobalt as a by-product.

In general, DSX (Direct Solvent Extraction) process is performed to recover cobalt and zinc after extraction of copper solvent and iron removal after ore mining. First, the mined ore is pulverized, and then useful minerals such as copper, zinc, and cobalt are dissolved through redox leaching.

After that, electrolytic extraction is performed on a solution obtained by selectively extracting copper through a solvent extraction process to produce electrolytic copper. After copper solvent extraction, cobalt and zinc are extracted from the raffinate that has gone through the iron removal process through a solvent extraction process, and zinc from the concentrated cobalt and zinc solution is separated/concentrated with cobalt through solvent extraction, and zinc sulfate is crystallized through sulfate crystallization. Is produced. Cobalt is recovered from the zinc solvent-extracted raffinate through a solvent extraction-ion exchange-electrolytic extraction process.

LIX-63 (5,8-diethyl-7-hydroxyl) that has an α-hydroxy oxime structure as an extractant in the DSX process performed to recover cobalt and zinc from raffinate after the iron removal process. Dodecan-6-one oxime; 5,8-diethyl-7-hydroxy dodecan-6-oxime) is mainly used.

In addition to the above uses, LIX-63 is also used as an extractant for separating vanadium from a hydrochloric acid solution in which rhenium and vanadium are mixed, or as an extractant for separating and recovering the metal from a hydrochloric acid solution containing gold, platinum and palladium.

On the other hand, while research on the use and use of LIX-63 is actively progressing, there is little research on how to manufacture (synthesis) LIX-63.

Korean Registered Patent Publication No. 10-1950111 (2019. 02. 19)

Under the above technical background, the present invention provides a method for preparing 5,8-diethyl-7-hydroxydodecan-6-one oxime as α-hydroxy oxime used in various metal extraction processes as well as the DSX process. It is aimed at.

In addition, an object of the present invention is to provide a method for producing a hydroxy oxime capable of achieving a final yield of 70% or more by improving the yield of each process step.

In addition, the present invention is capable of reducing the generation of by-products including diketone and/or ketoxime, which act as a cause of lowering the metal extraction ability of hydroxy oxime prepared according to the above-described method. It is an object of the present invention to provide a method for producing a hydroxy oxime.

In order to solve the above technical problem, according to an aspect of the present invention, (a) reacting a first precursor represented by the following formula (1) in the presence of a metal catalyst to obtain a second precursor represented by the following formula (2) Steps to and

[Formula 1]

(Wherein, R ₁ to R ₃ are each independently C ₁ -C ₁₀ alkyl)

[Formula 2]

(Wherein, R ₁ and R ₂ are each independently C ₁ -C ₁₀ alkyl)

(b) reacting the second precursor with a hydroxyl amine salt to obtain a hydroxy oxime represented by the following formula (3)

[Formula 3]

(Wherein, R ₁ and R ₂ are each independently C ₁ -C ₁₀ alkyl)

There is provided a method for producing a hydroxy oxime comprising a.

According to an embodiment of the present invention, the step (a) may further include attaching a protecting group to the intermediate produced by oxidative ionization of the first precursor material by the metal catalyst.

Here, the protecting group is acetal, acetyl, benzoyl, benzyl, β-methoxyethoxymethyl, dimethoxytrityl, methoxymethyl, methoxytrityl, p-methoxybenzyl, p-methoxyphenyl, methylthio Omethyl, trityl, tetrahydropyranyl, tetrahydrofuran, trimethylsilyl, tert-butyldimethylsilyl, tri-iso-propylsiloxymethyl and may be at least one selected from tri-iso-propylsilyl, Preferably, it may be at least one selected from trimethylsilyl, tert-butyldimethylsilyl, tri-iso-propylsiloxymethyl and tri-iso-propylsilyl.

In the step (a), the metal catalyst may be used in an amount of 2.0 to 4.0 equivalents based on 1 equivalent of the first precursor.

The content of diketone in the resultant of step (a) may be 5% or less. When the content of diketone in the result of step (a) exceeds 5%, the content of ketoxime in the result of step (b) to be described later may exceed 4%.

According to the present invention, a method for producing a scale-up capable of hydroxy oxime (e.g., 5,8-diethyl-7-hydroxydodecan-6-one oxime) for a metal extraction process for which the synthesis method is not yet clearly known Can be provided.

The hydroxy oxime (e.g., 5,8-diethyl-7-hydroxydodecan-6-one oxime) prepared according to the method for producing a hydroxy oxime according to the present invention is a DSX process as well as a variety of metal extraction processes. Can be used for

In particular, according to the present invention, it is possible to achieve a final yield of 70% or more by securing a high yield of about 90% or more for each process step, it is possible to provide a method for producing a hydroxy oxime excellent in productivity and economy.

In addition, the final product prepared according to the present invention contains a small amount of by-products including diketone and/or ketoxime, which act as a cause of lowering the metal extraction ability. It is possible to manufacture.

1 shows the results of NMR analysis of the result of step 1 of the preparation example of hydroxy oxime.
Figure 2 shows the results of NMR analysis of the result of step 2 of the preparation example of hydroxy oxime.
3 shows the results of NMR analysis of the result of step 3 of the preparation example of hydroxy oxime.

Certain terms are defined herein for convenience in order to make the present invention easier to understand. Unless otherwise defined herein, scientific and technical terms used in the present invention will have the meanings generally understood by those of ordinary skill in the art. In addition, unless otherwise specified in context, terms in the singular form are to include their plural forms as well, and terms in the plural form are to be understood as including the singular form thereof.

Hereinafter, a method for producing a hydroxy oxime according to the present invention will be described in more detail.

According to an aspect of the present invention, (a) reacting a first precursor represented by the following formula (1) in the presence of a metal catalyst to obtain a second precursor represented by the following formula (2), and

[Formula 1]

(Wherein, R ₁ to R ₃ are each independently C ₁ -C ₁₀ alkyl)

[Formula 2]

(Wherein, R ₁ and R ₂ are each independently C ₁ -C ₁₀ alkyl)

(b) reacting the second precursor with a hydroxyl amine salt to obtain a hydroxy oxime represented by the following formula (3)

[Formula 3]

(Wherein, R ₁ and R ₂ are each independently C ₁ -C ₁₀ alkyl)

There is provided a method for producing a hydroxy oxime comprising a.

The step (a) is a step of preparing a second precursor material represented by Chemical Formula 2 by reacting (condensation reaction) the first precursor material represented by Chemical Formula 1 with each other.

The first precursor may be prepared through esterification of a carboxylic acid represented by Formula 1-1 below.

[Formula 1-1]

Typically, for the esterification reaction, a carboxylic acid may be reacted with an alcohol under an acid catalyst.

In this case, a strong acid such as sulfuric acid, nitric acid, hydrochloric acid, etc. may be used as the acid catalyst, and _{an alcohol containing R 3} as defined in Formula 1 as an alkyl group may be used as the alcohol.

For example, when the first precursor is methyl 2-ehtylhexanoate, the carboxylic acid represented by Formula 1-1 is 2-ethylhexanoic acid, and methanol is used as the alcohol.

In step (a), the condensation reaction of the first precursor may be a reductive coupling reaction promoted by a metal catalyst. In this case, Na metal may be used as the metal catalyst.

Specifically, the carbonyl group of the first precursor is oxidatively ionized by Na ions released from the Na metal to form a radical on the carbonyl carbon. Subsequently, diketone is primarily produced by coupling between the radicals of the first precursor of the two molecules and recovery of the carbonyl group.

The diketone may be converted to sodium enodiolate by oxidative ionization by the Na ion and then obtained as the second precursor by tautomerization.

As described above, the condensation reaction of the first precursor includes a radical coupling step, and the intermediate between the first precursor and the second precursor is decomposed due to the property of the unstable radical, or the diketone, etc. There is a concern that by-products other than the second precursor may be obtained.

Accordingly, according to an embodiment of the present invention, the step (a) may further include attaching a protecting group to the intermediate produced by oxidative ionization of the first precursor material by the metal catalyst.

Here, the protecting group is acetal, acetyl, benzoyl, benzyl, β-methoxyethoxymethyl, dimethoxytrityl, methoxymethyl, methoxytrityl, p-methoxybenzyl, p-methoxyphenyl, methylthio Omethyl, trityl, tetrahydropyranyl, tetrahydrofuran, trimethylsilyl, tert-butyldimethylsilyl, tri-iso-propylsiloxymethyl and may be at least one selected from tri-iso-propylsilyl, Preferably, it may be at least one selected from trimethylsilyl, tert-butyldimethylsilyl, tri-iso-propylsiloxymethyl and tri-iso-propylsilyl.

For example, when using trimethylsilyl chloride as a raw material with a protecting group to introduce trimethylsilyl as a protecting group, sodium enodiolate represented by the following formula 1-2 is produced by oxidative ionization of the diketone. , Trimethylsilyl may be bonded to each enolate to form trimethylsilyl ether represented by Formula 1-3 below.

[Formula 1-2]

[Formula 1-3]

The trimethylsilyl bound to the enolate can be easily removed through work-up under an acid catalyst.

As described above, when the step (a) further includes attaching a protecting group to the intermediate produced by oxidative ionization of the first precursor by the metal catalyst, an unstable intermediate (e.g., a radical Intermediates, enodiolate intermediates, etc.) may be decomposed, radicals react with each other, or by-products other than the second precursor such as diketone may be obtained.

According to the above-described method, the content of diketone in the result of step (a) may be 5% or less.

When the content of diketone in the result of step (a) exceeds 5%, the content of ketoxime in the result of step (b) to be described later may exceed 4%.

The ketoxime is a substance that acts as a cause of lowering the metal extraction ability of the hydroxy oxime prepared according to the above-described method, and the diketone contained in the result of step (a) is the final product ( The result of step (b)) may serve as a cause of increasing the content of ketoxime.

In the step (a), the metal catalyst may be used in an amount of 2.0 to 4.0 equivalents based on 1 equivalent of the first precursor.

When the metal catalyst is used to exceed 4.0 equivalents based on 1 equivalent of the first precursor, the intensity of oxidative ionization induced in the metal catalyst in step (a) becomes too strong, and the die in the result of step (a) The content of ketones may exceed 5%.

On the other hand, when the metal catalyst is used in an amount of less than 2.0 equivalents based on 1 equivalent of the first precursor, the strength of oxidative ionization induced in the metal catalyst in step (a) is too weak, and the reaction time is excessively long. As the conversion rate of diketone to sodium enodiolate decreases, the content of diketone may exceed 5%.

Next, the step (b) is a step of reacting the second precursor with a hydroxyl amine salt to obtain a hydroxy oxime represented by Chemical Formula 3.

For example, when the first precursor is methyl 2-ethylhexanoate, the second precursor is 5,8-diethyl-7-hydroxydodecan-6-one, and the hydroxy oxime is 5,8-diethyl-7 May be -hydroxydodecan-6-one oxime.

The result of step (b) may include by-products such as diketone and/or ketoxime other than the hydroxy oxime represented by Formula 3 above.

When the result of step (b) includes ketoxime, the content of ketoxime in the result of step (b) is preferably 4% or less. If the content of ketoxime in the result of step (b) exceeds 4%, a low quality hydroxy oxime is obtained, such as lowering the metal extraction ability of the final product, hydroxy oxime, or from the final product. A separate process may be required to separate only the hydroxy oxime.

Hereinafter, specific embodiments of the present invention are presented. However, the examples described below are only for illustrating or explaining the present invention in detail, and the present invention is not limited thereto.

Manufacturing example. Manufacturing method of manufacturing method of hydroxy oxime

(Step 1) Preparation of the first precursor

에서 4시간 가열 및 교반한 다음 상온으로 냉각하였다.As a starting material, 2-ethylhexanoic acid (20g, _{139mmol) was diluted in MeOH (60ml), and H 2} SO ₄ (1.136ml, 20.85mmol) was added dropwise. The reaction solution is at an internal temperature of 65

It was heated and stirred at 4 hours and then cooled to room temperature.

Then, 10% NaHCO ₃ (aq) (100ml) was poured into the reaction solution and stirred. After extraction with MC (80ml) using a separatory funnel, the water layer was extracted once more with MC (80ml). The organic layer was _{filtered after anhydrous treatment with anhydrous Na 2} SO ₄ (5 g), and the filtrate was concentrated. The residual solvent was removed by vacuum to obtain a first precursor material containing methyl 2-ethylhexanoate.

In the result of step 1, the presence of methyl 2-ethylhexanoate in the first precursor was confirmed through NMR analysis. For the NMR analysis, Bruker 400 MHz NMR (Nuclear magnetic resonance) was used, and 10 mg of the result of Step 1 was taken _{, diluted in 0.7 ml of the NMR solvent CDCl 3} , and then NMR analysis was performed.

The results of the NMR analysis are shown in FIG. 1, and Table 1 below shows the yield for each reaction condition.

division MeOH (v) H ₂ SO ₄ (eq) Reaction time (h) yield(%) A-1 5 0.05 7 87 A-2 5 0.1 6 88 A-3 5 0.15 4 88 A-4 3 0.2 3 90 A-5 3 0.15 4 91

_{Referring to the results of Table 1, when 0.15 equivalent of H 2} SO ₄ is used per 1 equivalent of 2-ethylhexanoic acid as a starting material, the amount of MeOH is reduced and the reaction time can be shortened, and the reaction yield is also improved. Can be confirmed.

(Step 2) Preparation of the second precursor material

Na metal (1.81g, 79.0 mmol) was cut into solvent toluene and xylene (30ml) and charged with nitrogen. The mixture was stirred at an internal temperature of 105° C. for 1 hour, and the resultant first precursor (20 g, 126 mmol) prepared according to A-5 in Step 1 was dropwise.

After the reaction was completed, it was cooled in an ice bath, and MeOH (20 ml) was slowly added to quenching unreacted Na. Then, _{after slowly adding H 2} O (100 ml), the mixture was stirred for 30 minutes, and a 10% HCl solution (85 ml) was added, followed by stirring for another 1 hour.

In a separatory funnel, the organic layer was anhydrous _{treated with anhydrous Na 2} SO ₄ (10 g), filtered, and the filtrate was concentrated. The residual solvent was removed by vacuum to obtain a second precursor material containing 5,8-diethyl-7-hydroxydodecan-6-one.

In the result of step 2, the presence of 5,8-diethyl-7-hydroxydodecan-6-one in the second precursor was confirmed through NMR analysis. For the NMR analysis, Bruker 400 MHz NMR (Nuclear magnetic resonance) was used, and 10 mg of the result of step 2 was taken _{, diluted in 0.7 ml of the NMR solvent CDCl 3} , and then NMR analysis was performed.

The results of the NMR analysis are shown in FIG. 2, and Table 2 below shows the yield and the amount of by-products (diketone) by reaction conditions.

division menstruum Na (eq) Reaction time (h) diketone (%) yield(%) B-1 toluene 2.5 5 9 88 B-2 toluene 2.7 4 6 84 B-3 toluene 3 4 7 87 B-4 toluene 3.3 6 6 91 B-5 toluene 3.5 6 5 90 B-6 xylene 2.5 4 8.7 88.7 B-7 xylene 2.8 6 5.6 91.2 B-8 xylene 3 4 9.1 89.3 B-9 xylene 3.5 4 10.9 86 B-10 xylene 2.5 14 2.68 90.91

Referring to the results of Table 2, both B-1 to B-9 show a yield of mid-80%, and the reaction time is also good at 4 to 6 hours, but the contents of diketone in the result of step (B) are all It can be seen that it is more than 5%.

On the other hand, referring to B-10, when the reaction time is 14 hours, it can be seen that the content of diketone in the result of step (B) is 3% or less.

Accordingly, 10.06ml (79.0 mmol) of TMSCl was additionally added and stirred at 170° C. for 1 hour, and the resultant prepared according to A-5 in Step 1 was dropwise. Then, after heating and stirring for 14 hours, it was cooled in an ice bath, and MeOH (20 ml) was slowly added to quenching unreacted Na. Then _{, after slowly adding H 2} O (10 ml) and stirring for 30 minutes, TFA (10 ml) was added. After stirring for 3 hours, a second precursor was obtained according to the method described above. As a result of NMR analysis of the second precursor, it was confirmed that the same compound as in FIG. 2 was synthesized.

Table 3 below shows the yield and by-product (diketone) content by reaction conditions.

division menstruum Na (eq) Reaction time (h) diketone (%) yield(%) B-11 xylene 2.2 4 13.1 84.2 B-12 xylene 2.5 7 1.7 90 B-13 xylene 4 10 2.4 83.2 B-14 THF 3 4 20.8 68.2 B-15 THF 4 4 6.9 92 B-16 dioxane 3 6 7.3 88.8 B-17 IPE 3 20 18.5 79.7

Referring to the results of Table 3, when TMSCl is added in a xylene solvent and then the first precursor is droppedwise, the reaction time slightly increases, but shows a yield of 80% or more, among the results of step (b). It can be seen that the content of diketone is 3% or less (2.5 equivalents of Na, 4 equivalents).

However, it was confirmed that the effect of reducing the diketone content by TMSCl was insignificant in THF, dioxane, or IPE solvent, and even in the xylene solvent, when Na metal was used in an amount of 2.2 equivalents, the diketone content was rather than when TMSCl was not used. It can be seen that it has increased.

(Step 3) Preparation of hydroxy oxime

After dissolving the resultant second precursor (20g, 78.0 mmol) prepared according to B-5, B-10 and B-12 in step 2 in pyridine (200ml), NH ₂ OH·HCl (27.1 g, 389 mmol) Put it and heated and stirred at an external temperature of 80 ℃. After reacting for 14 hours, it was cooled to room temperature and pyridine was distilled off. The distillation residue was extracted using EA (100ml) and 5% HCl (30ml), and the organic layer was washed with H ₂ O (60ml), and then _{anhydrous treatment with anhydrous Na 2} SO ₄ (5g) and then filtered. The filtrate was concentrated. The residual solvent was removed by vacuum, and a final product containing hydroxy oxime (5,8-diethyl-7-hydroxydodecan-6-one oxime) was obtained.

Among the results of step 3, the presence of 5,8-diethyl-7-hydroxydodecan-6-one oxime in the final product was confirmed through NMR analysis. For the NMR analysis, Bruker 400 MHz NMR (Nuclear magnetic resonance) was used, and 10 mg of the result of step 3 was taken _{, diluted in 0.7 ml of the NMR solvent CDCl 3} , and then NMR analysis was performed.

The results of the NMR analysis are shown in FIG. 3, and Table 4 below shows the yield and the content of ketoxime by reaction conditions.

division Starting material ketoxime (%) yield(%) C-1 B-5 5.5 82.8 C-2 B-10 3.8 83.0 C-3 B-12 2.4 85.0

Referring to the results of Table 4, it can be seen that when the content of diketone is lowered through the addition of TMSCl in step 2, the likelihood of ketoxime occurring in the step of preparing hydroxy oxime in step 3 is lowered.

However, if the second precursor is dissolved in pyridine, there is a limitation in that it is difficult to completely remove pyridine after completion of the reaction. Accordingly, in the following, the solvent for dissolving the second precursor was changed from pyridine to EtOH, and hydroxy oxime was prepared in the same manner.

Specifically, after dissolving the resultant second precursor (20g, 78.0 mmol) prepared according to B-11 in step 2 in EtOH (60ml), NH ₂ OH·HCl (7.67 g, 93.6 mmol) was added to an external temperature of 78 Heated and stirred at °C. After reacting for 10 hours, it was cooled to room temperature and EtOH was distilled off. After removing about 2/3 of EtOH, the distillation was extracted with EA (40ml) and 5% HCl (20ml), and the organic layer was washed with H ₂ O (10ml) and then anhydrous Na ₂ SO ₄ (20 g) After anhydrous treatment using, the filtrate was concentrated and filtered. The residual solvent was removed by vacuum, and a final product containing hydroxy oxime (5,8-diethyl-7-hydroxydodecan-6-one oxime) was obtained. As a result of NMR analysis of the hydroxy oxime, it was confirmed that the same compound as in FIG. 3 was synthesized.

Table 5 below shows the yield and by-product (ketoxime) content by reaction conditions.

division Starting material ketoxime (%) yield(%) C-3 B-11 2.7 93.0

Referring to the results of Table 5, when the solvent for dissolving the second precursor is changed from pyridine to EtOH, the reaction time can be reduced, and EtOH can be easily removed from the reaction solvent and at the same time, there is an advantage that it can be reused. . In addition, it is possible to improve the yield of hydroxy oxime compared to the case of using pyridine as a solvent.

As described above, one embodiment of the present invention has been described, but those of ordinary skill in the relevant technical field add, change, delete or add components within the scope not departing from the spirit of the present invention described in the claims. It will be possible to variously modify and change the present invention by the like, and it will be said that this is also included within the scope of the present invention.

Claims (5)

(a) reacting a first precursor represented by the following formula (1) in the presence of a metal catalyst to obtain a second precursor represented by the following formula (2); And
[Formula 1]

(Wherein, R ₁ to R ₃ are each independently C ₁ -C ₁₀ alkyl)
[Formula 2]

(Wherein, R ₁ and R ₂ are each independently C ₁ -C ₁₀ alkyl)
(b) reacting the second precursor with a hydroxyl amine salt to obtain a hydroxy oxime represented by the following formula (3);

[Formula 3]

(Wherein, R ₁ and R ₂ are each independently C ₁ -C ₁₀ alkyl)
Including,
The step (a) further comprising attaching a protecting group to the intermediate produced by oxidative ionization of the first precursor material by the metal catalyst,
Method for producing hydroxy oxime.
The method of claim 1,
The protecting group is acetal, acetyl, benzoyl, benzyl, β-methoxyethoxymethyl, dimethoxytrityl, methoxymethyl, methoxytrityl, p-methoxybenzyl, p-methoxyphenyl, methylthiomethyl , Trityl, tetrahydropyranyl, tetrahydrofuran, trimethylsilyl, tert-butyldimethylsilyl, at least one selected from tri-iso-propylsiloxymethyl and tri-iso-propylsilyl,
Method of making hydroxy oxime.
The method of claim 1,
In the step (a), the metal catalyst is used in an amount of 2.0 to 4.0 equivalents based on 1 equivalent of the first precursor,
Method of making hydroxy oxime.
The method of claim 1,
The content of diketone in the resultant of step (a) is 5% or less,
Method of making hydroxy oxime.
The method of claim 1,
The content of ketoxime in the result of step (b) is 4% or less,
Method of making hydroxy oxime.

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