KR950009744B1 - Process for producing alpha-hydroxy-lsobutoramide - Google Patents

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Description

Method for producing α-hydroxyisobutyric acid amide

The present invention relates to a method for producing α-hydroxyisobutyric acid amide, and more particularly, α-hydroxyisobutyric acid amide (hereinafter referred to as ACH) and water are continuously reacted in a liquid phase. , HAM).

It is generally known that the amide compound is a reaction of the corresponding nitrile compound and water, and various catalysts effective for this reaction are known. Manganese dioxide described in US Pat. No. 3,366,639 is one such. While copper-containing catalysts do not show sufficient effects on the hydration of α-hydroxynitrile compounds such as ACH, while manganese dioxide is disclosed in West German Patent No. 2,131,813, Likewise, there is a characteristic that is very effective in hydration of ACH.

Further, Japanese Patent Application Laid-open No. 52-222 (U.S. Patent No. 4,018,829) discloses acetone in the raw material liquid in the production of HAM by performing hydration of ACH at a temperature range of 60-90 ° C. using brownstone as a catalyst. It is described that the addition of HAM can raise the yield. Furthermore, when using manganese dioxide obtained from a hexavalent manganate and hydrofluoric acid, there is little variation in catalytic activity and the performance of the catalyst is also improved in Japanese Patent Laid-Open No. 63-57535.

However, as disclosed in Japanese Patent Application Laid-open No. 52-222 (U.S. Patent No. 4,018,829), a method of industrial continuous production of HAM by hydration of ACH using an acetone aqueous solution as a solvent and using a catalytic suspension reactor is examined. As a result, the catalytic activity was found to decrease rapidly with time. A method for solving such a problem is disclosed in Japanese Patent Laid-Open No. 2-196763. This is a method of controlling the deactivation of a catalyst by setting the hydrogen ion concentration (pH) of the raw material liquid supplied to a reactor to the range of 4-8. However, even in this method, there is no explanation according to the embodiment as to whether or not the reduction in catalytic activity is controlled over a long period of one week or longer.

Further, in order to extend the life of the manganese dioxide catalyst, the improvement of the preparation method of the manganese dioxide catalyst is disclosed in Japanese Patent Application Laid-Open No. 3-68447, and manganese dioxide in which a second component is added is disclosed in U.S. Patent No. 4,987,256 and European Patent No. It is described in. However, in either of these methods, the effect is seen once, but it cannot be said that the lifetime of the manganese dioxide catalyst is still sufficient.

As described above, in the continuous manufacture of HAM by hydration of ACH industrially, the activity of the manganese dioxide catalyst is increased due to the decrease in the activity of the manganese dioxide catalyst or the loss of activity. Is the greatest challenge.

The present inventors consider that the liquid crystallization of glass contained in the ACH of the raw material adversely affects the life of the manganese dioxide catalyst, and the method disclosed in Japanese Patent Laid-Open No. 2-196763 is for the purpose of neutralizing this. Tried. That is, for a raw material liquid having a pH of 2.0-3.5 supplied to a catalyst stationary reactor, (1) passing the raw material liquid through a basic ion exchange resin tower, and (2) sodium hydroxide in the raw material liquid. Or addition of potassium hydroxide was attempted. However, on the contrary, since the ACH is decomposed from the moment of this treatment, the raw material liquid is colored until it is supplied to the reactor, and the catalyst life is hardly extended. In addition, although the same operation was performed in the catalyst suspension type reactor, the same tendency was observed in the raw material liquid, and the HAM product liquid flowing out of the reactor was further colored brown, in which case the catalyst life was shortened.

MEANS TO SOLVE THE PROBLEM The present inventors earnestly examined in order to solve the said subject with respect to a manganese dioxide catalyst in the continuous manufacture of HAM by the hydration reaction of ACH industrially, As a result, it is known that it is the sulfuric acid currently disclosed by Unexamined-Japanese-Patent No. 2-196763. Although acids belonging to the same inorganic acid were thought to shorten the life of the manganese dioxide catalyst, surprisingly, the lifetime of the manganese dioxide catalyst was extended by supplying oxanes or salts thereof, such as bongsan, which fall into the acid range alone, or by adding them to the raw material solution. The present invention has been found to be greatly extended.

That is, the present invention hydrates acetonecyanhydrin using manganese dioxide as a catalyst in a liquid phase, and thus, boron, aluminum, silicon, germanium, tin, lead, arsenic, and antimony in the continuous preparation of α-hydroxyisobutyric acid amide. ? -Hydroxyisobutyric acid amide, wherein vanadium, niobium, molybdenum and / or tungsten and one or more selected from oxygen and hydrogen oxo acid, its alkali metal salt and its alkaline earth metal salt coexist in the reaction solution It is a manufacturing method of.

In the present invention, the precondition for hydration of ACH using a manganese dioxide catalyst is to maintain the stability of ACH as a raw material satisfactorily. If the stability of the ACH is not maintained, it is not possible to stably continue the hydration reaction of the ACH in the decomposition of the ACH and the polymerization of the resulting acid produced at this time. Furthermore, how to extend the life of the manganese dioxide catalyst is a secondary problem. Therefore, the operation according to the pH rise of the raw material liquid as disclosed in the prior art, for example, Japanese Patent Laid-Open No. 2-196763, is basically undesirable. The inventors of the present invention, based on the state that the pH of the raw material liquid containing ACH stabilized by sulfuric acid or the like to keep the stability of the ACH to less than 4, the mechanism of the mechanism and the method of extending the life of the conventional manganese dioxide catalyst It is to provide a completely new method.

In other words, the functional mechanism is not detoxified by a trace amount of inorganic acid or clear acid alkali neutralization, etc. contained in the raw material liquid, but a catalyst poison, mainly by adding a small amount of oxo acid, alkali metal salt and / or its alkaline earth metal salt to the reaction solution. The catalyst lifetime was extended by blocking the adsorption of cyanide to manganese dioxide catalyst.

The manganese dioxide catalyst used in the present invention may be either anhydrous or hydrated. Manganese dioxide catalysts are known in the art, for example, in the neutral to alkaline region, a method of reducing a hexavalent manganese compound at 20-100 ° C. (Zeit. Anorg. Allg, Chem., 309, p. 1-32 and p 121- 150 (1961)), methods of treating potassium permanganate and manganese sulfate in acidity (Biochem. J., 50, p. 43, (1951) and J. Chem. Soc., 1953, p. 2189 (1953)), Manganese dioxide obtained by the method of reducing the hexavalent manganese salt with hydrochloric acid (Japanese Patent Laid-Open No. 63-57535), electrolytic oxidation of an aqueous solution of manganese sulfate is used. In particular, manganese dioxide obtained by the reaction of permanganate and manganese sulfate under acidity is preferable. This catalyst is usually used as a powder of suitable particle size.

Water used in the present invention is usually 1 mol or more, preferably 2-20 mol, and particularly preferably 4-10 mol, per 1 mol of ACH. As a reaction solvent, an inert solvent can be used for a new reaction besides water. For example, acetone disclosed in Japanese Patent Laid-Open No. 52-222 (U.S. Patent No. 4,018,829) and the like are preferably used. It is preferable to use the amount of acetone in the range of 01-6.0 mol normally with respect to 1 mol of ACH.

Catalytic reactors used in the present invention include a fixed bed type and a suspended type. In view of the unit amount of the catalyst and the HAM production per unit time, the catalyst suspended reactor is advantageous.

In the catalyst suspension reactor used in the present invention, the catalyst concentration in the catalyst solution is not particularly limited, but is usually 2% by weight or more, preferably 5-50% by weight. The feed rate of the raw material liquid to the catalyst suspension reactor is preferably set to ACH in the ratio of 1 part by weight of catalyst and 0.05-1.0 parts by weight per hour. The catalyst suspension reactor is operated so that the catalytic activity is exhibited to the maximum, and a filter made of metal or glass may be provided at the outlet of the reactor of the HAM production liquid so that the small particle size of the suspended catalyst does not flow out of the system. In this case, the catalyst suspension reactor can be reacted with a maximum of ACH conversion rate in one unit, but can also be connected in series with two or three groups.

Reaction temperature in this invention is 0-150 degreeC normally, Preferably it is 20-100 degreeC, Especially preferably, it is the range of 30-80 degreeC. At temperatures below 0 ° C., the activity of the catalyst is low and not practical. Moreover, although the catalytic activity is high at the temperature over 150 degreeC, since the yield of HAM is rapidly low, it is not preferable.

In the present invention, oxo acid is used to extend the life of the manganese dioxide catalyst. Boron, aluminum, silicon, germanium, tin, lead, phosphorus, arsenic, antimony, vanadium, niobium, molybdenum and or tungsten may be mentioned as the central element constituting oxo acid.

This oxo acid may be represented by the oxide represented by General formula (1) or General formula (3) which shows weak acidity or strong acidity in the state which the hydroxide represented by General formula (2) dissolved in water.

M ¹ _s Ot · aH ₂ O (1)

(In Formula (1), O is an oxygen atom, H is a hydrogen atom, and M ¹ is an element having a valence m. In addition, a is an integer of 0 or more and s and t are integers satisfying a relationship of mxs = 2xt). )

M ¹ (OH) _m (2)

(In Formula (2), O is an oxygen atom, H is a hydrogen atom, and M ¹ is an element having a valence m.)

H _x M ¹ _y O _z (3)

(In Formula (3), O is an oxygen atom, H is a hydrogen atom, M ¹ is an element having a valence m. In addition, x, y and z are integers satisfying a relationship of 2xz = mxy + x.)

Moreover, the heteropoly acid represented by General formula (4) is also included as oxo acid.

H _x M ¹ _s M ² tO _y (4)

(In Formula (4), O is an oxygen atom, H is a hydrogen atom, M ¹ is an atom having an atom m and M ² is an atom having an atom n. In addition, x, s, t and y are 2xy = mxs + nxt). The central element M ¹ is silicon, phosphorus, germanium, arsenic, and the like, and the isotope M ² includes molybdenum, tungsten, and vanadium.

Moreover, oxo acid can be used as a salt of the alkali metal salt or alkaline earth metal in order to increase the solubility in water. In this case, the alkali metal salt or alkaline earth metal salt of oxo acid is obtained by replacing all or some of the hydrogen atoms with the metal in the general formula (3) or (4). Moreover, compounds which are likely to produce oxo acid in the catalytic reactor, for example, oxo acid ester, can also be used because they are sufficiently suitable for the purpose of the present invention. The reason for extending the life of the manganese dioxide catalyst is that oxo acid is mainly derived from the anionic species, so that even if a small atom is substituted with another stable metal ion, it can be used sufficiently.

As the oxo acid and / or salt thereof in the present invention, strongly acidic oxo acid and / or salt thereof and weakly acidic oxo acid are preferable. Strong acid seongok dissipation is that of the M ¹ arsenic, antimony, vanadium, niobium, molybdenum and tungsten of the general formula (3) and a heteropoly acid, or a weak acid oxo acid has the general formula (3) in M ¹ is boron, aluminum, silicon, germanium , Tin and lead.

The usage-amount of oxo acid and / or its salt in this invention is the range of 0.0001-0.50 mol normally with respect to 1 mol of raw materials ACH. This amount is usually in the range of 10-20,000 ppm, preferably in the range of 20-15,000 ppm on the basis of the reaction solution. If the amount is less than 0.0001 mol based on the raw material ACH or less than 10 ppm based on the reaction solution, the catalyst life is hardly extended. On the other hand, when the amount exceeds 0.5 mol or 20,000 ppm, the tendency of inhibiting the hydration activity of the manganese dioxide catalyst appears. .

In particular, the amount of boric acid used is usually in the range of 0.001-0.50 moles, preferably 0.005-0.30 moles per mole of ACH based on the raw material ACH, and in the range of 100-20,000 ppm on the basis of the reaction solution. The amount of borate used is usually in the range of 0.0001-0.10 moles, preferably 0.001-0.05 moles per mole of ACH based on the ACH of the raw material.

For acidic oxo acids and salts thereof, such as silicic acid, molybdic acid, tungstic acid, metavanadinic acid, silicotungstic acid, and silomolybdic acid phosphomolybdic acid, and the salt thereof, the amount thereof is preferably in the range of 10-1,000 ppm. .

In order to coexist the oxo acid, its alkali metal salt and / or its alkaline earth metal salt used in the present invention in the reaction solution, a method of supplying these powders, preferably aqueous solutions, directly and directly to the catalytic reactor is usually employed. This method greatly extends the life of the manganese dioxide catalyst regardless of the liquidity such as acidity in an aqueous solution of oxo acid, its alkali metal salt and / or its alkaline earth metal salt.

On the other hand, when adding oxo acid, its alkali metal salt, and / or its alkaline earth metal salt to the raw material liquid which mixed ACH, acetone, and water as another supply method, it is necessary to consider the pH of those aqueous solution beforehand. This is because the stability of the ACH in the raw material liquid changes due to the pH change of those aqueous solutions. In other words, alkali metal salts of oxo acids or alkaline earth metal salts which show weak acidity in aqueous solutions generally have a pH buffering effect. Therefore, when these are added to the raw material liquid, the effect of raising the pH of the raw material liquid is small. As the amount increases, the pH of the raw material solution is increased, and sometimes the pH becomes near neutral to destabilize the ACH. This is the same as the operation of neutralizing the raw material liquid with alkali as described above, and as a result, the ACH hydration reaction is forced to stop through decomposition of the ACH and polymerization of the incidentally generated cyanide.

In addition, as a feeding method to the catalytic reactor of the oxo acid which shows strong acidity, the alkali metal salt or its alkaline earth metal salt, and the oxo acid which shows weak acidity in aqueous solution, these aqueous solutions are added independently, and it adds to raw material liquid, etc. Method may be employed. The reason for adding these to the raw material liquid is that it does not increase even if the pH of the raw material liquid decreases by adding them, and it does not become a liquid which makes the ACH unstable.

Hereinafter, the present invention will be described in detail in Examples and Comparative Examples.

In addition, the Example and the comparative example were performed by the catalyst high load test which increases the quantity of ACH supplied with respect to a catalyst in order to evaluate the effect of this invention more quickly. Below, "%" and "ppm" are basis of weight except the case where it mentions specially.

ㆍ Preparation of standard catalyst (hereinafter referred to as Std.)

Sulfuric acid was added to 2 liters of an aqueous solution of manganese sulfate (concentration 395 g / liter) to prepare an aqueous solution of manganese sulfate of pH = 1. After 557 g of potassium permanganate was added to this solution for oxidation, 1 liter of water was added to the slurry solution while maintaining the temperature at around 50 ° C to mature for 30 minutes. This slurry solution was suction filtered with an aspirator and dried at 110 ° C. for 12 hours in a drier to obtain 680 g of a manganese dioxide catalyst. This manganese dioxide catalyst was ground to give 520 g as a 16-100 mesh powder catalyst (Std.).

ACH Preparation

580 g and 10 g of a 2% sodium hydroxide aqueous solution were placed in a reactor (glass round bottom flask, 2 liters of contents; reflux condenser, stirrer, thermometer, and liquid introduction portion attached), and 284 g of liquid clear liquid was injected while maintaining 20 ° C. After the reaction, sulfuric acid was added to prepare a pH of the solution to 3.5. The unreacted cyanide and acetone were then removed under reduced pressure to obtain 843 g of 99.8% ACH.

Example 1

(Continuous hydration reaction, catalyst high load test)

10 g of a manganese dioxide powder catalyst (Std.) And 300 g of water were charged into a reactor (with a glass round bottom flask, a content of 500 ml; a glass stirring rod, a mercury thermometer, a raw material supply port, and a liquid outlet with a glass ball filter). The internal temperature was raised to 60 ° C to maintain this temperature. Next, 48.5% ACH acetone solution (ACH: acetone = 1: 1.6 molar ratio) and 0.1% boric acid aqueous solution prepared using the previously prepared ACH were flown at a flow rate of 11.3 g / hr and 21.4 g / hr by a metering pump, respectively. It was fed continuously to the catalyst suspension reactor. At this time, the molar ratio of ACH: acetone: water: boric acid was 1: 1.6: 18.5: 0.0054, and the amount of boric acid was 650 ppm in the reaction reference solution. The reactor inside was kept at 58-62 degreeC, the liquid quantity in the reactor was adjusted to the range of 290-310 ml, and it operated continuously for 10 days. In the HAM production liquid obtained, the change of HAM yield according to a fixed date is shown in Table 1.

Comparative Example 1

In Example 1, it operated in the same manner as in Example 1 except that the aqueous 0.1% boric acid solution was changed to water and the number of operating days was 50 days. At this time, the molar ratio of ACH: acetone: water was 1: 1.6: 18.5. In the HAM production liquid obtained, the change of HAM yield according to the operation day was shown in Table 1 and Table 3.

Example 2

In Example 1, the same procedure as in Example 1 was conducted except that the aqueous 0.1% boric acid solution was changed to the 2.0% aqueous boric acid solution. At this time, the molar ratio of ACH: acetone: water: boric acid was 1: 1.6: 18.1: 10.108, and the amount of boric acid was 13,000 ppm based on the reaction solution. In the HAM production liquid obtained, the change of HAM yield according to the operation day was shown in Table 1.

Comparative Example 2

In Example 2, the same operation as in Example 2 was carried out except that the manganese dioxide powder catalyst was not charged in the reactor. At this time, the molar ratio of ACH: acetone: water: boric acid was 1: 1.6: 18.1: 10.108. In the HAM production liquid obtained, the change of HAM yield according to the operation day is shown in Table 1.

Example 3

10 g of a manganese dioxide powder catalyst and 300 g of water were charged into a reactor (with a glass round bottom flask content 500 ml; glass stirrer, mercury thermometer, raw material feed port and glass ball filter outlet), and then the internal temperature was 60 ° C. The temperature was maintained up to. Next, a 17.2% ACH acetone aqueous solution (ACH: acetone: water = 1: 3.0: 13 molar ratio) and 0.1% (sodium borate? The molar ratio of ACH: acetone: water: borax was 1: 3.0: 48.9: 0.0017, and the amount of borax was based on the reaction solution at a flow rate of g / hr and 45.4 g / hr. The internal temperature of the reactor was maintained at 58-62 ° C., and the liquid volume in the reactor was continuously operated for 10 days by adjusting it to the range of 290-310 ml. The pH of the liquid is shown in Table 2.

Comparative Example 3

In Example 3, it operated like Example 3 except changing only 0.1% borax aqueous solution into water. At this time, the molar ratio of ACH: acetone: water was 1: 3.0: 48.9. In the HAM production liquid obtained, the change of HAM yield according to the operation day, and the pH of the production liquid are shown in Table 2.

[Comparative Example 4]

In Example 3, the same operation as in Example 3 was carried out except that the manganese dioxide powder catalyst was not charged in the reactor. At this time, the molar ratio of ACH: acetone: water: borax was 1: 3.0: 48.9: 0.0017, and the amount of borax was 570 ppm based on the reaction solution. In the HAM production liquid obtained, the change of HAM yield according to the operation day, and the pH of the production liquid are shown in Table 2.

Example 4

In Example 2, it operated similarly to Example 2 except having set driving days to 50 days. In the HAM production liquid obtained, the change of HAM yield which differs in the operation day is shown in Table 3.

Example 5-27

Type of weakly acidic oxo acid shown in Table 3 by changing 2.0% boric acid aqueous solution in Example 4, type of strongly acidic oxo acid shown in Table 4 Type of weakly acidic oxoate shown in Table 5 and type of strong acidic oxoate shown in Table 6, and Those concentrations based on the reaction solution were added, and operation was performed in the same manner as in Example 4 for 50 days of continuous operation. In the HAM production liquid obtained, the change of HAM yield according to the operation day is shown in Table 3-Table 6.

In addition, the oxide in the column of the oxo acid column of Table 3 and 4 means the oxide used as a raw material of the oxo acid obtained by suspending in water and heat-dissolving, The addition amount was shown by the quantity added to ACH of a raw material in conversion of oxide. . At that time, the dissolved oxo acid amount was determined by a high frequency plasma emission spectrometer.

Or oxo acid or its salt in Table 3-Table 6 was added to raw material ACH.

[Comparative Example 5-15]

It replaced with the standard catalyst (Std.) As a catalyst in Example 4, and operated like Example 4 using the catalyst shown in the catalyst column of Table 3-Table 6. In the HAM production liquid obtained, the change of HAM yield according to the operation day is shown in Table 3-Table 6.

In the catalyst column of Table 3 to Table 6, the compound / Mn = value is the second element-containing manganese dioxide prepared by the coprecipitation method in which the compound coexists in the aqueous solution of first manganese sulfate in the catalyst production method of the standard catalyst (Std.). Means catalyst. The value is the ratio of the number of moles of the compound to the total number of moles of divalent and manganese manganese.

TABLE 1

TABLE 2

TABLE 3

TABLE 4

TABLE 5

TABLE 6

* One ; HAM production amount per unit of catalyst (g-HAM / -g catalyst)

According to the present invention, the lifetime of the catalyst in the industrial continuous production method of HAM by hydration of ACH using a conventional manganese oxide catalyst can be seen in the examples by using oxo acid, its alkali metal salt and / or alkaline earth metal salt. As can be seen, improvement has been made possible, and industrially advantageously, continuous production of HAM is possible.

Claims (16)

In the continuous preparation of α-hydroxyisobutyric acid amide by hydration of acetonecyanhydrin using a manganese dioxide catalyst in a liquid phase, boron, aluminum, silicon, germanium, tin, lead, phosphorus, arsenic, antimony, vanadium, niobium A method for producing α-hydroxyisobutyric acid amide, wherein at least one selected from the group consisting of molybdenum and / or tungsten and oxygen and hydrogen is selected from an oxo acid, an alkali metal salt and an alkali earth metal salt thereof. The method for producing α-hydroxyisobutyric acid amide according to claim 1, wherein the amount of oxo acid and / or salt thereof added to the reaction solution is in the range of 0.0001-0.5 mole with respect to 1 mole of acetonecyanhydrin. The method for producing α-hydroxyisobutyric acid amide according to claim 1, wherein the amount of oxo acid and / or salt thereof added to the reaction solution is in the range of 10-20,000 ppm. The method for producing α-hydroxyisobutyric acid amide according to claim 1, wherein the oxo acid of boron is boric acid. The method for producing α-hydroxyisobutyric acid amide according to claim 4, wherein the amount of boric acid added to the reaction solution is in the range of 0.001-0.50 mole to 1 mole of acetonecyanhydrin. The method for producing α-hydroxyisobutyric acid amide according to claim 4, wherein the amount of boric acid added to the reaction solution is in the range of 0.005-0.3 moles with respect to 1 mole of acetonecyanhydrin. The method for producing α-hydroxyisobutyric acid amide according to claim 2, wherein the amount of borate added to the reaction solution is in the range of 0.0001-0.10 moles to 1 mole of acetonecyanhydrin. The method for producing α-hydroxyisobutyric acid amide according to claim 2, wherein the amount of borate added to the reaction solution is in the range of 0.001-0.05 moles with respect to 1 mole of acetonecyanhydrin. The method for producing α-amide according to claim 1, wherein the oxo acid of silicon is silicic acid. The method for producing α-hydroxyisobutyric acid amide according to claim 1, wherein the oxo acid of molybdenum is molybdate. An oxo acid of tungsten is characterized in that tungstic acid. A process for the preparation of hydroxyisobutyric acid amide. The method for producing α-hydroxyisobutyric acid amide according to claim 1, wherein the alkali metal oxo acid salt of vanadium is an alkali metal salt of metavanadate. 10. The process for producing α-hydroxyisobutyric acid amide according to claim 9, wherein the amount of silicic acid added to the reaction solution is 10-1,000 ppm. The method for producing α-hydroxyisobutyric acid amide according to claim 10, wherein the addition amount of molybdate to the reaction solution is 10-1,000 ppm. 12. The method for producing α-hydroxyisobutyric acid amide according to claim 11, wherein the amount of tungstic acid added to the reaction solution is 10-1,000 ppm. The method for producing α-hydroxyisobutyric acid amide according to claim 12, wherein the amount of metavanadate alkali metal salt added to the reaction solution is 10-1,000 ppm.