KR100750054B1 - Method for preparing 3,5,5-trimethyl-3-cyclohexenone with high purity - Google Patents

Abstract

The present invention provides 0.1 to 30 parts by weight of Groups Ia, IIa, and IIIa metal sulfates with respect to 100 parts by weight of α-isophorone in a temperature range of 180 ° C to 300 ° C and a pressure range of 0 to 5 kg / cm 2 from α-isophorone. Obtaining β-isophorone through an isomerization reaction using a heterogeneous catalyst consisting of: separating the β-isophorone through a distillation reaction and recovering unreacted α-isophorone to the reactor It relates to a method for producing β-isophorone. The catalyst system according to the present invention is not only economical as a general-purpose chemical, but also a heterogeneous catalyst system, which can be designed as a continuous process of continuously injecting reactants while maintaining the catalyst in the reactor because deterioration does not occur for a certain period of time. Do.

α-isophorone, β-isophorone, metal sulfates, metal halides, isomerization

Description

Method for preparing 3,5,5-trimethyl-3-cyclohexenone with high purity {Method for preparing 3,5,5-trimethyl-3-cyclohexenone with high purity}

The present invention relates to 3,5, through isomerization of 3,5,5-trimethyl-2-cyclohexenone (hereinafter referred to as "α-isophorone"). It relates to a method for preparing 5-trimethyl-3-cyclohexenone (hereinafter referred to as "β-isophorone"), and more specifically, as shown in Scheme 1 below. The present invention relates to a method for economically producing β-isophorone with high purity through an isomerization reaction using a heterogeneous catalyst selected from metal sulfate and metal halide as a reactant α-isophorone alone or in combination.

β-isophorone is an important synthetic component of carotenoids, vitamins and pharmaceutical products, in particular trimethylhydroquinone (hereinafter "TMHQ") which produces α-tocopherol through condensation with isophytol under appropriate catalytic conditions. Or trimethylhydroquinone diacetate (hereinafter referred to as "TMHQDA").

The production method of TMHQ or TMHQDA is classified into two methods using trimethylphenol (hereinafter referred to as "TMP") and α-isophorone depending on the reaction starting material.

In the method using TMP, TMHQ is prepared by a two-step reaction as in Scheme 2 below, and TMP itself is relatively expensive, and the yield of the oxidation step, which is the first step in Scheme 2, is not high, and a large amount of by-products are generated during oxidation. Therefore, although the reaction is simple in two steps, it is judged that there is no great advantage in the commercialization process.

On the other hand, the reaction using α-isophorone as a reaction starting material requires three steps of isomerization, oxidation and esterification as shown in Scheme 3 below, but the starting material α-isophorone is cheaper than TMP, Increasing the yield of each reaction is relatively competitive in terms of cost                         

The present invention relates to the isomerization reaction, which is the first step in the above scheme for preparing TMHQDA from α-isophorone.

α-isophorone is prepared by the tripolymerization of acetone, where α-isophorone is much more than β-isophorone because the double bond exists at positions 2 and 3 in the ring, conjugating with the double bond of oxygen. Stable (equilibrium concentration of β-isophorone is about 1-2% at room temperature).

Keto-isophorone (hereinafter referred to as KIP), which is an intermediate material necessary for preparing TMHQDA in Scheme 3, can be generally prepared by two methods, the first method of directly oxidizing α-isophorone, and Another method is to prepare β-isophorone by isomerization of α-isophorone, followed by oxidation of β-isophorone. However, the second method is known to be more competitive because the first method, which has been directly oxidized α-isophorone to produce keto-isophorone, has very low values in conversion and selectivity.

The method for producing β-isophorone by isomerization of α-isophorone has been continuously developed until now, and more research has been conducted recently. The contents of the research so far are as follows.

Degussa, in US Pat. No. 6,005,147, uses a group of IIa, IIIa, VIII, Ib, Va metal oxides (particularly Co ₃ O ₄ , MgO, CaO) as a catalyst or a mixture of α-isophorones. Β-isophorone of about 2% purity was prepared through the isomerization reaction, and distillation was performed again to prepare β-isophorone having a purity of 97%. At this time, the yield of the catalyst production (Y = ml _β / hr / g _cat , that is, the amount of β-isophorone per ml per g of the catalyst per ml) was found to be about 1.98. In addition, the space time yield (liter yield of β-isophorone per hour per liter of reactant) was about 0.07.

Roche manufactured U.S. Patent No. 5,276,197 using β-isophorone of up to 11.3% under reaction conditions of 300 ° C to 450 ° C using oxides of metals such as Mg, Al, Si, and Ni, alone or in a mixed form. (The remaining approximately 89% was α-isophorone). At this time, the yield (Y = ml _β / hr / ml _cat catalyst per ml of the amount of β-isophorone per hour ml) was found to be about 0.45. This technique has some advantages in terms of manufacturing yield, but has the disadvantage that the operating cost increases due to the high temperature reaction and a certain amount (0.3 to 0.6%) of by-products are generated at a high temperature.

Roche also discloses a ring, aromatic or aliphatic mono, such as 4-nitro-m-toluic acid, 4-hydroxybenzoic acid, adipic acid, etc. in US Pat. No. 4,005,145. Β-isophorone of about 83% to 96% purity was prepared through reactive distillation using (or di-, tri-) carboxylic acid. In this case, the yield (ml of β-isophorone per 1 g of catalyst) was somewhat lower than about 0.25 to 0.3. In addition, this method has a disadvantage in terms of economics because the liquid catalyst must be continuously injected like the reactant α-isophorone.

Daicel Co., Ltd. produced β-isophorone having a purity of 99% by distillation using fatty acids having 12 to 25 carbon atoms in EP-A-0842918A1. At this time, the yield (Y = g _β / hr / g _cat , the amount g of β-isophorone per 1 g of the catalyst) showed a somewhat low value of about 0.25 to 0.65. In addition, this method has the disadvantage of continuously injecting a liquid catalyst as described in the patent.

Thus, in the present invention, by using a heterogeneous catalyst selected from a metal sulfate and a metal halide alone or in combination to obtain β-isophorone from the α-isophorone reactant as shown in Scheme 1 through the isomerization reaction under a certain reaction conditions, distillation Through the unreacted α-isophorone was recovered to the reactor to develop a method for producing β-isophorone with high purity.

Accordingly, an object of the present invention is to provide a method for producing β-isophorone with high purity through isomerization from α-isophorone.

Another object of the present invention is to develop a process that is easy and commercially competitive in designing a manufacturing process and purification process in a continuous process and commercializing.                         

Method of the present invention for achieving the above object isomerization reaction using a heterogeneous catalyst consisting of 0.1 to 30% by weight of metal sulfate in the temperature range of 180 ℃ to 300 ℃ and the pressure range of 0 to 5 kg / ㎠ Β-isophorone of 10 to 39% purity was obtained in a high yield (Y = ml _β / hr / g _cat , the amount of β-isophorone produced per ml per 1 ml of catalyst per ml of catalyst), and distilled again. It is composed of recovering unreacted α-isophorone into the reactor and finally producing high purity β-isophorone with a purity of 98% or more.

Looking at the present invention in more detail as follows.

The present invention relates to an isomerization reaction to prepare β-isophorone, which is the first step in the reaction to obtain TMHQDA from α-isophorone as in Scheme 3.

According to the present invention, it was confirmed that no by-products were produced at a temperature below 300 ° C. when β-isophorone was prepared through isomerization of α-isophorone. However, it was confirmed that β-isophorone was much more unstable than α-isophorone, so that even when a catalyst was used, the equilibrium was almost maintained in a large number (97-98%) of α-isophorone. Therefore, the important point of this reaction is to increase the production rate of β-isophorone while continuously separating the β-isophorone produced by the isomerization reaction by distillation reaction.

Since the distillation apparatus necessary for the distillation reaction and the post-stage process can be sufficiently solved by the process design, the most important variables of this reaction are how much the reaction equilibrium can be moved toward β-isophorone and the production of β-isophorone. How big is the speed? Among them, the factors affecting the reaction equilibrium are temperature, and the factors affecting rate are temperature and catalyst.

Therefore, the present inventors isomerized under certain reaction conditions by using a heterogeneous catalyst of a metal sulfate and a metal halide alone or in combination, and separating β-isophorone obtained in the liquid phase into a pure substance through distillation, and further, unreacted α. A method of economically producing high purity β-isophorone by recovering isophorone into a reactor has been developed.

The catalyst used in the present invention is a heterogeneous catalyst selected from metal sulfates and metal halides, and the metal sulfates are sulfates of Group Ia, IIa and IIIa metals, more preferably CaSO ₄ , MgSO ₄ , Na ₂ SO ₄ and Al. ₂ (SO ₄ ) ₃ , wherein the metal halide is a halogen of F, Cl, Br or I and a Group Ia, IIa, VIII, Ib, or IIb metal, for example LiCl, CaCl ₂ , CuCl, CuCl ₂ and FeCl ₂ . On the other hand, the usage-amount of the said catalyst is 0.1-30 weight part with respect to 100 weight part of (alpha)-isophorone, Preferably it is 0.5-10 weight part. At this time, if the amount of the catalyst used is less than 0.1 parts by weight, there is almost no effect of addition, and if it exceeds 30 parts by weight, the production rate of β-isophorone does not increase significantly due to the increase of the amount of catalyst, and thus the yield tends to decrease. In particular, in this case, there is a disadvantage that the stirring is not easy.

In the case of using the heterogeneous catalyst selected from the metal sulfate and the metal halide used in the present invention, it is possible to operate continuously injecting the reactants while maintaining the catalyst in the reactor. At this time, the precondition is that the catalyst should not deteriorate for a certain period of time. The metal sulfate used in the present invention was confirmed that there is no deterioration phenomenon, and the price is relatively inexpensive.

In addition, the metal sulfate or metal halide catalyst showed a relatively good value at the concentration of β-isophorone measured after maintaining a constant time at a constant temperature. The kinetic aspect is difficult to measure directly and can be compared with yield (ml = amount of β-isophorone produced per hour per gram of Y = ml _β / hr / g _cat catalyst), which represents both the effects of equilibrium and speed. In the case of using MgSO ₄ or CaSO ₄ as a catalyst according to the present invention, the yield was excellent at about 2.0 to 2.1.

On the other hand, in the constant reaction conditions, the higher the temperature, the concentration of β-isophorone increases, but when the side reaction exceeds 300 ℃, less than 300 ℃, 180 ℃ to 300 ℃, preferably 250 ℃ to 300 ° C., in the case of pressure, 0 to 5 kg / cm 2, preferably 1.5 to 3 kg / cm 2.

Another factor influencing the yield of the isomerization reaction in the present invention is Liquid Hourly Space Velocity (LHSV) including the concept of reaction time. In the case of the metal sulfate or metal halide, which is the catalyst of the present invention, the isomerization equilibrium is deviated considerably toward the α-isophorone, but the rate of reaching equilibrium was found to be very large (ie very fast reaction). In addition, as the amount of the catalyst increases, the production yield does not increase significantly, but the yield increases as the liquid space velocity increases.

In the present invention, the reaction was carried out at a liquid space velocity of 0.1 to 0.5, where the liquid space velocity is defined by Equation 1 as a ratio of the volume of the reactant charged into the reactor and the volume of the reactant solution injected per hour for the reaction. do.

As described above, in the present invention, β-isophorone is prepared from α-isophorone as a reactant through isomerization under constant reaction conditions by using a heterogeneous catalyst selected from metal sulfate and metal halide alone or in combination, and distillation reaction. β-isophorone was separated and unreacted α-isophorone was recovered to the reactor, thereby obtaining β-isophorone with high purity.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited to the following examples.

Example 1

1700 g (1848 ml) of α-isophorone and 17 g (1 part by weight) of MgSO ₄ are placed in a 3 L reactor, and a separation column having a diameter of 40 mm and a height of 100 cm is installed at the top, and the packaging material for separation is placed inside the column. To charge. At this time, the separation column is wrapped with a line heater and a heat insulating material on the outside. 171 g (186 ml) of α-isophorone per hour were injected through the pump while stirring while maintaining the reactor internal temperature at 218 ° C. (liquid space velocity, LHSV = 0.1). In order to keep the amount of reactant constant in the reactor, the same amount of product (171.1 g) was obtained at the rear of the column, where the concentration of β-isophorone was 6.14% and the actual amount of β-isophorone produced per hour was It was 10.5 g (12.4 ml), and the yield of catalyst production (Y = ml _β / hr / g _cat, that is, the amount of β-isophorone produced per ml of catalyst per ml ml) was 0.67.

Example 2

Β-isophorone was prepared while increasing the concentration of the catalyst to 42.5 g (2.5 parts by weight) and 85 g (5 parts by weight) under the same conditions as in Example 1, and the experimental results are shown in Table 1 below.

Production yield according to the change of catalyst concentration Example Catalyst concentration (parts by weight) Pressure (kg / ㎠) Temperature (℃) Formation rate (ml / hr) β-IP concentration (% by weight) β-IP production rate (ml / hr) Yield (Y = ml _β / hr / g _cat ) One One 0 218 186.0 6.14 11.42 0.67 2 2.5 0 218 193.4 7.25 14.02 0.33 3 5 0 218 188.3 9.93 18.7 0.22

This reaction was a fast reaction, and when the amount of catalyst was increased and the amount of reactant injected was kept constant, the reaction rate of β-isophorone was lower than the increase rate of the amount of catalyst. That is, from the standpoint of the yield of the catalyst, the yield of the catalyst was rather decreased as the amount of catalyst increased.                     

Example 3

Under the same conditions as in Example 1, the reactant was injected at a constant rate while maintaining the catalyst amount at 85 g (5 parts by weight), and the reaction was performed while increasing the reaction temperature to 276 ° C. Increasing the temperature, it is advantageous in the isomerization reaction in terms of reaction equilibrium and reaction rate to increase the production rate and yield. At this time, the increase in pressure with increasing reaction temperature was to keep the reactants in the liquid state. The results are shown in Table 2 below.

Production yield according to the change of reaction temperature Example Catalyst concentration (parts by weight) Pressure (kg / ㎠) Temperature (℃) Formation rate (ml / hr) β-IP concentration (% by weight) β-IP production rate (ml / hr) Yield (Y = ml _β / hr / g _cat ) One 5 0 218 188.3 9.93 18.7 0.22 2 5 0.5 232 180.2 11.32 20.4 0.24 3 5 1.0 248 188.9 15.78 29.8 0.35 4 5 1.5 262 189.3 26.99 51.1 0.60 5 5 2.0 276 192.9 39.2 75.65 0.89

Example 4

Under the same conditions as in Example 1, the reaction was carried out while increasing the liquid space velocity of the reactants to 0.5, as defined by Equation 1 above, with the catalyst amount fixed at 5 parts by weight and the temperature maintained at 218 ° C.                     

Production Yield According to the Liquid Space Velocity of Reactant Liquid space velocity (1 / hr) Catalyst concentration (parts by weight) Pressure (kg / ㎠) Temperature (℃) Formation rate (ml / hr) β-IP concentration (% by weight) β-IP production rate (ml / hr) Yield (Y = ml _β / hr / g _cat ) 0.1 5 0 218 168.9 11.57 19.55 0.23 0.2 5 0 218 399.5 8.3 33.15 0.39 0.3 5 0 218 567.9 6.44 36.55 0.43 0.5 5 0 218 949.2 4.48 42.5 0.50

Example 5

Under the same conditions as in Example 1, the reaction was carried out at 276 ° C and a liquid space velocity of 0.5, which are reaction conditions showing excellent results in Examples 3 and 4. As a result, β-isophorone production rate (ml / hr) was 181.05, and the production yield (Y = ml _β / hr / g _cat ) was 2.13.

Example 6

Isomerization was carried out by replacing the catalyst with CaSO ₄ , CaCl ₂ and CuCl ₂ at a reaction temperature of 276 ° C. and a liquid space velocity of 0.5, which were the same as in Example 5. As a result, the production yield (Y = ml _β / hr / g _cat ) was 2.0 to 2.1, showing a similar excellent value compared to MgSO ₄ .

The results of Examples 5 and 6 are shown in Table 4 below.                     

Production yield according to the change of catalyst catalyst LHSV (1 / hr) Catalyst concentration (parts by weight) Pressure (kg / ㎠) Temperature (℃) Formation rate (ml / hr) β-IP concentration (% by weight) β-IP production rate (ml / hr) Yield (Y = ml _β / hr / g _cat ) MgSO ₄ 0.5 5 2 276 948.9 19.08 181.05 2.13 CaSO ₄ 0.5 5 2 275 956.5 18.7 178.5 2.10 CaCl ₂ 0.5 5 2 276 940.2 18.9 177.65 2.09 CuCl ₂ 0.5 5 2 278 946.8 18.0 170.1 2.0

Example 7

The reaction products having a purity of 18 to 19% prepared in Examples 5 and 6 were separated again using a separation column to finally prepare β-isophorone having a purity of 98.7%, and α-isophorone generated in the separation process isomerized. Recovery to the reactor was used.

Example 8

The reaction was carried out for 60 days at 276 ° C. and the liquid space velocity of 0.5. At this time, β-isophorone production rate (ml / hr) and the production yield of the 60 days was maintained at the initial value, it was confirmed that there is almost no deterioration phenomenon in the metal sulfate salt of the catalyst system of the present invention. The results are shown in Table 5 below.

Degradation of the catalyst with the reaction time Reaction days LHSV (1 / hr) Catalyst concentration (parts by weight) Pressure (kg / ㎠) Temperature (℃) Formation rate (ml / hr) β-IP concentration (% by weight) β-IP manufacturing speed (ml / hr) Yield (Y = ml _β / hr / g _cat ) One 0.5 5 2 276 948.9 19.08 181.05 2.13 20 0.5 5 2 276 956.1 18.95 181.18 2.13 30 0.5 5 2 276 945.3 19.0 179.60 2.11 60 0.5 5 2 276 949.7 18.98 180.25 2.12

As described above, in the present invention, α-isophorone is a reactant through an isomerization reaction under a pressure of 250 ° C. to 300 ° C. and 0 to 5 kg / cm 2 using a heterogeneous catalyst selected from metal sulfates and metal halides alone or in combination. Β-isophorone was prepared at a level of 18-19% purity, and distilled to prepare β-isophorone having a purity of 98% or higher.

This showed a good catalyst production yield (Y = ml _β / hr / g _cat , i.e., β-isophorone produced per hour per g of catalyst) compared to the prior art, which was about 2.0 to 2.1. Not only is it economical as a material, but as a heterogeneous catalyst system, deterioration does not occur for a certain period of time (at least 60 days of operation). Can be.

Claims (9)

From 0.1 to 30 parts by weight of Group Ia, IIa and IIIa metal sulfates with respect to 100 parts by weight of α-isophorone in a temperature range of 180 ° C to 300 ° C and a pressure range of 0 to 5kg / cm 2 from the reactant α-isophorone Obtaining β-isophorone through an isomerization reaction using a heterogeneous catalyst formed; Separating the β-isophorone through a distillation reaction; And A method for producing high purity β-isophorone, comprising recovering unreacted α-isophorone to a reactor. delete The method of claim 1, wherein the metal sulfate is selected from CaSO ₄ , MgSO ₄ , Na ₂ SO ₄ and Al ₂ (SO ₄ ) ₃ . delete delete The method for producing high purity β-isophorone according to claim 1, wherein the amount of the catalyst used is 0.5 to 10 parts by weight. The method of claim 1, wherein the isomerization condition is a temperature range of 250 to 300 ° C. and a pressure range of 1.5 to 3 kg / cm ² . The method of claim 1, wherein the reactant α-isophorone is injected into the reactor at a liquid space velocity (LHSV) in the range of 0.1 to 0.5. 9. The high purity β-iso according to any one of claims 1, 3, 6, 7, and 8, wherein the method is operated continuously while the catalyst is maintained in the reactor. Production method of poron.