JPH05279292A - Cocatalyst for bromic acid salt catalyst to be used in isomerization reaction - Google Patents

Abstract

PURPOSE:To keep high reaction yield even at a relatively low temperature and enable the recycled use of a catalyst by using the catalyst in combination with a cocatalyst. CONSTITUTION:A cis-form organic compound is made to react in an aqueous solution to form a trans-isomer of the organic compound. In the above reaction, an isomerization reaction catalyst consisting of a bromic acid salt is used in combination with a water-soluble salt of a metal having variable atomic valence and selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Mo, Ag, Pb and Ce.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an isomerization used in a reaction in which an cis-type organic compound is used as a reactant and a bromate is used as a catalyst to isomerize a trans-type product of the organic compound. It relates to a co-catalyst for the bromate catalyst of the reaction.

[0002]

2. Description of the Related Art In a method of isomerizing a cis-type organic compound such as maleic acid in an aqueous solution to produce a trans-type organic compound or fumaric acid, the catalyst is
Bromine supplying compound (for example, ammonium bromide) and oxidant (for example, ammonium persulfate) (Japanese Patent Publication No. 41-425), bromate or bromate and perborate (USP291455).
9) etc. are used.

These bromine-based catalysts include bromine (B
r ₂ ), hydrogen bromide (HBr), bromate (KBrO ₃ , N
aBrO ₃ , NH ₄ BrO ₃ ) and bromine compounds (AlB
Compounds having a bromine valence of less than 5 such as r ₃ and N-bromosuccinimide) are known. Further, hydrogen peroxide (H 2
₂ O ₂ ), ammonium persulfate ((NH ₄ ) ₂ S ₂ O ₈ ), inorganic peroxides such as chlorate, peracetate and perborate, and organic peroxides such as benzoylperoxide are known. There is.

However, the method using ammonium bromide as a catalyst and ammonium persulfate as a co-catalyst requires a relatively small amount of catalyst, but
It is known that the catalyst effect easily disappears under the influence of impurities contained in the aqueous solution of the cis-type organic compound of the reaction product, and that the reaction yield decreases when it is circulated, and the catalyst causes corrosion of the equipment. There are drawbacks such as marked.

Further, a method using bromate or bromate as a catalyst and perborate as a cocatalyst is
Although the required amount of the catalyst is a relatively small amount of 1% by weight or less, the reaction rate is slow when the reaction rate is 100 ° C or lower, and there is a drawback that the product is colored when the catalyst is circulated and used at 100 ° C or higher. The peroxide-based cocatalyst used in combination with these bromine-based catalysts is generally excellent in activating the catalytic action of the isomerization reaction catalyst used, but the peroxide itself easily Since it is consumed by the reaction, it has a poor function of sustaining its action, and there is a drawback that the required amount of the cocatalyst increases.

[0006]

The problem to be solved by the present invention is that a trans product of an organic compound is produced in an aqueous solution by using a cis organic compound as a reactant and a bromate as a catalyst. In the isomerization reaction, the advantage of a bromate catalyst requiring a small amount of catalyst is utilized, and
It is to develop a cocatalyst or a combination thereof that promotes its main reaction and maintains its action even at a relatively low temperature of 100 ° C or lower. The promotion of this main reaction and the sustained effect of its action allow the isomerization catalyst to be reused even at a reaction temperature of 100 ° C or lower, enhance the economic efficiency of the process, prevent the coloring of the product, and stabilize the quality. Can be made possible.

[0007]

SUMMARY OF THE INVENTION The present invention is
In an isomerization reaction in which a cis-type organic compound is used as a reaction product to form a trans-type product of the organic compound, a bromate catalyst in an aqueous solution, and a water-soluble salt of a variable valence metal as a co-catalyst, Element symbols Ti, V, Cr, Mn, F
The atom represented by e, Co, Ni, Cu, Mo, Ag, Pb, or Ce, provided that a water-soluble salt of Pd and Sn is added and made to coexist, and an isomerization reaction is performed, bromic acid is obtained. It has been found that it exhibits a reaction promoting action equal to or higher than that of the catalyst relating to the combination of the salt catalyst and the peroxide co-catalyst, and that the action continues even when the catalyst is circulated.

That is, using a cis-type organic compound as a reactant,
In the isomerization reaction that produces a trans-type product of the organic compound, by taking advantage of the bromate catalyst requiring a small amount of catalyst and adding a cocatalyst,
Even in the reaction at a relatively low temperature of 0 ° C. or less, it is possible to maintain the reaction yield and reuse the catalyst without being affected by impurities contained in the aqueous solution of the cis-type organic compound of the reaction product. The purpose is to find a co-catalyst for industrial use.

According to the present invention, even when a high-purity cis-type organic compound is isomerized from a reaction product such as maleic acid to produce fumaric acid in an aqueous solution, it can be handled at a relatively low temperature. The reaction product of the raw material is less affected by the heat history, that is, the trans-type organic compound in the high purity without coloring can be obtained as the product. The amount of the bromate catalyst used here is, for example, in the case of isomerizing maleic acid, based on maleic acid of the reaction product, 0.1 to
It is 1.0% by weight, preferably 0.25 to 0.5% by weight, and the concentration of the catalyst in the aqueous solution is 1.0 to 10.0% by weight, and preferably the concentration in the aqueous solution is 4.0 to 6.0% by weight.

As the water-soluble salt of a variable-valent metal used as a cocatalyst, a water-soluble salt of a variable-valent metal other than Pd and Sn which have a negative catalytic action, for example, Ti, V, C.
Water-soluble salts of r, Mn, Fe, Co, Ni, Cu, Mo, Ag, Pb, Ce,
For example, Ti ₂ (SO ₄ ) ₃ , VOSO ₄ , Cr ₂ (SO ₄ ) ₃ , MnSO ₄ , Fe
_{SO 4, CoSO 4, NiSO 4} , CuSO 4, Ag 2 SO 4, Ce 2 (SO 4) sulfates such as _{3, Ti (NO 3) 2} , Cr (NO 3) 3, Mn (NO 3) 2, Fe (N
_{O 3) 2, Co (NO} 3) 2, Ni (NO 3) 2, Cu (NO 3) 2, AgNO 3, Pb (N
_{O 3) 2, Ce (NO} 3) nitrates _{3 etc., TiCl 3, VCl 4, CrCl} 2, Mn
Cl ₂ , FeCl ₂ , CoCl ₂ , NiCl ₂ , CuCl ₂ , PbCl ₂ , CeCl
Examples of such salts include hydrochlorides and molybdates such as _3, but in the case of maleic acid, for example, a water-soluble salt of Mn or Ce, which has a high action to accelerate the reaction rate, particularly a sulfate thereof is used, Converted to Mn, 0.1 ppm or more, usually 0.5 to 50 p
pm, preferably 5-10 ppm, is present with maleic acid.

The reaction temperature is a cis-type organic compound, for example,
In the case of maleic acid, it is selected from the temperature range of 70 to 110 ° C, usually 80 to 100 ° C. Also, if the reaction temperature is kept high at normal pressure, the aqueous solution bumps due to the rapid progress of the reaction,
When the generated aqueous solution overflows and becomes a loss, and the reaction temperature is kept high under pressure, the reaction product solution is colored due to decomposition of the bromate catalyst, etc., and the heat-resistant coloring property of the product specifications of the trans-type organic compound is deteriorated. .. On the other hand, if the reaction temperature is kept low, the reaction progresses slowly, the production reaction takes a long time to complete, and the productivity decreases.

The reaction time depends on the cis type organic compound, for example,
In the case of maleic acid, it is usually selected from the reaction treatment time range of 2 minutes to 2 hours in relation to the reaction temperature, but it is selected from 5 minutes to 1 hour in consideration of productivity. INDUSTRIAL APPLICABILITY The present invention can be used in a batch or continuous reaction process in which the catalyst is circulated or not circulated.

The effect of the present invention was generally confirmed as follows. In the case of a cis-type organic compound, for example, maleic acid, a fixed amount of maleic acid is added to water to form an aqueous solution, and a fixed amount of a water-soluble salt of a variable valence metal according to the present invention is added, and the aqueous solution is stirred. While raising the temperature to a predetermined temperature, the catalyst aqueous solution was added all at once and reacted for a certain period of time, after the reaction was completed, the reaction solution was rapidly cooled to 20-40 ° C. and filtered, and the obtained crystals were washed with pure water, Dry at 60-100 ° C. To the reaction filtrate separated by filtration, a certain amount of newly dissolved maleic acid was added to form a certain amount of aqueous solution, and the reaction was continued,
From the yield and quality of the obtained trans-type organic compound, the optimum reaction conditions such as the catalyst performance, the number of times the catalyst is circulated and the amount of replenishment of the catalyst are confirmed and determined for practical use.

[0014]

EXAMPLES Next, the present invention will be described in detail by taking the case where the cis-type organic compound is maleic acid as an example. "Examples 1 to 12 and Comparative Examples 1 to 3" 25.3 g of maleic anhydride was dissolved in 70 g of pure water, and 0.5 or 5.0 ppm of Mn as maleic acid (MA in Table 1) as Mn shown in Table 1 was further dissolved in this aqueous solution. In the case of adding 4.7 g of an aqueous solution of a variable valence metal water-soluble salt of Example 1) or not adding a water-soluble salt of a variable valence metal as a comparative example (however, the total solution amount is the same as that in the example). Was adjusted) and 4.7 g of an aqueous solution of Pd salt or Sn salt shown in Table 1 as a water-soluble salt of a variable valence metal was added, and the temperature was raised to 90 ° C. with stirring. To this aqueous solution was added at once a 5.0% by weight aqueous solution containing 0.5% by weight of potassium bromate corresponding to maleic acid,
The temperature was maintained for 2 hours while stirring. After the reaction is completed, the reaction solution is rapidly cooled to 40 ° C., filtered, and the crystals are washed with pure water.
After drying at 50-60 ° C, 17-29 g of white fumaric acid was obtained. The purity of this crystal was 99.5% or more, the heat-resistant coloring of quality standard was Hazen color number (Hz), No. 10, and the melting point was 286.7 ° C or more. The results are shown in Table 1.

[0015]

[Table 1]

[Examples 13 to 21 and Comparative Examples 4 to 8] An aqueous solution of manganese sulfate was used as an aqueous solution of a water-soluble salt of a variable valence metal, and, as a comparative example, manganese sulfate was not added (Comparative Examples 4 to 8). The results shown in Table 2 were obtained in the same manner as in Examples 1 to 12 except that the conditions were changed to those shown in Table 2. The obtained fumaric acid crystal has a purity of 99.5%.
As mentioned above, the heat-resistant coloring of the quality standard is 10 in Hazen color number (Hz).
The melting point was 286.7 ° C or higher. The results are shown in Table 2.

[0017]

[Table 2]

[0018]

INDUSTRIAL APPLICABILITY In an isomerization reaction in which a cis-type organic compound is used as a reaction product to form a trans-type product of the organic compound, a cocatalyst that is allowed to coexist in an aqueous solution is added to the bromate catalyst at 100 ° C. Even in the following reaction at a relatively low temperature, the reaction yield can be maintained and the catalyst can be circulated for reuse. As a result, it is possible to improve the economical efficiency of the process and stabilize the quality. ..

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical display location C07C 51/353 // C07B 61/00 300 (72) Inventor Akito Komatsu Kawasaki-ku, Kawasaki-shi, Kanagawa Chidori-cho 1-2 Kawasaki Chemical Industry Co., Ltd.

Claims (2)

[Claims] 1. A cis-type organic compound as a reactant in an aqueous solution, which is used as a main catalyst in an isomerization reaction at a relatively low temperature of 100 ° C. or lower to produce a trans-type product of the organic compound. As a variable valence metal atom for the main catalyst, which promotes the catalytic action of bromate and is allowed to coexist in an aqueous solution in order to maintain its action,
A water-soluble salt of a variable-valent metal having a concentration of 100 ppm or more,
Here, the variable valence metal atoms include the element symbols Ti, V,
Cr, Mn, Fe, Co, Ni, Cu, Mo, Ag, P
An atom represented by b or Ce, except for Pd and Sn. 2. A bromate as a catalyst, which forms a trans-type product of the organic compound, fumaric acid, in an aqueous solution using the cis-type organic compound, maleic acid as a reaction product.
In a method of performing an isomerization reaction at a temperature of 0 ° C. or lower, fumaric acid characterized in that a water-soluble salt of a variable valence metal represented by the element symbol Mn or Ce is used as a cocatalyst in an amount of 100 ppm or more in an aqueous solution. Production method.