JPH07215897A - Method for co-producing cyclohexanol, cyclohexene and phenols - Google Patents

Abstract

(57) [Summary] [Structure] 100-150 in the presence of heteropolyacid and water.
A method for co-producing cyclohexanol, cyclohexene and phenols, which comprises hydrolyzing phenylcyclohexyl ether at ℃. [Effect] Cyclohexanol and the like can be produced in high yield from phenylcyclohexyl ether. In addition, the aqueous phase and the organic phase of the reaction solution can be easily separated,
The catalyst separation step is also simplified, which is an industrially excellent method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for producing cyclohexanol, cyclohexene and phenols by hydrolysis of phenylcyclohexyl ether.

[0002]

2. Description of the Related Art Conventionally, a method for producing cyclohexanol by hydrating a cyclic olefin, in particular cyclohexene, has been described by using a zeolite (Japanese Patent Publication No. 4-4113).
1), a method using a cation exchange resin (Japanese Patent Publication No. 38-1)
5619), a method using an aromatic sulfonic acid (Japanese Examined Patent Publication No. 43-8104), a method using a heteropolyacid (Japanese Examined Patent Publication No. 58-1089), and the like.

Further, a method of adding phenols to the strongly acidic cation exchange resin catalyst (Japanese Patent Laid-Open No. 62-12033).
3), a method of adding phenols to a solid acid catalyst such as zeolite (JP-A-62-126141), a method of adding phenols to an aromatic sulfonic acid catalyst (JP-A-62-126141).
No. 126141) has been reported. The method of adding phenols to the reaction system as described above is excellent as a method of improving the yield of cyclohexanol.

However, in the above reaction system, by-products of phenylcyclohexyl ether are unavoidable due to the reaction between phenols and cyclohexane or the reaction between cyclohexanol and phenols, which not only lowers the selectivity of cyclohexanol. In the purification process, it is necessary to separate phenylcyclohexyl ether as one of the high boiling impurities. The formation of phenylcyclohexyl ether is an equilibrium reaction, but even if it is hydrolyzed using a catalyst such as aromatic sulfonic acid, the reaction rate is slow, so industrially it is circulated and accumulated during the reaction process. easy.

[0005]

If phenylcyclohexyl ether can be effectively used, for example, if it can be hydrolyzed into cyclohexanol, phenols, etc., the yield of cyclohexanol is improved, which is industrially advantageous. Then, the subject which this invention tends to solve is providing the method of obtaining cyclohexanol, phenols, etc. by hydrolyzing phenyl cyclohexyl ether efficiently.

[0006]

Means for Solving the Problems As a result of intensive studies on the above-mentioned problems, the present inventors have found that in the hydrolysis of phenylcyclohexyl ether, hydrolysis is carried out in the presence of a heteropolyacid within a predetermined temperature range. It was found that an effective ingredient such as cyclohexanol can be efficiently obtained by carrying out the method, and the present invention has been accomplished. That is, the gist of the present invention resides in a co-production method of cyclohexanol, cyclohexene and phenols, which is characterized by hydrolyzing phenylcyclohexyl ether at 100 to 150 ° C. in the presence of heteropolyacid and water.

The present invention will be described in detail below. The phenylcyclohexyl ether used as a raw material in the present invention may be obtained by any method, but industrially, phenyl obtained as a by-product when cyclohexanol is obtained by hydrating cyclohexene in the presence of phenols. The method utilizing cyclohexyl ether is preferred. Here, as the phenols, in addition to phenol, those having a substituent such as cresol and xylenol are also included. Further, in the hydration reaction of cyclohexene, as a catalyst, usually zeolite, cation exchange resin,
Aromatic sulfonic acid or the like is used. The phenols are usually 0.01 to 1 per 1 mol of cyclohexene.
The hydration reaction is carried out in the presence of about 0 mol.

The cyclohexene is hydrated in the presence of phenols, the produced cyclohexanol is separated by distillation, and the high boiling substances in the rest of the reaction solution contain cyclohexene dimer or dehydrogenation. In addition to the diene compound and the like, a considerable amount of phenylcyclohexyl ether is usually contained and accumulated. Therefore, the high boiling point is hydrolyzed in the same manner as in the present invention to give cyclohexanol, cyclohexene and phenols. Can be co-produced. The cyclohexene and the phenols in the hydrolyzate can be reused after being separated from cyclohexanol and then circulated to the original cyclohexene hydration reaction system.

The heteropolyacid used as a catalyst in the present invention usually contains, as a condensation coordination element, at least one element selected from molybdenum (Mo), tungsten (W) and vanadium (V). Other elements such as niobium (Nb) and thallium (Ta) may be contained as condensation coordination elements. The central elements of this heteropolyacid are usually P, Si, As, Ge, Ti, Ce,
One selected from the group of Th, Mn, Ni, Te, I, Co, Cr, Fe, Ga, B, V, Pt and Be is used. Among them, the condensed coordination element / center in the heteropolyacid is used. The atomic ratio of elements is usually preferably 2.5 to 12. Further, the heteropolyacid is not limited to a monomer, and a polymer such as a dimer or trimer can be used.

Specific examples of the heteropolyacid include phosphotungstic acid, silicotungstic acid, phosphomolybdic acid,
Phosphomolybdovanadic acid, Phosphomolybdotungstovanadic acid, Phosphotungstovanadic acid, Molybdenum silicic acid, Molybdotungstic acid, Molybdotungstovanadic acid, Borotungstic acid, Cobalt molybdic acid, Cobalt tungsten arsenic molybdate, Arsenic Examples thereof include tungstic acid. Of these, phosphotungstic acid, silicotungstic acid and phosphomolybdic acid are particularly preferred.

The above reaction rate of hydrolysis of phenylcyclohexyl ether largely depends on the concentration of the aqueous solution of the heteropolyacid used, and the production ratio of cyclohexanol and cyclohexene to phenol is influenced by the reaction conditions. That is, a part of the generated cyclohexanol is converted into cyclohexene by the dehydration reaction. The aqueous solution concentration of the heteropolyacid is usually 0.1 to 1.0, preferably 0.2 to 1.0 as a weight ratio of water to the heteropolyacid.
It is 0.8. The weight ratio of water to heteropolyacid is 1.
When it exceeds 0, the hydrolysis rate of phenylcyclohexyl ether is remarkably reduced, which is not practical. On the other hand, when the weight ratio of water to the heteropolyacid is less than 0.1, the reaction equilibrium is biased to the phenylcyclohexyl ether side, and the hydrolysis rate becomes slow, which is not preferable. In addition, the condensation reaction of the produced cyclohexene and cyclohexanol and the high boiling point are promoted, which is not preferable. further,
It is not preferable because the separability between the organic phase and the aqueous phase of the reaction liquid becomes poor.

The amount of the heteropolyacid used is usually 0.01 or more, preferably 0.05 or more, in weight ratio with respect to the dicyclohexyl ether. Under conditions where the amount of heteropolyacid is large, it is possible to shorten the reaction time, but under conditions where the amount of heteropolyacid is significantly large, it tends to be difficult to separate the organic phase and the aqueous phase containing heteropolyacid, so the upper limit is set. Is usually preferably 30 or less in weight ratio.

Further, the hydrolysis reaction of phenylcyclohexyl ether is greatly affected by the reaction temperature, and is 100 to 100%.
It is carried out in a temperature range of 150 ° C, preferably 110 to 140 ° C. When the reaction temperature is less than 100 ° C, it is difficult to obtain a sufficient cyclohexanol yield, while when the reaction temperature exceeds 150 ° C, the amount of cyclohexene produced by the dehydration reaction of the produced cyclohexanol increases, and cyclohexanol, cyclohexene and This is not preferable because the high boiling of phenols is promoted.

The reaction time of the above hydrolysis reaction of phenylcyclohexyl ether is usually 10 minutes to 1
It is within 0 hours. The reaction pressure is not particularly limited as long as it maintains the liquid phase of water, and it may be carried out under pressure, and is usually 50 Kg / cm ² or less, preferably 20 Kg / cm ² or less. To be selected. An organic solvent inert to the reaction can be present in the phenylcyclohexyl ether hydrolysis reaction system of the present invention. Examples of the solvent include saturated aliphatic hydrocarbon compounds such as hexane, alicyclic hydrocarbon compounds such as cyclohexane, and aromatic compounds such as benzene and toluene. The coexistence of these inert solvents brings about an advantage that the separability between the organic phase and the aqueous phase of the reaction solution becomes good.

After the hydrolysis reaction liquid is separated into an organic phase and an aqueous phase, cyclohexanol, cyclohexene and phenols in the organic phase, and unreacted phenylcyclohexyl ether can be separated by distillation. Unreacted raw materials can be recycled to the hydrolysis reaction system.

[0016]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples unless it exceeds the gist.

Example 1 2.2 g of phenylcyclohexyl ether, commercially available phosphorus
Tungstic acid (H₃PW ₁₂O₄₀-nH₂O, n = 25-30) 35.0
g, 23.0 g water, titanium-lined autoclave
The mixture was charged into the reactor and reacted at 120 ° C. for 30 minutes. The reaction solution is water
The aqueous phase separated into organic and organic phases is
The tungstic acid was neutralized. For gas chromatography
Table 1 shows the results of analysis of the reaction solution. The yield
For the charged phenylcyclohexyl ether
Expressed in mol%.

Example 2 Except that 2.2 g of phenylcyclohexyl ether, 46.20 g of phosphotungstic acid and 11.6 g of water were used,
Table 1 shows the results of the hydrolysis reaction of phenylcyclohexyl ether carried out in the same manner as in Example 1. Comparative Example 1 2.0 g of phenylcyclohexyl ether and 0.4 g of phosphotungstic acid were charged into an autoclave and heated to 160 ° C.
Table 1 shows the results of the reaction for 30 minutes. The reaction solution was in a homogeneous phase.

[0019]

[Table 1]

[0020]

EFFECT OF THE INVENTION From phenylcyclohexyl ether,
Cyclohexanol, cyclohexene and phenols can be produced in high yield. Further, the aqueous phase and the organic phase of the reaction solution can be easily separated, and the catalyst separation step is simplified, which is an industrially excellent method.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display location C07C 35/08 37/06 39/04 // C07B 61/00 300 (72) Inventor Takao Maki Kanagawa Sanryo Kasei Co., Ltd. Research Institute, 1000 Kamoshida-cho, Midori-ku, Yokohama

Claims (2)

[Claims] 1. 100 to 1 in the presence of heteropolyacid and water
A method for co-producing cyclohexanol, cyclohexene and phenols, which comprises hydrolyzing phenylcyclohexyl ether at 50 ° C. 2. A cyclohexene hydration reaction is carried out in the presence of phenols, and cyclohexanol produced is separated by distillation, and the high-boiling substances in the remaining reaction solution are removed in the presence of heteropolyacid and water. A method for co-producing cyclohexanol, cyclohexene, and phenols, which comprises hydrolyzing at 100 to 150 ° C.