JPS63303936A - Production of cyclohexanol and cyclohexanone - Google Patents

Abstract

PURPOSE:To easily produce the objective compounds in high selectivity, by using a cobalt-containing phyllosilicate as a catalyst in the production of cyclohexanol and cyclohexanone by the oxidation of cyclohexane with molecular oxygen. CONSTITUTION:Cyclohexanol and cyclohexanone useful as an intermediate for epsilon-caprolactam, etc., are produced by oxidizing cyclohexane with molecular oxygen in the presence of a catalyst produced by interchanging at least a part of cations of a phyllosilicate of formula (E is one or more cations interchangeable with Co ion and selected from group IA element, group IIA element and Al; X is Li, Mg, Al, Fe, Ni or Mn; Y is Si which may be partially substituted with Al, Fe, Ge or B; Z is F or OH; a is 1/3-1; b is 2-3) with Co ion. The objective compounds can be produced at a low cost suppressing unnecessary precipitation of insoluble substances and remarkable deterioration of the reaction product.

Description

[Detailed description of the invention] [Industrial application field] The present invention is used as a fine medical intermediate.

It also relates to a method for producing cyclohexanol and cyclohexanone, which are industrially important intermediates for monocablockam. More specifically, it is a simple and highly selective oxidation reaction using monomolecular oxygen using cyclohexane as a starting material. The present invention relates to a method for producing cyclohexanol and cyclohexanone.

[Conventional technology]

Conventionally, the catalyst used to produce cyclohexanol and cyclohexanone TG by oxidizing cyclohexane with molecular oxygen has generally been a trace amount of soluble cobalt compound or a relatively large amount of boron-based compound. As the compound, for example, cobalt nanthenate is used, and as the boron compound, for example, metaboric acid is used.

In this case, the yield is generally low and the selectivity decreases due to the secondary reaction of the obtained product, so it is necessary to suppress the conversion rate of the oxidation reaction to an extremely low level. There were also problems in the operation of the reactor because the catalyst became an insoluble substance during the reaction and was likely to precipitate.

In addition, when boric acid compounds are used as catalysts, although the yield is relatively high, the use of large amounts of boric acid compounds causes various problems in the process of recycling. had.

Measures for Solving Problems c] Therefore, the inventors of the present invention have attempted to solve these problems.As a result of intensive study, they have discovered that the above problems can be solved by using a catalyst with a specific structure. The invention has been achieved.

That is, an object of the present invention is to provide a method for easily and highly selectively producing cyclohexanol and cyclohexanone by oxidizing cyclohexane with molecular oxygen.

This objective is achieved by using a cobalt-containing phyllogate as a catalyst in the oxidation reaction.

The present invention will be explained in detail below.

In the method of the present invention, as a catalyst, an inorganic substance having a layered structure generally called a phylloguic acid salt to which cobalt is added is used. I don't know much about phylloguic acid salts, but basically, oxygen tetrahedrons centered on phylloid, in which phylloid or a part of it is substituted with aluminum, iron, germanium, or boron, are connected in a layered manner, and between the layers, It has a structure containing exchangeable cations or hydration water, and can be represented by the following general formula (1). In the formula, E is an exchangeable cation, usually a Group 1 element, a Group IIA element or ammonium, which cation is often in an irrigated state. Further, X is an element that interconnects oxygen tetrahedra and is usually selected from lithium, magnesium, aluminum, iron, niraglu, and himanganese. Y is the central element of the oxygen tetrahedron.
Gyrite substituted with germanium or boron.

2 is fluorine or OH.

In addition, a and b in the above formula are numbers determined by electrostatic balance, but a is //j~/, 1) is 2 to 3, and specifically, a is usually l. /3゜2/3 and /,
b is (-2-1ILna)7m.

Here, λ- is the sum of negative charges of oxygen and fluorine or OH, n is the valence of Y, and m is the valence of X.

An example of a phyllogate having such a structure is montmorillonite ((!E7. Mgt/s)(81,O
,,)(OH) Goose), Hectorite C(E-凰/,)(M
ga7m Li) (Si, O
S1x7m 01°) (OH)t).

Taeniolite ((E) (MgtLi) (81i0凰・) (E'fi) ).

Mica ((E)CMg*,s) (Siant.) (F*
)) etc.

The catalyst used in the method for producing cyclohexanol and cyclohexanone of the present invention is one in which at least a portion of the cations of the above-mentioned phyllogate are exchanged with cobalt ions. The valence of cobalt may be either divalent or trivalent, or both may be used simultaneously. Cobalt is added by a conventional method such as an ion exchange method, a forced loading method, or a crosstalk method, and the cobalt compound used at that time is preferably one that is soluble in water or an aqueous acid solution. There are no particular restrictions on the cobalt content in the catalyst, but
0 for phyllogate. / ~ iox may be sufficient.

In the present invention, in order to further improve the selectivity of one reaction, one reaction rate, etc., at least a part of the cations of the phyllogate are added to cobalt ions, and silver, zinc, lanthanum, zirconium, lead, vanadium, etc. It is also possible to use as a catalyst an ion exchanged with one or more elemental ions selected from barium and hiniggle.

These elements can be added in the same manner as in the case of cobalt. Furthermore, the content of these elements in the catalyst may be the same as that for cobalt.

1. When preparing the catalyst of the present invention, after adding cobalt etc. to the phyllogate as described above, deionized water,
The vehicle is washed with pure water, etc. and then dried, but in order to dry the vehicle well, it is recommended to first wash it with deionized water, pure water, etc., then wash it with an easily volatile hydrophilic solvent such as methanol, and then dry it. preferable.

The oxidation reaction of cyclohexane can be carried out either in a batch manner or in a continuous manner.
Ko! It is carried out at a temperature of θ°C, preferably about III to /10°C. Further, the reaction pressure is selected from a range of not less than the vapor pressure of cyclohexane and not more than 100 kQ/cd. Although air can be used as the oxidizing gas, it is preferable to use a gas with a low oxygen concentration in order to avoid the formation of an explosive composition mixture and to control the reaction rate. The amount of catalyst to be used varies depending on the reaction mode, cobalt content in the catalyst, etc. For example, l! ! When used in a turbid bed, it is used in an amount of 0.1 to 1 oxH relative to cyclohexane. Note that if the conversion rate of cyclohexane is too high, the amount of by-products produced becomes significant, so it is preferable to suppress it to 30% or less.

) is preferably λoX or less.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples.
The present invention does not exceed its gist! ij) It is not limited to the following examples.

Example 1-μ Cobalt acetate (1) hydrate Co (CH,Co,),
@4AH,.

tj (lImmol) was dissolved in a mixture of water ion, acetic acid
hr, air u j OML/hr) oxidation was performed. Water/10- and about 1 liter of phyllogate shown in fi/ were added to this Co''+ solution, and after ion exchange at 10°C or less for 2 hours, the mixture was separated, washed with deionized water, then methanol, and dried to remove the catalyst. Prepared.

In Example 2, cobal acetate) (1) Water/! Add Od and approximately μg of phyllogate.

After performing ion exchange, a catalyst was prepared in the same manner as above.

Next, cyclohexane! 0.7 II and catalyst O0l to 8tl (rjppm as Co to cyclohexane) were charged, and Ov'N@ mixed gas (0
, JOX)'&: After pressurizing to 2tJCfl/ai, the temperature was raised to /J'c, and an oxidation reaction was carried out at a high rpm.

The reaction rate was calculated by reading the oxygen consumption from a pressure gauge. It was. Cyclohexane conversion rate! After reaching X, the reactor was cooled and the reaction product was analyzed by gas chromatography and neutralization titration. The results are shown in fi/.

Table 7 (Note) Calculation example by dividing the cyclohexane conversion rate by the reaction time! ~IJ The exchangeable potassium ion of the elements shown in Table 1 = 7 elements and 4 elements is 2.2 times mo/l/.

water as chloride, acetate, nitrate or sulfate
The mixture was washed with fluorine tetraglyceride mica and dried. Subsequently, ion exchange was performed with JI Co in the same manner as in Example/1, and cleaning was performed.

It was dried and used as a catalyst. Oxidation of cyclohexane was carried out in the same manner as in Example except that the catalysts fgO and Ji were used.

The results are shown in R.

Table 2 (Note) Calculated by dividing the cyclohexane conversion rate by the reaction time. In the autoclave used in Comparative Example/Example/, AX cobalt heptathenate 70111FC was used as a catalyst for cyclohexane, and Ilppm) f: The method was exactly the same as in Example except for the preparation.

Oxidation of cyclohexanone was carried out.

The results are shown in Shigeru 3.

Comparative Examples 2 to J 73 m of water was added to the Co''+ solution synthesized by the same method as in Examples, and after addition of 2 p of silica gel or silica alumina, the solution was melted at a temperature below J'θ℃ under reduced pressure. The catalyst was obtained by distillation. Cyclohexane was oxidized in the same manner as in Example, except that 0.JI of this catalyst was charged into the autoclave used in Example.

The results are shown in Table 3.

Comparative Example: In the autoclave used in Example 1, 0.0% of monofluorine and tetrafluoride was added as a catalyst. The same method as in Example 1 was used except that Jji was added.

The oxidation of cyclohekip was carried out.

The results are shown in Table 31C.

Table 3 (Calculation of L1 by dividing the conversion rate of phantom cyclohexane by the reaction time [Effect of the invention]) According to the production method of the present invention, cyclohexane undergoes an oxidation reaction with molecular oxygen and becomes an insoluble substance in the reaction system. unnecessarily precipitated.

Furthermore, cyclohexanol and cyclohexanone can be produced easily and highly selectively without significant deterioration of the reaction products.

Claims (3)

[Claims] (1) In the method of producing cyclohexanol and cyclohexanone by oxidizing cyclohexanone with molecular oxygen, the following general formula (1) (Ea) (Xb) (Y_4O_1_0) (Z)_2...
・(1) (wherein, E is a cation exchangeable with one or more cobalt ions selected from group IA elements, group IIA elements, and ammonium, and X is selected from lithium, magnesium, aluminum, iron, nickel, and manganese. element, Y represents silicon which may be partially substituted with aluminum, iron, germanium or boron, Z represents fluorine or OH, a = 1/3 to 1, b = 2 to 3.) A method for producing cyclohexanol and cyclohexanone, which comprises using a phyllosilicate represented by the formula in which at least a portion of the cations have been exchanged with cobalt ions. (2) As a catalyst, at least a part of the cations of the phyllosilicate represented by the general formula (I) are used in addition to cobalt ions such as copper, silver, zinc, lanthanum, zirconium, lead,
The method for producing cyclohexanol and cyclohexanone according to claim 1, characterized in that cyclohexanol and cyclohexanone are exchanged with one or more element ions selected from panadium, barium, and nickel. (3) The method for producing cyclohexanol and cyclohexanone according to claim 1 or 1, characterized in that the conversion rate of cyclohexane is 30% or less.