JP2008222683A - Method for producing cycloalkanol and cycloalkanone - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an industrially desirable method for producing cycloalkanols and cycloalkanones which exhibits high decomposition activity and high selectivity for objective products. <P>SOLUTION: The method for producing cycloalkanols and cycloalkanones comprises decomposing a cycloalkyl hydroperoxide in the presence of an imidazole complex represented by formula (I): [MXn(Het)m] (wherein M is copper, cobalt, or iron; X is a Broensted base; Het is an unsubstituted or substituted imidazole compound; n is an integer of 1-3; and m is an integer of 1-4). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing cycloalkanol and cycloalkanone by decomposing cycloalkyl hydroperoxide obtained by oxidation reaction of cycloalkane. Cycloalkanol and cycloalkanone are extremely useful compounds as raw materials for producing polyamide-based polymer monomers such as nylon, synthetic raw materials for chemicals, and organic solvents.

As a method for producing cycloalkanol and cycloalkanone by decomposing cycloalkyl hydroperoxide in the presence of a metal catalyst, the decomposition of cyclohexyl hydroperoxide in cyclohexane or other solvent described in Non-Patent Document 1 is performed by using cobalt, molybdenum, manganese. Although a method using a naphthenate such as is known, since it is necessary to keep the reaction temperature high in order to obtain a sufficient reaction rate, for example, cyclohexanol and cyclohexanone are lost in a side reaction due to heat. Not a satisfactory way. Patent Document 1 discloses a method using an organometallic complex in which a metal selected from cobalt, manganese, chromium, iron or vanadium is bonded to a phthalocyanine or porphyrin structure fixed to a support material, and Patent Document 2 discloses cobalt, Although a method using a metal complex consisting of manganese or iron and some isoindoline is described, in either case, a large amount of catalyst must be used and the ligand is not necessarily thermally stable. There is a problem that it is not expensive. Patent Document 3 describes a method of using cobalt oxide supported on zeolite, but this method requires a very large amount of catalyst in order to obtain a sufficient reaction rate.
JP-A-2-164836 JP 56-115729 A JP 58-219132 A Occupational Chemical Journal, 73, 2388 (1970)

  The present invention is capable of producing cycloalkanol and cycloalkanone with high decomposition rate and high yield by decomposing cycloalkyl hydroperoxide in the reaction system in the presence of a small amount of highly active imidazole complex. It is an object of the present invention to provide a process for producing cycloalkanol and cycloalkanone suitable for the above.

  INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide an industrially suitable process for producing cycloalkanol and cycloalkanone exhibiting high decomposition activity and high selectivity of a target product.

The object of the present invention is to prepare cycloalkyl hydroperoxides of the general formula (I)

(In the formula, M represents copper, cobalt or iron, X represents a Bronsted base, Het represents an unsubstituted or substituted imidazole compound, n represents 1 to 3, and m represents an integer of 1 to 4. .)

It is achieved by a process for producing cycloalkanol and cycloalkanone characterized by decomposing in the presence of an imidazole complex represented by
The present invention is described in detail below.

  Examples of the cycloalkyl hydroperoxide used in the present invention include hydrocyclohexanes having 5 to 20 carbon atoms such as cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, cyclododecane, cyclopentadecane, and cyclohexadecane. Peroxides are mentioned.

  The cycloalkyl hydroperoxide is usually obtained by subjecting cycloalkane to a liquid phase contact reaction with molecular oxygen such as air in the presence of a transition metal under the conditions of a reaction temperature of 120 to 180 ° C. and a reaction pressure of 1 to 20 atmospheres. I can do it. In the present invention, not only cycloalkyl hydroperoxide separated from the resulting cycloalkane oxidation reaction solution by distillation or extraction, but also unpurified cycloalkyl hydroperoxide (that is, the above oxidation reaction solution) is used as it is. Even if it is used, it can be efficiently decomposed to produce cycloalkanol and cycloalkanone.

  When a cycloalkane oxidation reaction solution is used, in addition to the production of the target product directly from the cycloalkyl hydroperoxide, a significant amount of unreacted cycloalkane remaining reacts with the cycloalkyl hydroperoxide to react with the cycloalkane hydroperoxide. Since alkanone and cycloalkanol are produced, there is an advantage that the yield of the target product is increased. In addition, when using this oxidation reaction liquid, it is preferable to remove the acid contained by water washing or alkali washing of this oxidation reaction liquid as needed before decomposing | disassembling cycloalkyl hydroperoxide. At this time, as the alkali, for example, hydroxides or carbonates of alkali metals or alkaline earth metals such as sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate, and calcium carbonate are used.

  Examples of the central metal M of the complex catalyst represented by the general formula (I) used in the present invention include copper, cobalt, and iron, and copper and cobalt are preferable. X represents a Bronsted base, preferably a halogen atom, a sulfonic acid group or an acetoxy group, and particularly preferably a chlorine atom, a sulfonic acid group or an acetoxy group. Het represents an unsubstituted or substituted imidazole compound. The substituent of the substituted imidazole is an alkyl group having 1 to 4 carbon atoms, preferably a methyl group. Particularly preferred are imidazole (Him), N-methylimidazole (nmi), and 1,2-dimethylimidazole (1,2-dmi). n represents 1 to 3, and m represents an integer of 1 to 4. Moreover, although a water | moisture content may be contained in a complex, such a complex is also contained.

  In the decomposition of the cycloalkyl hydroperoxide, usually, the imidazole complex is present in the reaction solution in an amount of 0.01 to 250 ppm by weight, preferably 0.1 to 150 ppm by weight, and the reaction temperature is 25 to 180 ° C., preferably 80. It is carried out under conditions of ˜160 ° C. and a reaction pressure of 1 to 30 atmospheres. When the reaction temperature is lower than 25 ° C., the reaction rate is decreased, and when the reaction temperature is higher than 180 ° C., the yield of the target product is decreased, which is not preferable. Moreover, since the special effect is not seen even if the density | concentration of a catalyst is made high, said range is preferable.

  The decomposition reaction is carried out in a reactor equipped with a stirrer in order to make the temperature in the system uniform.

  As described above, cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, cyclononanone, cyclodecanone, cyclododecanone, cyclopentadecanone, cyclohexadecanone, and cyclopentanol, cyclohexanol, cycloheptanol, cyclohexane Cycloalkanones such as octanol, cyclononanol, cyclodecanol, cyclododecanol, cyclopentadecanol, cyclohexadecanol, and the like, and cycloalkyl hydroperoxide-containing decomposition reaction liquid are obtained. If necessary, the cycloalkanol is separated and purified by distillation or the like after washing the decomposition reaction solution with water or alkaline water to remove the acid.

Next, the present invention will be specifically described with reference to examples and comparative examples.
In this example, an oxidizing solution obtained by air-oxidizing cyclohexane at 8 to 15 MPa and 150 to 160 ° C. under a cobalt octylate catalyst was used as a raw material. The composition differs slightly depending on the batch. The oxidizing liquid A is cyclohexyl hydroperoxide (CHP) 0.94 wt%, cyclohexanone (ON) 1.38 wt%, cyclohexanol (OL) 2.19 wt%, and the oxidizing liquid B is cyclohexyl hydro Peroxide (CHP) 0.93 wt%, cyclohexanone (ON) 1.40 wt%, cyclohexanol (OL) 2.21 wt%, oxidation solution C is cyclohexyl hydroperoxide (CHP) 0.92 wt%, cyclohexanone (ON) 1.40 wt% %, Cyclohexanol (OL) 2.25 wt%. Oxidizing solution D is cyclohexyl hydroperoxide (CHP) 0.94 wt%, cyclohexanone (ON) 1.30 wt%, cyclohexanol (OL) 2.13 wt%, oxidizing solution E is cyclohexyl hydroperoxide (CHP) 0.95 wt%, cyclohexanone (ON) 1.24 wt%, cyclohexanol (OL) 2.02 wt%, oxidation solution F is cyclohexyl hydroperoxide (CHP) 0.95 wt%, cyclohexanone (ON) 1.29 wt%, cyclohexanol (OL) 2.07 wt% %, The oxidizing liquid G is a cyclohexane oxidizing liquid concentrated under reduced pressure, and the composition thereof is cyclohexyl hydroperoxide (CHP) 3.22 wt%, cyclohexanone (ON) 3.97 wt%, cyclohexanol (OL) 7.18 wt%. Met.

[Comparative Example 1]
To a pressure resistant glass autoclave having an internal volume of 50 mL, 0.53 mg of cobalt octylate [Co (C ₇ H ₁₅ CO ₂ ) ₂ ] was added to 10 g of the above cyclohexane oxidizing solution A. Next, the inside of the vessel was replaced with Ar gas, pressurized to 0.2 MPa, and heated and stirred in a 90 ° C. oil bath for 1 hour. After completion of the reaction, the reaction solution was analyzed. As a result, cyclohexyl hydroperoxide (CHP) was 0.76 wt% (decomposition rate 19%), cyclohexanone (ON) was 1.46 wt%, and cyclohexanol (OL) was 2.34 wt%.

[Comparative Example 2]
100 mg of cuprous chloride was added to 10 g of the above cyclohexane oxidizing solution B in a pressure-resistant glass autoclave having an internal volume of 50 ml. Next, the inside of the vessel was replaced with Ar gas, pressurized to 0.2 MPa, and heated and stirred in a 90 ° C. oil bath for 1 hour. After completion of the reaction, the reaction solution was analyzed. As a result, cyclohexyl hydroperoxide (CHP) was 0.49 wt% (decomposition rate 48%), cyclohexanone (ON) was 1.56 wt%, and cyclohexanol (OL) was 2.48 wt%.

[Comparative Example 3]
To a pressure-resistant glass autoclave having an internal volume of 50 mL, 1 mg of cuprous chloride and 1.7 mg of N-methylimidazole were added to 10 g of the above cyclohexane oxidizing solution C. Next, the inside of the vessel was replaced with Ar gas, pressurized to 0.2 MPa, and heated and stirred in a 90 ° C. oil bath for 1 hour. As a result, cyclohexyl hydroperoxide (CHP) was 0.21 wt% (decomposition rate 78%), cyclohexanone (ON) was 1.67 wt%, and cyclohexanol (OL) was 2.60 wt%.

[Comparative Example 4]
In a pressure resistant glass autoclave having an internal volume of 50 mL, 0.2 mg of copper naphthenate was added to 10 g of the above cyclohexane oxidizing solution E. Subsequently, the inside of the vessel was replaced with Ar gas, pressurized to 0.2 MPa, and heated and stirred in an oil bath at 120 ° C. for 0.5 hour. As a result, cyclohexyl hydroperoxide (CHP) was 0.53 wt% (decomposition rate 44%), cyclohexanone (ON) was 1.46 wt%, and cyclohexanol (OL) was 2.39 wt%.

[Example 1]
To a pressure-resistant glass autoclave having an internal volume of 50 mL, 0.8 mg of CuCl ₂ (nmi) ₃ .0.3H ₂ O was added to 10 g of the above cyclohexane oxidation solution D. Next, the inside of the vessel was replaced with Ar gas, pressurized to 0.2 MPa, and heated and stirred in a 90 ° C. oil bath for 1 hour. After completion of the reaction, the reaction solution was analyzed. As a result, CHP was 0.09 wt% (decomposition rate 91%), cyclohexanone (ON) was 1.65 wt%, and cyclohexanol (OL) was 2.53 wt%.
Hereinafter, the reaction was performed in the same manner as in Example 1 except that the catalyst type, the catalyst amount, the reaction temperature, and the time were changed, and the results are summarized in Table 1.

1)nmi=N-メチルイミダゾール、Him=イミダゾール、1,2-dmi=１，２−ジメチルイミダゾール 2)0.3水和物 3)0.4水和物 4)0.5水和物 5)0.6水和物 6)1.2水和物

1) nmi = N-methylimidazole, Him = imidazole, 1,2-dmi = 1,2-dimethylimidazole 2) 0.3 hydrate 3) 0.4 hydrate 4) 0.5 hydrate 5) 0.6 hydrate 6 ) 1.2 Hydrate

[Example 22]
Synthesis method 1
1.02 g of imidazole was added to 0.85 g of cupric chloride dihydrate, and then stirred for 2 hours. After standing overnight, the blue solid was scraped off and vacuum dried at 50 ° C. for 4 hours to obtain 1.8 g of a blue powder.
Elemental analysis calculated value (as CuCl ₂ (Him) ₃ )
H; 3.57 C; 31.92 N; 24.81
Found H; 3.44 C; 31.66 N; 24.82

[Example 23]
Synthesis method 2
A mixture of 0.79 g of cobalt chloride dihydrate, 0.82 g of N-methylimidazole and 1 ml of ethanol was stirred for 1 hour. After standing overnight, it was vacuum dried at 50 ° C. for 4 hours to obtain 1.1 g of a blue powder.
Elemental analysis Calculated value (as CoCl ₂ (nmi) ₃ · 0.6H ₂ O)
H; 5.00 C; 37.25 N; 21.72
Found H; 4.81 C; 36.93 N; 21.73

[Example 24]
Synthesis method 3
1.34 g of cupric chloride was dissolved in 5 ml of ethanol, and 6 g of N-methylimidazole was added. The reaction solution exothermed slightly and turned from dark green to dark blue. After stirring at room temperature, the mixture was allowed to stand overnight and further stirred for 2 hours. 5 ml of isopropanol was added to the reaction solution, and the precipitated crystals were collected and washed with toluene to obtain 1.4 g of the desired product as a blue powder.
Elemental analysis calculated value (CuCl ₂ (nmi) ₄ · 0.5H ₂ O
H; 5.34 C; 40.73 N; 23.75
Found H; 5.35 C; 40.02 N; 23.62

Hereinafter, according to the production methods of Examples 22, 23, and 24, the complexes produced by appropriately adjusting the raw materials and addition amounts are shown in Table 2. The synthesized complex was confirmed using means such as elemental analysis.

Claims (1)

Cycloalkyl hydroperoxides are represented by the general formula (I)

(In the formula, M represents copper, cobalt or iron, X represents a Bronsted base, Het represents an unsubstituted or substituted imidazole compound, n represents 1 to 3, and m represents an integer of 1 to 4. .)
A process for producing cycloalkanol and cycloalkanone, which is decomposed in the presence of an imidazole complex represented by the formula: