JP3392928B2 - Method for producing 2-chlorocyclohexanol - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a process for producing 2-chlorocyclohexanol, which is a useful compound that can be used as an intermediate for medicines and agricultural chemicals, an intermediate for polymer raw materials, and the like.

[0002]

2. Description of the Related Art Cyclohexene is treated with an aqueous solution of sodium hypochlorite and an acid to produce 2-chlorocyclohexanol. A method of treating cyclohexene with an aqueous solution of sodium hypochlorite and nitric acid (Org. Col. Vol.l, 158 (1967)) and a method of reacting cyclohexene containing cyclohexane with an aqueous solution of sodium hypochlorite and sulfuric acid (US Pat. No. 2,119,48).
No. 5) is known.

[0003]

These methods are excellent in that 2-chlorocyclohexanol can be easily obtained, but the yield is not always satisfactory.

Therefore, an object of the present invention is to provide a method for obtaining 2-chlorocyclohexanol in a good yield and industrially advantageously.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have made it possible to produce cyclohexene with an aqueous solution of sodium hypochlorite and an acid under specific conditions, which is industrially advantageous in good yield. The inventors have found that chlorocyclohexanol can be produced, and arrived at the present invention.

That is, according to the present invention, cyclohexene is treated with an aqueous solution of sodium hypochlorite and an acid to chlorohydrinate cyclohexene to produce 2-chlorocyclohexanol. Hydrogen ion concentration pH 3 to 6
And a reaction temperature of 30 to 70 ° C. for the production of 2-chlorocyclohexanol. In the method of the present invention described above, cyclohexene, an aqueous solution of sodium hypochlorite, and sulfuric acid are continuously supplied to a reactor, and a reaction liquid containing 2-chlorocyclohexanol is continuously taken out. It is a characteristic method for producing 2-chlorocyclohexanol.

The present invention will be described in detail below.

Examples of the cyclohexene used in the present invention include those produced by various methods. Examples thereof include dehydrated cyclohexanol, dehydrochlorinated chlorocyclohexane, and partially hydrogenated benzene. In addition, there may be no problem even if the cyclohexene containing raw materials or by-products derived from production is used. That is, cyclohexanol, chlorocyclohexane, benzene, cyclohexane, methylcyclopentane, methylcyclopentene and the like can be used as they are, even if they exist in several to several equivalents, and in some cases several times as much as cyclohexene.

The sodium hypochlorite as referred to in the present invention generally includes those produced by introducing chlorine gas into a caustic soda aqueous solution, those produced by electrolyzing a sodium chloride aqueous solution, and the like. The sodium hypochlorite concentration in the aqueous solution of sodium hypochlorite in the present invention is usually 2 to 40% by weight, preferably 5 to 30%.
% By weight. If the concentration is too low, 2-
The concentration of chlorocyclohexanol becomes low and the production efficiency decreases. If the concentration is too high, by-products will increase,
The yield of chlorocyclohexanol decreases, which is not preferable.

In the method of the present invention, sulfuric acid is used as an acid that functions to neutralize sodium hypochlorite and generate free hypochlorous acid for chlorohydrination. The concentration of sulfuric acid in the present invention is usually 3 to 70% by weight, preferably 5 to 60% by weight. If the concentration of sulfuric acid is too low, the concentration of 2-chlorocyclohexanol produced will be low and the production efficiency will be reduced. If the concentration is too high, by-products increase and the yield of 2-chlorocyclohexanol decreases, which is not preferable.

In the present invention, it is important to keep the pH of the reaction mixture and the reaction temperature within a specific range. The reaction of cyclohexene with sodium hypochlorite and sulfuric acid in the present invention is sufficiently fast, and it is not necessary to take a long time even at a temperature of 10 ° C. or lower. However, since the reaction is exothermic, in order to bring the temperature to ambient temperature or lower, a large amount of cost is required for the refrigerant and the device for cooling. However, by keeping the pH of the reaction mixture in a certain range, without cooling or with very little cooling, it is possible to obtain 2-chlorocyclohexanol at ambient temperature or above without lowering the yield. You can That is, the pH of the reaction mixture is kept at 3 to 6 and the reaction temperature is kept at 30 to 70 ° C, preferably 35 to 60 ° C. When the pH is out of the above range, the yield of 2-chlorocyclohexanol decreases. Reaction temperature is 30 ℃
The yield below is not affected even if it becomes less, but the cost for cooling is increased. When the temperature exceeds 70 ° C, the yield of 2-chlorocyclohexanol decreases. The sulfuric acid used to maintain the above pH is generally between 1.0 and 1.5 equivalents relative to sodium hypochlorite, although it varies depending on the concentration and the type and amount of those that coexist in the reaction solution. .
The amount of cyclohexene is not limited, but is 0.8 to 3.0 mol, preferably 1.0 to 2.0 mol, per 1 mol of sodium hypochlorite.

The present invention can be implemented in various ways. For example, in batch reaction, after adding a predetermined amount of cyclohexene to the reactor, the hydrogen ion concentration pH of the reaction mixture
Controlling the amount to be 2 to 7, a method of simultaneously adding a predetermined amount of an aqueous solution of sodium hypochlorite and sulfuric acid, a method of adding a predetermined amount of cyclohexene and an aqueous solution of sodium hypochlorite to a reactor, and then adding a reaction mixture While controlling the hydrogen ion concentration pH of 2 to 7
The method such as adding only the acid can be appropriately selected.

The reaction time depends on the amount and temperature,
Usually, after 10 minutes to 100 hours, the necessary raw materials are sequentially added, and then the reaction may be further performed for 1 minute to 10 hours. The progress of the reaction is sufficiently fast even at a temperature of about 30 ° C., and it is not particularly necessary to take a long time.

In the present invention, carrying out the reaction continuously is one of the preferable modes. That is, cyclohexene, a sodium hypochlorite aqueous solution, and an acid are continuously supplied to the reactor, and a reaction mixture containing 2-chlorocyclohexanol is continuously withdrawn from the reactor. The reaction solution may be withdrawn in the form of an overflow from the upper part, or from the withdrawal port attached to the lower part or the side surface of the reactor. The reaction time, that is, the residence time varies depending on the temperature, but may be 1 minute to 10 hours.

In the reaction, a surfactant may be added in order to improve the contact between cyclohexene which is an "oil" and an aqueous solution of sodium hypochlorite or an aqueous layer containing an acid.

From the reaction solution thus obtained, 2-chlorocyclohexanol can be isolated and purified by a known method such as extraction or distillation. The cyclohexene separated from the reaction solution can be reused in the reaction as it is or after purification treatment if necessary.

Further, one of the important uses of 2-chlorocyclohexanol is a precursor of cyclohexene oxide, which is used as a raw material for medicines and agricultural chemicals and polymers. When used for this purpose, 2-
It is possible to produce cyclohexene oxide directly without isolation of chlorocyclohexanol. That is, cyclohexene oxide can be produced by directly adding and reacting 2-chlorocyclohexanol contained in the reaction solution of the present invention with an equimolar amount and an amount of alkali such as caustic soda or caustic potash, which corresponds to the acid.
High-purity cyclohexene oxide can be obtained from the reaction solution by a known method such as liquid separation, extraction, or distillation.

[0018]

EXAMPLES The present invention will be described more specifically below based on examples. However, the following examples do not limit the present invention in any way.

Example 1 Cyclohexene is 1.3 relative to sodium hypochlorite.
A continuous reaction was carried out at 50 ° C. for a residence time of 3 hours using a double molar amount of sulfuric acid so that the pH of the reaction mixture became 3 to 4.

[Reactor] A mechanical stirrer, a thermometer and a pH meter were set in a 1000 ml five-necked flask. A silicone rubber tube was attached to each of the three dropping funnels for supplying raw materials, and the tip of the tube was introduced into the flask through a tube pump. On the other hand, in order to draw out the reaction solution, insert a silicone rubber tube from the flask through a tube pump and
It was introduced into a 000 ml graduated cylinder.

[Prepared reaction solution] A reaction solution prepared separately using 3 mol of sodium hypochlorite as a preparation,
An oil layer and an aqueous layer were separated, and each was analyzed by gas chromatography (hereinafter abbreviated as GC). The composition of 73.0 g of an oil layer corresponding to 0.500 mol of sodium hypochlorite was 8.52 g of cyclohexene, 51.0 g of 2-chlorocyclohexanol, and the composition of 433 g of the same aqueous layer was 2-3.0 g.
It was 2.63 g of chlorocyclohexanol. All 2-
Chlorocyclohexanol was 53.6 g.

[Continuous Reaction] Cyclohexene, while thoroughly stirring the reaction liquid of the oil / water layer corresponding to 0.500 mol,
While the sodium hypochlorite aqueous solution and sulfuric acid were added dropwise at the same time, the reaction liquid was extracted and a continuous reaction was carried out for 15 hours. The dripping rate was as follows: cyclohexene 54.5 g / 3h (purity 98%, 0.650 mol / 3h), sodium hypochlorite aqueous solution 282g / 3h (concentration 13.2% by weight, 0.1%).
For 500 mol / 3 h) and sulfuric acid (20% by weight), the pH of the reaction mixture was controlled to be 3 to 4, and the reaction liquid withdrawing rate was kept constant. The reaction temperature was controlled at about 50 ° C. by warming the flask with a warm bath. The total amount of sulfuric acid used is 706 g (20
% By weight, 1.44 mol).

An oil layer and an aqueous layer were separated from the reaction solution every 3 hours and the reaction solution in the flask after the reaction was completed, and G and
Analyzed in C. The composition in 463 g of the total reaction oil layer was 77.9 g of cyclohexene and 301 g of 2-chlorocyclohexanol, and the composition of 2420 g of the total reaction water layer was 12.0 g of 2-chlorocyclohexanol. The total amount of 2-chlorocyclohexanol was 313 g.

The product of the continuous reaction portion was obtained by subtracting the composition of the charged reaction solution from the composition of the entire reaction solution, to give 69.4 g (0.845 mol) of cyclohexene and 259 g (1.92 mol) of 2-chlorocyclohexanol, , 272 g of cyclohexene used in the continuous part (purity 98%,
Based on (3.25 mol), the average reaction results of the continuous portion were cyclohexene conversion of 74% and 2-chlorocyclohexanol selectivity of 80%.

EXAMPLE 2 Cyclohexene was added to sodium hypochlorite at 1.1
A continuous reaction was carried out at 50 ° C. for a residence time of 1 hour by using a double molar amount of sulfuric acid so that the pH of the reaction mixture became 4 to 6.

[Reactor] The same reactor as in Example 1 was used.

[Prepared Reaction Solution] The same reaction solution as in Example 1 was used.

[Continuous Reaction] Cyclohexene, while thoroughly stirring the reaction liquid of the oil / water layer corresponding to 0.500 mol,
While the sodium hypochlorite aqueous solution and sulfuric acid were added dropwise at the same time, the reaction liquid was extracted and the continuous reaction was carried out for 6 hours.
The dropping rate was 46.1 g / h of cyclohexene (purity: 98
%, 0.550 mol / h), an aqueous solution of sodium hypochlorite 282 g / h (concentration 13.2 wt%, 0.500 mol / h), and sulfuric acid (20 wt%), p of the reaction mixture.
The H was controlled so as to be from 4 to 6, and the reaction liquid withdrawing rate was kept constant. The reaction temperature was controlled at about 50 ° C. by warming the flask with a warm bath. The total amount of sulfuric acid used is 819 g (20% by weight, 1.6
7 mol).

An oil layer and an aqueous layer were separated from the reaction solution every hour and the reaction solution in the flask after the reaction was completed, and G and
Analyzed in C. The composition in 485 g of the total reaction liquid oil layer was 46.5 g of cyclohexene and 337 g of 2-chlorocyclohexanol, and the composition of 2801 g of the total reaction water layer was 14.2 g of 2-chlorocyclohexanol. The total amount of 2-chlorocyclohexanol was 352 g.

The product of the continuous reaction portion was obtained by subtracting the composition of the charged reaction solution from the composition of the entire reaction solution, whereby 38.0 g (0.462 mol) of cyclohexene and 298 g (2.21 mol) of 2-chlorocyclohexanol were obtained. , 277 g of cyclohexene used in the continuous part (purity 98%,
Based on (3.30 mol), the average reaction results of the continuous portion were a cyclohexene conversion rate of 86% and a 2-chlorocyclohexanol selectivity of 78%.

Comparative Example 1 Cyclohexene was added to 1.3 parts with respect to sodium hypochlorite.
A continuous reaction was carried out at 50 ° C. for a residence time of 3 hours by using a double molar amount of sulfuric acid so that the pH of the reaction mixture was around 1.

[Reactor] The same reactor as in Example 1 was used.

[Prepared Reaction Solution] The same reaction solution as in Example 1 was used.

[Continuous Reaction] Cyclohexene, while thoroughly stirring the reaction liquid of the oil / water layer corresponding to 0.500 mol,
While the sodium hypochlorite aqueous solution and sulfuric acid were added dropwise at the same time, the reaction liquid was extracted and a continuous reaction was carried out for 15 hours. The dripping rate was as follows: cyclohexene 54.5 g / 3h (purity 98%, 0.650 mol / 3h), sodium hypochlorite aqueous solution 282g / 3h (concentration 13.2% by weight, 0.1%).
500 mol / 3 h) and sulfuric acid (20% by weight) were controlled so that the pH of the reaction mixture was around 1.
The reaction liquid withdrawing rate was set so that the reaction liquid amount was constant. The reaction temperature was controlled at about 50 ° C. by warming the flask with a warm bath. The total amount of sulfuric acid used was 922 g (20% by weight, 1.88 mol).

The oil layer and the water layer were separated from the reaction solution every 3 hours and the reaction solution in the flask after the reaction was completed,
Analyzed in C. The composition in the total reaction liquid oil layer 473 g was 83.3 g of cyclohexene and 248 g of 2-chlorocyclohexanol, and the composition in the total reaction water layer 2628 g was 13.2 g of 2-chlorocyclohexanol. The total amount of 2-chlorocyclohexanol was 261 g.

The product of the continuous reaction portion was obtained by subtracting the composition of the charged reaction solution from the composition of the entire reaction solution, and thus 74.8 g (0.910 mol) of cyclohexene and 208 g (1.54 mol) of 2-chlorocyclohexanol, , 272 g of cyclohexene used in the continuous part (purity 98%,
Based on (3.25 mol), the average reaction results of the continuous portion were a cyclohexene conversion rate of 72% and a 2-chlorocyclohexanol selectivity of 66%.

Comparative Example 2 Cyclohexene was added to 1.3 against sodium hypochlorite.
A continuous reaction was carried out at 50 ° C. for a residence time of 3 hours by using a double molar amount of sulfuric acid so that the pH of the reaction mixture became 7 to 9.

[Reactor] The same reactor as in Example 1 was used.

[Prepared Reaction Solution] The same reaction solution as in Example 1 was used.

[Continuous Reaction] Cyclohexene, while thoroughly stirring the reaction liquid of the oil / water layer corresponding to 0.500 mol,
While the sodium hypochlorite aqueous solution and sulfuric acid were added dropwise at the same time, the reaction liquid was extracted and a continuous reaction was carried out for 15 hours. The dripping rate was as follows: cyclohexene 54.5 g / 3h (purity 98%, 0.650 mol / 3h), sodium hypochlorite aqueous solution 282g / 3h (concentration 13.2% by weight, 0.1%).
With respect to 500 mol / 3 h) and sulfuric acid (20% by weight), the pH of the reaction mixture was controlled so as to be 7 to 9, and the reaction liquid withdrawing rate was kept constant. The reaction temperature was controlled at about 50 ° C. by warming the flask with a warm bath. The total amount of sulfuric acid used is 642 g (20
% By weight, 1.31 mol).

An oil layer and an aqueous layer were separated from the reaction solution every 3 hours and the reaction solution in the flask after completion of the reaction.
Analyzed in C. The composition in the total reaction liquid oil layer 468 g was 80.6 g of cyclohexene and 261 g of 2-chlorocyclohexanol, and the composition in the total reaction water layer 2355 g was 9.8 g of 2-chlorocyclohexanol. The total amount of 2-chlorocyclohexanol was 271 g.

The product of the continuous reaction part was obtained by subtracting the composition of the charged reaction solution from the composition of the entire reaction solution, whereby 72.1 g (0.878 mol) of cyclohexene, 217 g (1.61 mol) of 2-chlorocyclohexanol, and , 272 g of cyclohexene used in the continuous part (purity 98%,
Based on (3.25 mol), the average reaction results of the continuous portion were a cyclohexene conversion rate of 73% and a 2-chlorocyclohexanol selectivity of 68%.

Comparative Example 3 Cyclohexene was added to 1.3 against sodium hypochlorite.
A continuous reaction was carried out at 75 ° C. and a residence time of 3 hours by using a double molar amount of sulfuric acid so that the pH of the reaction mixture became 3 to 4.

[Reactor] The same reactor as in Example 1 was used.

[Prepared reaction solution] The same reaction solution as in Example 1 was used.

[Continuous Reaction] Cyclohexene, while thoroughly stirring the reaction liquid of the oil / water layer corresponding to 0.500 mol,
While the sodium hypochlorite aqueous solution and sulfuric acid were added dropwise at the same time, the reaction liquid was extracted and a continuous reaction was carried out for 15 hours. The dripping rate was as follows: cyclohexene 54.5 g / 3h (purity 98%, 0.650 mol / 3h), sodium hypochlorite aqueous solution 282g / 3h (concentration 13.2% by weight, 0.1%).
For 500 mol / 3 h) and sulfuric acid (20% by weight), the pH of the reaction mixture was controlled to be 3 to 4, and the reaction liquid withdrawing rate was kept constant. The reaction temperature was controlled at about 75 ° C by warming the flask with a water bath. The total amount of sulfuric acid used is 696 g (20
% By weight, 1.42 mol).

An oil layer and an aqueous layer were separated from the reaction solution every 3 hours and the reaction solution in the flask after completion of the reaction.
Analyzed in C. The composition of 472 g of the total reaction liquid oil layer was 110 g of cyclohexene and 1 part of 2-chlorocyclohexanol.
The composition in 89 g and the total reaction water layer 2395 g was 13.5 g of 2-chlorocyclohexanol. The total amount of 2-chlorocyclohexanol was 203 g.

The product of the continuous reaction part was obtained by subtracting the composition of the charged reaction solution from the composition of the entire reaction solution to obtain 101 g (1.24 mol) of cyclohexene and 149 g (1.11 mol) of 2-chlorocyclohexanol, and thus the continuous reaction product. 272 g of cyclohexene used in part (purity 98%, 3.
25 moles), the average reaction results of the continuous portion were cyclohexene conversion of 62% and 2-chlorocyclohexanol selectivity of 55%.

[0049]

INDUSTRIAL APPLICABILITY According to the present invention, useful 2-chlorocyclohexanol, which can be used as a medical / agrochemical intermediate, a polymer raw material intermediate, etc., can be produced from cyclohexene in a high yield and by an industrially advantageous method. it can.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kouki Kobayashi, 161 Kambara, Kambara-cho, Anbara-gun, Shizuoka Prefecture Japan Light Metal Co., Ltd./Kamahara Factory (56) References JP-A-6-321832 (JP, A) JP-A-7-188081 (JP, A) JP-A-7-196566 (JP, A) JP-B-48-43881 ( JP, B2) US Patent 2119485 (US, A) Org. Synth. , JOHN WILLEY & SONS, INC., USA. , 2nd Ed. , Col. Vol. 1,158-159 (58) Fields surveyed (Int.Cl. ⁷ , DB name) C07C 35/00 C07C 29/00

Claims (2)

(57) [Claims] 1. A method for producing 2-chlorocyclohexanol by chlorohydrinating cyclohexene by reacting cyclohexene with an aqueous solution of sodium hypochlorite and an acid, wherein sulfuric acid is used as the acid, and the hydrogen ion concentration of the reaction solution is pH. Is maintained at 3 to 6 and the reaction temperature is 30 to 70 ° C.
-Method for producing chlorocyclohexanol. 2. The process according to claim 1, wherein cyclohexene, an aqueous solution of sodium hypochlorite and sulfuric acid are continuously supplied to the reactor, and the reaction liquid containing 2-chlorocyclohexanol is continuously taken out. Method.