JP2006096701A - 2,2-bis(3'-cyclohexenyl)propane of high purity and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture 2,2-bis(3'-cyclohexenyl)propane having a low isomer content in a high yield without using a solvent. <P>SOLUTION: 2,2-Bis(3'-cyclohexenyl)propane is manufactured by a dehydration reaction, without using a solvent, of 2,2-bis(4'-hydroxycyclohexenyl)propane in the presence of, for example, 0.08-0.25 mole of an alkali metal hydrogen sulfate based on 1 mole of 2,2-bis(4'-hydroxycyclohexenyl)propane, the dehydration reaction comprising a first step for distilling out only about 50%, based on a theoretical yield, of by-produced water, and a subsequent second step for distilling out the remaining by-produced water and 2,2-bis(3'-cyclohexenyl)propane. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to high-purity 2,2-bis (3′-cyclohexenyl) propane having a low content of isomers obtained by dehydrating 2,2-bis (4′-hydroxycyclohexyl) propane, and production thereof. Regarding the method. Specifically, 2,2-bis (4′-hydroxycyclohexyl) propane was distilled off only about half the theoretical amount of water in the first step, and only one cyclo ring was dehydrated to form a double bond. This is a method in which a reaction intermediate is mainly produced in a reactor, a target compound is further obtained from the reaction intermediate by dehydration in the second step, and water and the target compound are distilled off.

  As for the production of various olefin compounds having a cyclohexene skeleton, a method for producing a corresponding alcohol compound by a dehydration reaction is widely known. For example, by an alcohol dehydration reaction using an inorganic acid such as concentrated sulfuric acid or phosphoric acid. Techniques for producing olefin compounds are known.

Also disclosed is a technique for producing an olefin compound by dehydration of alcohol using potassium hydrogen sulfate (KHSO ₄ ), which is a widely used acidic salt.
However, when these known inorganic acids such as concentrated sulfuric acid and phosphoric acid and potassium hydrogen sulfate are used, an attempt to obtain an alicyclic diolefin compound by dehydration reaction of the alicyclic diol compound is not always satisfactory. There wasn't. That is, when concentrated sulfuric acid is used, since the acidity is too high, there is a problem that an undesirable side reaction occurs other than the desired alicyclic diolefin compound, and the yield is lowered.
On the other hand, when a weak acid such as phosphoric acid or potassium hydrogensulfate is used, the acidity is weak. Therefore, in the above technique, the reaction time is too long or the reaction temperature is too high, causing side reactions. Thus, there is a problem in that the yield is reduced and a color component and an isomer component that cannot be separated from the desired alicyclic diolefin compound are generated.

In JP 2000-169399 A, hydrogenated bisphenol A is used as a raw material, dehydrated sodium hydrogen sulfate is used as a dehydration catalyst, Solvesso 150 (trade name) is used as a solvent, and 2, -Bis (cyclohexenyl) propane was produced with a yield of 99%, and this was distilled under reduced pressure to obtain the desired product with a recovery rate of 98%. (See Patent Document 1.)
However, in this technique, since the raw material, the intermediate, and the by-product water coexist, the addition reaction of water to the double bond site as well as the dehydration reaction proceeds, and the isomerism represented by the following formula (4) An isomer as shown in the following formula (5) is generated by the chemical reaction.
Since isomers are similar in physical properties to the target product, it is usually difficult to separate by general distillation or the like, and it has been a problem to improve the yield by suppressing the formation of isomers.

The properties of the compound represented by the formula (3) described later generated as a reaction intermediate are not known.
In the examples of the above publication, the reaction is carried out in the presence of a large amount of an organic solvent. However, the reaction system becomes larger, more heat is needed for distillation, or impurities derived from the organic solvent are mixed. There is a problem that it is easy.
When the reaction is carried out without a solvent, the white solid of the above reaction intermediate is fixed inside the distillation column provided in the reaction apparatus, the distillation column is blocked, the pressure inside the reaction vessel rises, the reaction apparatus breaks down, the reaction Liquid splashes were predicted. Therefore, a safe manufacturing method is necessary.
JP 2000-169399 (Claims 1 to 5, paragraphs 0015, 0016, 0020 and 0021, Examples 1 and 7-3)

  An object of the present invention is a method for safely producing 2,2-bis (3'-cyclohexenyl) propane having a low isomer content in a solvent-free and high yield.

  The present inventor has found that the above problem can be solved by performing the dehydration reaction process in two stages, an intermediate production process and a target product production process, and has completed the present invention.

That is, according to the first aspect of the present invention, 2,2-bis (4′-hydroxycyclohexyl) propane is subjected to a dehydration reaction in the presence of a catalyst in the absence of a solvent to 45 to 60% of the theoretically produced by-product water. The first step of distilling only 2, and 2,2-bis (3 carried out by the second step of distilling the remaining by-product water and 2,2-bis (3′-cyclohexenyl) propane after the first step A process for producing '-cyclohexenyl) propane is provided.
A second aspect of the present invention provides the method for producing 2,2-bis (3′-cyclohexenyl) propane according to the first aspect of the present invention, wherein the catalyst is an alkali metal hydrogen sulfate.
A third aspect of the present invention is the first or second aspect of the present invention in which the reaction is carried out at a molar ratio of alkali metal hydrogen sulfate of 0.08 to 0.25 to 1 mole of 2,2-bis (4′-hydroxycyclohexyl) propane. The manufacturing method of 2, 2-bis (3'- cyclohexenyl) propane as described in 1. is provided.
4th of this invention provides the manufacturing method of 2, 2-bis (3'- cyclohexenyl) propane of any one of 1st-3rd of this invention whose reaction temperature is 150-220 degreeC. .
In the fifth aspect of the present invention, a distillation column having 5 to 20 theoretical plates is provided at the top of the reactor, and the second step is performed at a reactor internal temperature of 150 to 220 ° C. and a column top pressure of 5 to 20 Torr. The manufacturing method of 2, 2-bis (3'- cyclohexenyl) propane of any one of -4 is provided.
The sixth aspect of the present invention provides high purity 2,2-bis (3′-cyclohexenyl) propane having a total content of various isomers of 10% or less.

According to the present invention, the production of isomers is suppressed, and high-purity 2,2-bis (3′-cyclohexenyl) propane can be produced with high yield without risk of clogging the distillation column.
High-purity 2,2-bis (3′-cyclohexenyl) propane can be used as an alicyclic epoxy resin raw material.

The present invention will be described in detail below.
The compound used as a raw material in the present invention is 2,2-bis (4′-hydroxycyclohexyl) propane represented by the following formula (1), and hereinafter abbreviated as hydrogenated BPA.
Hydrogenated BPA has a molecular formula of C ₁₅ H ₂₈ O ₂ , a molecular weight of 240.4, a melting point of about 100 ° C., a boiling point of about 255 ° C./20 Torr (2.67 kPa), a white solid at room temperature, and is obtained by hydrogenation of bisphenol A. .

The target compound obtained in the present invention is 2,2-bis (3′-cyclohexenyl) propane represented by the following formula (2), molecular formula C ₁₅ H ₂₄ , molecular weight 204.4, boiling point 280 ° C./760 Torr ( 101.3 kPa), 160 ° C./10 Torr (1.33 kPa), a colorless and transparent liquid at room temperature, hereinafter abbreviated as BC′P.

The intermediate obtained in the present invention is 2- (4′-hydroxycyclohexyl), 2- (3 ″ -cyclohexenyl) propane represented by the following formula (3), molecular formula C ₁₅ H ₂₆ O, molecular weight 222. 4. A white solid at room temperature having a sublimation property of 230 ° C./10 Torr (1.33 kPa), hereinafter referred to as an intermediate.

The dehydration catalyst used in the present invention is preferably an alkali metal hydrogen sulfate, and examples thereof include potassium hydrogen sulfate, sodium hydrogen sulfate, and lithium hydrogen sulfate.
The amount of the catalyst used is preferably 0.08 to 0.25 molar ratio, more preferably 0.10 to 0.20 molar ratio, relative to the raw hydrogenated BPA. If it is less than the above range, the reaction becomes too slow. If it is more than the above range, the isomerization reaction becomes remarkable, resulting in a decrease in yield and purity.
The dehydration catalyst may be charged as a solid, charged as an aqueous solution into the reactor, or may be generated by adding sulfuric acid to an aqueous alkali metal solution in the reactor. Remove water from the reaction system before starting.

In the present invention, the dehydration reaction is carried out in the absence of a solvent, and high-purity hydrogenated BPA is melted near the melting point and used in the reaction.
Since hydrogenated BPA is solid at room temperature, it can be handled by dissolving it in an organic solvent such as alcohols such as methanol or ketones to facilitate its handling, but before starting the dehydration reaction. The organic solvent is previously removed from the reaction system. Insufficient removal is not preferable because the alcohol solvent reacts with the dehydration catalyst during the dehydration reaction, and the corresponding olefin compound is produced, causing the pressure inside the reaction vessel to increase and the activity of the dehydration catalyst to be lost.

  The reaction temperature in the present invention may be a temperature at which an intramolecular dehydration reaction is substantially caused by a dehydration catalyst, but is preferably 150 to 220 ° C, more preferably 180 to 200 ° C. If the reaction temperature is too low, the reaction rate is extremely slow, which is disadvantageous. If the reaction temperature is too higher than the above range, it will result in promoting the coloring and isomerization reaction of the raw material, which is contrary to the object of the present invention.

In the present invention, the dehydration reaction is performed in the following two steps.
First step: Only 45 to 60%, preferably about 50% of the theoretically produced by-product water is distilled to give 2- (4′-hydroxycyclohexyl), 2- (3 ″ -cyclohexenyl) propane ( Intermediate) is obtained.
Second step: After the first step, the remaining by-product water and 2,2-bis (3′-cyclohexenyl) propane are at least distilled. However, in the second step, it is preferable to distill only the remaining by-product water and 2,2-bis (3′-cyclohexenyl) propane.

In the present invention, the dehydration / hydration equilibrium is shifted to the dehydration side by reactive distillation.
For this purpose, a distillation apparatus, preferably a distillation column, is provided at the top of the reactor. As the distillation column, the same reactor and distillation column may be used in the first step and the second step, or they may be transferred to another reactor and performed in another distillation column.
The distillation column provided in the reaction vessel may be a commonly used plate column or packed column type continuous distillation apparatus, or an Oldershaw type distillation column used in a laboratory.

In the first step, in order to distill only water, a distillation column having 5 to 20 theoretical plates, preferably 10 to 15 is provided at the top of the reactor. Since the temperature in the reaction vessel is as described above, the top pressure of the distillation column is 250 Torr or more, preferably 250 to 760 Torr, more preferably normal pressure. The distillate is mainly water. The reflux ratio is preferably 0.5 or less, and more preferably total distillation.
If the above distillation conditions are inappropriate, (i) the yield of the target product is reduced due to the distillation of the reaction intermediate, or (b) the reaction intermediate is a sublimable solid. If solids are deposited in the distillation path, the distillation column is blocked.

In the second step, a distillation column having 5 to 20 theoretical plates, preferably 10 to 15 is provided at the top of the reactor. The distillation column may be a plate column or a packed column.
Since the temperature in the reaction vessel is as described above, the top pressure of the distillation column is 5 to 20 Torr, preferably 10 to 15 Torr. The distillate is preferably refluxed with water and the target component after separation. The reflux ratio is preferably 0.5 or less, and more preferably total distillation. The reflux position is preferably at the top of the column or at the bottom of the column.
If the above distillation conditions are inappropriate, it takes too much time to distill, causing isomerization of the target product BC′P, or distilling intermediates and the like, leading to a decrease in product purity.
The target product is recovered from the top of the column, preferably from the top.

The first step and the second step may be performed in the same reactor, or the reaction solution obtained in the first step may be transferred to another reactor.
The reaction mode may be any of batch, semi-batch or continuous. For example, both the first step and the second step are batch or continuous, or the first step is batch and the second step is continuous. May be. By these reaction modes, the dehydration reaction of hydrogenated BPA is promoted, the reverse hydration reaction is less likely to occur, the raw material conversion rate is increased, and the target product selectivity is increased.

Since the remaining by-product water distilled in the second step and the target product BC′P are separated into two layers in a liquid state, the BC′P layer is separated.
Since the BC'P layer contains a very small amount of moisture, it is desirable to further dehydrate it by distillation purification, drying with an adsorbent, blowing dry air, or the like.

  The high purity 2,2-bis (3′-cyclohexenyl) propane obtained in the present invention has a purity of 90% or more, preferably 99% or more, and the isomer content is 10% or less in total, preferably 1 %, The hue (APHA) is 10 or less, preferably 3 or less, and the moisture is 1% or less, preferably 0.1% or less.

(Example)
EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples. “%” And “part” indicate “% by weight” and “part by weight”, unless otherwise specified.

Example 1
[Synthesis of 2,2-bis (3′-cyclohexenyl) propane]
A 10-liter four-necked flask equipped with a stirrer, a 20-stage distillation column, and a thermometer is charged with 6 kg (25.0 mol) of hydrogenated bisphenol A and 490 g (36.3) of potassium hydrogen sulfate (formula weight 136.2). 6 mol) and heated to 140 ° C. to melt hydrogenated bisphenol A. After melting, when the mixture was further heated to 180 ° C. and stirring was started, the reaction started gradually, and 505 ml (28 mol) of water corresponding to 56% of the theoretical amount was distilled off at normal pressure for 4 hours.
Thereafter, the pressure in the reaction system is reduced to 10 Torr (1.33 kPa) at the same temperature, and water and 2,2-bis (3′-cyclohexenyl) propane are distilled off from the top of the distillation column over 5 hours. It was. The distilled water and 2,2-bis (3′-cyclohexenyl) propane were separated into two layers by a decanter, and the upper 2,2-bis (3′-cyclohexenyl) propane was taken out.
Thereafter, the reaction was terminated when the distillation of water and 2,2-bis (3′-cyclohexenyl) propane ceased. The yield of the distillate crude liquid of 2,2-bis (3′-cyclohexenyl) propane was 4840 g, the purity measured by gas chromatography was 98%, and the remaining 2% was an isomer of multiple target products. It was.

[Purification of 2,2-bis (3′-cyclohexenyl) propane]
Subsequently, 4800 g of the distillate crude liquid was placed in a 5-liter four-necked flask equipped with a stirrer, a 20-stage distillation column, and a thermometer, and the temperature was raised to 170 ° C. in an oil bath. Thereafter, the pressure in the reaction system is reduced to 10 Torr (1.33 kPa), water is distilled off, the temperature at the top of the distillation column is maintained at 160 ° C., and 2,2-bis ( 3'-Cyclohexenyl) propane was rectified to obtain a colorless and transparent liquid.
The yield of 2,2-bis (3′-cyclohexenyl) propane thus obtained was 4573 g. The purity measured by gas chromatography was 99.6%, the iodine value was 247 (I ₂ · g / 100 g), and APHA was 10 or less.
The balance was 0.4% isomer.

(Comparative Example 1)
[Synthesis of 2,2-bis (3′-cyclohexenyl) propane]
To a 15-liter four-necked flask equipped with a stirrer, thermometer, and dehydrator at the top, 6 kg of hydrogenated bisphenol A, 490 g of potassium hydrogen sulfate as a catalyst, and 6 kg of Solvesso 150 (manufactured by Exxon Chemical) as a solvent were reacted. The inside of the system was replaced with nitrogen. Subsequently, the flask was heated to 140 ° C., hydrogenated bisphenol A was dissolved, stirring was started, and then dehydration reaction was performed at 180 ° C. It was confirmed that the distillation of water had stopped after 89% of the theoretical amount of water had been distilled over 9 hours, and the reaction was completed.
The obtained reaction solution was washed with 6 kg of water using a separatory funnel to remove the catalyst, and then the organic layer was rectified under reduced pressure to obtain 3,835 g of colorless and transparent liquid 2,2-bis (3′-cyclohexenyl) propane. Got.
On the other hand, when the purity of the rectified product was measured by gas chromatography, the content of 2,2-bis (3′-cyclohexenyl) propane was 72%, but it contained 26% by-product of unknown structure. It was out.
By gas chromatograph mass spectrometer, by-products of unknown structure were 2- (2′-cyclohexenyl), 2- (3 ″ -cyclohexenyl) propane, 2,2-bis (2′-cyclohexenyl) propane, It was confirmed to be an isomer of the desired product such as-(1'-cyclohexenyl), 2- (3 "-cyclohexenyl) propane, 2,2-bis (1'-cyclohexenyl) propane.
These by-products are considered to be isomers produced by repeating the addition reaction and the dehydration reaction between the double bond produced by the dehydration reaction and the water remaining in the reaction solution. The iodine value was 237 (I ₂ · g / 100 g), and APHA was 50.

(Comparative Example 2)
The same procedure as in Example 1 was performed except that 1650 g (12.1 mol) of potassium hydrogen sulfate was added as a catalyst. As a result, the purity of the obtained purified product was 89.0%, the iodine value was 280 (I ₂ · g / 100 g), and APHA was 60.

(Comparative Example 3)
Synthesis of 2,2-bis (3′-cyclohexenyl) propane was attempted in the same manner as in Example 1 except that 2 g (0.015 mol) of potassium hydrogen sulfate was added as a catalyst. However, even if heating was continued for 6 hours, the reaction did not proceed and the experiment was stopped.

(Comparative Example 4)
In the intermediate production process, 505 ml corresponding to 56% of the theoretical amount of water was distilled out after 4 hours, and then the pressure in the reaction system was reduced to 0.05 Torr (6.7 Pa). Thus, an attempt was made to synthesize 2,2-bis (3′-cyclohexenyl) propane. However, the reaction intermediate was deposited in the distillation column, the inside of the distillation column was blocked, and the inside of the reaction vessel was in a pressurized state, so the experiment was stopped.

(Comparative Example 5)
Synthesis of 2,2-bis (3′-cyclohexenyl) propane was attempted in the same manner as in Example 1 except that the pressure in the reaction system was reduced to 200 Torr (26.6 kPa) immediately after the start of the reaction. However, the reaction intermediate was deposited in the distillation column, the inside of the distillation column was blocked, and the inside of the reaction vessel was in a pressurized state, so the experiment was stopped.

Claims (6)

2,2-bis (4′-hydroxycyclohexyl) propane is dehydrated in the presence of a catalyst without solvent.
A first step of distilling only by-product water of 45-60% of the theoretical production amount, and after the first step, the remaining by-product water and 2,2-bis (3′-cyclohexenyl) propane are distilled. A method for producing 2,2-bis (3′-cyclohexenyl) propane, which is carried out in the second step.   The method for producing 2,2-bis (3'-cyclohexenyl) propane according to claim 1, wherein the catalyst is an alkali metal hydrogen sulfate.   The 2,2-bis (2) according to claim 1 or 2, wherein the reaction is carried out at a molar ratio of alkali metal hydrogen sulfate of 0.08 to 0.25 mole per mole of 2,2-bis (4'-hydroxycyclohexyl) propane. 3′-Cyclohexenyl) propane production method.   The method for producing 2,2-bis (3'-cyclohexenyl) propane according to any one of claims 1 to 3, wherein the reaction temperature is 150 to 220 ° C.   5. A distillation column having 5 to 20 theoretical plates is provided at the top of the reactor, and the second step is performed at a reactor internal temperature of 150 to 220 ° C. and a column top pressure of 5 to 20 Torr. Of 2,2-bis (3′-cyclohexenyl) propane.   High purity 2,2-bis (3'-cyclohexenyl) propane having a total content of various isomers of 10% or less.