JPS5941975B2 - Production method of tricyclic ketone - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention provides 2,6-di(1'-cyclohexenyl)cyclohexanone 12-cyclohexylidene-6-(1
'-cyclohexenyl)cyclohexanone and 2,
A compound selected from the group consisting of 6-di(cyclohexylidene)cyclohexanone (hereinafter referred to as tricyclic ketone)
The present invention relates to a method for manufacturing.

These tricyclic ketones can be dehydrogenated to form 2,6-
Diphenylphenol is useful as a raw material for polyphenylene oxide, which has heat resistance and flame retardancy.

Conventionally, as a method for producing Ξ cyclic ketones,
Publication No. 6779 discloses that a reaction product liquid obtained by heating and condensing cyclohexanone in the presence of an alkaline substance is neutralized with an acid to form an aqueous phase, and this aqueous phase is separated from an organic phase.
A method for obtaining tricyclic ketones from the organic phase is described.

However, according to this method, a new neutralizing agent is required in order to obtain the tricyclic ketone from the reaction product liquid, and an operation for separating and removing the neutralized product is also required.

Therefore, the inventors conducted various research on methods for obtaining tricyclic ketones by directly filtering such reaction product liquids without neutralizing them, and as a result, they arrived at the present invention.

That is, the present invention provides a method for treating a compound selected from the group consisting of cyclohexanone, 2-cyclohexylidenecyclohexanone, 2-(1'-cyclohexenyl)cyclohexanone, and 2-(1'-hydroxycyclohexyl)cyclohexanone with water of an alkali metal. While removing water in the presence of an oxide and a solvent azeotropic with water, heat condensation is performed so that the dehydration rate is 90% or less, the alkali metal hydroxide is separated by filtration, and the tricyclic ring is extracted from the filtrate. The present invention relates to a method for producing a tricyclic ketone, which is characterized by obtaining a ketone of the formula.

The raw materials used in the method of this invention are cyclohexanone,
and 2-cyclohexylidenecyclohexanone, 2-(1'-cyclohexenyl)cyclohexanone, and 2-(1'-hydroxycyclohexyl)cyclohexanone, which are obtained as intermediates when producing tricyclic ketones by heating and condensing cyclohexanone. compound (hereinafter referred to as
It is called a bicyclic ketone).

Further, as a catalyst, an alkali metal hydroxide is used, and sodium hydroxide and potassium hydroxide are particularly preferred.

The amount of catalyst used is suitably in the range of 0.5 to 5% by weight based on the raw material, but there is no particular restriction. The catalyst may be used in solid form or in an aqueous solution. Examples of solvents that are azeotropic with water include benzene, toluene, and xylene. Addition of small amounts of these solvents can increase the dehydration rate and advantageously produce tricyclic ketones.

A suitable reaction temperature is 150 to 200°C.

If the temperature is below 1500C, the rate of conversion to tricyclic ketones such as cyclohexanone and bicyclic ketones becomes too slow, which is economically unsatisfactory.

Moreover, at temperatures above 200°C, the amount of high-boiling substances contained in the reaction product liquid increases and the reaction product liquid becomes viscous. This is not preferable because it causes problems in the preparation of tricyclic ketones and reduces the content of tricyclic ketones or compounds that can be converted into tricyclic ketones. The reason for this is not clear, but it is probably because a portion of the alkali metal hydroxide forms an enolate type compound with the high condensate. Further, the reaction pressure is normal pressure. In the method of the present invention, it is important to control the condensation reaction of cyclohexanone, bicyclic ketones, etc. to tricyclic ketones under such reaction conditions so that the dehydration rate is 90% or less. In other words, when the dehydration rate is 90% or less, the viscosity of the reaction product liquid obtained is relatively low because the amount of high-boiling substances produced is extremely small, and it can be easily filtered by ordinary filtration means without causing clogging. This is because alkali metal hydroxides can be separated. On the other hand, the dehydration rate was set to 90 (
If the temperature is higher than F6, a large amount of high-boiling substances will be produced, and the reaction product liquid will become viscous, making it difficult to easily separate the alkali metal hydroxide by ordinary sifting operations. In this specification, "dehydration rate" refers to cyclohexanone, 2
-cyclohexylidenecyclohexanone, 2-(1'-
cyclohexenyl)cyclohexanone and 2-(1'
It represents the ratio (percentage) of the amount of water produced by the actual condensation reaction to the amount of water (theoretical amount) produced when the total amount of cyclohexanone (-hydroxycyclohexyl) is converted into tricyclic ketone.

The dehydration rate can be controlled by charging raw materials, catalysts, etc. into a reactor equipped with a cooling pipe and a trap, and then heating and re-exchanging the condensation reaction. Since water accumulates, the amount of water is measured and the condensation reaction is stopped when the dehydration rate is 90% or less. The reaction product liquid obtained under such reaction conditions consists of cyclohexanone, bicyclic ketone, tricyclic ketone, and high boiling point substances.
Since the content of high-boiling substances is extremely small, the viscosity of the reaction product liquid is relatively low, and the alkali metal hydroxide can be separated and removed as a cake by ordinary filtration means. The oxide is recycled again as a catalyst for the condensation reaction.

On the other hand, the sap liquid does not contain any alkali metal hydroxides, and the desired product, tricyclic ketone, is generally obtained by distilling the sap liquid; The cyclohexanone and bicyclic ketone produced are recovered and reused as raw materials for the condensation reaction. This ▲over-operation is
In general, filler layers such as diatomaceous earth, asbestos, and charcoal, various fabrics such as fibers and glass fibers, unglazed boards,
It is preferable to use a porous material such as alundum, add a filter aid if necessary, and carry out under reduced pressure or increased pressure.

In addition, on a small scale, separation can be achieved by filtering under reduced pressure using a filter paper. According to the method of this invention,
When producing a tricyclic ketone by condensing cyclohexanone and a bicyclic ketone, it is possible to separate the alkali metal hydroxide by a normal sifting operation by keeping the dehydration rate below 9001). A reaction product liquid is obtained, from which a tricyclic ketone can be easily obtained.

Next, examples and comparative examples of the present invention will be shown. Example
Into a reactor (contents: 51) equipped with a stirrer, a thermometer, a nitrogen inlet/outlet, and a reflux condenser with a water draining hole, 2 kg of bicyclic ketone obtained as an intermediate product by condensing cyclohexanone, 2 k9 of cyclohexanone, and sex soda 4
09 and toluene 1009 were charged, stirred, and heated gently under nitrogen flow.

Separation of produced water was observed from around 150°C, and the librax depth gradually increased, and the condensation reaction continued for 6 hours to 190°C. When the dehydration rate reached 76%, the condensation reaction was stopped by cooling. .

Next, 1.11 l of toluene was added to this reaction product liquid, and it was filtered under reduced pressure (degree of vacuum: 50 mmHg absolute pressure) using a filter filled with diatomaceous earth 1009 and having a filter area of 314~. Furthermore, the ▲ layer was washed with a small amount of toluene. The time required for this filtration operation was 2 hours, and the filtrate did not contain any sodium hydroxide at all. Then, when this slurry was distilled, cyclohexanone 7wt%, bicyclic ketone 40%
Wt (: fl), 50 wt % of tricyclic ketone and 3 wt % of high boilers (each shows Wt % with respect to the total distillate amount) were obtained. Comparative Example Using the same reactor and reaction mixture as in Example 1, at 200'C
The condensation reaction was continued for 7 hours until the dehydration rate reached 94%.

An attempt was made to filtrate the reaction product liquid in the same manner as in Example 1, but filtration was impossible because a jelly-like substance had been deposited on the slough layer. Therefore, the slurry was filtered by thinning the slurry layer until it could be filtered, but since the slurry contained a large amount of sodium hydroxide, hydrochloric acid was added and left to stir overnight to neutralize it, and then washed with water. Distilled. The distillate in this case was 33 wt% of bicyclic ketone,
It was found that the tricyclic ketone was 40 wt% and the high-boiling point substance was 27 wt%, indicating that a large amount of high-boiling point substances were contained. Example 2 Into the same reactor as in Example 1, cyclohexanone 4k9, hydric soda 409 and toluene 100ml were charged, and a condensation reaction was carried out for 5.5 hours under the same reaction conditions as in Example 1.
The reaction was stopped when the dehydration rate reached 83 Cff).

Claims (1)

[Claims] 1 A compound selected from the group consisting of cyclohexanone, 2-cyclohexylidenecyclohexanone, 2-(1'-cyclohexenyl)cyclohexanone and 2-(1'-hydroxycyclohexyl)cyclohexanone,
While removing water in the presence of an alkali metal hydroxide and a solvent azeotropic with water, heat condensation is performed so that the dehydration rate is 90% or less, and the alkali metal hydroxide is separated by filtration, A method for producing a tricyclic ketone, which comprises obtaining the tricyclic ketone from a filtrate.