JP4086493B2 - (4-Oxocyclohexyl)-(4-hydroxyphenyl) alkanes - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to (4-oxocyclohexyl)-(4-hydroxyphenyl) alkanes, which are novel alicyclic monoketones, which are industrially useful raw materials.
[0002]
[Prior art]
Alicyclic monoketones such as (4-oxocyclohexyl)-(4-hydroxyphenyl) alkanes are used as intermediates for pharmaceutical raw materials, industrial chemical raw materials, polymerization initiators, heat resistance improvers, antioxidants, etc. It is also useful as a raw material for electronic materials such as liquid crystal compounds. For this reason, the performance required for these alicyclic monoketones is becoming increasingly diversified and sophisticated. For example, the solubility in a solvent is improved or reduced. Melting point (4-oxocyclohexyl)-(4-hydroxyphenyl) alkanes are desired. Conventionally, among these (4-oxocyclohexyl)-(4-hydroxyphenyl) alkanes, a production method for 2- (4-oxocyclohexyl) -2- (4-hydroxyphenyl) propane is known ( JP-A-11-158108).
However, as described above, as an alicyclic monoketone that is expected to have improved solubility in a solvent or a low melting point, it has the structure of the following general formula (I) and has an alkyl group at the quaternary carbon atom of the central alkane. There is no substituent or a methyl group is substituted (R ₁ ), and the other has a linear or branched alkyl group larger than the methyl group (R ₂ ), and (4-oxocyclohexyl)-( 4-Hydroxyphenyl) alkanes have not been known so far.
[0003]
[Chemical 1]
Formula (I)
(Wherein R ₁ represents hydrogen or a methyl group, R ₂ represents an alkyl group having 1 to 8 carbon atoms when R ₁ is hydrogen, and 2 carbon atoms when R ₁ is a methyl group. Represents an alkyl group of ˜8.)
[0004]
[Problems to be solved by the invention]
The present invention relates to alicyclic monoketones as described above, that is, there is no alkyl substituent on the carbon atom of the central alkane, or a methyl group is substituted and the other is a linear or branched alkyl group larger than the methyl group. It is an object to provide (4-oxocyclohexyl)-(4-hydroxyphenyl) alkanes, which are alicyclic monoketones having an asymmetric alkane structure having the following.
[0005]
[Means for Solving the Problems]
According to the present invention, (4-oxocyclohexyl)-(4-hydroxyphenyl) alkanes which are alicyclic monoketones represented by the general formula (I) are provided.
[0006]
[Chemical 1]
Formula (I)
Wherein R ₁ represents hydrogen or a methyl group, R ₂ represents an alkyl group having 1 to 8 carbon atoms when R ₁ is hydrogen, and 2 carbon atoms when R ₁ is a methyl group. Represents an alkyl group of ˜8.)
[0007]
In the general formula (I), R ₁ is hydrogen or a methyl group, R ₂ is an alkyl group having 1 to 8 carbon atoms when R ₁ is hydrogen, and R ₁ is a methyl group. An alkyl group having 2 to 8 carbon atoms is represented. The alkyl group is a linear straight-chain or branched aliphatic saturated alkyl group, and specific examples of R ₂ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl, an isobutyl group, an s -Butyl group or t-butyl group, straight-chain to branched pentyl group, hexyl group, heptyl group, octyl group and the like.
[0008]
Therefore, preferred specific examples of (4-oxocyclohexyl)-(4-hydroxyphenyl) alkanes that can be provided in the present invention include, for example, 1- (4-oxocyclohexyl) -1- (4-hydroxyphenyl) ethane, 1- (4-oxocyclohexyl) -1- (4-hydroxyphenyl) propane, 1- (4-oxocyclohexyl) -1- (4-hydroxyphenyl) butane, 1- (4-oxocyclohexyl) -1- ( 4-hydroxyphenyl) -2-methyl-propane, 1- (4-oxocyclohexyl) -1- (4-hydroxyphenyl) pentane, 1- (4-oxocyclohexyl) -1- (4-hydroxyphenyl) -3 -Methylbutane, 1- (4-oxocyclohexyl) -1- (4-hydroxyphenyl) -2-ethylpropane, 1- (4-oxocyclohexyl) -1- (4-hydroxyphenyl) hexane, 1- (4- Oxocyclohexyl) -1- (4-hydroxyphenyl) heptane, 1- (4-oxocyclyl) Rohexyl) -1- (4-hydroxyphenyl) octane, 2- (4-oxocyclohexyl) -2- (4-hydroxyphenyl) butane, 2- (4-oxocyclohexyl) -2- (4-hydroxyphenyl) pentane 2- (4-oxocyclohexyl) -2- (4-hydroxyphenyl) -3-methylbutane, 2- (4-oxocyclohexyl) -2- (4-hydroxyphenyl) hexane, 2- (4-oxocyclohexyl) -2- (4-hydroxyphenyl) -3-ethylbutane, 2- (4-oxocyclohexyl) -2- (4-hydroxyphenyl) heptane, 2- (4-oxocyclohexyl) -2- (4-hydroxyphenyl) Examples include octane and 2- (4-oxocyclohexyl) -2- (4-hydroxyphenyl) nonane.
[0009]
Such (4-oxocyclohexyl)-(4-hydroxyphenyl) alkanes include, for example, bis (4-hydroxyphenyl) alkanes represented by the following general formula (II) in a solvent in the presence of a palladium catalyst. Can be produced by selective hydrogenation.
[0010]
[Chemical 2]
Formula (II)
[0011]
In bis (4-hydroxyphenyl) alkanes represented by the general formula (II), R ₁ and R ₂ are the same as R ₁ and R ₂ in the general formula (I).
Accordingly, specific examples of such bis (4-hydroxyphenyl) alkanes include, for example, 1,1-bis (4-hydroxyphenyl) -ethane, 1,1-bis (4-hydroxyphenyl) -propane, 1 , 1-bis (4-hydroxyphenyl) -butane, 1,1-bis (4-hydroxyphenyl) -2-methylpropane, 1,1-bis (4-hydroxyphenyl) -pentane, 1,1-bis ( 4-hydroxyphenyl) -hexane, 1,1-bis (4-hydroxyphenyl) -heptane, 1,1-bis (4-hydroxyphenyl) -octane, 2,2-bis (4-hydroxyphenyl) -butane, 2,2-bis (4-hydroxyphenyl) -pentane, 2,2-bis (4-hydroxyphenyl) -hexane, 2,2-bis (4-hydroxyphenyl) -heptane, 2,2-bis (4- Hydroxyphenyl) -octane, 2,2-bis (4-hydroxyphenyl) -nonane and the like.
[0012]
The palladium catalyst used in the present invention is not particularly limited, but from the viewpoint of the selectivity of the reaction, an alkali metal-containing palladium formed by supporting a palladium component as a cocatalyst component together with an alkali metal as a promoter. A combination of a palladium catalyst obtained by supporting a catalyst or a palladium component on a carrier and an alkali metal compound as a co-catalyst is preferable. Specific examples of the alkali metal-containing palladium catalyst include, for example, one in which about 0.5 to 5% by weight sodium and about 1 to 10% by weight palladium component are supported on a carrier. Specific examples of the combination include, for example, a combination of a palladium catalyst obtained by supporting about 1 to 10% by weight of a palladium component on a carrier and sodium carbonate.
[0013]
For example, carbon, alumina, titanium oxide, activated clay, or the like is used as the carrier, and carbon is particularly preferably used. In addition to palladium metal, palladium oxide and hydroxide are also used as the palladium component, but palladium metal is preferably used.
Further, in the alkali metal-containing palladium catalyst, lithium or potassium is used as the alkali metal in addition to sodium. In addition to sodium carbonate, sodium hydroxide, potassium hydroxide, potassium carbonate, lithium carbonate, lithium hydroxide and the like are used as the alkali metal compound for the promoter. The alkali metal-containing palladium catalyst can be easily obtained as a commercial product, but it is supported by carrying a metal palladium and an alkali metal salt on a carrier such as carbon and drying it, followed by firing at a temperature of 400 to 600 ° C. Prepare. Such an alkali metal-containing palladium catalyst is usually used as a water-containing product of about 50 wt%.
[0014]
The palladium catalyst used in the present invention is not particularly limited in its form, and an appropriate form such as powder or tablet is used. Further, the palladium catalyst is usually used in a range of 0.5 to 10 parts by weight, preferably 1.0 to 5.0 parts by weight with respect to 100 parts by weight of the bis (4-hydroxyphenyl) alkane as a raw material. The cocatalyst is usually used in an amount of 0.01 to 1.0 part by weight, preferably 0.05 to 0.5 part by weight, based on 100 parts by weight of the bis (4-hydroxyphenyl) alkane as a raw material.
[0015]
When reducing bis (4-hydroxyphenyl) alkanes in a solvent in the presence of such a palladium catalyst, the system is replaced with an inert gas such as nitrogen gas or argon gas, followed by hydrogen replacement. It is desirable to do so.
[0016]
In the present invention, the hydrogenation reaction of bis (4-hydroxyphenyl) alkanes is usually performed at a temperature of 80 to 180 ° C., preferably 100 to 160 ° C., and a hydrogen of 0.1 to 1.5 MPa, preferably 0.2 to 1.0 MPa. Performed under pressure. Preferably, the system is replenished with hydrogen and the reaction is carried out while keeping the hydrogen pressure in the system constant, and the reaction is terminated when the absorption of hydrogen in the system becomes 0.8 to 1.2 mol times the theoretical hydrogen amount. do it. The reaction time is usually in the range of 2 to 10 hours, preferably 4 to 6 hours.
[0017]
As the solvent, alcohols, esters, hydrocarbons, ethers and the like are used. Preferably, esters such as ethyl acetate and butyl acetate, isopropyl alcohol, s-butyl alcohol, isoamyl alcohol, capryl alcohol, cyclohexyl alcohol, By using aliphatic saturated alcohols having 3 to 12 carbon atoms such as cyclopentyl alcohol, the reaction can be carried out with high selectivity, and the starting materials and the target product are easily dissolved in the organic solvent. Convenient for operation.
These organic solvents are used alone or in combination of two or more.
[0018]
Such an organic solvent usually depends on the bis (4-hydroxyphenyl) alkane used and the type of solvent, but is usually 50 to 500 parts by weight per 100 parts by weight of the bis (4-hydroxyphenyl) alkane. Preferably it is used in the range of 100 to 300 weight.
[0019]
Here, the selectivity and yield of the target (4-oxocyclohexyl)-(4-hydroxyphenyl) alkanes by reduction of the bis (4-hydroxyphenyl) alkanes described above are as follows. -Hydroxyphenyl) alkane charge (mole), B is the amount of raw material consumed by the reaction (mole), C is the desired product (4-oxocyclohexyl)-(4-hydroxyphenyl) alkanes produced ( Mol) is obtained from the following equation.
Raw material conversion (%) = (B / A) x 100
Target selection rate (%) = (C / B) x 100
Target product yield (%) = (C / A) × 100
[0020]
After completion of the reaction, the catalyst is separated and removed from the resulting reaction mixture by filtration, followed by crystallization, filtration and drying to obtain the desired (4-oxocyclohexyl) -4-hydroxyphenyl) alkane. be able to. Preferably, for example, after performing the reaction using a reaction solvent such as 2-butanol, an appropriate crystallizing solvent is added to the obtained reaction mixture, and the catalyst is separated and removed by filtration, and then cooled. Or, if necessary, remove the reaction solvent by distillation, concentrate the reaction mixture, cool, and then crystallize to obtain a high-purity product of interest immediately. Can do.
[0021]
EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.
The purity is an area percentage value determined by gas chromatography.
[0022]
[Example 1]
Preparation of 1- (4-oxocyclohexyl) -1- (4-hydroxyphenyl) propane; 100 g (0.439 mol) of 1,1-bis (4-hydroxyphenyl) propane, 150 g of ethyl acetate, about 1.5% by weight of sodium and palladium 3g of palladium-carbon catalyst (5% by weight of dry catalyst equivalent of water-containing catalyst) supported on carbon powder was placed in a 1L glass autoclave, the system was heated to 70 ° C, and the internal pressure was released. The pressure (gauge pressure) was set to 0 MPa.
Next, the autoclave is sealed and the internal temperature is raised to 140 ° C., then hydrogen is introduced into the autoclave up to 0.5 MPa, and then the system is appropriately replenished with hydrogen so as to keep the hydrogen pressure at this pressure. When 1,1-bis (4-hydroxyphenyl) propane is hydrogenated, the amount of hydrogen absorbed in the system becomes 1.1 times the theoretical amount of hydrogen absorbed (2 times the amount of the raw material) The reaction was completed at 5 hours after the start of. As a result, the conversion rate of raw materials was 94.2%, and the selectivity for the target product was 92.2%.
[0023]
After completion of the reaction, the temperature in the system was lowered to 70 ° C., purged with nitrogen gas, and the catalyst was filtered off at 65 ° C. The filtrate was concentrated by heating to distill off 25 g of ethyl acetate, and then the concentrate was cooled to room temperature. The precipitated crystals were collected by filtration and dried to give 1- (4-oxocyclohexyl) -1- (4 Hydroxyphenyl) propane (58.0 g) was obtained as white crystals (purity 99.2%, yield 56.5% based on raw material).
Melting point: 122 ° C (JIS light transmission method)
Molecular weight: 232 (M ⁺ ) (mass spectrometry)
Infrared absorption spectrum (cm ^-1 ): 3232, 1694, 1515, 1270, 1225
Proton nuclear magnetic resonance spectrum (CDCl ₃ solvent, 400MH _Z)
As shown in FIG.
[0024]
[Example 2]
Production of 2- (4-oxocyclohexyl) -2- (4-hydroxyphenyl) -butane;
100 g (0.413 mol) of 2,2-bis (4-hydroxyphenyl) butane was used as a raw material, and the solvent was changed from ethyl acetate to 2-butanol, and 5% by weight of palladium was supported on carbon powder as a hydrogenation catalyst. The reaction was carried out for 2.5 hours in the same manner as in Example 1 except that 3 g of a palladium / carbon catalyst (a dry catalyst equivalent amount of a water-containing catalyst) and 0.1 g of sodium carbonate were used as a cocatalyst and the reaction pressure was 0.4 MPa.
As a result, the conversion rate of the raw materials was 95.5%, and the selectivity for the target product was 94.9%.
After completion of the reaction, the temperature in the system was lowered to 90 ° C., and after replacing with nitrogen gas, the catalyst was filtered off at 80 ° C. The filtrate was heated and concentrated to distill off 75 g of 2-butanol, and then the concentrate was cooled to room temperature. The precipitated crystals were collected by filtration and dried to give 2- (4-oxocyclohexyl) -2- ( 4-hydroxyphenyl) butane (57.9 g) was obtained as white crystals (purity 98.8%, yield 56.3% based on raw material).
Melting point: 146 ℃ (JIS light transmission method)
Molecular weight: 246 (M ⁺ ) (mass spectrometry)
Infrared absorption spectrum (cm ^-1 ): 3244, 1694, 1517, 1274, 1235
Proton nuclear magnetic resonance spectrum (CDCl ₃ solvent, 400 MHz):
As shown in FIG.
[0025]
[Example 3]
Production of 2- (4-oxocyclohexyl) -2- (4-hydroxyphenyl) -4-methylpentane;
Example 2 except that 100 g (0.370 mol) of 2,2-bis (4-hydroxyphenyl) -4-methylpentane was used as a raw material, the solvent was changed from ethyl acetate to 2-butanol, and the reaction pressure was 0.4 MPa. The reaction was carried out for 2.5 hours in the same manner as in 1.
As a result, the conversion rate of the raw materials was 93.9%, and the selectivity for the target product was 96.0%.
After completion of the reaction, the temperature in the system was lowered to 90 ° C., and after replacing with nitrogen gas, the catalyst was filtered off at 80 ° C. The obtained filtrate was evaporated to dryness, and 100 gr of toluene was added thereto and dissolved by heating. The solution was cooled to room temperature, crystallized, the crystals were filtered off and dried, and 52.1 gr of the desired product, 2- (4-oxocyclohexyl) -2- (4-hydroxyphenyl) -4-methylpentane, was white. Obtained as crystals. (Purity 98.5%, yield 50.6 mol% based on raw material).
Melting point: 106 ° C (JIS light transmission method)
Molecular weight: 274 (M ⁺ ) (mass spectrometry)
Infrared absorption spectrum (cm ^-1 ): 3336, 1699, 1514, 1211
Proton nuclear magnetic resonance spectrum (CDCl ₃ solvent, 400 MHz):
As shown in FIG.
[0026]
[Example 4]
Production of 2- (4-oxocyclohexyl) -2- (4-hydroxyphenyl) -octane; 100 g (0.336 mol) of 2,2-bis (4-hydroxyphenyl) octane was used as a raw material, and the solvent was extracted from ethyl acetate. The reaction was carried out for 4.5 hours in the same manner as in Example 1 except that the reaction pressure was changed to 0.4 MPa instead of -butanol.
As a result, the conversion rate of the raw materials was 98.5%, and the selectivity for the target product was 86.3%.
[0027]
After completion of the reaction, the temperature in the system was lowered to 90 ° C., and after replacing with nitrogen gas, the catalyst was filtered off at 80 ° C. A part of the filtrate was evaporated to dryness, dissolved in a methanol solvent, and 2- (4-oxocyclohexyl) -2- (4-hydroxyphenyl) octane, the target product, was obtained using preparative liquid chromatography. Isolated as a clear solid (purity 96.5%).
Molecular weight: 302 (M ⁺ ) (mass spectrometry)
Infrared absorption spectrum (cm ^-1 ): 3361, 1699, 1514, 1224
Proton nuclear magnetic resonance spectrum (CDCl ₃ solvent, 400 MHz):
As shown in FIG.
[0028]
[Example 5]
Preparation of 1- (4-oxocyclohexyl) -1- (hydroxyphenyl) ethane;
100 g (0.467 mol) of 1,1-bis (4-hydroxyphenyl) ethane was used as a raw material, the solvent was changed from ethyl acetate to butyl acetate, the autoclave internal temperature was 125 ° C., the introduced hydrogen pressure was 0.2 MPa, The reaction was performed in the same manner as in Example 1 except that the reaction was terminated when the hydrogen absorption amount reached the theoretical hydrogen absorption amount (2 times the molar amount of the raw material).
As a result, the conversion rate of the raw material was 87.5%, and the selectivity for the target product was 85.2%. After completion of the reaction, the temperature in the system was lowered to 70 ° C., and the atmosphere was replaced with nitrogen gas. Then, the catalyst was filtered off at 60 ° C. The filtrate was heated and concentrated to distill off 65 g of butyl acetate, and then the concentrate was cooled to room temperature. The precipitated crystals were collected by filtration, dried and 1- (4-oxocyclohexyl) -1- (hydroxy 49.5 g of phenyl) ethane were obtained as white crystals. (Purity 96.0%, yield 46.7% based on raw material)
Melting point: 94 ° C (JIS light transmission method)
Molecular weight: 218 (M ⁺ ) (mass spectrometry)
Infrared absorption spectrum (cm ^-1 ): 3204, 1696, 1516, 1272, 1227
Proton nuclear magnetic resonance spectrum (CDCl ₃ solvent, 400 MHz)
As shown in FIG.
[0029]
【The invention's effect】
In the present invention, the quaternary carbon atom of the central alkane has no alkyl substituent or is substituted with a methyl group (R ₁ ) and has an alkyl group on the other side (R ₂ ), and has an asymmetric alkane structure. (4-Oxocyclohexyl)-(4-hydroxyphenyl) alkanes can be newly provided. The resulting compound is a low-melting-point compound with improved solubility in a solvent, as an intermediate for pharmaceutical raw materials, industrial chemical raw materials, polymerization initiators, heat resistance improvers, antioxidants, etc. It is useful as a raw material for electronic materials such as compounds.
[Brief description of the drawings]
1 is a nuclear magnetic resonance spectrum of the compound of Example 1. FIG. 2 is a nuclear magnetic resonance spectrum of the compound of Example 2. FIG. 3 is a nuclear magnetic resonance spectrum of the compound of Example 3. Nuclear magnetic resonance spectrum of the compound [FIG. 5] Nuclear magnetic resonance spectrum of the compound of Example 5

Claims (6)

(4-Oxocyclohexyl)-(4-hydroxyphenyl) alkanes represented by the general formula (I):
Formula (I)
(Wherein R ₁ represents hydrogen or a methyl group, R ₂ represents an alkyl group having 1 to 8 carbon atoms when R ₁ is hydrogen, and 2 to 2 carbon atoms when R ₁ is a methyl group. 8 represents an alkyl group.) 1 -( 4 - Oxocyclohexyl )- 1 -( Hydroxyphenyl ) Ethane. 1- (4- Oxocyclohexyl ) -1- (4- Hydroxyphenyl ) propane. 2- (4- Oxocyclohexyl ) -2- (4- Hydroxyphenyl )- butane. 2- (4- Oxocyclohexyl ) -2- (4- Hydroxyphenyl )-Four- Methyl pentane. 2- (4- Oxocyclohexyl ) -2- (4- Hydroxyphenyl )- Octane.