JPH0466217B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention is a novel method for economically producing α-(p-isobutylphenyl)propionaldehyde, which is a complete precursor of α-(p-isobutylphenyl)propionic acid, with high purity. It concerns a method. α-(p-isobutylphenyl)propionic acid, which is easily derived from α-(p-isobutylphenyl)propionaldehyde, which is the object of the present invention, is disclosed in British Patent No. 971,700 and French Patent No.
No. 1549758, Special Publication No. 7178 and Special Publication No. 1977-
No. 7491, it is known as a beneficial compound with anti-inflammatory, analgesic and antipyretic properties. [Prior art and problems to be solved by the invention] α-(p-isobutylphenyl)propionic acid (IPA) or α-(p-isobutylphenyl)
Propionaldehyde (IPN) has conventionally been synthesized by various methods using a large number of starting materials. However, in order to synthesize IPA or IPN at low cost and economically, it is necessary to (a) use simple compounds as starting materials, and (b) use reactions that use as simple and stable compounds as possible as reaction intermediates. (c) use a reaction that does not cause isomerization of raw materials during the reaction; and (d) use inexpensive reagents or catalysts. However, for example, the method for manufacturing IPN,
-100042 starts from the Grignard compound of isobutylbenzene, but in addition to using a Grignard reagent, which is unstable and difficult to handle, it also uses a Lewis acid such as BF ₃ , so the isobutyl group is isomeric. easy to become Also, Tokukai Akira
No. 53-82740 uses compounds that are difficult to handle, such as metallic lithium. In addition, Japanese Patent Application Publication No. 49/1973 discloses a method for producing IPA.
No. 13351 and No. 50-4040 both use isobutylbenzene as a starting material, but since aluminum chloride is used as a catalyst, the isobutyl group is easily isomerized, and expensive reagents are used. Furthermore, French Patent No. 1549758, Special Publication No. 47
-24550, JP-A-49-95938, JP-A-52-
No. 57338, JP-A-52-97930, JP-A-52-131553
The methods described in JP-A-53-7643, JP-A-53-18535 and JP-A-56-154428 are
This method uses isobutylacetophenone as a starting material. However, p-isobutylacetophenone cannot be said to be an inexpensive compound as described below. It is most economical to synthesize this from isobutylbenzene, but converting isobutylbenzene to p-isobutylacetophenone itself is not preferable from an economic standpoint. In other words, in order to convert to p-isobutylacetophenone, acetyl chloride, which is an expensive and unstable raw material, must be used, and anhydrous aluminum chloride, which is extremely sensitive to moisture, must be used as a reaction catalyst. It must be used in a large amount, at least as many moles as acetyl chloride. For example, even if we consider that this conversion reaction had a stoichiometric yield of 100%, p
- To produce one ton of isobutylacetophenone, it is necessary to use a large amount of anhydrous aluminum chloride, 700 kg. Also, after the reaction is complete,
410Kg of aluminum hydroxide and 750Kg of chlorine ions are generated as a result of deactivating anhydrous aluminum chloride.
Therefore, it is necessary to process 1,160 kg of waste into a harmless form, which is far more than the amount of p-isobutylbenzene that was produced. Therefore, it goes without saying that p-isobutylacetophenone itself as a starting material is expensive. Furthermore, from p-isobutylacetophenone to α-(p-isobutylphenyl)
Conversion to propionaldehyde is also not necessarily an economical method from an industrial standpoint, as it involves complex intermediate products. [Means for solving the problems] The present invention comprises the following steps (), () and ().
The present invention relates to a method for producing α-(p-isobutylphenyl)propionaldehyde, characterized by comprising: That is, () a step of reacting isobutylbenzene and acetaldehyde in the presence of a sulfuric acid catalyst to produce 1,1-bis(p-isobutylphenyl)ethane; () a step of producing the above with a protonic acid and/or a solid acid catalyst; A step of producing isobutylbenzene and p-isobutylstyrene by catalytically decomposing 1,1-bis(p-isobutylphenyl)ethane at a temperature of 200 to 650°C, and () the above p-isobutylstyrene, hydrogen and This process consists of producing α-(p-isobutylphenyl)propionaldehyde by reacting carbon monoxide with carbon monoxide at a temperature of 40 to 150°C in the presence of a transition metal carbonylation catalyst. The method of the present invention is expressed as a reaction formula as follows. That is, according to the method of the present invention, common raw materials such as IBB, acetaldehyde, carbon monoxide, and hydrogen, which are commercially available at low cost, can be used, and in just three steps, the basic starting material IBB can be converted to the desired product. IPN, which is a product, can be easily obtained. Isobutylbenzene (IBB), which is the starting material of the present invention, includes JP-A-59-36627 and JP-A-57-
IBB produced by any known method such as the production method disclosed in British Patent No. 46927, and the production method from toluene and propylene with an alkali metal catalyst described in British Patent No. 857894 and British Patent No. 1269280. It is also used. The implementation method for each reaction will be specifically explained below. In step (), which is the first reaction in the method of the present invention, IBB and acetaldehyde are reacted in the presence of a sulfuric acid catalyst. ) with the aim of obtaining ethane (BBE). In step (), it is essential to use a method that can obtain BBE with good yield and with good p-position selectivity without isomerizing the isobutyl group in IBB. For example, a method using acetylene with sulfuric acid or sulfuric acid and mercury as a catalyst, a method using 1,1-dichloroethane or vinyl chloride with a metal halide as a catalyst, and a method using phosphoric acid or a complex of phosphoric acid and a metal halide as a catalyst. Methods such as those using acetaldehyde have extremely low BBE yields and are not practical. Also, the isomerization of the isobutyl group and the product diarylethane is the objective
In addition to BBE, methods containing a large amount of substituents at the m-position are not preferred methods. In step (), the sulfuric acid concentration during the reaction is maintained at 75% by weight or more (based on the sum of sulfuric acid and water), preferably 80-95% by weight. If the sulfuric acid concentration in the reaction solution is higher than 95% by weight, not only will the production of polymers increase, but side reactions such as sulfonation of the aromatic nucleus of IBB will occur, and the objective will not be effectively achieved. In addition, the sulfuric acid concentration in the reaction solution was 75% by weight.
If the reaction is not effectively achieved,
The concentration of aldehyde in the liquid increases, resulting in the formation of a polymer or the intermediate 1 (p-isobutylphenyl).
This is undesirable because a large amount of ethanol is produced. Since this reaction is a dehydration reaction, water is produced as the reaction progresses, and the sulfuric acid concentration of the sulfuric acid water in the reaction solution decreases as the reaction progresses, inhibiting the reaction. It is necessary to maintain it at a certain level. For this purpose, it is also a preferable method to continuously add concentrated sulfuric acid or the like during the reaction. In order to maintain the sulfuric acid concentration, in addition to concentrated sulfuric acid, it is preferable to add oleum, sulfuric anhydride, and other substances with a sulfuric acid concentration exceeding 90% by weight. Furthermore, if the concentration of the sulfuric acid added is less than 90% by weight, the amount of sulfuric acid used will be large, which is not economical. The amount of sulfuric acid used in step () is 1 to 10 times the molar amount of acetaldehyde normally used, and more preferably 2 to 8 times the molar amount. If the amount of sulfuric acid is too small than this range, the reaction will not be effectively achieved and a large amount of polymer will be produced, which is not preferable. On the other hand, it is not economical if the amount of sulfuric acid exceeds this range. Further, the sulfuric acid used in step () can be adjusted to a predetermined concentration after use and used again. In step (), the acetaldehyde may be paraaldehyde, hydrous acetaldehyde, or the like. In step (), more preferable results can be obtained if the concentration of acetaldehyde in the reaction system is maintained at 1% by weight or less. If the concentration of acetaldehyde is greater than 1% by weight, the amount of intermediate 1-(p-isobutylphenyl)ethanol produced increases. Moreover, not only side reactions such as polymerization reactions increase, but also the purity of the sulfuric acid used decreases, making recovery and reuse difficult, which is not preferable. The IBB used in step () can be either pure or diluted with an inert solvent such as an aliphatic hydrocarbon such as hexane or pentane. IBB is usually added in excess of acetaldehyde, and the amount added is at least 2 times the mole of acetaldehyde, more preferably at least 2.2 times the mole of acetaldehyde. If IBB is too small than this range, the reaction will not be effectively achieved and a polymer will form.
The higher the amount of IBB used, the better the results.
Since the amount to be processed increases accordingly, the upper limit for usage should be determined from an economic standpoint.
Therefore, it is usually practical to use 100 times the molar amount, more preferably 20 times the molar amount. In step (), the reaction temperature is increased while stirring.
It is necessary to maintain the temperature at 40°C or lower, preferably between -20 and 20°C. If the temperature exceeds 40°C, side reactions such as polymerization reactions and IBB sulfonation reactions will rapidly increase, which is not preferable. For this reason, it is desirable to cool the reactor externally or internally. A preferred reaction format in step () is to charge one reactant, IBB, and sulfuric acid at a predetermined concentration into a reactor, and simultaneously add and react a predetermined amount of acetaldehyde or its IBB solution little by little over two hours or more. , the sulfuric acid concentration of the sulfuric acid water in the reaction system is maintained by adding sulfuric acid at a higher concentration than the sulfuric acid water in the reaction solution. If the addition time of acetaldehyde or its IBB solution is shorter than 2 hours, the concentration of acetaldehyde in the reaction solution increases and the amount of polymerized product increases. Since the reaction of the present invention has a relatively high reaction rate, a long reaction time is not necessarily required. Preferably 3
~10 hours. The reaction pressure is not particularly limited, but it is preferably carried out at normal pressure or autogenous pressure at the reaction temperature of a closed reactor. After the reaction is completed, stirring is stopped, and the reaction mixture is allowed to stand still in the reactor or transferred to a standing tank.
The lower layer is a sulfuric acid layer that dissolves most of the sulfonated products such as IBB produced in the side reaction sulfonation reaction, but this layer can be recovered, adjusted to a predetermined concentration, and reused. The upper hydrocarbon layer contains most of the BBE, unreacted IBB, and by-product hydrocarbons. Separate this upper layer and remove the remaining sulfuric acid.
Neutralize with an alkali such as NaOH, KOH, Ca(OH) ₂ , Na ₂ CO ₃ or an aqueous solution thereof, and wash with water. At this time, a solvent such as ether or n-hexane may be added for the purpose of preventing the formation of emulsion due to sulfonated substances or the like. IBB and BBE are obtained by distilling the hydrocarbon layer after neutralization, preferably under reduced pressure. In the method of the present invention, isomerization of IBB as an unreacted product does not occur at all, so IBB obtained by distillation
can be recycled and reused without special purification. In addition, the obtained BBE has a highly selective p
Since it is a -substituted product and is symmetrical, it is preferable as a raw material for the next decomposition reaction, step (). The second step () of the present invention is to catalytically decompose the BBE obtained in step () in the presence of a protonic acid, a solid acid, or a protonic acid-supported solid acid catalyst to produce p-isobutylstyrene (PBS). and,
This is a step of producing IBB, which is the starting material for the step (). The catalytic cracking temperature can be selected within the range of 200 to 650°C depending on the type of catalyst and the reaction format, such as gas phase or liquid phase. Catalysts for catalytic cracking are preferably inorganic protonic acids such as phosphoric acid, sulfuric acid, hydrochloric acid, and heteropolyacids such as tungstic silicoic acid, and organic protonic acids such as p-toluenesulfonic acid, as well as silica, alumina, silica/alumina, silica magnesia,
Synthetic silica/alumina catalysts such as synthetic zeolite, solid acids such as clay-based silica/alumina produced from natural clay minerals such as kaolin, attapulgiaite, acid clay, and Fuller's earth, or the protonic acids mentioned above, are added to these solid acids. Supported solid acids are also preferably used. On the other hand, with so-called Lewis acid catalysts, which are aprotic acids represented by metal halides such as silicon fluoride, aluminum chloride, iron chloride, iron bromide, and zinc chloride, isobutyl groups are removed during catalytic cracking. It is not preferable because it isomerizes to sec-butyl groups and promotes the polymerization of PBS once formed. The reaction phase can be catalytically cracked in either a liquid phase or a gas phase, but preferably a method in which the reaction phase is decomposed in a liquid phase using a protonic acid catalyst, and a solid acid or the above-mentioned protonic acid supported solid acid catalyst is used. A method of catalytic cracking in the gas phase can be adopted. In particular, considering equipment corrosion, continuity, etc., gas phase catalytic cracking using a solid acid catalyst is preferred. For catalytic cracking in the liquid phase using a protonic acid catalyst, the reaction temperature is preferably 200 to 350°C, and 250 to 325°C.
C is particularly preferred. If the reaction temperature is too high above this range, side reactions will increase and selectivity will deteriorate. Furthermore, if the reaction temperature is too low than this range, the reaction rate will be low and economical efficiency will be poor, which is not preferable. In the liquid phase decomposition of step (), the protonic acid used is suitably 0.001 to 100 times mole, preferably 0.005 to 10 times mole, relative to BBE. If the amount of protonic acid used is less than this range, the BBE conversion rate will be too low. Further, if the amount of protonic acid used is larger than this range, there is no particular disadvantage in terms of the reaction, but it is not preferable because it becomes uneconomical. The acid used in this case is an inorganic acid such as phosphoric acid, sulfuric acid, or a heteropolyacid, or a protonic acid such as an organic sulfonic acid such as p-toluenesulfonic acid, and among these, phosphoric acid is particularly preferred. Examples of phosphoric acid include orthophosphoric acid, pyrophosphoric acid, polyphosphoric acid, and metaphosphoric acid, but any phosphoric acid can be used. The acid used in the present invention may be a commercially available product as it is, or may be used in the form of an aqueous solution. The reaction pressure is not particularly limited as long as the PBS and IBB produced under the reaction conditions can be vaporized, but normal pressure to reduced pressure is usually preferred. The contact time of the raw material BBE and the catalyst in the present invention can be selected as appropriate, but is 0.001 to 1000 hr.g.cat/g.
is preferable, and particularly preferably 0.01 to 100 hr.g.cat/g. On the other hand, the reaction pressure in the process of gas-phase catalytic cracking using a solid acid and a supported solid acid is as long as the reaction gas remains in the gas phase under the temperature conditions.
The pressure may be normal pressure, high pressure, or reduced pressure. Furthermore, the objects of the present invention can be achieved by using any of a solid bed, moving bed, and fluidized bed as the reaction phase. Furthermore, regarding the solid acid applicable to the present invention, it is better if it has a certain amount of surface area.
For example, the surface area is 250 m ² /g or more, preferably 350 m 2 /g or more.
~1000m ² /g is sufficient. Smaller surface areas may result in a somewhat lower conversion rate than larger surface areas. The contact time of the reaction gas with the solid acid is usually 0.05~
Although 5 seconds is appropriate, it can be further changed as desired depending on various combinations such as the reaction gas composition, the type of solid acid, the reaction temperature, or the preheating temperature of the reaction gas. The decomposition reaction temperature is preferably 300°C to 650°C, and 350°C to 650°C.
C to 500 C is particularly preferred. If the reaction temperature is too high above this range, side reactions will increase and selectivity will deteriorate. Moreover, if the reaction temperature is too low than this range, the decomposition rate will be low and economical efficiency will be poor, which is not preferable. In addition, in either liquid phase decomposition or gas phase decomposition, it is possible to dilute with an inert gas for the purpose of quickly distilling the generated PBS or for the purpose of preventing deterioration of the catalyst. These inert gases include hydrogen, nitrogen, helium, methane, and mixed gases thereof, as well as water vapor. In particular, in the case of gas phase decomposition, the production of p-isobutylethylbenzene (PBE), a byproduct, is suppressed,
Furthermore, in order to improve the yield of PBS, it is preferable to carry out the reaction in the presence of water vapor. water vapor is
It is 2 times or more by weight, preferably 4 times or more by weight relative to BBE. There is no particular upper limit to the amount of water vapor that can coexist, but from an economic point of view it is usually BBE.
It is preferable not to exceed 100 times the amount by weight. Used in a process () that is a catalytic cracking reaction
BBE is a symmetric diaryl alkane. Therefore, what is produced in step () is mainly IBB, which is the starting material for step (), that is, the starting material of the present invention, PBS, which is the starting material for the next step (), and, depending on the type of catalyst, , a small amount of side reaction products include hydrocarbons saturated with vinyl groups in PBS, such as p-isobutylethylbenzene. Therefore, not only the generated IBB but also stable PBS can be recovered with sufficiently high purity by simple purification such as simple distillation. Therefore it was collected
IBB is returned to the step () and used as a starting material again. Further, PBS can be used as a raw material for the next carbonylation step [step ()]. This is important from an economic point of view, that is, to make the method of the invention inexpensive and economical. The third step of the reaction of the present invention is step (), in which the PBS obtained in step () is carbonylated,
This process produces α-(p-isobutylphenyl)propionaldehyde (IPN). This method can be carried out in accordance with a known carbonylation method in which an olefinically unsaturated compound is reacted with hydrogen and carbon monoxide in the presence of a carbonylation complex catalyst. The carbonylation complex catalyst used is
There are complexes of noble metals such as Rh, Ir, Pt, and Ru. As noble metals, acid numbers ranging from 0 to the highest acid number can be used, including halogen group atoms, trivalent phosphorus compounds, π-
Those containing an allyl group, amine, nitrile, oxime, olefin, or carbon monoxide as a ligand are effective. Specific examples include bistriphenylphosphine dichloro complex, bistributylphosphine dichloro complex, bistricyclohexylphosphine dichloro complex, π-allyltriphenylphosphine chloro complex, triphenylphosphine piperidine dichloro complex, bisbenzonitrile dichloro complex, biscyclohexyloxime dichloro complex,
1,5,9-cyclododecatriene-dichloro complex, bistriphenylphosphine dicarbonyl complex, bistriphenylphosphine acetate complex, bistriphenylphosphine dinitrate complex, bistriphenylphosphine sulfate complex, tetrakistriphenyl Examples include phosphine complexes and chlorocarbonylbistriphenylphosphine complexes, hydridocarbonyltristriphenylphosphine complexes, bischlorotetracarbonyl complexes, dicarbonylacetylacetonate complexes, etc. that have carbon monoxide as part of the ligand. be able to. Moreover, a compound capable of forming the above-mentioned complex can be used in the reaction system. That is, a compound that can serve as a ligand for the above noble metal oxide, sulfate, chloride, etc., such as phosphine, nitrile, allyl compound, amine, oxime, olefin, or carbon monoxide, is simultaneously present in the reaction system. It's a method. Phosphines include, for example, triphenylphosphine, tritolylphosphine, tributylphosphine, tricyclohexylphosphine, triethylphosphine, etc. Nitriles include, for example, benzonitrile, acrylonitrile, propionitrile, benzylnitrile, etc., and allyl compounds include is, for example, allyl chloride, allyl alcohol, etc., and the amine is, for example, benzylamine,
Pyridine, piperazine, tri-n-butylamine, etc.; oximes include cyclohexyloxime, acetoxime, benzaldoxime, etc.;
Examples of the olefin include 1,5-cyclooctadiene and 1,5,9-cyclododecatriene. The amount of the complex catalyst or the compound capable of forming a complex used is 0.0001 to 0.5 mol, preferably 0.001 to 0.1 mol, per 1 mol of PBS. Further, when a compound capable of forming a complex is used, the amount of the compound capable of becoming a ligand added is 0.8 to 10 mol, preferably 1 to 4 mol, per 1 mol of the compound capable of forming a complex. In order to further improve the reaction rate, hydrogen chloride,
Inorganic halides such as boron trifluoride, organic iodides such as methyl iodide, etc. can be added. When adding these halides, per mole of complex catalyst or compound capable of forming a complex,
The halogen atom is used in an amount of 0.1 to 30 times the mole, preferably 1 to 15 times the mole. If the amount added is less than 0.1 mol, the effect of the addition may not be seen, although it depends on the type of catalyst. In addition, when the amount exceeds 30 times the mole, the catalytic activity decreases and
The desired reaction is inhibited by addition of halogen to the double bond of PBS. The carbonylation reaction, which is the reaction in step (), is
The reaction temperature is 40-150°C, preferably 55-110°C. If the reaction temperature is lower than 40°C, the reaction rate will be extremely slow and it cannot be carried out practically. Also
Temperatures exceeding 150°C are undesirable because side reactions such as polymerization and hydrogenation and decomposition of the complex catalyst occur. The reaction pressure can be appropriately selected as long as it is 5 Kg/cm ² or more. If it is less than 5 Kg/cm ² , the reaction becomes so slow that it cannot be carried out practically. Further, the higher the pressure, the more quickly the reaction proceeds, which is preferable, but too high a pressure naturally has its limits in terms of production equipment, such as the need to make the pressure resistance of the reactor extremely high. Therefore, in practice, a pressure of 500 kg/cm ² or less is sufficient. The reaction may be carried out until no pressure decrease is observed due to absorption of the mixed gas of carbon monoxide and hydrogen, and a reaction time of 4 to 20 hours is usually sufficient. Carbon monoxide and hydrogen necessary for the reaction may be supplied in the form of a premixed gas mixture, or each may be supplied separately to the reactor. The molar ratio of carbon monoxide and hydrogen when supplied to the reaction system can be selected as appropriate.
That is, in the carbonylation reaction, which is step () of the present invention, carbon monoxide and hydrogen are absorbed and consumed at a molar ratio of exactly 1:1. Therefore, since the component supplied in excess remains unreacted, if the other component is supplied once the pressure decrease is no longer observed, the reaction will proceed again. Therefore, depending on the size of the reactor and the type of reaction, it is most efficient if the molar ratio of carbon monoxide to hydrogen is supplied at 1:1. In the carbonylation of the present invention, a solvent inert to carbonylation can also be used for purposes such as removing reaction heat. Examples of solvents inert to carbonylation include polar solvents such as ethers, ketones, and alcohols, and nonpolar solvents such as paraffins, cycloparaffins, and aromatic hydrocarbons. but,
Generally, satisfactory results can be obtained without a solvent. The reaction product thus completed can be easily separated into IPN and the catalyst by separating the product by distillation, preferably under reduced pressure. The recovered complex catalyst can be used again in the carbonylation reaction. In step () of the present invention, the carbonylation reaction is carried out using stable and highly purified PBS obtained from step () as a raw material, so the produced IPN contains some β-(p-isobutylphenyl) as a by-product.
Since it only contains propionaldehyde (NPN), purification is easy and highly pure IPN can be obtained. Since IPN can be obtained with extremely high purity by the method of the present invention, α-(p-isobutylphenyl)propionic acid (IPA) can be easily obtained by oxidizing this by a conventionally known method. [Effects of the present invention] In step () of the present invention, IBB is reacted with acetaldehyde using a sulfuric acid catalyst, so that isomerization of isobutyl groups does not occur. Also, p-
A new compound, BBE, can be obtained with good position selectivity. Therefore, as a result of step (), unreacted IBB can also be effectively recovered, and BBE can also be produced at a good yield. Further, in step (), BBE of step (), which is a symmetric diaryl alkane, is catalytically cracked.
Since it decomposes symmetrical diarylalkane, the main decomposition products are PBS and IBB. IBB can be reused as starting material for the step (), making the process of the invention economically valuable. Catalytic cracking catalysts use protonic acids, solid acids, etc., so they are
PBS polymerization rarely occurs. Therefore
IBB and PBS can be obtained in good yield. In addition, since PBS is stable, it is easy to purify by separating and removing impurities by-products during decomposition, and a product of high purity can be obtained. High purity PBS from step () is carbonylated in step () to produce IPN.
In the carbonylation of PBS, there are few NPNs,
IPN is produced with high purity. As explained above, the present invention utilizes isobutylbenzene (IBB), acetaldehyde, which is a safe, stable, and inexpensive raw material that is easily available industrially and does not require special treatment for handling.
α-(p-isobutylphenyl)propionaldehyde (IPN) can be easily derived from the basic raw material IBB to IPA in just three steps from sulfuric acid, carbon monoxide, and hydrogen. It can be produced through simple operations and through a stable intermediate that can be easily purified industrially, and it can be said that an easy and economical method has been completed when carried out on an industrial scale. Furthermore, by focusing on the BBE of a new compound, the present invention has completed a method for efficiently producing IPN by using cheaper raw materials and passing through simple and easy-to-operate intermediates compared to conventional methods. This can be called a groundbreaking invention. The present invention will be explained in detail with reference to Examples below. Example process () Experiment No. 1 IBB 402g (3 moles) and 95% by weight sulfuric acid 600
g (5.8 mol) was supplied to a two-round bottom flask equipped with a stirrer, and the outside was cooled with ice to maintain the temperature below 10°C. 44g (1 mol) of acetaldehyde and 67g of IBB for stirring
(0.5 mol) was gradually added dropwise over 4 hours. The reaction temperature was kept below 10°C. After the completion of the dropwise addition, the mixture was further stirred for 2 hours. After the reaction was completed, the reaction solution was transferred to a separating funnel and allowed to stand still. After removing the sulfuric acid in the lower layer, about 2% NaOH aqueous solution was added while shaking until the solution became neutral. The lower aqueous layer was removed, the oil layer was placed in a distillation pot, and the product was purified by vacuum distillation to obtain 260 g of BBE exhibiting the physical properties described below. The yield of BBE was 88 mol% based on acetaldehyde. The acetaldehyde concentration in the reaction solution during the addition of the acetaldehyde solution was 0.5% by weight or less, and the sulfuric acid concentration in the reaction solution at the end of the reaction was 93% by weight.
It was hot. Further, when a fraction with a distillation temperature range of 60 to 80°C at a pressure of 3 mmHg was analyzed by GLC and NMR, it was confirmed that the substance was exactly the same as IBB used as a raw material. Physical properties of BBE Boiling point 180-183℃/3mmHg (colorless liquid) Infrared absorption spectrum (liquid film method) 2960cm ^-1 , 1540cm ^-1 , 1480cm ^-1 , 1390cm ^-1 ,
1370cm ^-1 , 1210cm ^-1 , 850cm ^-1 , 800cm ^-1 Nuclear magnetic resonance spectrum (CCl ₄ solvent, δppm) 6.95 (8H singlet) 3.7-4.2 (1H quadruplet) 2.39 (4H doublet) 1.58 (3H doublet) 0.87 (12H doublet) 1.6~2.2 (2H multiplet) Elemental analysis Theoretical value C: 89.80 H: 10.20 Analytical value C: 89.83 H: 10.06 Experiment No. 2~4 Mols of IBB and acetaldehyde BBE was produced by reacting in the same manner as in Experiment No. 1, except that the ratio was changed. The results are shown in Table 1. Experiment Nos. 5 to 8 BBE was produced in the same manner as in Experiment No. 1 except that the sulfuric acid concentration was changed. The results are shown in Table 2.

【table】

[Table] Experiment No. 9 IBB 402g (3 moles) and 95% by weight sulfuric acid 600
g (5.8 mol) was supplied to a two-round bottom flask equipped with a stirrer, and the outside was cooled with ice to maintain the temperature below 10°C.
44 g (1 mol) of acetaldehyde and
A mixture of 67 g (0.5 mol) of IBB was gradually added dropwise over 4 hours. At the same time, sulfuric acid with a concentration of 98% by weight
100 g (1 mol) was gradually added dropwise over 4 hours.
The reaction temperature was kept below 10°C. After the completion of each dropwise addition, the mixture was further stirred for 2 hours. After the reaction was completed, the reaction mixture was transferred to a separating funnel and allowed to stand still. After removing the sulfuric acid in the lower layer, an approximately 2% NaOH aqueous solution was added while shaking until the mixture became neutral.
When the lower aqueous layer was extracted and the oil layer was purified by vacuum distillation, the yield of BBE was based on acetaldehyde.
It was 89%. The acetaldehyde concentration in the reaction solution during addition of the acetaldehyde solution was 0.5% by weight or less, and the sulfuric acid concentration after the reaction was completed was 95% by weight. Experiment No.10 IBB402g (3 moles) and 85% by weight sulfuric acid 400
g (3.5 mol) was supplied to a two-round bottom flask equipped with a stirrer, and the outside was cooled with ice to maintain the temperature below 10°C. 44 g (1 mol) of acetaldehyde and
A mixture of 67 g (0.5 mol) of IBB was gradually added dropwise over 4 hours. Also, at the same time 30% oleum 150
g was gradually added dropwise over 4 hours. The reaction temperature is 10
It was kept below ℃. After the dropwise addition was completed, the mixture was further stirred for 2 hours. After the reaction was completed, BBE was obtained in the same manner as in Experiment No. 1. The yield of BBE is 87% based on acetaldehyde.
It was %. The sulfuric acid concentration after the reaction was 88% by weight. Comparative experiment No. 1 to 6 Using sulfuric acid from IBB and acetaldehyde
Instead of producing BBE, change the sulfuric acid as a catalyst and the alkylating agent for IBB as shown in the following table,
The rest was carried out in the same manner as Experiment No. 1. All alkylating agents for IBB were used at 0.2 mol. As can be seen from the results shown in Table 3 below, BBE cannot be produced in good yield and with good p-position selectivity, and when using IBB, it is difficult to react acetaldehyde in the presence of sulfuric acid. It turns out to be the most economical.

【table】

[Table] Process () Production experiment of p-isobutylstyrene (PBS) and isobutylbenzene (IBB) by decomposition of 1,1-bis(p-isobutylphenyl)ethane (BBE) No. 11 Distillation cooling device, stirring device and a reactor with a solvent volume of 500 ml equipped with a gas introduction device.
148 g (0.5 mol) of BBE and 50 g (0.02 mol) of silicotungstic acid as a catalyst were charged and heated to 280°C for decomposition. When the temperature exceeded 200°C, hydrogen was introduced from the gas introduction device at a rate of 1/min, and the decomposition products were introduced into the distillation cooling device, where they were cooled and the decomposition products were collected. The decomposition operation was carried out until no decomposition products were observed to be distilled out. GIC analysis of the distillate revealed that p-isobutylethylbenzene (PBE), in which the double bonds of PBS are hydrogenated, was 7%, IBB was 47%, and PBS was 39%.
BBE was 6%. When each component was separated and confirmed by MASS, IR, and NMR, both IBB and BBE were exactly the same as those used as raw materials, and it was confirmed that no side reactions such as isomerization of isobutyl groups had occurred. Furthermore, in PBE and PBS, the butyl group was an isobutyl group, and the substitution position was at the p-position. Experiment Nos. 12 to 14 and Comparative Experiment No. 7 According to Experiment No. 11, a catalytic cracking reaction was carried out by changing the catalyst. The results are shown in Table 4.

[Table] Experiment No. 15 Synthetic silica/alumina-based FCC-HA catalyst (manufactured by Catalysts & Chemicals Co., Ltd.) was adjusted to a particle size of 0.5 mm to 1 mm.
A stainless steel tube with an inner diameter of 10 mm and a length of 60 cm was filled with 5 ml. 5ml/hr of BBE obtained in Experiment No. 1, hydrogen 200
ml/min and water 30ml/hr through the preheating tube to the temperature
It was decomposed by passing it through a catalyst bed at 450°C. The decomposed product was ice-cooled, and after separating the gas and liquid, the decomposition rate and selectivity of the organic layer was confirmed by GLC analysis. The composition of the decomposition product is IBB30wt%, PBE6wt%,
It was confirmed that the decomposition was highly selective with PBS 26wt%, BBE 37wt%, and unknowns 1wt%. Further, structural analysis of each component was performed in the same manner as in Experiment No. 11, and it was confirmed that the isobutyl group was not isomerized and that the p-position selectivity of the decomposition product was high. Experiment Nos. 16 to 25 BBE obtained in Experiment No. 1 was catalytically cracked in the same manner as Experiment No. 15 using various solid acids instead of the FCC-HA catalyst. The results are shown in Table 5.

[Table] [Synthesis and decomposition of asymmetric diarylalkane] Reference experiment No. 1 Synthesis of asymmetric diarylalkane 670 g (5 moles) of IBB and 100 g of 95% sulfuric acid
The mixture was placed in a flask equipped with a stirrer and cooled on ice to a temperature of 10°C. Maintain the temperature at 10℃ and add 134g of IBB (1
4 moles) and 104 g (1 mole) of styrene.
Added dropwise over time. After the dropwise addition was completed, the mixture was stirred for an additional hour to complete the reaction. After decomposing and removing the sulfuric acid layer,
Neutralize, wash with water, distill under reduced pressure of 3 mmHg, and reduce the distillation temperature.
120 g of 1-(p-isobutylphenyl)-1-phenylethane (PBPE), a fraction of 145 to 160°C, was obtained. Reference Experiment No. 2 In the same manner as Reference Experiment No. 1, using 118 g (1 mol) of p-methylstyrene instead of styrene,
80 g of 1-(p-isobutylphenyl)-1-(p-tolyl)ethane (PBTE), which is a fraction with a distillation temperature of 150 to 165°C, was obtained. Comparative experiment No. 8 PBPE synthesized in reference experiments No. 1 and 2
PBTE was catalytically decomposed in the same manner as in Experiment No. 15. In all cases, the weight decomposition rate was 55-60%. However, as shown in the chemical formula below, the ratio of the decomposition at A to the decomposition at B is A/B = 9 to 8, and the decomposition at A is higher than that at PBS of the target product.
That is, the decomposition was overwhelming in the direction of returning to the raw material styrene or p-methylstyrene. In addition, the composition of the decomposition product in the case of PBPE was as follows. wt% Benzene 2 Ethylbenzene 2 Styrene 17 IBB 20 PBE 1 PBS 2 PBPE 55 From the above results, the decomposition efficiency to PBS is low, and in order to reuse IBB as a raw material, it is necessary to go through a complicated purification process. I understand something. Process () From p-isobutylstyrene (PBS) to α-(p
-Isobutylphenyl)propionaldehyde (IPN) Production Experiment No. 26 30 g of PBS obtained in Experiment No. 15 and 0.3 g of rhodium hydridocarbonyl triphenylphosphine were placed in an autoclave with an internal volume of 500 ml and equipped with a stirrer.
℃ and pressurized to 50 Kg/cm ² with an equimolar mixed gas of hydrogen and carbon monoxide, allowing the reaction to occur until no absorption of the mixed gas was observed. After the reaction is complete, cool to room temperature, release the remaining mixed gas, transfer the contents to a vacuum distillation vessel, and adjust the distillation temperature range from 60 to 90.
34 g of crude IPN fraction with a temperature of 0.degree. C./2 mmHg was obtained. Its composition was as follows. Composition of the crude IPN fraction PBE 0.3wt% PBS 0.1 IPN 89.9 NPN 9.7 This crude IPN fraction was again subjected to vacuum distillation to obtain 27 g of IPN having a boiling point range of 70 to 76° C./3 mmHg. The purity of this IPN was 99.6%. Also, IR
The structure was confirmed by analysis and comparison with the standard specimen. Example 25 Experiment No. 25 was carried out using 0.1 g of rhodium oxide and 0.6 g of triphenylphosphine instead of rhodium hydridocarbonyl tristriphenylphosphine.
It was carried out in the same manner as in 26. As a result, PBE0.3wt
%, PBS0.1wt%, IPN83.5wt%, and
31 g of crude IPN fraction containing 16.1 wt% NPN was obtained.

Claims (1)

[Claims] 1. α-(p-isobutylphenyl) characterized by comprising the following steps (), () and ().
A method for producing propionaldehyde, () A step of reacting isobutylbenzene and acetaldehyde in the presence of a sulfuric acid catalyst to produce 1,1-bis(p-isobutylphenyl)ethane, () A protonic acid and/or a solid acid. A step of producing isobutylbenzene and p-isobutylstyrene by catalytically decomposing the 1,1-bis(p-isobutylphenyl)ethane at a temperature of 200 to 650°C using a catalyst, and () the above p-isobutylstyrene. , hydrogen and carbon monoxide in the presence of a carbonylation catalyst at a temperature of 40 to 150°C to produce α-(p-isobutylphenyl)propionaldehyde.