Mitsubishi Gas Chemical Company, Inc.

Kenji Inamasa

Makoto Takagawa

Norio Fushimi

Ko Kedo

Yoshikazu Shima

Takeshi Kawai

Akio Hashimoto

Kumiko Watabe

Ken Yamagishi

Shinji Ozawa

Takayo Sasaki

Kentaro Kataoka

Jyun Yoshihara

Yoichi Kyuko

A process is provided for producing an alkyl aromatic compound having substituents at the 3- and 5-positions by alkylating an aromatic compound having two substituents in the meta positions with an olefin having 2 to 4 carbon atoms in the presence of a Broensted acid, followed by addition of a Lewis acid and isomerization in the copresence of the Broensted acid and the Lewis acid. According to the present invention, 3,5-dimethylethylbenzene, 3,5-dimethylcumene, etc. may be produced in a stable manner with high yield and high selectivity under mild and simple reaction conditions. The alkyl aromatic compounds having substituents at the 3- and 5-positions are useful as intermediates for functional chemicals for use in pharmaceutical, agricultural and electronic materials. With the method of the present invention, the catalyst used can be recovered and recycled. Thus, desired alkyl aromatic compounds may be obtained economically in an industrially advantageous manner while reducing the load on the environment.

Process for producing alkyl aromatic compound

In the production method of the invention, a cyclic aldehyde having an alkyl group and/or a cycloalkyl group directly bonded to a skeletal ring and a formyl group directly bonded to the skeletal ring is brought into contact with ammonia and oxygen in vapor phase in the presence of a catalyst. As a result thereof, the formyl group is selectively ammoxidized into a cyano group to convert the cyclic aldehyde into a corresponding cyclic nitrile. The method enables a long-term, high-yield production of the cyclic nitrile using a reduced amount of ammonia.

Method for producing alkyl and/or cycloalkyl-substituted cyclic nitrile

There is disclosed a process for producing a monoalkenylbenzene which comprises alkenylating a side chain of an aromatic hydrocarbon compound having at least one hydrogen atom bonded at .alpha.-position of the side chain (such as xylene) with a conjugated diene having 4 or 5 carbon atoms (such as butadiene) in the presence of a catalyst produced by calcining the mixture of a basic potassium compound and alumina and then heat treating the calcined product together with metallic sodium in an atmosphere of an inert gas. According to the aforesaid process, an industrially useful monoalkenylbenzene can be produced in high yield at a low cost with enhanced safety.

Process for producing a monoalkenyl aromatic hydrocarbon compound

A process for producing dimethylnaphthalene by the dehydrogenation of dimethyl-tetrahydronaphthalene which comprises carrying out the dehydrogenation reaction in a gaseous state at a temperature of 200.degree. to 350.degree. C. in the presence of a diluting medium and by the use of a platinum and/or palladium catalyst supported on an activated carbon carrier. The process is capable of producing industrially useful dimethylnaphthalene with a high yield and a high selectivity and minimized side reactions, over a long stabilized period.

Process for production of dimethylnaphthalene

A process for producing a monoalkenyl aromatic hydrocarbon compound which comprises alkenylating a side chain of an aromatic hydrocarbon compound having at least one hydrogen atom bonded at an .alpha.-position of the side chain (such as xylene) with a conjugated diene having 4 or 5 carbon atoms (such as butadiene) in the presence of a catalyst comprising a mixture obtained by heat treating metallic sodium together with a mixture of an aluminum oxide and a potassium compound in an inert gas atmosphere. The process produces a commercially useful monoalkenyl aromatic hydrocarbon compounds in a high yields and at a low cost with enhanced safety.

Process for producing monoalkenyl armomatic hydrocarbon compound

There is disclosed a process for producing a monoalkenyl aromatic hydrocarbon compound which comprises alkenylating a side chain of an aromatic hydrocarbon compound having at least one hydrogen atom bonded at .alpha.-position of the side chain (such as xylene) with a conjugated diene having 4 or 5 carbon atoms (such as butadiene) in the presence of a catalyst comprising the mixture obtained by heat treating metallic sodium together with an alkaline earth metal oxide containing a potassium compound in the atmosphere of an inert gas. According to the aforesaid process, a monoalkenyl aromatic hydrocarbon compound such as industrially useful monoalkenylbenzene can be produced in high yield at a low cost with enhanced safety from a specific aromatic hydrocarbon compound and a specific conjugated diene compound.

Process for producing monoalkenyl aromatic hydrocarbon compound

A process for producing a monoalkenyl aromatic hydrocarbon compound which comprises alkenylating a side chain of an aromatic hydrocarbon compound having at least one hydrogen atom bonded at an .alpha.-position of the side chain (such as xylene) with a conjugated diene having 4 or 5 carbon atoms (such as butadiene) in the presence of a catalyst comprising a mixture obtained by heat treating metallic sodium together with a mixture of a zirconium oxide and a potassium compound in an inert gas atmosphere. An industrially useful monoalkenyl aromatic hydrocarbon compound is produced in a high yield at a low cost with enhanced safety from a specific aromatic hydrocarbon compound and a specific conjugated diene compound.

A process for efficiently producing 2,6-dimethylnaphthalene which comprises subjecting 2-methyl-1-(p-tolyl)butene and/or 2-methyl-1-(p-tolyl)butane as the starting raw material to a cyclization dehydrogenation reaction in the presence of a catalyst comprising (a) a palladium component, (b) an alkali or alkaline earth metal compound and (c) aluminum oxide. The process enables the production of highly pure 2,6-dimethylnaphthalene in a high yield at a low cost. The catalyst used in the process affords high safety and stability.

Process for producing 2,6-dimethylnaphthalene

There is disclosed a process for efficiently producing 2,6-dimethylnaphthalene used for the production of polyethylene naphthalate which comprises subjecting 2-methyl-1-(p-tolyl)butene and/or 2-methyl-1-(p-tolyl)butane as a starting raw material to cyclization dehydrogenation reaction by the use of a catalyst comprising a platinum component and at least one component selected from the group consisting of alkali metals and alkaline earth metals each being supported on aluminum oxide. The above process enables the production of the objective compound in a high yield at a low cost by using the catalyst having high safety and stability from the widely available starting material, thereby enhancing the industrial significance of the process.

Process for production of 2,6-dimethylnaphthalene

A process for producing 2,6-dimethylnaphthalene, which comprises subjecting 2-methyl-1-(p-tolyl)-butene, 2-methyl-1-(p-tolyl)-butane or a mixture of these to cyclization and dehydrogenation in the presence of a catalyst comprising lead oxide and/or indium oxide and aluminum oxide.

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Tsukuba, Japan

Kenji Inamasa