Mitsubishi Gas Chemical Company, Inc.

Shinji Ozawa

Makoto Takagawa

Takayasu Fujimori

Kenji Inamasa

Yoichi Kyuko

Kenji Dnamasa

A process for efficiently producing dimethylnaphthalene by a single-step reaction which comprises cyclizing dehydrogenating 5-tolyl-penta-2-ene in the presence of a catalyst comprising in combination (a) a solid acid such as crystalline aluminosilicate, silica-alumina or alumina; (b) a noble metal such as palladium and platinum; and a carrier such as carbon, silicon oxide, titanium oxide and zirconium oxide. The process results in simplification of production, effective utilization of reaction heat and rationalization of the heat balance.

Process for producing dimethylnaphthalene

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

There is disclosed a process for producing dimethyltetralin consisting of 1,5-, 1,6- and 2,6-dimethyltetralin which comprises cyclizing 5-tolyl-penta-2-ene in gaseous state in the presence of diluent by the use of a catalyst comprising a crystalline aluminosilicate and a carrier and optionally a molding assistant. The abovementioned process is capable of producing industrially useful dimethyltetralin as the starting raw material for dimethylnaphthalene with high yield and high selectivity with minimized side reactions over a long stabilized period.

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Tsukuba, Japan

Shinji Ozawa