Amoco Corporation

Gregory S Williams

David L Sikkenga

Ian C Zaenger

Joyce D Lamb

A method for preparing one or more specific dimethyltetralins from either 5-(o-, m-, or p-tolyl)-pent-1- or -2-ene or 5-phenyl-hex-1- or -2-ene, and optionally for preparing one or more specific dimethylnaphthalenes from the aforesaid dimethyltetralins is disclosed wherein the orthotolylpentene or phenylhexane is cyclized to the dimethyltetralin using an ultra-stable crystalline aluminosilicate molecular sieve Y-zeolite.

Preparation of a dimethyltetralin by cyclizing an orthotolylpentene

A method for the acid catalyzed cyclization of an alkenylbenzene feedstock to a dimethyltetralin in a liquid phase reaction wherein the desired dimethyltetralin is removed from the reaction mixture by distillation simultaneously with the addition of the feedstock to the reaction mixture.

Preparation of a dimethyltetralin in a distillation reactor

A method for preparing one or more diemthylnaphthalenes from one or more dimethyltetralins, and optionally for preparing one or more other specific dimethylnaphthalenes by isomerization of the aforesaid dimethylnaphthalene(s) is disclosed.

Preparation of a dimethylnaphthalene

A method for preparing one or more specific dimethyltetralins from either 5-(o-, m-, or p-tolyl)-pent-1-or -2-ene or 5-phenyl-hex-1- or -2-ene, and optionally for preparing one or more specific dimethylnaphthalenes from the aforesaid dimethyltetralins is disclosed.

Preparation of a dimethyltetralin

A method is provided for cyclizing an alkenylbenzene to a dialkyltetrahydronaphthalene (dialkyltetralin) in the presence of a solid cyclization catalyst constituted by a relatively low acidity, ultrastable, hydrogen form of crystalline aluminosilicate zeolite Y having a sodium oxide-to-alumina bulk molar ratio in the range of about 0.001 to about less than 1, a unit cell size no greater than about 24.3 Angstroms, and a sodium content of no more than about 0.4 percent by weight, calculated as elemental sodium and based on the weight of the zeolite. This catalyst provides more activity, more stability, higher product purity, and higher product yields than known prior art zeolite cyclization catalysts notwithstanding its relatively lower acidity. A preferred alkenylbenzene is 5-(o-tolyl)-pent-2-ene which is converted in relatively high yields and relatively high selectivities to 1,5 dimethyltetrahydronaphthalene.

Catalytic alkenylbenzene cyclization

A method for preparing one or more specific dimethyltetralins by cyclization of either 5-(o-, m, or p-tolyl)-pent-1- or -2-ene or 5-phenyl-hex-1- or -2-ene, with additional cyclization treatment, and optionally cracking, of a heavy fraction of the cyclization product, is disclosed.

A method for preparing one or more dimethylnaphthalenes from one or more dimethyltetralins, and optionally for preparing one or more other specific dimethylnaphthalenes by isomerization of the aforesaid dimethylnaphthal-dimethylnaphthalene(s) is disclosed.

A reactivation process for a deactivated supported palladium catalyst involves contacting the catalyst with an organic polar solvent for naphthalenic compounds at a temperature below about 200.degree. C. The organic polar solvent has a dielectric constant at 25.degree. C. in the range of about 4 to about 80 and has a boiling point at atmospheric pressure in the range of about 30.degree. C. to about 230.degree. C. Preferred organic polar solvents are acetone and methanol, as well as mixtures thereof.

Palladium catalyst reactivation

A method is disclosed for preparing one of more specific dimethylnaphthalene isomers by the isomerization of one or more other specific dimethylnaphthalene isomers in the liquid phase and in the presence of a solid zeolitic isomerization catalyst.

A method for preparing one or more specific dimethyltetralins from either 5-(o-, m-, or p-tolyl)-pent-1- or -2-ene or 5-phenyl-hex-1- or -2-ene, and optionally for preparing one or more specific dimethylnaphthalenes from the aforesaid dimethyltetralins is disclosed.

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Tampa, FL, United States of America

Gregory S Williams