Preparation of 2,6-dimethylnaphthalene

Abstract

Abstract A MULTISTEP PROCESS IS DISCLOSED WHEREIN 5-O-TOLYLPENTENE-2 IS CONVERTED TO 1,5-DIMETHYLTETRALIN IN THE PRESENCE OF A SOLID ACIDIC CATALYST AT 200-450*C. AND PREFERABLY ALSO RECYCLED HYDROGEN, VAPORS FROM THIS CONVERSION ARE REACTED BY CONTACT AT 300-500*C. IN A HYDROGEN ATOMSPHERE WITH A SOLID DEHYDROGENATION CATALYST, PREFERABLY PLATINUM ON NON-ACIDIC ALUMINA, TO FORM 1,5-DIMETHYLNAPHTHALENE AND HYDROGEN, VAPORS FROM THE DEHYDROGENATION REACTION ARE CONTACTED AT 275-500*C. WITH A SOLID ACIDIC ISOMERIZATION CATALYST TO FORM 2,6-DIMETHYLNAPHTHALENE IN ADMIXTURE WITH MAINLY 1,6-DIMETHYLNAPTHALENE AND A SMALL PROPORTION OF THE 1,5-ISOMER, 2,6-DIMETHYLNAPHTHALENE IS RECOVERED FROM THE ISOMERIZATION PRODUCT, E.G. BY CRYSTALLIZATION, AND PART OF THE GENERATED HYDROGEN IS RECYCLED IN THE SYSTEM. THE PROCESS CAN BE VARIED IN SEVERAL WAYS, INCLUDING THE UTILIZATION OF A LIQUID ACIDIC CATALYST IN EITHER THE FIRST STEP OR THE ISOMERIZATION STEP.

Inventors

• 👤 S Thompson

Bibliographic Details