Process for preparing dialkylnaphthalene

A process of preparing a polyester resin comprising:

• 1) oxidizing 2,6-dimethylnaphthalene to form 2,6-naphthalenedicarboxylic acid;
• and
• 2) manufacturing a polyester resin from said 2,6-naphthalenedicarboxylic acid,
• wherein said 2,6-dimethylnaphthalene is prepared from a feedstock comprising isomers of dimethylnaphthalene and naphthalene comprising:
• I) transalkylating isomers of dimethylnaphthalene and said naphthalene to produce monomethylnaphthalene;
• and
• isomerizing isomers of dimethylnaphthalene to produce a dimethylnaphthalene isomerizate;
• II) separating the product of step I) into fractions of naphthalene, monomethylnaphthalene and dimethylnaphthalene;
• III) alkylating said fraction of monomethylnaphthalene of step II) with an alkylating agent to produce dimethylnaphthalene;
• IV) separating the product of step III) into fractions of monomethylnaphthalene and dimethylnaphthalene;
• and
• V) separating 2,6-dimethylnaphthylene from said fractions of dimethylnaphthalene of steps II) and IV),
• wherein steps I) and III) are each conducted in the presence of a catalyst composition comprising a synthetic zeolite characterized by an X-ray diffraction pattern including interplanar d-spacing
• 12. 36.+-.0.4
• 11.03.+-.0.2
• 8.83.+-.0.14
• 6.18.+-.0.12
• 6.00.+-.0.10
• 4.06.+-.0.07
• 3.91.+-.0.07
• 3.42.+-.0.06 .ANG..