Di-isopropylnaphthalene

An analogous process has been used industrially for the synthesis of 2,6-di-isopropylnaphthalene from naphthalene and propylene in the presence of H-mordenite, another shape-selective zeolite (Equation 7). Oxidation of 

6-di-isopropylnaphthalene gives 2,6-naphthalenedicarboxylic acid, an important monomer for condensation polymers with ethylene glycol. 

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Alkylates made specifically as feedstocks for synthetic petroleum sulphonates are typically long chain (average C chain > 16) and may use propylene oligomers which result in branched chains. Naphthalene products use the same propylene technology but tend to shorter chains (di-isopropylnaphthalene, di-nonylnaphthalene). 

Di-isopropylnaphthalene is an important precursor for polyesters and can be produced using dealuminated mordenites with unidimensional channels (Dow Chemical, Catalytica, Monsanto) with the preferential formation of 2,6-isomer with an... 

Isopropylnaphthalenes can be prepared readily by the catalytic alkylation of naphthalene with propjiene. 2-lsopropylnaphthalene [2027-17-0] is an important intermediate used in the manufacture of 2-naphthol (see Naphthalenederivatives). The alkylation of naphthalene with propjiene, preferably in an inert solvent at 40—100°C with an aluminum chloride, hydrogen fluoride, or boron trifluoride—phosphoric acid catalyst, gives 90—95% wt % 2-isopropylnaphthalene however, a considerable amount of polyalkylate also is produced. Preferably, the propylation of naphthalene is carried out in the vapor phase in a continuous manner, over a phosphoric acid on kieselguhr catalyst under pressure at ca 220—250°C. The alkylate, which is low in di- and polyisopropylnaphthalenes, then is isomerized by recycling over the same catalyst at 240°C or by using aluminum chloride catalyst at 80°C. After distillation, a product containing >90 wt % 2-isopropylnaphthalene is obtained (47). 

Trimethylpentane 1-Heptene Di-isobutene Cyclohexane Methylcyclohexane Di-sec-amvlbenzene Naphthalene (m.p. 80) sec-Amylnaphthalene D i isopropylnaphthalene Di-sec-amylnaphthalene Camphene (m.p. 50) Paraffin wax (m.p. 53) Paraffinic oil... 

On the more spacious zeolite HY the isopropylation of naphthalene is faster but the main procucts are mono-, di- and tri-isopropylnaphthalene. 

Al2O3 = 240) under microwave irradiation [184]. For the microwave-assisted reaction, high reaction rates and high selectivities for 2,6-dialkylnaphthalenes were found. In the reaction of 2-isopropylnaphthalene with isopropyl alcohol, the conversion and the selectivity were 43.5 and 66.4%, respectively. In di-tert-butylation of naphthalene with tert-huty alcohol, the conversion and the selectivity reached 86.5 and 70.4%, respectively. The conversions and the selectivities were enhanced by microwave heating. 

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