Naphthalene → 1-(1-Methylethyl)naphthalene

Beteiligte Stoffe

Reaktionsschritte

These and other objects and advantages of the invention by the instant process comprises (1) alkylating naphthalene with propylene in the presence of a phosphoric acid catalyst supported on SiO2, at a temperature of 150°-280° C. and a pressure of 5-30 atm. using a mol ratio of 1/5 to 1/20 mol propylene per 1 mol of starting naphthalene, until in the reaction 45 to 65% of the naphthalene has been isopropylated and then without separating off the unreacted naphthalene, (2) further treating the alkylation mixture by heating it in the presence of a phosphoric acid catalyst supported on SiO2 under an inert gas pressure of 5 to 30 atm. to a temperature of 180° to 280° C. until substantially no more β-isopropylnaphthalene is formed from the α-isopropylnaphthalene. There is thereby obtained an isomeric mixture consisting of 90-95% of the β-isopropylnaphthalene isomer. Pure β-isopropylnaphthalene can be recovered from this isomeric reaction product by distillation and crystallization.

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