The Synthesis of Some t- Alkylnaphthalenes

Abstract

Alkylation of aromatics with olefins using boron trifluoride-phosphoric acid has been reported to give high yields of monoalkylates with a minimum of side reactions.¹ However, much of this previous work was carried out without the use of modern techniques to separate and identify various fractions. Relatively little, in general, is known about the products resulting from the reaction of naphthalene with olefins using acidic catalysts.^1,2,3 This is probably because of the difficulty involved in separating the various isomers. The relatively mild and non-destructive properties reported for boron trifluoride-phosphoric acid catalyst suggested that it might be suitable for the preparation of 2-t-alkyl naphthalene derivatives in high yield and with little isomerization. This proved to be true and below are reported t- alkylnaphthalenes prepared from olefins using this catalyst.