BASE-CATALYZED REACTIONS .33. SODIUM- AND POTASSIUM-CATALYZED REACTIONS OF METHYLNAPHTHALENES WITH ETHYLENE

Sodium or potassium dispersed in 1- or 2-methylnaphthalene are active catalysts for the reaction of these hydrocarbons with ethylene, under pressure and at temperatures from 90 to 210°. To form an active sodium catalyst a promoter is needed, while in the case of potassium the initiator is not always required. The reaction in the presence of sodium results exclusively in side-chain ethylation (compounds 2-4, 6, and 8-10). All hydrogen atoms at the α carbon of the side chain can be replaced with ethyl groups, though in case of 1-alkylnaphthalenes steric hindrance can considerably retard the reaction. The potassium-catalyzed reaction with ethylene is more complex. In addition to the side-chain ethylation reaction, products of cyclization (12,17, and 18) and nuclear alkylation (11 and 16) were isolated. Also, all of these primary products undergo further alkylation (13 and 14) and formation of higher boiling hydrocarbons can take place. © 1969, American Chemical Society. All rights reserved.