Study of regioselective dialkylation of naphthalene in the presence of reusable zeolite catalysts.
Highly regioselective dialkylation of naphthalene using various alkylating agents can be achieved over zeolite catalysts. For example, the tert-butylation of naphthalene (1) using tert-butanol in cyclohexane over a dealuminated H-Mordenite (HM) zeolite has been optimised to give a 60% yield of 2.6-di-tert-butylnaphthalene (3) with a 2.6/2.7 ratio of over 50. This has been achieved by varying the reaction time, temperature, solvent, pressure, amount of tert-butanol, solvent and catalyst, Si/Al ratio of the catalyst, and the mode of addition. The zeolites can be easily regenerated by heating and reused.
Smith
Keith
K
Centre for Clean Chemistry, Department of Chemistry, University of Wales Swansea, Singleton Park, Swansea, UK SA2 8PP.
Roberts
Simon D
SD
el-Hiti
Gamal A
GA