Demethylation of N-[2-(7-methoxynaphth-1-yl)ethyl]acetamide (I) with boron tribromide-dimethyl sulfide complex affords phenol (II). This is then alkylated with 3-bromopropanol (III) in the presence of K2CO3 to provide the hydroxypropyl derivative (IV). After conversion of alcohol (IV) into the corresponding mesylate (V), condensation with a further equivalent of phenol (II) in hot DMF furnishes the target dimeric compound
In an alternative method, the title dimer compound is obtained by condensation of two equivalents of N-[2-(7-hydroxynaphth-1-yl)ethyl]acetamide (I) with 1,3-dibromopropane (II) in the presence of K2CO3 in acetonitrile