In an orthoxylene solvent, 1-aminonaphthalene was reacted with 4-methoxybenzyl-5-(4-bromobenzyl)pentyl sulfide in the presence of Pd/phosphine and t-butoxy sodium to obtain 4-(6-(4-methoxybenzylthio)hexyl)phenyl-1-naphthylamine. Then, 4,4′-dibromobiphenyl was added into the resultant compound to obtain N,N′-bis(4-(6-(4-methoxybenzylthio)hexyl)phenyl)-N,N′-bis(α-naphtyl)-1,1′-biphenyl-4,4′-diamine through the same reaction. N,N′-bis(4-(6-mercaptohexyl)phenyl)-N,N′-bis(α-naphtyl)-1,1′-biphenyl-4,4′-diamine, the intended product having a mercapto group, was removed from the compound in the presence of anisole in a trifluoroacetic acid. Its structure was confirmed by the elementary analysis or NMR analysis.
