Forming a 4-aminobiphenyl derivative arylamine compound, includes (i)
providing a first disubstituted 4-aminobiphenyl compound; (ii) optionally
formylating the first disubstituted 4-aminobiphenyl compound to form a
bisformyl substituted compound where the first disubstituted
4-aminobiphenyl compound is not a bisformyl substituted compound; (iii)
acidifying the bisformyl substituted compound to convert formyl
functional groups into acid functional groups to form an acidified
compound; and (iv) hydrogenating the acidified compound to saturate at
least one unsaturated double bonds in the acidified compound.