Synthesis of Anthradan analogues by regioselective Friedel–Crafts reactions on N,N-dihexylanthracen-2-amine

An efficient synthetic route using a Friedel–Crafts acylation approach was developed to obtain fluorophores such as 1-(6-(dihexylamino)anthracen-1-yl)propan-1-one (1b) and 1-(7-(dihexylamino)anthracen-1-yl)propan-1-one (1c) with a push–pull electronic conjugation starting from 2-aminoanthracene-9,10-dione (4). These compounds are analogues of 1-(6-(dihexylamino)anthracen-2-yl)propan-1-one (Anthradan) and they exhibit the same additional redshift emission and absorption spectra. Furthermore, we have synthesized other derivatives of Anthradan via the Friedel–Crafts approach in good yields.