Synthesis of 2-((4-aminophenyl)amino)- and 2-(4-hydroxyphenoxy)-substituted-1,4-naphthoquinones and Preliminary Studies on Their Use in Fingermark Detection

Naphthoquinone derivatives are among the promising compounds that can be an alternative to amino acid reagents that are currently widely used on porous surfaces. Studies to determine the mechanism of reaction of naphthoquinones with amino acids in fingermark residue are still ongoing. In this study, 2-((4-aminophenyl)amino)-5,8-dibromonaphthalene-1,4-dione (2a) and 5,8-dibromo-2-(4-hydroxyphenoxy)naphthalene-1,4-dione (2b) were synthesized and characterized by spectral (1H NMR, 13C NMR, and HPLC-TOF/MS) methods. Latent fingermarks on copier paper were treated with these naphthoquinones by the dipping method. Both naphthoquinones developed latent fingermarks as photoluminescence impressions under the illumination of 440 nm light and observed through a red filter. The study also provided a comparison of the naphthoquinones and 1,8-diazafluoren-9-one (DFO).