Fluorescent probes have been widely applied in the investigation of the structure and behavior of proteins. One probe that has found extensive use is 8-anilino-1- naphthalenesulfonate (1). l A related probe, 8, 8'-di-anilino-5, 5'-binaphthalene-l, l'- disulfonate (2), is potentially more useful than 1 because it binds more tightly to proteins2 and has a larger fluorescence quantum yield. 3 However, the current syntheses of 2, 3-5 ...