ChemInform Abstract: Synthesis of Naphth(1,2,3-cd)indol-6(2H)-one Derivatives and Their Fluorescence Properties.

Highly fluorescent 1-phenylnaphth[1,2,3-cd]indol-6(2H)-one (3b) and its 7-chloro and 7-amino derivatives were synthesized by reaction of 1-aminoanthraquinones with benzyl chloride in KOH–DMSO system, followed by treatment with aluminium chloride. The compound 3b was easily N-alkylated with various alkyl halides in KOH–DMSO system. The fluorescence quantum yields (Qf) of naphth[1,2,3-cd]indol-6(2H)-one derivatives 3 were high (0.5–0.7), except for 7-amino derivatives which did not fluoresce. The Qf of 7-chloro derivative (3d) was strongly dependent on solvent: 0.37 in ethanol; 0.02 in acetonitrile; 0 in benzene. The compounds 3 were demonstrated to be efficient laser dyes for 500–550 nm region.