RIGID SPIRO ORTHO-AMINO AROMATIC KETONES - PREPARATION OF HIGHLY FLUORESCENT CARBONYL DERIVATIVES

A possible synthetic pathway to highly fluorescent spiro carbonyl deri vatives at room temperature is reported. N-Benzyl spiro[cyclopentane-1 ,2'-indolin-3'-one] can be considered as the first highly fluorescent phenone derivative at room temperature. The fluorescence is due to its rigid structure and the pi, pi nature of the first excited singlet s tate.