Synthesis of 3-Aryl-7-diethylaminocoumarin Derivatives: Reaction with Isatin and Their Fluorescent Properties

Abstract

Very recently, isatin has received considerable attention, because it plays physiologically important roles, for example, as a marker of stress and anxiety, an inhibitor of enzymes such as an endogenous monoamine oxidase (MAO) inhibitor, an antiseizure agent, and so forth. 2 Therefore, chemical tools for measuring isatin in various biological systems and human biological specimens are required.Although there are a few analytical methods for isatin, 3 little is known about more sensitive and practically useful analytical methods.In the previous papers, we have shown that 3-phenyl-7-diethylaminocoumarin (1a) was one of the most promising candidates as a fluorophore, and developed the most sensitive and practically useful fluorescent derivatization reagents for carboxylic acids (MPAC-Br) 4, 5 and alcohols (MACB-CN 6 and