Abstract
7-Methoxycoumarin-4-carbonyl chloride (1), 7-methoxycoumarin-4-carbohydrazide (2), 4-methylcoumarin-7-isothiocyanate (3), and 7-dimethylamino-4-methylcoumarin-3-isothiccyanate (4) were synthesized to examine their reactivities with various functional groups and the fluorescence characteristics of the resulting derivatives. The reaction of 1 with alcohols and amines readily yielded the esters and the amides respectively. The hydrazones were obtained by the reaction of 2 with carbonyl compounds, and 3 and 4 reacted with amines to yield the thioureides. The fluorescence spectra and the quantum yields of these coumarin derivatives were measured, and it was found that 1 was useful as a fluorescent acylating reagent for alcohols and primary amines. The thioureides derived from 4 also showed a high quantum fluorescence yield.
