Synthesis And Characterization Of New Coumarin Derivatives Modified With N,N’- Diethylamino Group

Coumarins and their Schiff derivatives are very important organic compounds which have been applied in a range from p Harmaceuticals, antimicrobials to optical materials. In order to research for more interesting targets, a serials of new coumarins Schiff derivatives were developed in this thesis. The corresponding work was described as follows:Synthesis of coumarins Schiff derivatives from diethylamino salicylaldehyde with aromatic amines, hydrazines and hydroxylamine hydrochloride has been developed respectively. Structures of the corresponding products were elucidated by IR, 1HNMR and MS spectra. The optical properties were carried out by means of UV and fluorescence spectrum.The fluorescent properties of N, N’- diethylamino coumarin thiourea quenched by addition of copper ions and the recovery of fluorescence emission in the presence of mercapto group compound were determined, which will be useful for detection of GSH in cells as a fluorescent probe in future;Synthesis of coumarins 1,3,4-oxadiazole derivatives from diethylamino salicylaldehyde with aromatic hydrazine has been developed. Structures of the corresponding products were elucidated by IR, 1HNMR and MS spectra.Upon the above 1,3,4-oxadiazoles, their antibacterial activity against Stappylococcus aureus, Escherichia coli and Bacillus subtilis were studied. The results showed that the targeted compounds have a certain effect on inhibition of the above bacteria, in which the antibacterial activities are above 90% for Escherichia coli and nearly to 85% for the two others.