Synthesis of new 3-(2-aminothiazol-4-yl)-4-hydroxy-2H-chromen-2-one derivatives

Aminothiazole derivatives of 4-hydroxy-2H-chromen-2-one were prepared by the Hantzsch reaction1 using 3-(2-bromoacetyl)-4-hydroxy-2H-chromen-2-one and thiourea derivatives. Starting compound for this synthesis 3-(2-bromoacetyl)-4-hydroxy- 2H-chromen-2-one (1) was prepared previously.2 Also, for this synthesis we used thiourea derivatives (2a-j) as compounds which possess groups with biological activity. Reactions are carried out in refluxing ethanol for a period of 30 - 45 min. Final products (3a-j) are obtained in a high yield. Chemical structure of the obtained compounds was confirmed by elemental and structural analysis (IR and 1H NMR spectroscopy). U ovom radu predstavljena je izuzetno efikasna metoda sinteze novih 2-aminotiazolskih derivata 4-hidroksikumarina. Eksperimentalna merenja su potvrdila visok prinos i jednoznacnost reakcije u slucaju svih sintetisanih kumarinskih derivata.