SYNTHESIS AND BIOLOGICAL EVALUATION OF 1,2,3-THIA AND SELENADIAZOLES-4-DERIVATIVES

Abstract

Abstract Visnagin-9-sulfonyl chloride (Ic) reacted with p-aminoacetophenone to give visnagin-9-N-(p-acetophenyl) sulfonamide (II), which in turn was reacted with semicarbazide hydrochloride in the presence of sodium acetate to give the corresponding visnagin-9-N-(p-acetophenyl semicarbazone) sulfonamide (IV). The latter compound was cyclized through oxidation with thionyl chloride to yield 1,2,3-thiadiazol-4derivative (V), while the oxidative cyclization with selenium dioxide led to the formation of 1,2,3-selenadiazol-4-derivative (VI). Visnaginone (VIIa) or khellinone (VIIb) was reacted with p-aminoacetophenone in absolute ethanol to give the Schiff's bases (VIIIa,b), respectively. The latter compounds were condensed with semicarbazide hydrochloride to yield the corresponding semicarbazone derivatives (IXa,b), respectively. The oxidative cyclization of IXa or IXb using thionyl chloride gave 1,2,3-thiadiazol-4-derivatives (Xa) and (Xc), while the oxidative cyclization of IXa or IXb using selenium dioxide gave 1,2,3-selenadiazol-4-derivatives (Xb) and (Xd), respectively. The antimicrobial and antiaflatoxigenic activities of thia and selenadiazoles were also investigated.