Author(s): D. Ramesh2, VP. Vaidya1*, MN. Kumaraswamy2 and C. Chandrashekhar3
The reaction of ethyl 8-bromonaphtho[2,1-b]furan-2-carboxylate 2 obtained by the bromination of ethyl naphtho[2,1-b]furan-2-barboxylate 1 with hydrazine hydrate, afforded 8- bromonahtho[2,1-b]furan-2-carboxyhydrazide 3 which served as an excellent intermediate for the synthesis of title compounds. These were obtained by two different routes from hydrazide 3. The first route involved the conversion of hydrazide 3 into N-aroyl 8-bromonaphtho[2,1-b]furan2-carbohydrazides 4(a-f), which underwent smooth cyclization on treatment with phosphorus oxychloride to furnish 2-(8-bromonaphtho[2,1-b]furan-2-yl)-5-aryl-1,3,4-oxadiazoles 5(a-k). In the second methodology the oxadiazoles 5(a-k) were obtained by converting hydrazide 3 into corresponding Schiff bases 6(a-k) followed by ring closure using bromine in acetic acid in presence of anhydrous sodium acetate. The structures of newly synthesized compounds have been established by analytical and spectral studies. All the compounds in the series have been screened for their antibacterial and antifungal activities.