Synthesis and anti-microbial activities of oxadiazoles, thiadiazoles and triazoles containing 5-bromo-3-amino benzofuran nucleus from 5-bromosalicylonitrile

Abstract

5-Bromosalicylonitrile 2 has been prepared from 5-Bromosalicylladehyde 1 and hydroxylamine hydrochloride, which on further treatment with ethyl chloroacetate gave ethyl 5-bromo-3-amino-2-benzofurancarboxylate 4. The resulting compound 4 was treated with hydrazine hydrate in boiling ethanol gave the hydrazide compound 5. The resulting hydrazide was reacted with substituted aryl isothiocyanates and offered thiosemicarbazide compounds 6-9. 5Bromo-3-amino-2+--benzofurothiosemicarbazides underwent cyclization with different reagents under different reaction conditions to furnish benzofuran derivatives possessing oxadiazoles, triazoles and thiadiazoles 10-21 respectively. The structures of all the compounds have been assigned by elemental analysis and spectral studies. The synthesized compounds were screened for their antimicrobial and antifungal activities.