Abstract

Synthesis of new benzofuran analogues from 5-bromosalicylaldehyde and their biological activities

Author(s): Gangajji Parameshwarappa, Raga Basawaraj, Sushila S.Sangapure

The reaction of 5-bromosalicyladehyde (2) with hydroxylamine hydrochloride in dimethylfromamide gave 5-Bromosalicylonitrile (3) required in the present work has been obtained by a single step method by the reaction of 5-bromosalicylaldehyde (2) with hydroxylamine hydrochloride in dimethyl formamide. Condensation of 5-bromosalicylonitrile (3) with ethylchloro acetate/chloroacetamide gave ethyl-4-bromo 2-cyanophenoxyacetate and 4-bromo-2-cyanophenoxyacetamide (4-5) which underwent cyclisation in presence of base in dimethyl formamide to offer ethyl 5-bromo-3-amino-2- benzofurancarboxylate and 5-bromo-3-amino-2-benzofurancarboxamide (6-7). However the reaction of 5-bromosalicylonitrile with chloroacetone/ phenacylbromide furnished the formation of 5-bromo-3-aminobenzofuran- 2-acetate (8) and 5-bromo-3-aminobenzofuran-2-benzoate (9) in single step. The structures of all benzofuran analogues were assigned on the basis of spectral data. All the synthesized compounds were screened for antimicrobial and pharmacological activities.