Chloramine-T mediated synthesis of 1,8-naphthyridinyl-1,3,4-oxadiazoles

摘要

3-Phenyl-l,8-naphthyridin-2(lH)-one 1 on reaction with ethyl chloroacetate affords ethyl (2-oxo-3-phenyl-2H-[l,8]naphthyri-din-l-yl)acetate 2,which on treatment with hydrazine hydrate yields (2-oxo-3-phenyl-2H-[l,8]naphthyridin-l-yl)acetic acid hydrazide 3.The acid hydrazide 3 reacts with various aromatic aldehydes to give the corresponding (2-oxo-3-phenyl-2H-[l,8]naphthyridin-l-yl)acetic acid arylidenehydrazides 4.Oxida-tive cyclization of 4 with chloramine-T furnishes l-(5-aryl-[l,3,4]-oxadiazoI-2-ylmethyl)-3-phenyl-lH-[l,8]naphthyridin-2-ones 5.These compounds have been characterized on the basis of elemental analyses,IR,'H NMR and MS.Compounds 5 have been screened for their antibacterial activity.