in Wiley Online Library (wileyonlinelibrary.com).The chalcones, 2a-2l reacted with o-aminobenzenthiol to give a series of 1,5-benzothiazepines, 3a-3l. The [3þ2] 1, 3-dipolar cycloaddition reactions of 3a-3l with ethyl chlorooximidoacetate in the presence of Et 3 N afforded the target compounds, 4a-4l possessing an additional 1,2,4-oxadiazole ring fused to the heptaatomic nucleus. The structures have been elucidated by spectral methods and X-ray crystallographic analysis.