Stereoselective Synthesis of Novel Monocyclic cis-beta-Lactams Bearing 1,3,4-Thiadiazole Nucleus: Bioactive Agents and Potential Synthons

A simple and efficient procedure for the stereoselective synthesis of novel monocyclic cis-beta-lactams, pharmaceutically fascinating and potential synthons have been developed. The reaction of ketene derived insitu from phenoxyacetyl chloride with tetralone substituted imines resulted in the exclusive formation of monocyclic cis-beta-lactams containing 1,3,4-thiadiazole nucleus by [2+2] cycloaddition reaction. The structures of all the novel synthesized monocyclic cis-beta-lactams were verified using various spectroscopic techniques such as FT-IR, H-1 NMR, C-13 NMR, HRMS, and elemental analysis (CHN). The cis configuration of beta-lactams was deduced using the coupling constant (J) value of H-3 and H-4. The prominent features of this work are simple reaction conditions, good yields, easy isolation of products, and no column chromatography separation. All products were obtained by a simple crystallization technique.