The facile and efficient synthesis of novel monocyclic cis-β-lactam conjugates with a 1-methyl-1H-imidazole-2-thiol nucleus

Abstract

We developed a facile and efficient synthesis of novel monocyclic cis-β-lactam conjugates with a 1-methyl-1H-imidazole-2-thiol nucleus through a ketene-imine [2+2] cycloaddition reaction of acyl chloride and different Schiff bases. The important and attractive features of this synthesis are the readily available starting materials, easy aqueous workup, no column chromatography needed, a simple purification process, and a satisfactory yield. The newly synthesized products were characterized by spectral techniques. Purification of the obtained products was easily accomplished by the crystallization process. This work also confirmed the cis-stereochemistry of β-lactam derivatives at C-3 and C-4 stereocenters via the single-crystal X-ray diffractometry of two structures.