Novel Bis-spiro-β-lactams Derived from Some Quinolinones via the Staudinger Synthesis

A series of novel bis-spiro-β-lactams were obtained by the Staudinger synthesis. Pyrazine-2,3-dicarboxylic acid was cyclized with thiosemicarbazide to yield bis-2-amino-1,3,4-thiadiazole derivative which was further condensed with some commercial quinolinone derivatives to give imines. The reaction of these new imines with phenoxyacetyl chloride in the presence of triethylamine afforded spiro-β-lactams. The structures of the synthesized compounds were deduced from their FTIR, ¹H NMR, and ¹³C NMR spectra, and elemental analyses.