The 2,3‐dehydro analog 2 of the potent quinolone antibacterial agent ofloxacin (1) was synthesized by an efficient six step route beginning with ethyl 2,3,4,5‐tetrafluorobenzoylacetate. Formation of the oxazine ring of 2 was accomplished by ozonolysis of 1‐(1‐buten‐3‐yl)quinolone 5 to the corresponding aldehyde, which cyclized upon treatment with base via intramolecular displacement of the C‐8 fluorine to afford tricyclic ester 6. The antibacterial activities of 2,3‐dehydroofloxacin (2) and ofloxacin (1) are compared.
All Science Journal Classification (ASJC) codes
- Organic Chemistry