1-thia-5-aza-bicyclo(4.2.0)octane (including Unsaturated; E.g., Cepham, Etc.) Patents (Class 540/215)
- 2- or 4-position substituent contains hetero ring (Class 540/223)
- 3-position substituent contains a pyridine ring (e.g., quinoline, thienopyridine, lutidines, etc.) (Class 540/224)
- 3-position substituent contains sulfur (Class 540/226)
- Alkyl, hydroxyalkyl, alkoxyalkyl or alkanoyloxyalkyl bonded directly to 3 position (Class 540/228)