In summary

In summary, we have successfully synthesized and characterized two new examples of dihydroisoquinoline oxaziridines 3a and 3b. Their antimicrobial activities in vitro were evaluated against all the tested bacterial and fungal strains. These findings demonstrated that the presence of nitro group play an important role in the antimicrobial activities and the tested compounds are of a biological significance, which have the perspective to become new members of antimicrobial agents but paying the way for future investigations in this field.
The cold imine 2a (300 mg, 0. 93 mmol) was added dropwise to 6 ml of sulfuric acid 95 %, a solution of 233 mg potassium nitrate in 2 ml sulfuric acid was added dropwise by mainting the temperature at 0°C, the reaction medium was stirred at room temperature for 2h, then at 60°C for 4h. After return to room temperature, the reaction medium was versed on ice-cold water, and alkalized with ammonia. The organic phase was extracted with dichloromethane, washed with a saturated aqueous NaCl solution, dried over sodium sulfate, filtered and evaporated. The residue was purified by chromatography (silica gel, eluent dichloromethane/ methanol 98:2).