Orbifloxacin synthesis

Yield:113617-63-3 88 g

Reaction Conditions:

Stage #1:sparfloxacin with hydrogenchloride;sodium nitrite in water at 0 - 5;
Stage #2: with tetrafluoroboric acid in water at -10 - 0; for 5 h;
Stage #3:Heating;

Steps:

1.2; 1.3; 1.4 Example 1
(2) the diazotization reaction
In a 500 ml three-neck flask, add sparfloxacin 156.8 g (0.4 mol), mass concentration of 30% hydrochloric acid aqueous solution 105 ml. Under 0-5 °C ice salt bath cooling conditions, slowly drop 12 mol/L sodium nitrite aqueous solution 50 ml (0.6 mol), intense stirring, potassium iodide starch paper test diazotization reaction end point, diazonium salt solution is prepared.
(3) preparation of sparfloxacin tetrafluoroborate salt
The step (1) prepared tetrafluoroboric acid was cooled to 0 °C and added dropwise to the step (2) diazonium salt solution. The dropping ends. At -10 °C placed for 5 hours, separating solid, filtering, washing the solid with ethyl ether, vacuum drying, sparfloxacin tetrafluoroborate salt obtained.
(4) thermal decomposition reaction
The step (3) dried solid was placed into a 500 ml single-mouth flask. In an electric furnace directly heat on an asbestor gauze to carry out thermal decomposition reaction until no gas is produced, get orbifloxacin crude product. And then using anhydrous ethanol heating dissolved, decolorized with active carbon, filtering, the filtrate crystallization, filtration, crystal drying, to obtain the product orbifloxacin 88 g, yield 56%,

References:

Zhejiang University of Technology;Sun Li;Pei Wen;Wang Haibin;Yang Zhenping CN104817533, 2017, B Location in patent:Paragraph 0019; 0022; 0025-0030

FullText