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Dissolving the <strong>[91296-87-6]<strong>[91296-87-6]sarafloxacin</strong> hydrochloride</strong> in water,adjust the pH to about 7.5 with sodium hydroxide, precipitate solids, filter, collect <strong>[91296-87-6]sarafloxacin</strong> solid.
8 Example 8
Into a 50mL reaction flask, add 2.0g of compound IIe (4.47mmol), 13mL of acetonitrile and 1.06g of trimethylethoxysilane in turn, stirring continuously until completely dissolved, add piperazine IIIg (0.44g, 5.14mmol) to the reaction flask ), react at room temperature until TLC monitors that the reaction is complete. The temperature was lowered to 0°C, concentrated hydrochloric acid was added dropwise to the reaction solution under stirring to adjust the pH<1, and the temperature was kept and stirred for 4 hours, and a yellow solid was formed. After suction filtration, the filter cake was washed twice with 2 mL ethanol and dried to obtain a yellow solid, namely sarafloxacin hydrochloride, with a yield of 95.40% and a purity of 99.95%.
With Sodium hydrogenocarbonate In dichloromethane for 2.5h;
1.1.2 1.2 Synthesis of compound No. 221, namely compound 2 (referred to as 4C-SAR)
Into a 100mL round-bottomed flask, add 2mmol sarafloxacin (SAR) hydrochloride and 2mL DCM, cool in an ice-salt bath, stir magnetically, add 8mmol NaHCO3, and add 5.0 mmol 4-chlorobutyryl chloride dropwise with a constant pressure dropping funnel after 20 min DCM solution (the drop rate is about 1d/4s),. After the dripping was completed, the reaction was continuously stirred under an ice bath, and the TLC tracked and monitored until the end of the reaction. Stop stirring, add 15 mL of ice-cold saturated brine and 20 mL of DCM, adjust pH=2-3 with 2 mol/L HCl solution under stirring, there is an emulsified solid, let stand, filter with suction, and wash the filter cake with DCM 3 times. The filtrate was transferred to a separatory funnel, and the layers were separated. The aqueous phase was extracted with DCM (20 mL×2), the organic phases were combined, washed with saturated brine (20 mL×2), washed with a small amount of water (10 mL×1), and the organic phase was collected and anhydrous Na2SO4 was dried and rotary evaporated. The crude product was dispersed with PE/EA solution and a white solid was precipitated. The white solid was obtained by suction filtration, dispersed twice with PE-EA, and vacuum dried to obtain 0.78g of pure white solid with a yield of 85%.