1. Norfloxacin is the raw material, and the product is obtained by methylation.
2. Start with the intermediate boron chelate in norfloxacin. The boron chelate compound, acetonitrile, N-methylpiperazine and triethylamine were mixed, and reacted at room temperature before refluxing. The solvent was distilled off, water was added, and concentrated hydrochloric acid was adjusted to pH = 3 before refluxing. Add activated carbon to decolorize and filter. The filtrate was basified to pH = 11, and then activated carbon was decolorized, filtered, and neutralized with 30% acetic acid to pH = 6.7-7.2, overnight in the refrigerator. Filtration, washing with water and drying to obtain off-white pefloxacin with a yield of 82% and a melting point of 270-272 °C. Pefloxacin
is dissolved in absolute ethanol, and methanesulfonic acid is added dropwise at 60-70 °C to react. After cooling to 15 °C, the precipitated crystals were filtered and recrystallized with 10 times ethanol to obtain pefloxacin mesylate.
3. The boron chelate, N-methylpiperazine and triethylamine can also be refluxed together. After alkaline hydrolysis, acidify to pH = 7.2 to obtain pefloxacin; add it to the aqueous solution of methanesulfonic acid, and the crude product obtained by the reaction is recrystallized with 85% ethanol to obtain pefloxacin mesylate.
Its sterilization mechanism is to inhibit the activity of DNA gyrase, thereby inhibiting the replication of bacterial DNA.