Application [2-3]
CN201510096301.3 discloses a preparation method for cefuronin, which uses cefotaxinic acid and isonicotinamide as raw materials and reacts at low temperature to obtain a product. Cephalothiophenic acid is dissolved in organic solvents, protected by carboxyl groups using silanization protection reagents, and then undergoes an iodination reaction with trimethyliodosilane; Then, it undergoes an amination reaction with isonicotinamide, and finally undergoes alcohol desorption protection. The pH is adjusted to crystallize at low temperature to obtain cefuronin. The present invention selects silanization reagents in organic solvents to protect cephalothiophenic acid, and then reacts with trimethyliodosilane. The reaction time is short, the conditions are mild, the reaction is complete, and almost no side reactions occur; The use of mixed solvent crystallization method can achieve the characteristics of fast drying, light color, and high yield. In addition, the solvent can be recycled, reducing the amount of wastewater, which has significant economic and environmental benefits and is conducive to achieving industrial production.
CN201310106308. X discloses a chemical synthesis method of animal specific cephalosporin antibiotic cefquinoxime sulfate. The steps include: using 7-aminocephalosporin acid as the starting material, reacting with hexamethyldisilane under the catalysis of a small amount of trimethyliodosilane to obtain 7-ACA with protected amino and carboxyl groups; Then, 7-ACA, which is protected by amino and carboxyl groups, reacts with trimethyliodosilane and 5,6,7,8-tetrahydroquinoline in the presence of acid binding agent N, N-diethylaniline to synthesize the intermediate 7-aminocephaloquinoxime in one pot method; Then, it reacts with AE active ester, undergoes acylation and salt formation reactions to obtain cefquinoxime sulfate. The amount of trimethyliodosilane in the present invention is 1-2 times the amount of 7-ACA feed, and the amount of 5,6,7,8-tetrahydroquinoline is 1-3 times the amount of 7-ACA feed. Compared with prior art, the amount is greatly reduced, and it has the advantages of simple process conditions, high yield, and low cost, making it suitable for industrial production.