The present invention relates to a process for preparing a quinolone antibiotic intermediate having the formula:
1
wherein R is C
1
-C
2
alkyl, C
1
-C
2
fluoroalkyl, C
2
-C
4
alkenyl, methoxy, chloro, or bromo; R
1
is a unit selected from the group consisting of C
1
-C
2
alkyl, C
2
-C
3
alkenyl, C
3
-C
5
cycloalkyl, and phenyl, each of which can be substituted by one or more fluorine atoms; said process comprising the step of cyclizing an admixture of quinolone precursors, said admixture comprising a 2-ethoxy substituted intermediate having the formula:
2
in the presence of a silylating agent.
本发明涉及一种制备喹诺
酮类抗生素中间体的方法,该中间体的
化学式为:1,其中R为C1-C2烷基,C1-C2
氟代烷基,C2-C4烯基,甲氧基,
氯或
溴;R1为从C1-C2烷基,C2-C3烯基,C3-C5环烷基和苯基中选择的一个单元,每个单元可以被一个或多个
氟原子取代;该方法包括在
硅基化剂的存在下,使
喹诺酮前体混合物环化,所述混合物包括
化学式为2的2-乙氧基取代中间体。