A process to obtain benzoxazines useful for the synthesis of Ofloxazine, Levofloxazine and derivatives. The benzoxacines (I) where Xb is an halogen and R.sub.1 is H, alkyl or alkenyl of up to 6 atoms of C or aryl, can be obtained by means of cycling a compound of formula (II) through the reaction with triphenylphosphine and ethyl azodicarboxilate. The compounds of formula (II) can be obtained through the reaction of a compound (III) with an adequate epoxide. Through the use of the adequate chiral epoxide it is possible to obtain the enantiomerically desired intermediate and, therefore and selectively, it is possible to obtain the desired final product with the adequate enantiomeric form without the need to carry out a resolution stage. The Compounds (I) are useful and key intermediates for the synthesis of the antimicrobials Oflixazine and Levofloxazine. ##STR1##
一种用于合成Ofloxazine、Levofloxazine和衍
生物的苯并噁嗪的方法。苯并噁嗪(I)中Xb为卤素,R.sub.1为H、烷基或最多6个碳原子的烯基或芳基,可通过将式(II)的化合物与
三苯基膦和乙基
叠氮二
羧酸乙酯反应而获得。式(II)的化合物可通过将化合物(III)与适当的
环氧化物反应而获得。通过使用适当的手性
环氧化物,可以获得所需的对映异构体中间体,因此可以选择性地获得所需的最终产物,而无需进行分离阶段。化合物(I)是合成抗菌药Oflixazine和Levofloxazine的有用且关键的中间体。