Process and intermediates for quinolonecaboxylic acid.

摘要

The present invention is concerned with a certain novel process for the preparation of a quinolonecarboxylic acid of the following formula; and with intermediates of the following formula; wherein R is hydrogen atom or lower alkyl group, X is halogen atom, R<1> and R<2> each defined independently are hydrogen atom or a protective group for the amino group, or R<1> together with R<2> is a protective group, and wherein R, R<1>, R<2> and X are as defined above. l