Synthesis of 3-Fluoro-2-substituted amino-5,12-dihydro-5-oxobenzoxazoloquinoline-6-carboxylic Acids Employing the Tandem Double Ring Closure Reaction of N-Acetyl-N-(2-hydroxyphenyl)anthranilic Acid as the Key Step

Article abstract of DOI:10.1016/0040-4020(95)00809-M

A general synthetic method for the preparation of 5,12-dihydro-5-oxobenzoxazolo<3,2-a>quinoline-6-carboxylic acids has been developed making use of the tandem double ring closure reaction of N-(2-hydroxyphenyl)anthranilic acid as the key step. 2-(4-Methylpiperazin-1-yl)-3-fluoro-5,12-dihydro-5-oxobenzoxazolo<3,2-a>quinoline-6-carboxylic acid, an oxygen isostere of a potent antibacterial, A-57,207 was thus synthesized.