Practical synthesis of DQ-113, a new quinolone antibacterial agent, by using the intramolecular Horner-Wadsworth-Emmons reaction

A practical route was developed for synthesizing the C-7 substituent of DQ-113 (6, 5-amino-7-[(3S,4R)-4-(1-aminocycloprop-l-yl)-3-fluoro-pyrrolidin-l-yl]-6-fluoro-l-[(IR,2S)-2-fluorocyclopropan-l-yl]-1,4-dihydro- 8-methyl-4-oxoquinolin-3-carboxylic acid), a new quinolone antibacterial agent for serious infections caused by Gram-positive pathogens. The key step was the intramolecular Homer-Wadsworth-Emmons reaction. In addition, the yield of the final aromatic micleophilic substitution reaction was improved.