	US 7,576,216 B2
	Preparation of pyridonecarboxylic acid antibacterials
Anthony Haight, Wadsworth, Ill. (US); David M. Barnes, Lake Villa, Ill. (US); and Geoff G. Z. Zhang, Libertyville, Ill. (US)
Assigned to Abbott Laboratories, Abbott Park, Ill. (US)
Filed on Jul. 28, 2005, as Appl. No. 11/191,319.
Claims priority of provisional application 60/592893, filed on Jul. 30, 2004.
Claims priority of provisional application 60/617327, filed on Oct. 08, 2004.
Prior Publication US 2006/0128686 A1, Jun. 15, 2006
Int. Cl. C07D 215/16 (2006.01)

U.S. Cl. 546—156

2 Claims

1. A process for making 1-(6-amino-3,5-difluoropyridin-2-yl)-8-chloro-6-fluoro-7-(3-hydroxyazetidin-1-yl)-4-oxo-1,4-dihydroquinoline-3-carboxylic acid or a salt thereof, comprising:

(k) reacting ethyl 1-(6-amino-3,5-difluoropyridin-2-yl)-6-fluoro-7-(3-(isobutyryloxy)azetidin-1-yl)-4-oxo-1,4-dihydroquinoline-3-carboxylate or a salt thereof and N-chlorosuccinimide and isolating or not isolating the product; and

(l) reacting the product of step (k) and sodium hydroxide.