Thienopyridone Antibacterials V [1]. Synthesis of Some N(7)-Azacyclohexyl-4-oxothieno[2,3-b]pyridine-5-carboxylic Acids and Related Congeners

A series of N(7)-azacyclohexyl-4-oxo-4,7-dihydrothieno[2,3-b]-pyridine-5-carboxylic acids 9a - c, related congeners 9d - g and their methyl esters 8a - g were prepared by cyclization of the respective 2-[(2,5-dichlorothien-3-yl)carbonyl]-3-[(N(7)-azacyclyl/acyclic)amino]acrylates 7a - g. The latter intermediates are accessible from methyl 2-[(2,5-dichlorothien-3-yl)carbonyl]-3-ethoxyacrylate (6). Of the present series, the 7-(N,N-dimethylamino) derivative 9d exhibited good activity, especially against Klebsiella pneumoniae and Salmonella paratyphi A (MIC = 0.5 and 1.0 μgmL−1, respectively). Graphical Abstract Thienopyridone Antibacterials V [1]. Synthesis of Some N(7)-Azacyclohexyl-4-oxothieno[2,3-b]pyridine-5-carboxylic Acids and Related Congeners