Heterocycles [h]-fused onto 4-oxoquinolines. Part I. Synthesis of 6-oxo-6,9-dihydro[1,2,5]oxadiazolo[3,4-h]quinoline-7-carboxylic acid N-oxide.
In: Heterocycles, Jg. 68 (2006) ; Nr. 6, S. 1163-1172
Zeitschriftenaufsatz / Fach: Chemie
Et 9-cyclopropyl-4-fluoro-6-oxo-6,9-dihydro[1,2,5]oxadiazolo[3,4-h]quinoline-7-carboxylate N(3)-oxide (I) is synthesized via pyrolysis of the 7-azido-8-nitroquinoline-3-carboxylate precursor. Acid-catalyzed hydrolysis of I afforded the corresponding carboxylic acid, of which structures are confirmed by spectroscopic means. The antibacterial activity of I and the corresponding carboxylic acid were detd. The crystal structure of I is presented [triclinic, space group P.hivin.1, a 6.9065(11), b 9.5664(16), c 11.0724(18) .ANG., a 81.494(3), b 86.656(3), g 79.370(3) Deg, V 710.7(2) .ANG.3, Z 2].