Dichloromethane → HCID 73197256, compound

Participants

Reaction Steps

To a suspension of the 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-[4-(2-oxopropyl)-1-piperazinyl]-quinoline-3-carboxylic acid [H. Kondo et. al., J. Med. Chem., 29, 2020 (1986)] (0.38 g, 1 mmol) in absolute methanol (20 ml) was added a solution of hydroxylamine hydrochloride (0.14 g, 2 mmol) and sodium bicarbonate (0.17 g, 2 mmol) in water (2 ml). The mixture was stirred for 20 hr at room temperature, then CH2Cl2 (50 ml) was added, and the layers were separated. The organic phase was washed successively with water and brine, dried over Na2SO4, filtered and concentrated in vacuo to give a solid which was purified by flash column chromatography (silica gel, with CH2Cl2/methanol (10:1) as the eluant) and crystillization from CH2Cl2/methanol 5:1 to give 1-ethyl-6-fluoro-7-[4-(2-hydroxyiminopropyl)-1-piperazinyl]-4-oxo-1,4-dihydroquinoline-3-carboxylic acid as an off-white amorphous solid (0.28 g, 72%). Mp: 218° C. (dec). 1H NMR (DMSO-d6) δ1.41 (t, 3H, J=7.2), 1.81 (s, 3H), 2.54 (m, 4H), 3.03 (s, 2H2), 3.33 (m, 4H), 4.57 (q, 2H, J=7.2), 7.17 (d, H, J=7.2), 7.90 (d, 1H, J=13.6), 8.92 (s, 1H), 10,61 (s, 1H), 15.27 (br s, 1H). Anal. Calcd. for C19H23FN4O4•0.5 H2O: C, 57.14; H. 6.06; N, 14.03. Found: C, 57.43; H, 5.87; N, 13.83.

Provenance & Evidence