Hydrochloric Acid → 7-Bromo-9-cyclopropyl-6-fluoro-9H-isothiazolo[5,4-B]quinoline-3,4-dione

Participants

Reaction Steps

A mixture of NaHCO3 solution (51 mg, 0.9 ml water) and hydroxylamine-O-sulfonic acid (27 mg, 0.24 mmole, 4.2 equiv.) is added to a stirred solution of 7-Bromo-1-cyclopropyl-6-fluoro-2-mercapto-4-oxo-1,4-dihydroquinoline-3-carboxylic acid ethyl ester (6, 22 mg, 0.057 mmole) in THF (0.7 ml). The reaction mixture is stirred at room temperature for approximately 3 hours until the reaction is complete. The reaction mixture is acidified by the addition of 0.5N HCl and filtered. The resulting solid is washed with water (3×) and dried yielding 7 as a white solid. 1H NMR (DMSO-d6) δ: 8.39 (d, 1H), 8.06 (d, 1H), 3.63 (m, 1H), 1.41 (m, 2H), 1.26 (m, 2H). 19F NMR (DMSO-d6) δ: 114.9 (s, 1H).

Provenance & Evidence