1,1'-Carbonyldiimidazole → HCID 14576671, compound

Participants

Reaction Steps

Carbonyldiimidazole (32 mg) was added to a stirred solution of 6,7-difluoro-8-hydroxy-1-(methylamino)-4-oxo-1,4-dihydro-3-quinolinecarboxylic acid (50 mg) obtained in Reference example (i) in dry dimethylformamide (2 ml). Stirring was continued at room temperature for 2 hours and then at 80° C. for 5 hours. The solvent was removed under reduced pressure and the residue was suspended in water and the pH was adjusted to pH 5 with acetic acid. The precipitate which separated out was filtered and washed with methanol to give 35 mg of 6-fluoro-8-hydroxy-7-(1-imidazolyl)-1-(methylamino)-4-oxo-1,4-dihydro-3-quinolinecarboxylic acid as pale yellow powder, FAB-MS m/z 319 (MH+); 1H-NMR (d6 -DMSO) δ: 2.82 (3H, s), 7.10 (1H, d, J=10.7 Hz), 7.61 (1H, d), 7.75 (1H, d), 8.62 (1H, s), 8.92 (1H, s), 15.33 (1H, br.s)

Provenance & Evidence