Hydrochloric Acid → 1-(3-Bromo-2-fluorophenyl)-5-methoxy-4-oxo-1,4-dihydropyridazine-3-carboxylic acid

Participants

Reaction Steps

To a suspension of methyl 1-(3-bromo-2-fluorophenyl)-5-methoxy-4-oxo-1,4-dihydropyridazine-3-carboxylate (4.16 g, 11.7 mmol) in MeOH (46 mL) was added 1 M NaOH aqueous solution (23 mL) at 0° C. The mixture was stirred at room temperature for 1 h. To the solution was added 1 M HCl aqueous solution (23 mL) at 0° C. The mixture was concentrated in vacuo. The precipitates were collected by filtration, washed with water and dried in vacuo at 50° C. to yield the title compound (3.76 g, 94% yield) as a pale yellow solid: 1H NMR (DMSO-d6, 300 MHz): δ ppm 3.87 (3H, s), 7.43 (1H, td, J=8.1, 1.5 Hz), 7.76-7.85 (1H, m), 7.98 (1H, ddd, J=8.0, 6.5, 1.3 Hz), 8.86 (1H, s), 14.84 (1H, brs).

Provenance & Evidence