Hydrochloric Acid → 1,4-Dihydro-4-oxo-1-[3-(trifluoromethyl)phenyl]-3-pyridazinecarboxylic acid

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Reaction Steps

To a suspension of methyl 4-oxo-1-[3-(trifluoromethyl)phenyl]-1,4-dihydropyridazine-3-carboxylate (10.0 g, 33.5 mmol) in MeOH (150 mL) was added 1 M NaOH aqueous solution (50 mL) at 0° C. The mixture was stirred at room temperature for 30 min. To the suspension was added 1 M HCl aqueous solution (50 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 (9.25 g, 97% yield) as a pale yellow solid: 1H NMR (DMSO-d6, 300 MHz): δ ppm 7.02 (1H, d, J=7.7 Hz), 7.81-7.96 (2H, m), 8.06-8.21 (2H, m), 9.16 (1H, d, J=7.7 Hz).

Provenance & Evidence