Hydrochloric Acid → 2-Fluoro-5-[(4-oxo-3,4-dihydrophthalazin-1-yl)methyl]benzoic acid

Participants

Reaction Steps

To the mixture of 2-fluoro-5-((3-oxoisobenzofuran-1(3H)-ylidene)methyl)benzonitrile (1.2 g, 4.5 mmol) in water (6.5 ml) was added aqueous sodium hydroxide (0.84 g in 1.6 ml of water) drop-wise, then heated at 90 for 1 h. After cooled to 70, hydrazine hydrate (6.4 ml) was added and the reaction mixture was heated at 70 for overnight. Then the reaction mixture was cooled to room temperature, and adjusted to PH 3-4 by adding aqueous HCl (2N). The precipitated solid was collected by filtration, washed with water, and dried in vacuo to afford the target compound (0.9 g, 70%) as a pink solid, used in next step without further purification.

Provenance & Evidence