Sulfuric Acid → 2-Fluoro-5-(4-oxo-3,4,5,6,7,8-hexahydro-phthalazin-1-ylmethyl)-benzoic acid

Participants

Reaction Conditions

Reaction Steps

Crude 2-fluoro-5-(4-oxo-3,4,5,6,7,8-hexahydrophthalazin-1-ylmethyl)benzonitrile (10) (9.9 g, 34.9 mmol) was suspended in water (245 ml) and treated with sodium hydroxide (6.98 g, 174 mmol). The mixture was heated to 60° C. for 18 hours. The reaction was then cooled to 5° C. and concentrated sulfuric acid added dropwise until a precipitate formed (ca 10 ml, pH2). The suspension was stirred for 10 minutes at 5° C. and filtered. The solid isolated was washed with water (2×8 ml) and triturated with DCM (20 ml) before being dried. Single peak in LC-MS, (4.48 g, 98% purity) and was taken through to the next without any further purification; m/z (LC-MS, ESN), RT=1.96 mins (M−H 301.3).

Provenance & Evidence