Citric Acid → HCID 10275672, compound

Participants

Reaction Steps

A solution of 2-(4-acetoxybenzyl)-4-(4-fluorophenyl)-5-[4-(methylsulfonyl)phenyl]-3(2H)-pyridazinone (0.2 g, 4.06 mmol) (Example 114) in THF (20 mL) was treated with a solution of lithium hydroxide monohydrate (0.05 g, 1.22 mmol) in water (5 mL). Methanol (2 mL) was added to provide a homogeneous solution which was stirred at room temperature overnight. The reaction mixture was then acidified with 10% aqueous citric acid and extracted with ethyl acetate. The ethyl acetate layer was dried over MgSO4 and filtered. The filtrate was concentrated in vacuo to provide a white foam which was purified by column chromatography (silica gel, 65:35 hexanes/ethyl acetate). Product fractions were combined and concentrated in vacuo. The residue was crystallized from ethyl acetate/hexanes (yield: 195 mg, 70%). mp 225-226° C. 1H NMR (300 MHz, CDCl3) δ 3.05 (s, 3H), 4.86 (s, 1H), 5.33 (s, 2H), 6.80 (d, J=8.5 Hz, 2H), 6.95 (t, J=9 Hz, 2H), 7.15 (dd, J=9 Hz, 5 Hz, 2H), 7.30 (d, J=8.5 Hz, 2H), 7.46 (d, J=8.5 Hz, 2H), 7.83 (s, 1H), 7.87 (d, J=8.5 Hz, 2H). MS (DCI/NH3) m/z 451 (M+H)+. Anal. calc. for C24H19FN2O4S: C, 63.99; H, 4.25; N, 6.22. Found: C, 63.73; H, 4.16; N, 6.11.

Provenance & Evidence