Water → 1-[4-(5-Oxo-2,5-dihydro-1H-pyrazol-3-yl)-phenyl]-piperidin-4-one

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Reaction Steps

To a suspension of 5-[4-(1,4-dioxa-8-aza-spiro[4.5]dec-8-yl)-phenyl]-1,2-dihydro-pyrazol-3-one (which was obtained in Example 144) (0.15 g, 0.5 mmol) in acetone (5 mL) was added 5 mL of 10% sulfuric acid. The resulting solution was stirred at room temperature for 4 days. Water (5 mL) was then added, and the acetone was evaporated. The aqueous residue was treated with sodium carbonate until pH 8, and the resulting suspension was filtered. The precipitate was washed with water and ether, and dried in vacuo to give 0.15 g of tan solid; 1H NMR (DMSO-d6) δ 2.41 (t, 4 H), 3.64 (t, 4 H), 5.74 (s, 1 H), 7.04 (d, 2 H), 7.53 (d, 2 H), 9.55 (brs, 1 H), 11.80 (brs, 1 H); MS (ES) m/z: 258 (MH+).

Provenance & Evidence