[OH-].[Na+].[OH:3][C:4]1[CH:9]=[CH:8][C:7]([C:10](=[O:15])[CH2:11][CH2:12][CH2:13]Cl)=[CH:6][CH:5]=1.C(O)(=O)C>O>[CH:11]1([C:10]([C:7]2[CH:8]=[CH:9][C:4]([OH:3])=[CH:5][CH:6]=2)=[O:15])[CH2:13][CH2:12]1Sodium hydroxide in water (50% (w/w), 40.4 mL) was treated over a period of 15 minutes with para-hydroxy-4-chlorobutyrophenone (25.0 g, 137 mmol), followed by additional aqueous sodium hydroxide (25% (w/w), 177 mL). Additional para-hydroxy-4-chlorobutyrophenone (25.0 g, 137 mmol) was added portionwise to the reaction mixture, followed by solid sodium hydroxide (40.4 g) resulting in the formation of a yellow precipitate. After refluxing for 60 minutes, water (50 mL) was added and the resulting mixture was refluxed for another 60 minutes, allowed to cool to ambient temperature, diluted with water (100 mL) and neutralized with acetic acid. The precipitate was collected by filtration, washed with water, air-dried, and triturated at 40° C. with chloroform (1.5 L). The chloroform solution was dried (MgSO4), filtered, and concentrated. The residue was crystallized from chloroform/hexanes to provide 26.65 g (95%) of the title compound. MS (APCI(−)) m/z 161 (M-H)−; 1H NMR (300 MHz, CDCl3) δ 7.9 (d, 2H), 6.9 (d, 2H), 2.65 (m, 1H), 1.23 (m, 2H), 1.03 (m, 2H).
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