C[C:2]([O-:5])(C)C.[K+].[Cl-].COC[P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.[CH3:30][N:31]([CH3:46])[C:32]1([C:39]2[CH:44]=[CH:43][CH:42]=[C:41]([F:45])[CH:40]=2)[CH2:37][CH2:36][C:35](=O)[CH2:34][CH2:33]1>C1COCC1>[CH3:30][N:31]([CH3:46])[C:32]1([C:39]2[CH:44]=[CH:43][CH:42]=[C:41]([F:45])[CH:40]=2)[CH2:37][CH2:36][CH:35]([CH:2]=[O:5])[CH2:34][CH2:33]1KOtBu (2.15 g, 19.2 mmol) dissolved in abs. THF (25 mL) was added in drops to a solution of (methoxymethyl)triphenylphosphonium chloride (6.58 g, 19.2 mmol) in abs. THF (25 mL) at 0° C. in argon. The resulting red solution was mixed after 30 min at 0° C. with a solution of 4-dimethylamino-4-(3-fluorophenyl)cyclohexanone (3.0 g, 12.76 mmol) in abs. THF (25 mL) and stirred overnight at RT. The solvent was removed in a vacuum, the residue mixed with 1M sulphuric acid (50 mL) and stirred for 2 h. The precipitate precipitated out during this was separated and the filtrate (pH 1) washed with ether (6×30 mL). The aqueous solution was adjusted to pH 11 with 5N NaOH and extracted with ethyl acetate (3×50 mL). The combined organic phases were dried over Na2SO4 and concentrated to low volume in a vacuum.
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