[O:1]([C:8]1[CH:13]=[CH:12][C:11]([Mg]Br)=[CH:10][CH:9]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[CH2:16]([N:23]1[CH2:28][CH2:27][C:26](=[O:29])[CH2:25][CH2:24]1)[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1.Cl>O1CCCC1.C(OCC)C>[CH2:16]([N:23]1[CH2:28][CH2:27][C:26]([C:11]2[CH:12]=[CH:13][C:8]([O:1][C:2]3[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=3)=[CH:9][CH:10]=2)([OH:29])[CH2:25][CH2:24]1)[C:17]1[CH:18]=[CH:19][CH:20]=[CH:21][CH:22]=1A solution of 4-phenoxyphenylmagnesium bromide in tetrahydrofuran (30 mL, 15 mmol) is introduced in a flame dried flask placed under argon atmosphere. A solution of 1-benzyl-4-piperidone (2.84 g, 15 mmol) in dry tetrahydrofuran (12 mL) is added dropwise, while the temperature is maintained below 20° C. with an ice bath. After completion of the addition, the mixture is allowed to reach room temperature and is further stirred for 2 hours. Ice is then added to the reaction mixture and 1 N hydrochloric acid is added until the precipitate formed is completely dissolved. The reaction is then diluted with diethyl ether (100 mL) and washed with water (50 mL). The aqueous layer is then extracted with diethyl ether (2×50 mL) and the combined organic layers are sequentially washed with saturated aqueous sodium hydrogencarbonate (2×50 mL) and with water (50 mL), are then dried over magnesium sulphate, filtered and concentrated under vacuum. The crude product is then purified by column chromatography on silica gel (dichloromethane and then diethyl ether). The desired product is isolated as a colorless solid (1.74 g, 33% yield).
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