C([Li])CCC.Br[C:7]1[CH:12]=[C:11]([C:13]([F:16])([F:15])[F:14])[CH:10]=[CH:9][C:8]=1[S:17][C:18]1[CH:23]=[CH:22][C:21]([Cl:24])=[CH:20][CH:19]=1.[C:25]([O:29][C:30]([N:32]1[CH2:37][CH2:36][C:35](=[O:38])[CH2:34][CH2:33]1)=[O:31])([CH3:28])([CH3:27])[CH3:26].[Cl-].[NH4+]>C1COCC1>[C:25]([O:29][C:30]([N:32]1[CH2:37][CH2:36][C:35]([C:7]2[CH:12]=[C:11]([C:13]([F:16])([F:15])[F:14])[CH:10]=[CH:9][C:8]=2[S:17][C:18]2[CH:23]=[CH:22][C:21]([Cl:24])=[CH:20][CH:19]=2)([OH:38])[CH2:34][CH2:33]1)=[O:31])([CH3:28])([CH3:26])[CH3:27]A solution of n-butyl lithium (2.5 M in hexane, 6.5 mL, 16.2 mmol) was slowly added to a stirred solution of 1-bromo-2-(4-chlorophenylsulfanyl)-5-(trifluoromethyl)benzene (5.96 g, 16.2 mmol) in dry THF (40 mL) under argon at −78° C. The solution was stirred for 10 min before 4-oxo-piperidine-1-carboxylic acid tert-butyl ester (3.23 g, 16.2 mmol) was added in one portion. The solution was allowed to warm to rt and then stirred overnight. Saturated aqueous ammonium chloride (80 mL) was added and the solution was extracted with ethyl acetate (80 mL). The organic phase was washed with saturated aqueous sodium chloride (50 mL), dried over magnesium sulfate and the solvent was evaporated off. The crude product was purified by flash chromatography on silica gel (eluent: ethyl acetate/heptane 2:8) to produce the target compound as a white foam, yield: 4.53 g (57%).
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