[Cl:1][C:2]1[CH:11]=[C:10]2[C:5]([C:6](=[O:12])[CH2:7][S:8][CH2:9]2)=[CH:4][CH:3]=1.C[Si]([N-][Si](C)(C)C)(C)C.[Na+].[F:23][C:24]([F:33])([F:32])[C:25](C1NC=CN=1)=[O:26].Cl>O1CCCC1>[Cl:1][C:2]1[CH:11]=[C:10]2[C:5]([C:6](=[O:12])[CH:7]([C:25](=[O:26])[C:24]([F:33])([F:32])[F:23])[S:8][CH2:9]2)=[CH:4][CH:3]=17-Chloroisothiochroman-4-one from Step 3 (0.3 g, 1.5 mmol) was dissolved in tetrahydrofuran (15 mL) and cooled to -78° C. A solution of sodium bistrimethylsilyl amide (1.5 mL of a 1.0M tetrahydrofuran solution) was added and the reaction stirred for 0.5 hours at -78° C. Trifluoroacetyl imidazole (0.21 mL, 1.8 mmol) was added and the reaction was warmed to room temperature and stirred under a nitrogen atmosphere for 16 hours. 1N Hydrochloric acid (100 mL) was added to the reaction followed by extraction with ether (150 mL). The organics were washed with brine (75 mL), dried over MgSO4 and concentrated in vacuo. The resulting yellow oil was used in the next step without further purification.
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