Acetone → Tert-butyl 4-[2-tert-butyl-4-(1-hydroxy-1-methylethyl)phenyl]piperazine-1-carboxylate

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Reaction Steps

To a solution of n-BuLi (1.6 M in n-hexane, 10.6 mL, 6.62 mmol) in THF (30 mL) was added a solution of tert-butyl 4-(4-bromo-2-tert-butylphenyl)piperazine-1-carboxylate (Example 85, 4.5 g, 11.3 mmol) in THF (15 mL) at −80° C. After stirred for 2 h at that temperature, it was added acetone (4 mL) and allowed to be warmed to room temperature. After 16 h, it was added saturated ammonium chloride solution and extracted with ethyl acetate. The organic layer was washed with brine, dried over MgSO4, and the solvent was evaporated under reduced pressure to give the crude product. The product was purified by flash column chromatography (silica gel, n-hexane/ethyl acetate=98:2 to 80:20) to provide tert-butyl 4-[2-tert-butyl-4-(1-hydroxy-1-methylethyl)phenyl]piperazine-1-carboxylate (3.1 g, 73%) as a pale yellow solid.

Provenance & Evidence