Lithium diisopropylamide → HCID 178455347, compound

Participants

Reaction Conditions

Reaction Steps

Dissolve trans-1-(4-[tert-butyl-dimethyl-silanyloxy)-cyclohexyl]-piperidin-2-one (0.3 g, 0.96 mmol) in anhydrous THF (6 mL) under nitrogen, cool to −78° C. and add LDA (2M solution in THF) (0.72 mL, 1.44 mmol) dropwise. Stir the reaction mixture for 5 minutes and add 2-bromomethyl-1-chloro-3-fluoro-benzene (0.3 g, 1.44 mmol) in anhydrous THF (2 mL) dropwise. Stir the reaction mixture at −78° C. for 3 hours, slowly warm to room temperature, quench with saturated aqueous NH4Cl (5 mL) and extract with DCM (3×10 mL). Dry the organic layer over Na2SO4, remove the solvent and purify the residue by chromatography over silica gel (eluting with 0 to 20% EtOAc in hexane) to obtain trans-3-(-2-chloro-6-fluoro-benzyl)-1-(4-[tert-butyl-dimethyl-silanyloxy]-cyclohexyl)-piperidin-2-one as a white solid (0.2 g). Dissolve the trans-3-(-2-chloro-6-fluoro-benzyl)-1-(4-[tert-butyl-dimethyl-silanyloxy]-cyclohexyl)-piperedin-2-one in methanol containing concentrated hydrochloric acid (5% v/v) and heat at 40° C. for 1 hour. Evaporate the solvent, dissolve the residue in DCM (10 mL) and wash with saturated aqueous NaHCO3 (5 mL). Dry the organic layer over anhydrous Na2SO4, remove the solvent and purify the residue by chromatography over silica gel (eluting with 0 to 50% EtOAc in hexane) to obtain the title compound as a clear oil (110 mg, 34%): MS (ES+) m/z=340 (M+H)+.

Provenance & Evidence