Methyl iodide → racemic (2'R,3R,4'S)-6-chloro-4'-(3-chlorophenyl)-2,3-dihydro-1'-methyl-2'-(2-methylphenyl)-2,6'-dioxo spiro[indole-3,3'-piperidine]-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

To a solution of racemic (2′R,3R,4′S)-6-chloro-4′-(3-chlorophenyl)-2,3-dihydro-2′-(2-methylphenyl)-2,6′-dioxospiro[indole-3,3′-piperidine]-1-carboxylic acid tert-butyl ester (0.25 g, 0.45 mmol) in N,N-dimethyl-formamide (20 mL) at 0° C. was added LiH (90 mg, 11.2 mmol) (Aldrich), followed by the addition of iodomethane (0.39 g, 2.74 mmol). The reaction mixture was warmed up to room temperature and stirred at room temperature for 3 h. The mixture was diluted with ethyl acetate, and then washed with saturated NH4Cl solution. The aqueous layer was extracted with ethyl acetate and the combined organic layer was dried over MgSO4. The solvent was removed and the residue was purified by chromatography (EtOAc:hexanes=1:2) to give racemic (2′R,3R,4′S)-6-chloro-4′-(3-chlorophenyl)-2,3-dihydro-1′-methyl-2′-(2-methylphenyl)-2,6′-dioxospiro[indole-3,3′-piperidine]-1-carboxylic acid tert-butyl ester (Yield 0.20 g, 77%).

Provenance & Evidence