Trifluoroacetic acid → racemic (2'R,3R,4'S)-6-bromo-4'-(3-chlorophenyl)-2'-(1-methylene-propyl)-spiro[3H-indole-3,3'-piperidine]-2,6'(1H)-dione

Participants

Reaction Steps

To a solution of racemic (2′R,3R,4′S)-6-bromo-4′-(3-chlorophenyl)-2′-(1-methylene-propyl)-2,3-dihydro-2,6′-dioxospiro[indole-3,3′-piperidine]-1-methoxyethyl trimethylsilane (50 mg, 0.08 mmol) prepared in example 161b in dichloromethane (5 mL) was added trifluoroacetic acid (5 mL). The reaction mixture was stirred at room temperature for 0.5 h. After removing the solvent, the residue was dissolved in methanol (2 mL). To the resulting solution was added N,N′-diisopropylethylamine (1 mL). The reaction tube was then heated at 135 ° C. for 20 min. The reaction mixture was concentrated and the residue was purified by Prep-HPLC to obtain racemic (2′R,3R,4′S)-6-bromo-4′-(3-chlorophenyl)-2′-(1-methylene-propyl)-spiro[3H-indole-3,3′-piperidine]-2,6′(1H)-dione as solid (30 mg).

Provenance & Evidence