Methanol → HCID 76568123, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 1-{3-bromo-2-fluoro-6-[2-(tert-butyl-dimethyl-silanyloxy)-ethoxy]-phenyl}-3-trimethylsilyoxy-2-aza-1,3-butadiene prepared in example 183c in toluene (30 mL) was added E/Z-6-chloro-3-(3-chlorobenzylidene)-2-oxo-2,3-dihydro-indole-1-carboxylic acid tert-butyl ester prepared in example 24a (0.5 g, 1.28 mmol). The reaction mixture was stirred under nitrogen in a sealed tube at 140° C. for 45 min. After the solution was cooled to room temperature, methanol (10 mL) was added. The reaction mixture was filtered through a short pad of celite gel and washed with ethyl acetate. The filtrate was concentrated. The residue was dissolved in dichloromethane (20 mL) and trifluoroactic acid (15 mL) was added. After the reaction mixture was stirred at room temperature for 1 h, the mixture was concentrated. The residue was partitioned between saturated NaHCO3 solution and ethyl acetate. The aqueous layer was extracted with ethyl acetate. The combined organic layer was dried over Na2SO4 and concentrated. The residue was dissolved in tetrahydrofuran (10 mL) and tetrabutylammonium fluoride solution (1M in THF, 10 mL) was added. The reaction mixture was stirred at room temperature for 10 min, then poured into water and extracted with ethyl acetate. The combined organic layer was dried over MgSO4 and concentrated. The residue was purified by chromatography to give racemic (2′R,3R,4′S)-2′-[3-bromo-2-fluoro-6-(2-hydroxy-ethoxy)-phenyl]-6-chloro-4′-(3-chlorophenyl)spiro[3H-indole-3,3′-piperidine]-2,6′(1H)-dione as a yellow solid (Yield 0.4 g, 65.6%).

Provenance & Evidence