Methanol → 6-chloro-2'-(3-chlorophenyl)-4'-phenyl spiro[3H-indole-3,3'-piperidine]-2,6'(1H)-dione

Participants

Reaction Conditions

Reaction Steps

To a solution of 1-(3-chlorophenyl)-3-trimethylsilyoxy-2-aza-1,3-butadiene prepared in example 1c in toluene (30 mL) was added E/Z-3-benzylidene-6-chloro-2-oxo-2,3-dihydro-indole-1-carboxylic acid ethyl ester prepared in Example 12b (0.4 g, 1.22 mmol). The reaction mixture was stirred under nitrogen in a sealed tube at 140° C. for 1 h. After the solution was cooled to room temperature, methanol (40 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 methanol (30 mL) and 1N of NaOH solution (5 mL, 5 mmol) was added. The reaction mixture was stirred at room temperature for 0.5 h, then the mixture was concentrated. The residue was purified by chromatography (EtOAc:CH2Cl2=1:4) to give racemic (2′S,3S,4′R)-6-chloro-2′-(3-chlorophenyl)-4′-phenylspiro[3H-indole-3,3′-piperidine]-2,6′(1H)-dione as a yellow oil (Yield 0.5 g, 100%).

Provenance & Evidence