Z-6-chloro-3-(4-chloro-benzylidene)-2-oxo-2,3-dihydro-indole-1-carboxylic acid ethyl ester → racemic (2'S,3S,4'R)-6-chloro-2'-(3-chlorophenyl)-4'-(4-chlorophenyl)-2,3-dihydro-2,6'-dioxo spiro[indole-3,3'-piperidine]-1-carboxylic acid ethyl ester

Participants

Reaction Steps

In a manner similar to the method described in example 4c, E/Z-6-chloro-3-(4-chloro-benzylidene)-2-oxo-2,3-dihydro-indole-1-carboxylic acid ethyl ester (0.35 g, 0.97 mmol) prepared in example 9b was reacted with 1-(3-chlorophenyl)-3-trimethylsilyoxy-2-aza-1,3-butadiene prepared in example 1b, in toluene to give racemic (2′S,3S,4′R)-6-chloro-2′-(3-chlorophenyl)-4′-(4-chlorophenyl)-2,3-dihydro-2,6′-dioxospiro[indole-3,3′-piperidine]-1-carboxylic acid ethyl ester as a yellow solid (Yield 0.5 g, 95%).

Provenance & Evidence