6-Chloro-3-[5-chloro-2-(1-ethoxycarbonyl-1-methyl-ethoxy)-benzylidene]-2-oxo-2,3-dihydro-indole-1-carboxylic acid tert-butyl ester → racemic (2'R,3S,4'R)-6-chloro-4'-[5-chloro-2-(1-ethoxycarbonyl-1-methyl-ethoxy)-phenyl]-2'-(2,5-difluoro phenyl)spiro[3H-indole-3,3'-piperidine]-2,6'(1H)-dione

Participants

Reaction Conditions

Reaction Steps

Under argon protection, E/Z 6-Chloro-3-[5-chloro-2-(1-ethoxycarbonyl-1-methyl-ethoxy)-benzylidene]-2-oxo-2,3-dihydro-indole-1-carboxylic acid tert-butyl ester prepared in Example 229c (8 g, 15.4 mmol) and 1-(2,5-difluoro-phenyl)-3-trimethylsilyoxy-2-aza-1,3-butadiene (30.8 mmol) were dissolved in toluene. The solution was heated at 80° C. for 5 h. Then the solution was concentrated and the residue was purified by chromatography (CH2Cl2:CH3OH=50:1) to obtain 1.7 g crude product. The crude product (50 mg) was purified again by Prep-HPLC to obtain give title compound as a white solid (12 mg).

Provenance & Evidence