1-(5-Chloro-2-methylphenyl)-3-trimethylsilyoxy-2-aza-1,3-butadiene → 4'-[5-chloro-2-(1-ethyl-1-methoxycarbonyl-propoxy)-phenyl]-6-chloro-2'-(5-chloro-2-methyl-phenyl)spiro[3H-indole-3,3'-piperidine]-2,6'(1H)-dione

Participants

Reaction Conditions

Reaction Steps

A mixture of E/Z-3-[5-chloro-2-(1-methoxycarbonyl-1-ethyl-propoxy)-benzylidene]-6-chloro-2-oxo-2,3-dihydro-indole-1-carboxylic acid tert-butyl ester (2.63 g, 4.9 mmol) prepared in Example 16 and 1-(5-chloro-2-methylphenyl)-3-trimethylsilyoxy-2-aza-1,3-butadiene (20 mmol) in toluene (20 mL) was heated at 60° C. for 3 h, and concentrated in vacuo. To the residue was added DCM (20 mL) and TFA (10 mL), and the resulting solution was stirred at room temperature for 3 h, then concentrated, partitioned between ethyl acetate and diluted aqueous NaOH solution. The organic layer was separated, washed with water, dried over anhydrous Na2SO4, and concentrated. The residue was purified by flash column chromatography to give the title compound as white solid (600 mg).

Provenance & Evidence