Trifluoroacetic acid → 6-chloro-4'-[5-chloro-2-(1-methoxycarbonyl-cyclobutoxy)-phenyl]-2'-(5-fluoro-2-methyl-phenyl)-spiro[3H-indole-3,3'-piperidine]-2,6'(1H)-dione

Participants

Reaction Conditions

Reaction Steps

A mixture of E/Z-6-chloro-3-[5-chloro-2-(1-methoxycarbonyl-cyclobutoxy)-benzylidene]-2-oxo-2,3-dihydro-indole-1-carboxylic acid tert-butyl ester (1.5 g, 2.9 mmol) and 1-(5-fluoro-2-methylphenyl)-3-trimethylsilyoxy-2-aza-1,3-butadiene (10 mmol) prepared in Example 4 in toluene (10 mL) was heated at 60° C. for 3 h. To the mixture was added TFA (5 mL), and the resultant solution was stirred at room temperature for 20 min, then concentrated in vacuo. The residue was 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 chromatography to give the title compound as white solid (200 mg).

Provenance & Evidence