Trifluoroacetic acid → Rac-5-chloro-3-(4-methoxy-phenyl)-1,3-dihydro-indol-2-one

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A suspension of rac-5-chloro-3-hydroxy-3-(4-methoxy-phenyl)-1,3-dihydro-indol-2-one (1.0 g, 3.45 mmol) (from Example 1a supra) in a mixture of triethylsilane (2 mL, 12.5 mmol) (Aldrich) and trifluoroacetic acid (5 mL, 65 mmol) was heated at 100° C. for 24 hours. After cooling, mixture was diluted with toluene and concentrated to almost dryness. Residue was dissolved in dichloromethane and purified by flash chromatography (Biotage 40M, 5% then 10% ethyl acetate in dichloromethane as solvent). Fractions containing product were combined and concentrated. Residue was recrystallized from dichloromethane-hexanes in two crops to give rac-5-chloro-3-(4-methoxy-phenyl)-1,3-dihydro-indol-2-one as white needles. (Yield 0.60 g, 63.5%).

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