Trifluoroacetic acid → Rac-6-chloro-3-(3,5-dimethoxy-phenyl)-1,3-dihydro-indol-2-one

Participants

Reaction Conditions

Reaction Steps

Crude rac-6-chloro-3-(3,5-dimethoxy-phenyl)-3-hydroxy-1,3-dihydro-indol-2-one (0.3 g, 0.94 mmol) (from Example 40a supra) was suspended in a mixture of triethylsilane (0.45 mL, 2.82 mmol) (Aldrich) and trifluoroacetic acid (1.38 g, 14.1 mmol) and heated in an 90° C. oil bath for 17 hours. After cooling to room temperature, mixture was diluted with ethyl acetate and treated with solid sodium carbonate (1 g). After stirring for 30 minutes, mixture was extracted with water and brine. Aqueous layers were back washed with ethyl acetate. Organic layers were combined, dried (Na2SO4), filtered and concentrated. Residue was recrystallized from dichloromethane-hexanes to give rac-6-chloro-3-(3,5-dimethoxy-phenyl)-1,3-dihydro-indol-2-one as yellow solid. (Yield 0.2 g, 71%)

Provenance & Evidence