Trifluoroacetic acid → Ethyl {4-[4,9-bis(ethyloxy)-1-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl]-2-fluorophenyl}acetate

Participants

Reaction Conditions

Reaction Steps

Trifluoroacetic acid (1900 mL) was added to a stirred solution of ethyl {4-[4,9-bis(ethyloxy)-1-hydroxy-3-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl]-2-fluorophenyl}acetate (898 g, 1.92 mol) in dichloromethane (1900 mL) at 0° C. under a nitrogen atmosphere. Triethylsilane (465 mL, 2.92 mol) was added dropwise to the deep red solution ensuring that the temperature was maintained below 3° C. The reaction mixture was then stirred at 0° C. for 45 minutes, over which time the solution turned yellow and all ethyl {-4-[4,9-bis(ethyloxy)-1-hydroxy-3-oxo-1,3-dihydro-2H-benzo[f]isoindol-2-yl]-2-fluorophenyl}acetate was shown to be consumed by TLC analysis (silica, dichloromethane:methanol, 99:1). The reaction mixture was evaporated to dryness under reduced pressure, slurried in hexane (2×2.5 L) and then isopropanol (2.5 L) at 40° C. and dried under vacuum to give the desired product as a white solid (821 g, 95% yield).

Provenance & Evidence