Water → Rac-6-[(4-tert-butylphenyl)(fluoro)methyl]-5-(4-fluorophenyl)-7-isopropyl-2,2-dimethyl-2,3-dihydro-4h-chromen-4-one

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Reaction Steps

At −78° C., a solution of 46 μl (350 μmol) of diethylaminosulfur trifluoride in 1 ml of dichloromethane is slowly added dropwise to a solution of 150 mg (320 μmol) of rac-6-[(4-tert-butylphenyl)(hydroxy)methyl]-5-(4-fluorophenyl)-7-isopropyl-2,2-dimethyl-2,3-dihydro-4H-chromen-4-one (Example 27A) in 4.5 ml of dichloromethane, and the mixture is stirred at this temperature for 2.5 h. The mixture is then allowed to thaw slowly to −15° C. Water is then added, and the mixture is extracted twice with ethyl acetate. The combined organic phases are dried over sodium sulfate and concentrated under reduced pressure. Column chromatography of the residue on silica gel (mobile phase: gradient cyclohexane→cyclohexane/ethyl acetate 10:1→5:1) gives the target compound.

Provenance & Evidence