Water → 5-(4-Fluorophenyl)-6-{fluoro[4-(trifluoromethyl)phenyl]methyl}-7-isopropylspiro[chromen-2,1'-cyclobutan]-4(3H)-one

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Reaction Conditions

Reaction Steps

Under argon, 180 mg (0.32 mmol) of 5-(4-fluorophenyl)-6-{hydroxy[4-(trifluoromethyl)phenyl]-methyl}-7-isopropylspiro[chromen-2,1′-cyclobutan]-4(3H)-one (Example 52A) are dissolved in 3.2 ml of toluene, 52 μl (0.39 mmol) of diethylaminosulfur trifluoride are slowly added at −78° C. and the mixture is stirred at −78° C. for 1 h. The temperature is then slowly increased to −60° C. After 2 h, water is added and the mixture is extracted twice with ethyl acetate. The combined organic phases are washed once with saturated sodium bicarbonate solution and once with saturated sodium chloride solution, dried over sodium sulfate, filtered and concentrated. The crude product is purified on a silica gel column (mobile phase: cyclohexane/ethyl acetate 12:1). This gives 107 mg (66% of theory) of the title compound.

Provenance & Evidence